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A464 Human Tissue Biology
Laboratory Guide
Spring 2015
Anthony L. Mescher, Ph.D.
Emeritus Professor of Anatomy and Cell Biology
Indiana University School of Medicine
Bloomington
TABLE OF CONTENTS
Preface
Useful Greek and Latin Roots
Glossary
Laboratory Guide
Introduction to Light Microscopy and Electron Micrographs
Cell Structure and Function
Cell Division and Cell Death
Epithelia
Secretory Epithelia and Glands
Extracellular Matrix and Types of Connective Tissue
Muscle
Blood Cells and Hemopoiesis
Circulatory System
Immune (Lymphoid) System
Skin
Cartilage and Bone
Bone Formation
Teeth and Tooth Formation
Central Nervous System
Peripheral Nerves
Sensory Receptors
The Eye
Gastrointestinal Tract (Part 1)
Gastrointestinal Tract (Part 2)
Digestive Glands and Liver
Respiratory System
Urinary System
Endocrine System
Male Reproductive System
Female Reproductive System
Instructions for the Use of the Nikon Alphaphot 2 Microscope
PREFACE
Our course in Human Tissue Biology at I.U. covers features of the differentiated cells and
tissues that make up the body. The main goal of the course is to better understand how structure
and function are integrated in the molecules, cells, tissues, and organs of the body. A major
theme of the lectures and the focus of the laboratory studies is the area of histology, the branch of
biology that centers on the cells and tissues within an organism and which, as such, serves as the
foundation for other aspects of anatomy and physiology. The histological treatment of various
tissues and organs will often be supplemented in lecture with material more related to other
aspects of the subject, such as recent work on the tissue’s development or discussions of the
tissue’s structure or function that are medically important.
This Laboratory Guide for A464, Human Tissue Biology, is designed to be used with the
book Junqueira’s Basic Histology, 12th edition, which contains most of the required reading and
laboratory material to be studied in this course. An electronic version of the lab guide and the
slide collection with digitized slides are available at
http://medsci.indiana.edu/a464/start.html The Glossary of histological terms included here is from Introduction to Functional Histology by
I.R. Telford and C.F. Bridgman.
Each laboratory exercise in the Laboratory Guide is designed to occupy approximately
two hours of study for thorough understanding of the material, although some exercises require
more time than others. The guide for each lab session begins with a short list of objectives your
efforts are supposed to achieve. Always read these objectives carefully and make sure you have
completed each successfully before leaving the lab. Figures from Junqueira are referred to
continuously in every lab session and therefore the exercises MUST be undertaken with a copy
of Junqueira’s edition in front of you along with the microscope. Please remember to bring that
book along to class every day. Although the prepared student will come to class having read the
material to be covered that day, you should also read the captions to the figures in Junqueira
again while studying the slides and identifying the cells and other components listed in the
Laboratory Guide. This will greatly improve your understanding of the tissue’s functions. To
help you further improve your understanding of each histological topic, I have placed questions
in each lab exercise, with place for you to provide answers. Doing this will help insure that you
meet the Learning Objectives for the exercise. Lab exams will be designed to determine how
well you have met the objectives listed with each lab exercise. You will be expected to
recognize and know the basic information on the structures listed with the electron micrographs
and slide(s) assigned for study in each exercise.
Students in histology labs find that it is sometimes helpful to draw or sketch the
appearance of certain microscopic structures, such as the arrangement of cells in a specific tissue
or part of an organ. We have placed an extra page with each laboratory exercise in the Guide to
allow plenty of space for notes and drawings. Taking the time to sketch and label the parts of the
more complex tissues we will study during the semester will almost certainly improve your
recognition and understanding of the structures. To help you further in studying the material, we
have also included with most of the laboratory exercises unlabeled drawings of structures with
names of important components to be identified on the drawing and on your specimens.
The guides for the laboratory exercises in the course were written with help from the
individuals who have taught the labs in recent years, and I gratefully acknowledge their help.
Thanks are also due to Sue Childress for her work maintaining and steadily improving the
microscope slide collections.
Anthony L. Mescher
Introduction to Light Microscopy and Electron Micrographs
Various types of light and electron microscopes are the most important tools used for the
study of cells and tissues. Not only do these instruments provide the foundation of tissue biology
or histology, light microscopes are also the principal tool for pathologists, hematologists, and
certain other medical professionals. For effective learning in Tissue Biology you must become
proficient in the use of the basic bright-field light microscope, techniques associated with its use,
and in the study and interpretation of transmission and scanning images produced by electron
microscopes.
Objectives
v Learn the correct use and care of the light microscope, LM
v Understand the histological techniques used in preparing tissue samples for light and
transmission electron microscopy, TEM
v Understand the fundamentals of biological staining and the ways in which common stains
are used to provide more information about cells
v Begin learning to interpret images of cells and tissues seen with either the LM or EMs.
The Light Microscope
The major tool used in this laboratory will be the light microscope. Our microscopes are
high-quality binocular microscopes made by Nikon. A copy of the “owner’s manual” for your
microscope is included at the end of this Laboratory Guide. Read the Handling Precautions and
other sections of this manual and use the photographs to identify the various parts of the
microscope and learn their functions. Very few adjustments to the scope will be required
during its day-to-day use. Proper focusing, proper adjustment of the eyepieces, and proper
illumination are all important for comfortable and effective use of the scope. For proper
illumination of the slide, adjust your microscope as follows:
1.
2.
3.
4.
5.
6.
7.
8.
Plug the microscope into the outlet on the front of your table and turn on the light.
Place any slide from your collection on the stage and clip it into place.
Swing in the low-power 10X objective and focus on the specimen.
Adjust the brightness of the light to a fairly bright, but comfortable level.
Locate the condenser diaphragm below the stage and open it fully.
Swing in the high-power 40X objective.
Turn the condenser focus knob slightly, focusing it until maximum illumination is
obtained (usually the condenser is in the highest position.)
Slowly close the condenser diaphragm until you detect a slight darkening of the
field. Do not use the condenser diaphragm to control the amount of light since this
will introduce aberrations into the image. Control the amount of light with the
brightness control dial/power switch.
Check the “owner’s manual” at the end of this Lab Guide for further information about
your light microscope. Make certain that you can use your microscope correctly and are familiar
with its operation before leaving the first laboratory period.
If the eyepieces or objectives need cleaning use lens paper (NOT paper towels or
Kimwipes which can scratch lenses). Never remove the lenses from the microscope for any
reason. To avoid losing slides, always remember to return the slide to your collection before
turning off the microscope. After using the microscope, rewind the cord on its holder and cover
it. Always use both hands when carrying the microscope and be very careful not to bang or hit
any projecting part of the scope on the sides of the locker when removing or replacing the scope
in its locker. THE MICROSCOPES ARE NEVER TO LEAVE THE LAB, JORDAN 001.
Tissue Preparation and Stains
Details of the methods and techniques used to prepare tissues for histological study and
the chemistry of biological stains are extensive subjects and are beyond the scope of the course.
However, a basic understanding of tissue preparation for light microscopy and staining
mechanisms is essential to understand and interpret the images you will see with your
microscope. Very briefly, the steps involved in tissue and slide preparation are as follows:
1.
2.
3.
4.
5.
6.
7.
Tissue removal, trimming and sampling.
Fixation in an aqueous preservative solution.
Dehydration (replacing the water with alcohol.)
Clearing (replacing the alcohol with another solvent miscible with paraffin.)
Embedding (in paraffin for LM or in “plastics” for TEM.)
Sectioning on a microtome with steel or glass knives.
Staining (with dyes for LM or electron-opaque compounds for TEM.)
Most routine histological stains involve a combination of basic and acidic dyes/stains.
Basic stains such as hematoxylin contain positive charges (are cationic) and binds to negatively
charged substances. Such substances are said to be “basophilic.” Acidic stains such as eosin
contain negative charges (are anionic) and binds to positively charged substances in tissues. Such
substances are said to be “acidophilic” or “eosinophilic.” The hematoxylin and eosin
combination, a stain and a “counter stain,” is the most widely used staining method for routine
histology and most of the slides in your collection are H&E stained.
Hematoxylin binds cellular structures containing nucleic acid, such as the nucleus and
RNA-rich organelles, usually staining them a shade of dark blue or purple. The acidic counter
stain eosin binds proteins with many cationic groups, which includes many cytoplasmic proteins
and collagen outside the cells, staining this material pinkish or orange. Most of the light
micrographs in Junqueira show examples of tissues stained with hematoxylin and eosin (H&E).
Examine any three (3) slides of different tissues in your collection and in each locate
basophilic structures, such as cell nuclei, and eosinophilic structures, such as collagen bundles
and structures in cytoplasm.
Interpretation of Microscopic Structures
While examining sections with the microscope it is important to keep in mind that the
two-dimensional images you are seeing are actually sections of three-dimensional structures. By
studying the structures cut in different planes one can mentally reconstruct their three
dimensional appearance and interpret their shape accurately. Examine the diagrams shown here
and note the various appearances of structures when cut through different planes. After studying
the diagrams, examine an actual specimen such as the kidney section (slides 64 or 66) which
includes many tubes in many different orientations. Identify such tubular structures cut
transversely, longitudinally, and obliquely.
You must also be aware of common artifacts frequently encountered in tissue sections
prepared for LM. Such artifacts are due to minor problems in the slide preparation technique and
must not be interpreted as real features in the tissue. If a “structure” is not shown in the atlas’
depiction of a certain tissue, it may actually be an artifact unique to your slide. The types of
artifacts listed below are particularly common and some are likely to be present on some slides in
your collection. Wrinkles, folds, and knife scratches are especially hard to avoid completely and
you should expect to find these artifacts occasionally during the course.
1.
2.
3.
4.
5.
Notes
Wrinkles or folds in the section: well-defined very dense staining areas where
detail is obscured.
Knife marks on the section: usually straight cuts, fine lines, or “scuff marks”
across a section caused by nicks or dull spots on the cutting edge of the
microtome blade.
Poor fixation (postmortem degeneration): the tissue stains poorly and shows poor
microscopic detail in some areas but not others
Tissue shrinkage: components in the section are separated from each other giving
rise to irregular empty spaces, most often between different tissue components
or regions.
Precipitates from the stain: usually appear as small black particles scattered
across some regions of the section.
Cellular Organelles’ Structure and Function
While looking at the slides listed below, study the appropriate diagrams and electron
micrographs (EMs) in Junqueira. Compare the very high magnification “ultrastructural” EM
appearance of organelles and other structures with their appearance in Junqueira’s LM
photographs and in the cells on your slides. The EMs and other figures in Junqueira are an
important part of today’s lab. They will help you understand and interpret all other EMs you
will see later in the later labs. Carefully read the text accompanying each figure as you study it.
Identify the basic structural features that characterize each and every example you will see of
each organelle.
Objectives
v Gain experience in the ability to correlate two-dimensional images of organelles in both
the light microscope LM and transmission electron micrograph TEM with their actual
three-dimensional structure
v Recognize the important cytoplasmic organelles in both light microscopes and electron
micrographs
Micrographs and diagrams
-
Fig 2-1, 2-2, 2-3
o Plasma Membrane
In the fluid mosaic model for membrane structure, what is “fluid” and why?
-
Fig 3-2
o Nucleus
o Heterochromatin
o Euchromatin
o Nucleolus
-
Fig 3-5, 3-6
o Nuclear Envelope
o Nuclear Pore
Fig 2-16
o Rough ER
o Nucleolus
o Nuclear Envelope
o Nucleus
For what reason are polyribosomes attached to the endoplasmic reticulum in RER?
-
Fig 2-15, 2-16, 2-21, 16-10
o Smooth ER
o Rough ER
List 3 functions associated with the smooth ER.
-
Fig 2-20, 2-21, 2-22
o Golgi Apparatus
o Rough ER
o Nucleus
o Mitochondrion
o Secretory granule
What do the terms cis and trans Golgi mean?
-
Fig 2-23
o Golgi apparatus
o Secretory Granules
o Rough ER
What is the difference between a secretory vesicle and a secretory granule?
-
Fig 2-24, 2-25
o Primary Lysosome
o Secondary Lysosome
o Golgi apparatus
The enzymes in lysosomes are only active in a microenvironment with a pH of about 5. Why?
-
Fig 2-35
o Cellular Pigments
§ Lipofuscin
§ Melanin
§ Lipid droplets
§ Glycogen granules
Why is lipofuscin sometimes called an age pigment?
-
Fig 2-27
o Peroxisomes
Why are peroxisomes particularly abundant in neutrophils?
-
Fig 2-11, 2-12, 2-13
o Mitochondria
o Cristae
o Matrix
What can the number and location of mitochondria in a cell tell you about the cell’s function?
Slides
-
Slide Pancrease Fuchsin https://vmicro.iusm.iu.edu/virtual_h/msci_62_5.html
o
o
o
o
-
Nucleus
Nuclear Envelope
Nucleolus
Secretory Granules
Slide: Pancrease https://vmicro.iusm.iu.edu/virtual_h/msci_15_5.html
(Fig. 4-24)
o Basophilic Rough Endoplasmic Reticulum
o Secretory Granules
o Nucleus
o Golgi Apparatus (Golgi Ghost )
Why are acinar cells of the pancreas said to be polarized?
-
Slide: mamarygland https://vmicro.iusm.iu.edu/virtual_h/msci_108_5.html
(Fig. 6-1)
o Lipid (droplets)
-
Slide 95: eye https://vmicro.iusm.iu.edu/virtual_h/msci_120_5.html
(Fig. 2-25c)
o Melanin (Granules)
Notes
Cell Division and Cell Death
Cells throughout the body obviously exhibit a great degree of variation, both in their
morphology and function. As we have seen, however, many cellular structures are common to
most cell types. Structures segregated into distinct cellular compartments by membranes include
the nucleus and the various organelles in the cytoplasm outside the nucleus. Each of these
cellular components has a specific function and one can thus obtain a good indication of a cell’s
activity by examining the distribution and morphology of these components.
This lab will concentrate on the appearance of the cell nucleus and its contents. How
nuclear structures are subdivided during mitosis and how they change during apoptosis
(programmed cell death) are also considered.
Objectives
v Learn the probable functional activity of a cell based on the appearance of the nucleus
and cytoplasmic organelles that are visible
v Understand the structure and LM cytological appearance of chromosomes, chromatin,
during mitosis and in the inter-mitotic period
v Understand movements of chromosomes during mitosis and recognize the stages of
mitosis in sections of blastula and certain adult tissues
v Recognize cells in mitosis from cells undergoing programmed cell death, apoptosis
Terms
Cell (neuron)
Nucleus (of neurons)
Nucleolus (of neurons)
Chromatin [S21, 22]
Cytoplasm
Nuclear Envelope
Slides
Ø Spinal cord https://vmicro.iusm.iu.edu/virtual_h/msci_149_5.html
Ø Spinal ganglia https://vmicro.iusm.iu.edu/virtual_h/msci_09_5.html
Sympathetic ganglia https://vmicro.iusm.iu.edu/virtual_h/msci_135_5.html
Micrographs and diagrams
Ø Fig 3-3
What does the presence of nucleoli tell you about the function of the cells?
Nucleus
Chromatin
Nuclear Envelope
Slides
Ø 56: Liver cells https://vmicro.iusm.iu.edu/virtual_h/msci_29_5.html
Ø
How does the nuclear envelop differ structurally from the cell membrane and how are they
similar?
Chromosomes
Prophase
Metaphase
Anaphase
Telophase
Slide
Onion root tip https://vmicro.iusm.iu.edu/virtual_h/93_bl_5.html
Junqueira
Ø Fig 3-14, 3-15, 3-16
How do the events of mitosis relate to the events of the cell cycle’s S phase?
Apoptotic Cells https://vmicro.iusm.iu.edu/virtual_h/93_bl_5.html
Ø Fig 3-22, 3-23
Mitotic Cells
Mitotic epithelial stem cells are found in the crypts, while the apoptotic epithelial cells are
located near the tips of the villi.
Slides
Ø Lymph nodes https://vmicro.iusm.iu.edu/virtual_h/msci_79_5.html
Ø
Ø : Duodenum https://vmicro.iusm.iu.edu/virtual_h/msci_37_5.html
Ø
Micrograph
Ø Fig 3-17
What are some differences in the appearance of mitotic and apoptotic cells?
Notes
Intercellular Junctions and Types of Epithelia
Epithelium, one of the four primary tissues of the body, is characterized by having its
cells lined up and oriented with their apical ends or surfaces facing one compartment and their
basal ends on a basal lamina which anchors the epithelium to the underlying connective tissue.
Unlike some other tissue types, epithelia consist almost entirely of cells, with little intervening
space between the adjacent cells. Various types of junctions join adjacent epithelial cells. The
histological classification of an epithelial layer is based on the shape of cells that compose it,
particularly the cells on its apical or exposed surface and the number of cellular layers. These
structural features also reflect the principal activities of the epithelium.
Objectives
v Learn criteria for identifying the various types of simple and stratified epithelia in light
microscopy (LM) preparations
v Understand how epithelia are classified into simple, stratified and pseudostratified
v Understand that epithelium forms barriers and compartments by covering and lining the
body’s outer and inner surfaces
v Comprehend the general structure, organization and functions, as well as the
specializations within epithelial cells in both LM and EM preparations
v Understand the relationship between structure and function by comparing epithelia in
various organs
Electron Micrographs
-
-
Fig 4-5
o Intercellular Junctions
§ Tight Junction
§ Zonula Adherens
§ Desmosomes
Fig 4-6
o Tight Junction
Fig 4-2
o Hemidesmosome
Fig 4-7
o Gap Junction
Fig 4-10
o Cilia
o Microvilli
Fig 4-8
o Microvilli
Terms
Simple Squamous Epithelium
Simple Cuboidal Epithelium
Simple Columnar Epithelium
Examine the blood vessels and Bowman’s capsule to find simple squamous epithelium.
Examine the tubules in the renal cortex, or outer region, for simple cuboidal epithelium. To find
simple columnar epithelium, examine the ducts in the renal medulla, or inner region.
Slide
Ø Kidney https://vmicro.iusm.iu.edu/virtual_h/msci_14_5.html
Ø
Junqueira
Ø Figs. 4-11 through 4-13
In sections of the kidney you should be able to find simple squamous epithelium in three
different structures. How many do you see?
Simple Columnar Epithelium
Striated (Brush) Border (microvilli)
Study the lining of the gall bladder lumen for simple columnar epithelium and observe the
striated, or brush, border of the microvilli. Study the intestinal lining for simple columnar
epithelium and observe the striated border of the epithelium.
Slide
Ø
Ø
58: Gall Bladder https://vmicro.iusm.iu.edu/virtual_h/msci_105_5.html
43: Duodenum https://vmicro.iusm.iu.edu/virtual_h/msci_04_5.html
How does the simple columnar epithelium differ in the kidney ducts and in the intestinal lining?
Pseudostratified Columnar Ciliated Epithelium (PCCE)
Basement Membrane
Cilia
Examine the thick basement membrane of the epithelium. Notice that the nuclei are located at
varying levels throughout the epithelium. Observe the cilia lining the epithelium.
Slide
Ø
60: Trachea https://vmicro.iusm.iu.edu/virtual_h/140_bl_5.html
Junqueira
Ø Fig. 4-10, 4-16
Indicate three ways PCEE cells differ from simple columnar cells.
Stratified Squamous (Non-Keratinized) Epithelium
On Slide 91, examine the various layers of cells and the superficial layers lining the uterine
cervix. These are the cells that are sampled during “Pap tests” for cervical metaplasia. On Slide
95, observe the outer surface of the cornea to find stratified squamous (non-keratinized)
epithelium.
Slides
Ø 2T and 40: Esophagus https://vmicro.iusm.iu.edu/virtual_h/msci_43_5.html
Ø 91: Uterine Cervix https://vmicro.iusm.iu.edu/virtual_h/133_bl_5.html
Ø 95: Anterior Half of Eye https://vmicro.iusm.iu.edu/virtual_h/msci_120_5.html
Junqueira
Ø Fig. 4-14
Stratified Squamous Keratinized Epithelium
Slide
Ø
84: Thin skin, general body surface https://vmicro.iusm.iu.edu/virtual_h/msci_36_5.html
Junqueira
Ø Fig. 18-3
What do the various “strata” in this type of epithelium represent?
Transitional Epithelium (also called urinary epithelium or urothelium)
In Slide 69, examine the cell shapes in the layers of cells and notice that the epithelial lining is
disrupted in some places. In Slides 70 and 71, notice the differences in the thickness of the
lining, in the size and shape of the cells or nuclei, and in the convulsions of the epithelium.
Slides
Ø
Ø
Ø
Ø
Ø
Ø
69: Ureter https://vmicro.iusm.iu.edu/virtual_h/msci_48_5.html
70: Distended (Full) Urinary Bladder https://vmicro.iusm.iu.edu/virtual_h/464_70b.html
71: Not-Distended (Empty) Urinary Bladder
https://vmicro.iusm.iu.edu/virtual_h/msci_118_5.html
Junqueira
Ø Fig. 4-15
In what sense is this type of epithelium transitional?
Notes
Secretory Epithelia and Glands
Glands can be classified structurally based on both the duct and the secretory portions.
Ducts are said to be compound when they are branched and are simple when they are not
branched. The overall shapes of the secretory portions of glands can be tubular, acinar
(rounded), or tubulo-acinar (rounded with tubular end). The secretory portion can be further
described as branched tubular or coiled tubular (long and not branched). Study Figures 4-20
and 4-21 in Junqueira for diagrammatic depictions of each type of gland.
Objectives
v Recognize the major differences in the morphologically different types of glands
v Understand the various types of secretion shown by secretory cells of glands
v Recognize staining differences between serous and mucous secretory cells
v Understand the exocrine glands can be classified according to four features:
§ the secretory portion’s shape: alveolar vs. tubular
§ the duct system: simple vs. compound
§ the nature of the secretion: mucous vs. serous
§ the mode of secretion: merocrine, apocrine, or holocrine
Terms
Unicellular Glands (Goblet Cells)
Simple Tubular Glands (Crypts of Lieberkühn or intestinal glands)
Simple Columnar Epithelium
Slide
Ø
Ø
45: https://vmicro.iusm.iu.edu/virtual_h/msci_26_5.html
https://vmicro.iusm.iu.edu/virtual_h/msci_27_5.html
Junqueira
Ø Fig. 4-17
Ø Fig. 4-19
Ø Fig. 4-20
Ø Fig. 4-21
Try to distinguish the two significant parts of a gland: the secretory unit (acinus or tubule) from
the duct.
Simple branched tubular (Mucous) glands
Slide
Ø
Ø
42: Pyloric Region of Stomach https://vmicro.iusm.iu.edu/virtual_h/msci_101_5.html
How do simple branched tubular (mucous) glands resemble a unicellular gland?
Simple Coiled Tubular (Sweat) Glands
Secretory Portion
Duct
Slide
Ø
Ø
83: Sweat Glands in Thin Skin https://vmicro.iusm.iu.edu/virtual_h/msci_36_5.html
What type of epithelium do the ducts of these glands have?
Simple Branched Acinar (Sebaceous) Gland
Sebaceous glands undergo holocrine secretion.
Slide
Ø
Ø
85: Sebaceous Glands in Scalp http://medsci.indiana.edu/a464/virtual/464_85.html
How exactly does this type of secretion work?
Compound Acinar Glands
Ducts [S53 only]
Slides
Ø 1T: Pancreatic Acini and Ducts
Ø 53: Pancreatic Acini and Ducts https://vmicro.iusm.iu.edu/virtual_h/msci_154_5.html
Ø
What mode of secretion do pancreatic acinar cells show?
Compound tubuloacinar glands
Serous Cells
Mucous Cells
Ducts
Compound tubuloacinar glands are located in breast lobules and undergo apocrine secretion.
Slide
Ø
51: Submandibular Salivary Gland https://vmicro.iusm.iu.edu/virtual_h/msci_72_5.html
Which types of secretory cells in salivary glands are most like pancreatic acinar cells?
Compound Tubuloacinar Glands
Lactiferous Duct
Slide
Ø 88: Mammary Gland https://vmicro.iusm.iu.edu/virtual_h/msci_108_5.html
Ø
What specific material undergoes apocrine secretion in the mammary glands?
Notes
Extracellular Matrix and Types of Connective Tissue
Connective tissue supports other tissues and connects all of the body’s tissues and organs
together. In contrast to epithelium which is composed mainly of cells, connective tissues (CT)
consist of material between or outside of cells, largely fibers and a gel-like ground substance.
Cells tend to be widely separated among the masses of fibers and ground substances. The fibers
and the ground substance are collective termed the extracellular matrix (ECM). The fibers,
composed primarily of collagen or elastin, are responsible for the tensile strength and elasticity
of the tissue. The ground substance, substantially composed of hydrated proteoglycans, provides
the medium through which dissolved substances pass from capillaries to cells and back.
Objectives
v Identify and recognize the LM and TEM characteristics of extracellular matrix
components, including both ground substances and fibers, and understand their functional
significance
v Recognize the LM appearance and function of the major cell types normally found in the
different types of connective tissue
v Recognize the traditional types of connective/support tissue and their functional
significance
Connective Tissue Overview
•
Connective tissue is organized with cells and material outside of cells.
Connec&ve Tissue CT Extracellular Matrix ECM Cells Fibroblasts, macrophages, etc. •
Extracellular matrix, ECM, is composed of fibers of protein and ground substance.
Extracellular Matrix
ECM
Fibers of Protein Collagen and Elas9c Fibers
•
Ground Substance Ground substance consists of glycosaminoglycans and glycoproteins.
Ground Substance Glycosaminoglycans GAGs Hyaluronic acid, chondroitan sulfate Electron Micrographs
-
Fig 4-2
o Basement Membrane
o Collagen
Fig 5-8
o Collagen
o Fibroblast
Fig 5-16
o Elastin
o Collagen
Glycoproteins Fibronec9n, Laminin Terms
Mesenchyme
Mesenchymal Cell
Ground Substance (Glycosaminoglycans or GAGs)
Mesenchyme is the embryonic tissue from which all forms of connective tissue are derived.
Slide
Ø
40a: Fetal tissue, primitive mesenchyme
https://vmicro.iusm.iu.edu/virtual_h/464_40ab.html
Junqueira
Ø Fig. 5-1
Collagen
Fibroblasts
Areolar (loose) connective tissue
Notice how the collagen fibers are eosinophilic. The loose areolar connective tissue is located
around small blood vessels.
Slide
Ø
Ø
8: Mesentery https://vmicro.iusm.iu.edu/virtual_h/msci_116_5.html
https://vmicro.iusm.iu.edu/virtual_h/msci_45_5.html
Junqueira
Ø Fig. 5-21
Fibroblasts
Elastic Fibers
Slide
Ø
4a: Mesentery https://vmicro.iusm.iu.edu/virtual_h/464_4ab.html
Junqueira
Ø Fig. 5-13, 5-14
How does the appearance of loose connective tissue in a mesentery compare to that in sections?
Fibroblasts
Collagen
Basement Membrane
The fibroblasts and collagen bundles are located below the epithelium of the lumen. The thick
basement membrane of the epithelium lines the lumen.
Slide
Ø
Ø
60: Trachea https://vmicro.iusm.iu.edu/virtual_h/140_bl_5.html
Dense Irregular Connective Tissue
§ Fibroblast
§ Collagen
Adipocytes (Fat Cells)
Slide
Ø
83: Skin, dermis https://vmicro.iusm.iu.edu/virtual_h/msci_157_5.html
Junqueira
Ø Fig. 5-21
Ø Fig. 6-1
What are some differences and similarities between dense irregular and loose connective tissue?
Dense Regular Connective Tissue
§ Collagen
§ Fibroblasts
Examine the appearance of tendon. Note the regular parallel arrangement of the collagen fibers
and the relative absence of cells other than fibroblasts.
Slide
Ø 23a: Tendon https://vmicro.iusm.iu.edu/virtual_h_nw/nw_hist_1_16.html
Ø testes capsule https://vmicro.iusm.iu.edu/virtual_h/119_bl_5.html
Ø
Junqueira
Ø Fig. 5-22
What is the major difference between dense regular and dense irregular connective tissue?
Reticulin Fibers
This was stained specifically to highlight the black reticulin fibers.
Slide
Ø
5: Lymphoid tissue https://vmicro.iusm.iu.edu/virtual_h/99_bl_5.html
Junqueira
Ø Fig. 5-23
Speculate as to the general function of reticulin fibers in this special type of connective tissue.
Notes
Muscle
Movement of body parts depends primarily on muscular tissue, the third fundamental
tissue type. The importance of this tissue is emphasized by the fact that almost half the body’s
mass consists of muscle. There are three types of muscle, namely 1) skeletal muscle primarily
involved in voluntary movement of bones 2) cardiac muscle which enables the heart to beat so
blood can be circulated involuntarily and 3) visceral or smooth muscle which provides tone and
involuntary movement of hollow tubes and organs such as the blood vessels, intestine and uterus.
Objectives
v Understand the formation of skeletal muscle
v Understand the arrangement and relationship between muscle fibers and connective tissue
in skeletal muscle
v Identify the different unique structural features of skeletal, visceral and cardiac muscle at
the LM and EM levels and be able to distinguish these three muscle types
v Recognize the arrangement of myofilaments in skeletal muscle and the functional
significance of this arrangement for contraction
Electron Micrographs
-
-
-
Fig. 10-7
o Skeletal Muscle
§ Cross Striations
§ I Band
§ A Band
§ Z Band (Z line)
§ Sarcomere
Fig. 10-10
o Skeletal Muscle
§ T-tubules
§ Sarcoplasmic Reticulum
Fig. 10-20
o Smooth Muscle
Fig. 10-17, 10-18
o Cardiac Muscle
§ Intercalated Disk
Terms
Developing Skeletal Muscle
Myoblasts
Myotubes
Myoblasts illustrate the embryological development of muscle from mesenchymal cells. Later in
development myoblasts fuse to form multinucleated myotubes.
Slides
Ø 13, 40a: Fetal tongue https://vmicro.iusm.iu.edu/virtual_h/464_40ab.html
Ø
Junqueira
Ø Fig. 10-2
Make a sketch here showing how skeletal muscle forms.
(Mature) Skeletal Muscle (a.k.a. Striated Muscle)
Muscle Cells (Fibers)
Cross Striations
A Band [not in S17a, 35]
I Band [not in S17a, 35]
Perimysium
Endomysium [not in S17]
Epimysium [not in S17]
Fascicle
The most characteristic features of skeletal muscle are large, multinucleate fibers with crossstriations. Remember that in muscle, fibers are actually multinucleated cells. On the slides of
both tongue and lip, notice that the perimysium is the loose connective tissue between the
fascicles. Also on those slides, if epimysium is present, observe its dense irregular connective
tissue.
Slides
Ø 3T, 17: Skeletal muscle, longitudinal section
https://vmicro.iusm.iu.edu/virtual_h/464_17_5.html
Ø 17a: tongue https://vmicro.iusm.iu.edu/virtual_h/msci_70_5.html
Ø 35: lip https://vmicro.iusm.iu.edu/virtual_h/msci_67_5.html
Ø
Junqueira
Ø Fig. 10-3, 10-4
What are the functions of the endomysium and perimysium?
Most skeletal muscle associated with the GI tract is smooth, not skeletal. Why are lingual
muscles not composed of smooth muscle?
Smooth Muscle
Muscle Cells (Fibers)
Smooth muscle has non striated fibers of smaller diameter than skeletal muscle fibers, with one
nucleus/fiber. Notice how the muscle fibers have been cut in various planes. Compare the
features of smooth muscle with those you studied in skeletal muscle.
Slides
Ø 40: esophagus https://vmicro.iusm.iu.edu/virtual_h/66_bl_5.html
Ø 46: ileum https://vmicro.iusm.iu.edu/virtual_h/msci_37_5.html
Junqueira
Ø Fig. 10-19, 10-21
Are fiber diameters larger in skeletal or smooth muscle? How about fiber length?
Cardiac Muscle
Muscle Cells (Fibers)
Intercalated Disks
Cross Striations
Fibers of cardiac muscle have features somewhat intermediate between those of skeletal and
visceral muscle. The intercalated discs are key features of cardiac muscle.
Slides
Ø 5T, 18, 18a: Heart ventricle https://vmicro.iusm.iu.edu/virtual_h/msci_139_5.html
Ø
Junqueira
Ø Fig. 10-16
Can you give a functional explanation as to why cardiac muscle has many histological features
that are intermediate between skeletal and smooth muscle?
Notes
Blood Cells and Hemopoiesis
Blood can be considered a special form of connective tissue in which highly specialized
cells are suspended in a fluid matrix called plasma. Blood flow serves to transport many diverse
substances, from gases, nutrients, and wastes to “information-bearing” molecules such as
hormones and antibodies. In stained blood smears, one can quickly distinguish between the
oxygen-carrying erythrocytes which lack nuclei and the basophilic, nucleated leukocytes which
perform many diverse roles in bodily defense.
Objectives
v Learn and identify all types of mature blood cells and platelets by their morphological
characteristics
v Recognize precursors of various blood cells
v Understand the process of blood cell formation, hemopoiesis, in bone marrow
v Recognize the structural features and significance of bone marrow
Electron Micrographs
-
Fig. 12-4
o Erythrocytes
Fig. 12-8
o Neutrophil
Fig. 12-9
o Eosinophil
Fig 12-10
o Basophil
Fig. 12-11
o Lymphocyte
Fig. 12-12
o Monocyte
Fig. 12-13
o Platelets
Terms
Erythrocytes
Lymphocytes
Neutrophils
Eosinophils
Basophils
Monocytes
Platelets
Erythrocytes are red blood cells and are recognized by their anuclear, biconcave shape. Since
erythrocytes are the most abundant cells in blood, they will predominant in your field of view.
The various kinds of leukocytes are all much less numerous. Lymphocytes have spherical nuclei
with relatively little cytoplasm. Neutrophils are polymorphic and have highly lobulated nuclei.
Eosinophils may be the rarest of the blood cells. They have a bilobed nucleus and contain
eosinophilic granules, as their name indicates. Basophils, rare as well, also have a bilobed
nucleus and contain basophilic granules. Monocytes are the largest of the blood cells which
accounts for their large U-shaped nucleus. Platelets are small cell fragments of the blood derived
from megakaryocytes in bone marrow. Platelets and all blood cells are sometimes referred to as
the “formed elements” of blood.
Slide
Ø 23: Blood Smear https://vmicro.iusm.iu.edu/virtual_h/10_2_bl_5.html
Ø
Junqueira
Ø Figs. 12-6 through 12-13
In the space provided below, sketch an example of a lymphocyte, a neutrophil, a monocyte and
some platelets in a scale relative to one another.
Give at least one major function for each of the types of the seven formed elements just studied.
Blood Cell Precursors
Megakaryocytes
Adipocytes
Since bone marrow is the site of hemopoiesis, take note of the precursors which would
eventually develop into blood cells. Note the large, multiple, and polyploid nuclei of the
megakaryocyte.
Slides
Ø 77: Bone Marrow https://vmicro.iusm.iu.edu/virtual_h/127_bl_5.html
Ø 22a: Needle biopsy https://vmicro.iusm.iu.edu/virtual_h/msci_153_5.html
Junqueira
Ø Fig, 13-2
How do megakaryocytes form platelets?
Bone Marrow Cavity
Stroma
Blood Cell Precursors
Megakaryocytes
Examine the bony projections that line the marrow cavity. These are covered by a CT layer
called endosteum which may be difficult to see. The stroma, or loose connective tissue, is filled
with blood cell precursors which are organized in cords or clusters. Blood vessels with dilations
called vascular sinuses are also present in marrow.
Slides
Ø 13a: Developing Bone https://vmicro.iusm.iu.edu/virtual_h/34_bl_5.html
Ø
What is the cellular difference between red and yellow bone marrow?
How do newly formed blood cells move from the stroma into the bloodstream?
Notes
The Circulatory System
The circulatory system is responsible for the movement of blood throughout the body,
with the purpose of delivering oxygen and nutrients to tissues and disposing of waste products
from the tissues. The system consists of a pump, the heart, and an extensive network of
channels, the arteries, veins and capillaries. The arteries carry blood away from the heart.
Because their walls are very thin, the capillaries allow for exchange of material between the
blood and the tissues. The veins return the blood to the heart.
In addition to blood vessels, a second network of channels, the lymphatic vessels, will
also be studied in this exercise. Recall that these vessels carry lymph, intercellular fluid, which
is filtered through lymph nodes and eventually returned back to the blood.
Objectives
v to understand the overall organization and histological features of the heart and major
blood vessels
v to recognize the histological features that distinguish arteries from veins
v to recognize arterioles, capillaries and venules in LM preparations and understand how
their structures relate to their functions
v to be able to recognize lymphatic vessels
Terms
Heart
Epicardium
Myocardium
Cardiac Muscle
Purkinje Fibers
Endocardium
Endothelium
Identity the three lays of the heart wall. Note that the myocardium is the thickest layer due to the
presence of cardiac muscle, Purkinje fibers and small blood vessels. The epicardium is a
relatively thick layer of fatty connective tissue and contains small nerves and large coronary
vessels.
Slide
Ø 18: Heart https://vmicro.iusm.iu.edu/virtual_h/msci_139_5.html
Junqueira
Ø Figs. 11-3 through 11-6
Compare and contrast at least 3 histological features of the endocardium and the epicardium.
Artery (Elastic or muscular)
Tunica Intima
Endothelium
Tunica Media
Tunica Adventitia
Vasa Vasorum
Elastic arteries, for example, the aorta, receive blood directly from the heart and are hence, the
largest of the arteries.
Slide
Ø 25: Elastic Artery (Aorta) https://vmicro.iusm.iu.edu/virtual_h/msci_115_5.html
Ø Van Gieson stain Aorta https://vmicro.iusm.iu.edu/virtual_h/msci_100_5.html
Ø
Junqueira
Ø Figs. 11-7 through 11-11
Which is thicker in the media: one of the layers of smooth muscle or a layer of elastic material?
Vein (Vena Cava)
Tunica Intima
Tunica Media
Tunica Adventitia
Vasa Vasorum
Veins conduct blood away from body tissues. Veins generally have a larger diameter than
arteries, though the width of their walls are thinner than arteries. Like arteries, veins also have
three distinct layers: the tunica intima, the tunica media and the tunica adventitia. The vasa
vasorum supply both elastic and muscular arteries.
Slides
Ø 26: Vena Cava: https://vmicro.iusm.iu.edu/virtual_h/464_26b.html
Junqueira
Ø Fig. 11-21, 11-22
What are 2 major histological differences between veins and arteries?
Vein
Tunica Intima
Tunica Media
Tunica Adventitia
Vasa Vasorum
Muscular arteries send blood to various organs.
Slides
Ø 24: vein https://vmicro.iusm.iu.edu/virtual_h/msci_49_5.html
Ø 15: https://vmicro.iusm.iu.edu/virtual_h/464_15bb.html
Ø
Compare and contrast the muscular artery and the elastic artery.
What is major difference between these arteries and an elastic artery, besides their size?
How does the muscle in the large vessels differ from that in the heart?
Arterioles
Tunica Intima
Tunica Media
Tunica Adventitia
Meta-Arterioles
Capillaries
Post-Capillary Venules
Venules
Tunica Intima
Tunica Media
Tunica Adventitia
Vein
Tunica Intima
Tunica Media
Tunica Adventitia
Lymphatic Vessel (only on 8)
Neurovascular Bundle (only on 8)
Arteries have three distinct layers: the tunica intima, the tunica media and the tunica adventitia.
The smallest branches of arteries are the arterioles, a term Junqueira defines as a vessel in which
the tunica media has six or fewer layers of smooth muscle. Lymphatic vessels drain interstitial
fluid, lymph, from lymphatic spaces and eventually join the thoracic duct and the right lymphatic
duct. From there, the lymph drains into the venous system. Lymph travels through the vessels
primarily by the movement of surrounding organs and tissue.
Slide
Ø 8: Mesentery https://vmicro.iusm.iu.edu/virtual_h/mesent_464_8.html
Ø 18: Heart https://vmicro.iusm.iu.edu/virtual_h/65_bl_5.html
Ø
Junqueira
Ø Figs. 11-13 through 11-20
What is the most important part of the microvasculature? State some of its functions.
What are the 3 general kinds of capillaries and how do their functions differ?
What is the best method to tell a lymphatic vessel from a small vein?
Notes
The Immune (Lymphoid) System
Lymphoid tissues and organs, along with the lymphatic vessels constitute a very
widespread and extremely important filtering system between the body tissues (where foreign
substances and organisms can enter) and the blood stream. Today’s lab will focus on distinct
lymphoid organs, like the lymph nodes, the thymus and the spleen as well as more diffuse
collections of lymphocytes, which are primarily located along the mucosa of the digestive and
respiratory tracts.
Objectives
v Recognize lymphocytes in the various immune organs
v Distinguish the different lymphatic organs in LM preparations
v Recognize the different regions of lymph nodes, spleen and thymus
v Know the major functional significance of the lymph nodes, spleen and thymus
v Understand the filtration mechanism for lymph in the lymph nodes and for blood in the
spleen
Electron Micrographs
-
Fig. 12-11
o Lymphocytes
Terms
Thymus
Capsule
Septa
Cortex
Epithelial Reticular Cell (or Cortical Thymic Epithelial Cell)
Medulla
Hassall’s Corpuscle
Epithelial Reticular Cell (or Medullary Thymic Epithelial Cell)
First note the capsule and septa. Next notice the organization of lobes into a basophilic cortex
and eosinophilic medulla. A key feature of the medulla is the presence of Hassal’s corpuscles,
which are masses of degenerated epithelial cells. The epithelial reticular cells make up the
framework of the thymus.
Slide
Ø 29: Adult Thymus https://vmicro.iusm.iu.edu/virtual_h/464_29b.html
Ø 27a: Child Thymus https://vmicro.iusm.iu.edu/virtual_h/msci_126_5.html
Junqueira
Ø Figs. 14-10 through 14-13
What is the function of the individual epithelial reticular cells?
How do the lymphocytes seen here differ from those in the blood smears studied earlier?
Lymph Node
Capsule
Subcapsular Space
Trabeculae
Reticulin Fibers (only S5)
Cortex
Lymphoid Follicle
Paracortex
Medulla
Medullary Cord
Plasma Cell (not on S5)
Efferent Lymphatic (only S28a)
Slide
Ø 28: Lymph Node (Giemsa stain) https://vmicro.iusm.iu.edu/virtual_h/464_28b.html
Ø 28a: Lymph Node https://vmicro.iusm.iu.edu/virtual_h/msci_42_5.html
Ø 5: Lymph Node (Silver Impregnation)
https://vmicro.iusm.iu.edu/virtual_h/99_bl_5.html
Junqueira
Ø Fig. 14-17 through 14-22
How does the stroma of a lymph node differ from that of the thymus?
How is lymph filtered as it moves through the nodes?
Mucosa-Associated Lymphoid Tissue (MALT)
Ileum
Lymphoid Follicle
Lymphocyte
Peyer’s Patches
Tonsil
Lymphoid Follicle
Lymphocyte
Appendix
Lymphoid Follicle
Lymphocyte
Slides
Ø 45: Ileum https://vmicro.iusm.iu.edu/virtual_h/msci_37_5.html
Ø 27: Tonsil https://vmicro.iusm.iu.edu/virtual_h/msci_136_5.html
Ø 47: Appendix https://vmicro.iusm.iu.edu/virtual_h/msci_41_5.html
Junqueira
Ø Figs. 14-14 through 14-16
Ø Fig. 15-32
Ø Fig. 15-39
In what sense is the MALT system the first line of the body’s defense? Does it resemble more
closely a lymph node or the thymus?
Spleen
Capsule
Trabeculae
Red Pulp
Pulp Cord
Vascular Sinusoids
Stave Cells
White Pulp
Lymphocyte
Central Arteriole
Slide
Ø 30: Spleen https://vmicro.iusm.iu.edu/virtual_h/msci_68_5.html
Ø 30a: Spleen https://vmicro.iusm.iu.edu/virtual_h/msci_18_5.html
Junqueira
Ø Figs. 14-24 through 14-29
What is one unique aspect of the spleen compared to other immune organs?
In what sense is blood filtered as it moves through the spleen?
Notes
Central Nervous System
Nervous tissue is the fourth and last fundamental tissue type to be considered and is
actually a complex organization of several cell types. In addition to various kinds of neurons, it
contains glial cells of several different varieties and blood vessels with connective tissue
coverings. The neurons are specialized to conduct impulses. The glial cells are involved in the
nutrition and the formation of sheaths around the neurons and play an important role in
inflammatory reactions.
Objectives
v Understand the major histological differences between central nervous tissues and other
tissues
v Recognize the major components of the spinal cord in transverse section
v Recognize certain regions and specific neuronal types in the brain
v Identify and learn the specific roles of the major types of glial cells in the CNS
Terms
Spinal Cord
White Matter
Neuropil
Gray Matter
Neuron Cell Bodies
Nissl Substance (Rough ER)
Glial cell nuclei
Dorsal Horns
Ventral Horns
Central Canal
Ependymal Cell
Slide
Ø 6T: Spinal Cord https://vmicro.iusm.iu.edu/virtual_h/msci_149_5.html
Ø 19a: Spinal Cord (Myelin Stain) https://vmicro.iusm.iu.edu/virtual_h/464_19ab.html
Junqueira
Ø Figs. 9-3, 9-14, 9-17, 9-18
What are the major types of glial cells in the spinal cord and where are they located?
How are the appearances of white and gray matter different in the myelin-stained and the H&E
stained slides?
Indicate three functions of the cells present in the ependyma.
Cerebrum
Meninges
Pia
Arachnoid
White Matter
Gray Matter
Pyramidal Cell
Neuroglial Cell
Astrocyte
Oligodendrocyte
Slide
Ø 94: Cerebrum https://vmicro.iusm.iu.edu/virtual_h/msci_125_5.html
Junqueira
Ø Figs. 9-15 and 9-19
Is dura mater present on your slide? If not, can you guess why?
List several functions of astrocytes.
Cerebellum
White Matter
Myelinated Axon
Gray Matter
Molecular Layer
Purkinje Cell
Granular Layer
Slide
Ø 96: Cerebellum https://vmicro.iusm.iu.edu/virtual_h/msci_148_5.html
Ø Nissl stain https://vmicro.iusm.iu.edu/virtual_h/71_bl_a.html
Junqueira
Ø Fig. 9-16
List names of neurons found in the cerebellum and give their most important cytological
features.
What features do Purkinje cells show especially well?
Notes
Peripheral Nervous System
The peripheral nervous system is an extension of the central nervous system. The
reception of information is the function of the sensory component of the peripheral nervous
system, or PNS. The transmission of the response to the effector organ is relegated to the motor
component of the PNS. Peripheral nerves are composed of bundles of axons and dendrites.
Each nerve is enclosed by an epineurium. Bundles, or fascicles of axons are surrounded by
several layers of flattened fibroblastic cells, the perineurium. Each axon and dendrite is invested
by a Schwann cell which is surrounded by basal lamina. The Schwann cells are also surrounded
by another thin layer of CT, the endoneurium.
Objectives
v Recognize the microscopic features of peripheral nerves and ganglia in light microscopy
v Recognize the structural and ultrastructural features of the myelin sheath
v Understand the role of Schwann cells in myelinated and unmyelinated nerves
v Identify the ultrastructural features of synapses
Electron Micrographs
Study the EMs and diagrams on Junqueira pages 160 through 163 and identify the following
components of the peripheral nervous system.
Schmidt-Lantermann clefts
Myelin
Axons
Terminal Bouton
Synaptic vesicles
Postsynaptic cleft
Mitochondria
Terms
Nerve (Fibers)
Schwann Cell
Myelin Sheath
Node of Ranvier
Axon
Examine
Slide
Ø 44: Isolated Nerve Fibers https://vmicro.iusm.iu.edu/virtual_h/msci_151_5.html
Ø
Junqueira
Ø Figs. 9-23 and 9-26
What exactly is a node of Ranvier?
Nerve
Epineurium
Perineurium
Fascicles
Endoneurium (only on 19)
Myelin Sheath
Axons (only on 19)
Slide
Ø 19: Peripheral Nerve https://vmicro.iusm.iu.edu/virtual_h/464_19b.html
Ø 20: Peripheral Nerve (Osmium Treatment)
https://vmicro.iusm.iu.edu/virtual_h/150_bl.html
Junqueira
Ø Figs. 9-26, 9-27
What are the major histological and functional differences between the myelin sheath and the
endoneurium?
Small nerves and Neurovascular Bundle
Nerve (Fibers)
Schwann Cell
As is demonstrated by the neurovascular bundle, arteries and veins are associated with nerves.
Slide
Ø 8: Mesentery https://vmicro.iusm.iu.edu/virtual_h/mesent_464_8.html
Ø
Junqueira
Ø Fig. 9-28
Does the outer layer of connective tissue in the small nerves resemble a perineurium or an
epineurium?
Spinal and sympathetic Ganglia
Capsule
Satellite Cell
Nerve (fibers, myelinated)
Neuron
Cell Body
Schwann Cell
Slide
Ø
Ø
Ø
Ø
21: Spinal Ganglion https://vmicro.iusm.iu.edu/virtual_h/msci_137_5.html
22a: Spinal Ganglion (Osmium Treatment)
6T: Spinal Cord https://vmicro.iusm.iu.edu/virtual_h/msci_09_5.html
22: Sympathetic Ganglion https://vmicro.iusm.iu.edu/virtual_h/msci_135_5.html
Junqueira
Ø Fig. 9-29
What is the significance of Nissl substance?
What is the function of the satellite cells?
Notes
Sensory Receptors
There is quite a variety of structures throughout the body whose function is to detect
stimuli of different types and have that stimulus initiate a nerve impulse for transmission back to
the CNS. Many such sensory receptors are little more than bare, unmyelinated axon endings and
are usually not visible histologically. Others are more complex and are associated with CT or
cellular structures. Some of these more complex sensory strictures will be studied here.
Physiologically these receptors can be considered as chemoreceptors or mechanoreceptors.
Objectives
v Recognize taste buds on lingual papillae and understand how their structure facilitates
taste perception
v Recognize Meissner’s and Pacinian corpuscles in the skin
v Identify olfactory epithelium and understand its function
v Learn the general structure of the organ of Corti in the inner ear and the roles of its
structural components in hearing
Terms
Tongue
Circumvallate Papilla
Taste Buds
Gustatory Cells
Taste Pores
Von Ebner’s Glands
Slide
Ø 36a: Tongue https://vmicro.iusm.iu.edu/virtual_h/msci_70_5.html
Ø https://vmicro.iusm.iu.edu/virtual_h/8_bl_5.html
https://vmicro.iusm.iu.edu/virtual_h/77_bl_5.html
Junqueira
Ø Fig. 15-4, 15-5, 15-6
What is the difference between gustatory and sustentacular cells?
Is Von Ebner’s gland serous or mucous and how does its function relate to sensation?
Skin
Epidermis
Dermis
Dermal Papillae
Meissner’s (Tactile) Corpuscle
Hypodermis
Pacinian (Lamellated) Corpuscle
Slide
Ø 7T: Skin https://vmicro.iusm.iu.edu/virtual_h/msci_36_5.html
Ø https://vmicro.iusm.iu.edu/virtual_h/msci_05_5.html
Ø 87: Fingertip https://vmicro.iusm.iu.edu/virtual_h/464_87b.html
Junqueira
Ø Fig. 18-10
Ø Fig. 18-11
What physiological “type” of receptor would Meissner’s and Pacinian corpuscles both represent?
Olfactory Epithelium
Respiratory Epithelium
Slide
Ø 8a: Nasal cavity (dog) https://vmicro.iusm.iu.edu/virtual_h/464_8b.html
Ø 12a: Fetal Pig Head https://vmicro.iusm.iu.edu/virtual_h/464_12ab.html
Junqueira
Ø Fig. 17-2 and 17-3
Compare and contrast olfactory and respiratory epithelia.
What is the physical basis of olfaction?
Cochlea
Scala Vestibuli
Scala Tympani
Scala Media (Cochlear Duct)
Vestibular Membrane
Basilar Membrane
Tectorial Membrane
Organ of Corti
Spiral Ganglion
Slides
Ø 92: Cochlea (Guinea Pig) https://vmicro.iusm.iu.edu/virtual_h/121_bl_5.html
Junqueira
Ø Fig. 23-29, 23-30
What is the function of the stria vascularis?
How exactly does movement of the oval and round windows produce auditory sensations via the
organ of Corti?
Notes
The Eye
Each eye is derived as an outgrowth of the brain in the early embryo and the unique and
highly complex structure of the eye reflect its origin. In studying a histological section of the
eye, one must keep in mind the fact that it is composed basically of three layers and that, in the
living state, the anterior portion of the eye is filled with fluid which is being continually
produced and absorbed. The posterior region behind the lens is filled with an almost fluid form
of CT called vitreous humor. The lens itself always hardens very severely during fixation and is
difficult to section.
Objectives
v to understand the general organization of the eye and recognize the major tissues of the
eye and their basic functions
v to be able to recognize the various major layers of the eye (corneosclera, uvea, and retina)
Slides
Ø 93: Eye https://vmicro.iusm.iu.edu/virtual_h/msci_78_5.html
Ø 95: Eye (Anterior) https://vmicro.iusm.iu.edu/virtual_h/msci_120_5.html
Ø
Junqueira
Ø Fig. 23-1 through 23-17
Terms
Eye
Anterior Chamber
Anterior Cavity
Posterior Cavity
Posterior Chamber
Sclera (Fibrous Tunic)
Cornea
Corneal Epithelium
Bowman’s (external) Membrane
Stroma
Descemet’s (internal) Membrane
Corneal Endothelium
How does the cornea differ histologically and functionally from the sclera?
Compare and contrast Bowman’s and Descemet’s membranes.
Canal of Schlemm
What is one important function of this canal?
Uvea (Uveal Layer, Vascular Tunic)
Choroid
Ciliary Body
Ciliary Muscle
Ciliary Processes
Supsensory Ligaments (or Zonule)
Iris
What is the functional significance of the ciliary processes?
Indicate some unusual histological features of the iris.
Lens
Capsule
Fibers
What is a “cataract” of the eye and why would they form in lens tissue but not in other tissue?
The structures below are only found on slide 93
Sensory Tunic
Retina
Pigmented Layer
Processes of Rods and Cones
Nuclei of Rods and Cones
Inner Nuclear Layer
Ganglion Layer
What must light pass through before it hits rods and cones?
What exactly are the “photoreceptors” in the rods and cones?
What is the significance of the neuronal cell bodies in the retina?
Indicate three functions of the pigmented layer of the retina.
Notes
Integument (Skin)
The skin constitutes an organ system with a variety of important functions. Consisting of
dermal and epidermal layers, the skin protects the body from various kinds of mechanical injury
and constitutes a major defense against invasion of foreign organisms. Having various
“epidermal appendages” (hair, nails, sweat glands and sebaceous glands), skin is also critical for
maintaining the body’s temperature and preventing desiccation. The skin contains many sensory
receptors for various kinds of stimuli and represents the site of interaction between the body and
the environment. In addition, skin has various metabolic functions such as synthesis of vitamin
D by cells of the epidermis. The protective, sensory and thermoregulatory functions of the
integument are reflected in its complex histology.
Objectives
v Understand the major layers and tissue components of skin and their functional
significance
v Recognize the different histological layers within the epidermis and how these relate to
the process of keratinization and epidermal function
v Understand the formation and function of various epidermal appendages such as hair and
nails
Terms
Epidermis
Stratum Corneum
Stratum Granulosum
Stratum Spinosum
Stratum Lucidum (slide 33a only)
Stratum Basale
Melanocytes
Keratinocytes
Dermis
Papillary Layer
Dermal Papillae
Reticular Layer
Hypodermis (Subcutis)
Thick skin is found on fingertips, palms and soles of feet. It is specialized for protection during
friction and contains sensory receptors responsive to pressure, the Pacinian corpuscles. Thin
skin covers most of the body and is similar in many respects to thick skin. For example, thin
skin contains hair follicles but does not have Pacinian corpuscles to respond to pressure and
friction.
Slide
Ø 83: Thick Skin https://vmicro.iusm.iu.edu/virtual_h/msci_05_5.html
Ø 33a: Thick Skin https://vmicro.iusm.iu.edu/virtual_h/89_bl_5.html
Ø 84: Thin Skin https://vmicro.iusm.iu.edu/virtual_h/msci_36_5.html
Ø
Junqueira
Ø Figs. 18-2 through 18-9
What do the small “spines” on keratinocytes of the spinous layer represent?
What is contained in the granules of the keratinocytes of the granular layer?
Since the cells there are dead, why is the cornified layer so critically important?
How does melanin get from the melanocytes into the keratinocytes?
List several functions of the dermis and hypodermis.
Eccrine and apocrine Sweat Glands
Secretory Portion
Duct
Slide
Ø 44a: Skin of Axilla https://vmicro.iusm.iu.edu/virtual_h/464_44b.html
Junqueira
Ø Figs. 18-16, 18-17
What is the functional significance of having apocrine sweat glands in skin of only certain body
areas?
Hair Follicles
Internal Root Sheath
External Root Sheath
Hair Bulb
Dermal Papillae (of hair)
Arrector Pili Muscle
Sebaceous Gland
Slides
Ø 85: Skin of Scalp (Vertical Section) https://vmicro.iusm.iu.edu/virtual_h/464_85b.html
Ø 86: Skin of Scalp (Oblique Section) https://vmicro.iusm.iu.edu/virtual_h/464_86b.html
Junqueira
Ø Figs. 18-12, 18-13, and 18-15
What is the function of the “pilosebaceous unit” in the skin?
Nail Plate
Nail Bed
Nail Root
Nail Fold
Eponychium
Hyponychium
Slide
Ø 42a: Fingertip
Junqueira
Ø Fig. 18-14
How exactly does cell proliferation and keratinization produce a nail?
Notes
Cartilage and Bone
Cartilage is a form of CT that forms the supportive framework of certain organs, the
articulating surface of bones and the greater part of the fetal skeleton. The cartilage of the fetal
skeleton is eventually replaced by bone. Three types of cartilage will be studied in today’s lab:
hyaline cartilage, elastic cartilage and fibrocartilage. Cartilage is a nonvascular and pliable, yet
strong, material composed of proteoglycan matrix. Embedded in this matrix are the fibrous and
cellular components of cartilage.
Objectives
v Recognize the microscopic features of both the matrix and the cells in cartilage and bone
v Understand the structural and functional differences among types of cartilage
v Understand the microscopic structure of bone and the functional significance of osteons
Electron Micrographs
-
Fig 7-7
o Chondrocytes
Terms
Hyaline Cartilage
Perichondrium
Chondroblasts
Lacunae
Chondrocytes
Slide
Ø 60: Trachea https://vmicro.iusm.iu.edu/virtual_h/140_bl_5.html
Ø 13: Fetal Foot https://vmicro.iusm.iu.edu/virtual_h/464_13b.html
Junqueira
Ø Fig. 7-1, 7-2
What is a major physiological property of hyaline cartilage?
Elastic Cartilage
Perichondrium
Chondroblasts
Lacunae
Chondrocytes
Elastic Fibers
Slide
Ø 9: Ear https://vmicro.iusm.iu.edu/virtual_h/056_bl_5.html
Ø
Junqueira
Ø Figs. 7-1, 7-4
What is the function of perichondrium?
Fibrocartilage
Lacunae
Chondrocytes
Collagen Bundles
Note the absence of the perichondrium.
Slides
Ø 14a: Fibrocartilage https://vmicro.iusm.iu.edu/virtual_h/131_bl_5.html
Junqueira
Ø Fig. 7-5
How does the location of fibrocartilage help explain why it must be different from hyaline and
elastic cartilage?
Bone (Ground)
Osteon (Haversian System) (not on longitudinal sections)
Lamellae
Lacunae
Canaliculi
Haversian Canal (aka Central Canal)
Interstitial Lamellae (not on longitudinal sections)
Volkmann’s Canal (longitudinal section on Slide 11 only)
Slide
Ø 11: Ground Bone (Cross section and Longitudinal)
https://vmicro.iusm.iu.edu/virtual_h/32_bl_5.html
Junqueira
Ø Figs. 8-1, 8-9, 8-10
What is the function of canaliculi and how do they form?
What other structure in bone do Volkmann’s canals resemble functionally?
Bone (Decalcified)
Periosteum
Osteoblasts
Osteon
Central Canal
Lacunae
Osteocytes
Endosteum
Marrow
Notice that the periosteum consists of both a fibrous layer and an osteogenic layer with
osteoblasts.
Slide
Ø 12: Decalcified Bone http://medsci.indiana.edu/a464/virtual/464_12.html
Junqueira
Ø Figs. 8-2, 8-5, 8-6, 8-8
Compare and contrast the structures of periosteum and endosteum.
Notes
Bone Formation
Bone is the other specialized connective tissue in which extracellular specializations for
support are maximal within the limits required for development and remodeling. There are two
types of bone development: intramembranous and endochondral ossification or osteogenesis.
Intramembranous ossification gives rise to “membrane bones,” these being the flat bones of the
skull and parts of the mandible. This process involves the deposition of bone matrix, osteoid,
directly in regions, or membranes, of embryonic mesenchyme. Bones of the extremities, pelvis
and vertebral column, cartilage bones, are formed by endochondral ossification. This process
involves the initial formation of a hyaline cartilage model followed by its replacement with bone.
Regardless of the ossification process, the histological structure of the bone is the same.
Objectives
v Understand the two mechanisms of bone formation, their differences and similarities
v Recognize the appearances and significance of the various zones present in a bone
v Recognize and know the functional significance of the parts comprising a synovial joint
Terms
Intramembranous Bone Formation
Mesenchyme
Periosteum
Trabeculae
Osteoblasts
Osteoid (Demo)
Lacunae
Osteocytes
Bone (Calcified)
Note that the mesenchyme is embryonic loose connective tissue.
Slide
Ø 12a: Fetal Guinea Pig Head https://vmicro.iusm.iu.edu/virtual_h/msci_130_5.html
Junqueira
Ø Figs. 8-12, 8-13
Where would you expect mesenchyme to persist the longest during formation of the skull?
What is happening chemically in osteoid that converts it to bone?
Endochondral Bone Formation
Epiphysis
Hyaline Cartilage
Diaphysis
Primary Ossification Center
Secondary Ossification Center
Periosteum
Bone
Lacunae
Osteocytes
Epiphyseal Growth Plate
Zone of Proliferation
Zone of Maturation and Hypertrophy
Zone of Degeneration and Osteogenesis
Slide
Ø 15a: Fetal Joint https://vmicro.iusm.iu.edu/virtual_h/464_15b.html
Ø https://vmicro.iusm.iu.edu/virtual_h/34_bl_5.html
Junqueira
Ø Figs. 8-14 through 8-17
Why are periosteal cells and osteoprogenitor cells not necessarily the same thing?
List exactly what is happening at the cellular level as you move from the epiphyseal cartilage to
the diaphyseal bone marrow.
Joint Cavity
Joint Capsule
Ligaments
Slides
Ø 15a: Fetal Joint https://vmicro.iusm.iu.edu/virtual_h/464_15b.html
Junqueira
Ø Figs. 8-19, 8-20, 8-21
What type of tissue is the synovium and what is its function?
What feature(s) of a synovial joint often decrease with age, requiring the joint to be replaced
with a artificial joint?
Fibrocartilage / Intervertebral disk
Slide
14a: Intervertebral disk https://vmicro.iusm.iu.edu/virtual_h_nw/nw_hist_1_23.html
Junqueira
Fig. 8-22
Notes
Teeth and Tooth Formation
Like bone, teeth include very hard calcified components, but unlike bone this tissue does
not turnover or get repaired in the course of a person’s lifetime. Teeth are usually considered in
the context of the digestive system or oral cavity, as in Junqueira, but will be covered here in the
context of calcified tissue. As you study tooth biology here, note the similarities and differences
between the formation and maintenance of this tissue with bone.
Objectives
v Recognize the major components of teeth in the LM
v Understand the process of tooth formation and recognize the basic embryonic structures
involved in tooth development
Terms
Tooth (Ground)
Pulp Cavity
Dentine
Enamel
Cementum
Slide
Ø 38: Ground Tooth https://vmicro.iusm.iu.edu/virtual_h/129_bl_5.html
Junqueira
Ø Figs. 15-7 through 15-9
Which hard component of the tooth most resembles bone histologically?
What do the parallel line (rods or prisms) in enamel represent?
Tooth (Developing)
Enamel Organ
Ameloblasts
Enamel
Dentine
Predentine
Odontoblasts
Slide
Ø 38a: Developing Tooth (need demo too thick to scan)
Ø https://vmicro.iusm.iu.edu/virtual_h/msci_130_5.html
Junqueira
Ø Fig. 15-10, 15-11, 15-12
Explain the relationship of ameloblasts and odontoblasts to the formation of enamel and dentine.
Which layer disappears before eruption of the tooth and which layer persists?
Notes
The Digestive System Part I
The digestive system consists of a long muscular tube, extending from mouth to anus,
and a large number of associated glands which secrete substances that aid food digestion. The
digestive tube is generally made up of four structurally and functionally distinct layers: the
mucosa, the submucosa, the muscularis and the serosa. The mucosa, which is in contact with the
contents of the lumen, is constructed to resist abrasion and to perform secretory and absorptive
functions. The muscular layer which serves to propel the food through the tube is attached to the
mucosa by way of the submucosa, a loose connective tissue layer. The serosa is called the
adventitia when it is not covered by mesothelium. The serosa or adventitia carries blood vessels
and nerves into the wall of the digestive tract.
Objectives
v Recognize the major features histological and physiological features of oral mucosa
v Understand the relationship between structure and function in the esophagus
v Recognize specific cell types in the lining of the stomach and their roles
Electron micrograph
-
Fig. 15-22 Parietal cell
Terms
Lip
Oral Mucosa
Skin
The oral (or buccal) cavity contains structures for ingestion and fragmentation of food, resulting
in formation of a bolus of food for swallowing. We have already studied teeth. In this lab note
the abundance of skeletal muscle and small salivary glands in the lip. The skin on the external
surface merges into the nonkeratinized, stratified squamous epithelium of the oral mucosa on the
internal surface.
Slide
Ø 35: Lip https://vmicro.iusm.iu.edu/virtual_h/msci_67_5.html
Junqueira
Ø Fig. 15-3
What are the major differences between oral mucosa and skin?
Soft Palate
Oral Mucosa
Stratified Squamous (non-keratinized) Epithelium
Nasal Mucosa
Pseudostratified Ciliated Columnar Epithelium
Mucous Glands
Stratified squamous (non-keratinized) epithelium lines the oral surface of the soft palate and
interdigitates with the lamina propria. The soft palate contains mucous glands that secrete their
product into the oral cavity.
Slide
Ø 37: Soft Palate https://vmicro.iusm.iu.edu/virtual_h/464_37b.html
Why would you expect that the epithelia lining the soft palate and the nasal cavity are so
different?
Esophagus
Mucosa
Epithelium
Stratified Squamous (non-keratinzed) Epithelium
Lamina Propria
Muscularis Mucosae
Submucosa
Esophageal Mucous Glands
Muscularis
Inner Circular Layer
Outer Longitudinal Layer
Adventitia
Slides
Ø 40: Esophagus https://vmicro.iusm.iu.edu/virtual_h/msci_43_5.html
Ø 2T: Esophagus https://vmicro.iusm.iu.edu/virtual_h/66_bl_5.html
Junqueira
Ø Fig. 15-14
What does the histology of the esophagus tell you about the protective functions of this organ?
What type of muscle do you see in slides of esophagus and what does this tell you about the level
from which the biopsy was taken?
Gastro-esophageal Junction
Esophagus (portion)
Stratified Squamous (non-keratinzed) Epithelium
Stomach (portion)
Simple Columnar Epithelium
Slide
Ø 41a: Gastro-esophageal Junction
https://vmicro.iusm.iu.edu/virtual_h_nw/nw_hist_1_124.html
Junqueira
Ø Fig. 15-17
Stomach
Mucosa
Gastric Pits
Gastric Glands
Neck Mucous Cell
Parietal Cell
Peptic Cell
Lamina Propria
Muscularis Mucosa
Submucosa
Muscularis
Inner Oblique Layer
Middle Circular Layer
Outer Longitudinal Layer
Slide
Ø 43a: Stomach, body and pylorus
https://vmicro.iusm.iu.edu/virtual_h/msci_101_5.html
Junqueira
Ø Figs. 15-18 through 15-24
What is the function of each epithelial cell type in the stomach?
Why do you suppose most of these cells are protected down inside the gastric pits/glands?
Stomach
Gastric Pits
Pyloric Glands
Slides
Ø 42: Stomach, Pyloric Region https://vmicro.iusm.iu.edu/virtual_h/464_42b.html
Junqueira
Ø Fig. 15-19
What is the functional significance of the main difference between the glands in the pylorus and
in the rest of the stomach?
Notes
The Digestive System Part II
The digestive tract continues from the stomach through the small and large intestines or
bowels. The small intestine is a long organ with three regions along its length: the duodenum, the
jejunum, and the ileum. Except for specialized structures that are present, such as Brunner’s
mucous glands in the duodenum and Peyer’s patches in the ileum, all three regions of the small
intestine are rather similar histologically and all are involved primarily in food digestive and in
absorbing the products of digestion.
Objectives
v Understand the structural basis of absorption in the small intestine
v Recognize the histological and functional differences between the small and large
intestines
Electron Micrographs
-
Fig. 15-28 and 15-29
o Enterocytes
Fig. 15-31
o Endocrine cells
Terms
Gastroduodenal Junction
Brunner’s Glands
Pyloric Sphincter
It is important to note the differences in the mucosa between the stomach and the small intestine.
Slide
Ø 5a: Gastroduodenal Junction https://vmicro.iusm.iu.edu/virtual_h/464_5b.html
Junqueira
Ø Fig. 15-34
What is lacking in the mucosa of the duodenum compared to that of the stomach?
Duodenum
Mucosa
Simple Columnar Epithelium
Villi
Enterocytes
Microvilli
Goblet Cell
Intestinal Gland
Lacteals
Muscularis Mucosae
Submucosa
Brunner’s Gland
Muscularis
Inner Circular Layer
Outer Longitudinal Layer
Serosa
Slide
Ø 43: Duodenum https://vmicro.iusm.iu.edu/virtual_h/msci_04_5.html
Ø
Junqueira
Ø Figs. 15-25, 15-26, and 15-28
Describe the process by which enterocytes and goblet form, migrate, and eventually disappear
from the surface of villi.
Brunner’s glands supplement what other glands?
Lacteals are an example of what structure studied earlier in the course?
What is the specific function of lacteals in villi?
Ileum
Plicae Circularis (only on 46)
Mucosa
Simple Columnar Epithelium
Goblet Cell
Enterocyte
Crypts of Lieberkühn
Paneth Cell (only on 46)
Mitotic cell
Lamina Propria
Lacteals
Villi
Peyer’s Patches (only on 45)
Submucosa
Muscularis
Inner Circular Layer
Outer Longitudinal Layer
Serosa
Note the some examples of Slide 45 contain roundworms! Lacteals can be found in the lamina
propria of villi.
Slide
Ø 45: Ileum https://vmicro.iusm.iu.edu/virtual_h/464_45b.html
Ø 46: Ileum https://vmicro.iusm.iu.edu/virtual_h/msci_21_5.html
Junqueira
Ø Figs. 15-27, 15-30, and 15-33
What is the function of the Paneth cells?
What is the function of the muscularis mucosae in the ileum?
Colon
Mucosa
Simple Columnar Epithelium
Simple Tubular Glands (Colonic)
Lamina Propria
Muscularis Mucosae
Submucosa
Muscularis
Inner Circular Layer
Outer Longitudinal Layer
Serosa
Slide
Ø 48a: Colon https://vmicro.iusm.iu.edu/virtual_h/464_48b.html
Ø https://vmicro.iusm.iu.edu/virtual_h/msci_06_5.html
Ø
Junqueira
Ø Figs. 15-36 through 15-38
Indicate three histological features of the colon which clearly pertain to its function.
Notes
Digestive Glands and Liver
The large number of glands associated with the digestive canal range from unicellular
components such as goblet cells and small tubuloalveolar units residing in the mucosa to very
large separate organs such as the pancreas and liver. Although their secretions can be quite
dissimilar, they all function to promote the digestive process by imparting enzymes or mucus
into the ingested food. Bile, the exocrine secretion of the liver, is stored and concentrated in
another organ, the gallbladder.
Objectives
v to recognize and understand the difference between serous and mucous acini in salivary
glands
v to understand histological and functional differences between the salivary glands and the
exocrine pancreas
v to understand the microscopic anatomy of the liver and how the arrangement of cells in
this organ relates to the diverse functions of the liver
Electron Micrographs
-
Figs. 16-15 and16-16
o Liver
• Hepatocytes
• Space of Disse
• Microvilli
• Lysosomes
Terms
Parotid Gland
Serous Acini
Serous Cell
Slide
Ø 50: Parotid gland https://vmicro.iusm.iu.edu/virtual_h/msci_132_5.html
Junqueira
Ø Figs. 16-1 through 16-3
What is the general function of serous glands?
Salivary Gland
Serous Acini
Mucous Acini
Serous Demilunes
Slide
Ø 51: Submandibular Gland https://vmicro.iusm.iu.edu/virtual_h/msci_72_5.html
Ø 3a: Sublingual Gland https://vmicro.iusm.iu.edu/virtual_h/464_3b.html
Junqueira
Ø Figs. 16-1 through 16-6
What is the usual function of mucus?
Pancreas
Acini
Acinar Cell
Intercalated Duct
Interlobular Duct
Slides
Ø 53: Pancreas https://vmicro.iusm.iu.edu/virtual_h/044_bl_5.html
Ø https://vmicro.iusm.iu.edu/virtual_h/msci_154_5.html
Junqueira
Ø Figs. 16-7 through 16-10
Indicate one secreted factor of intercalated ducts.
Liver
Septa (Slide 55)
Lobules
Central Vein
Portal Tract
Portal Triad
Branch of Hepatic Portal Vein
Branch of Hepatic Artery
Bile Ductule
Simple Cuboidal Lining
Hepatic Plate
Hepatocytes
Hepatic Sinusoid (Slide 56 and Slide 59)
Endothelial Lining
Slide
Ø 59: Liver https://vmicro.iusm.iu.edu/virtual_h/msci_141_5.html
Ø 56: Liver https://vmicro.iusm.iu.edu/virtual_h/msci_29_5.html
Ø 6a: Liver pig https://vmicro.iusm.iu.edu/virtual_h/464_55b.html
Junqueira
Ø Figs. 16-11 through 16-19
How does the organization of hepatocytes as plates facilitate their functioning?
Where is most of the connective tissue of the liver located?
Where exactly does blood entering a liver lobule from the hepatic artery and the portal vein mix?
Gall Bladder
Mucosa
Simple Columnar Epithelium
Submucosa
Slide
Ø 58: Gall Bladder https://vmicro.iusm.iu.edu/virtual_h/msci_105_5.html
Junqueira
Ø Fig. 16-20 and 16-21
How does the histology of this mucosa facilitate the gall bladder’s function?
Notes
The Respiratory System
The main function of the respiratory system is the transferring of gases between the air
and the blood. The system is comprised of tubes and highly branched channels which terminate
in dead-end sacs where gas transfer occurs. Air brought into the body is first conditioned and
filtered in the first part of the respiratory system, the conducting portion, which extends from the
nasal cavity to the bronchioles. The second part of the system, the respiratory portion, consists
of the respiratory bronchioles and alveoli are involved with gas exchange.
Objectives
v Understand the general organization of the respiratory system and recognize LM
preparations of the various regions
v Understand the structure and functional significance of respiratory alveoli
v Recognize the different cell types in an alveolus
Electron Micrographs
-
Fig. 17-15
o Alveolar Walls
• Type I pneumocytes
• Capillary
Fig. 17-16
o Type II pneumocyte
-
Terms
Trachea
Tracheal Rings
Hyaline Cartilage
Trachealis Muscle
Mucosa
Respiratory Epithelium (PCCE)
Ciliated Cell
Goblet Cell
Basement Membrane
Submucosa
Sero-Mucous Gland
Ø Slide60: Trachea https://vmicro.iusm.iu.edu/virtual_h/002_bl_5.html
Ø https://vmicro.iusm.iu.edu/virtual_h/140_bl_5.html
Junqueira
Ø Figs. 17-5 through 17-7
What is the function of the rings of hyaline cartilage?
Why are they made of hyaline rather than elastic cartilage?
What is the muscle type in the trachealis muscle and what function does it serve here?
How do the ciliated cells and the goblet cells work together in a protective function?
Lung
Bronchi
Branch of Pulmonary Artery (only 61)
Bronchioles
Simple Columnar to Cuboidal Epithelium
Smooth Muscle
Goblet Cell
Terminal Bronchiole
Simple Cuboidal Epithelium
Smooth Muscle
Respiratory Bronchiole
Simple Cuboidal Epithelium
Alveoli
Alveolar Duct
Simple Squamous Epithelium
Alveolar Sac
Simple Squamous Epithelium
Alveoli
Type I Pneumocyte (only 61)
Type II Pneumocyte (only 61)
Dust Cell (Macrophage) (only 61)
Interalveolar Septa
Capillary (only 61)
Endothelial Cell (only 61)
Slide
Ø 61: Lung https://vmicro.iusm.iu.edu/virtual_h/97_bl_5.html
Ø 62: Lung https://vmicro.iusm.iu.edu/virtual_h/98_bl_5.html
Junqueira
Ø Figs. 17-7 through 17-14
Indicate the function of the cells that air contacts as it moves deeper and deeper into the lung?
What is the major histological difference between the conducting and the respiratory portions of
the airway?
What is the major chemical property of surfactant?
Compare and contrast type I and type II pneumocytes.
What one alveolar cell type is often critically lacking in premature infants, causing respiratoru
distress syndrome?
Notes
The Urinary System
The urinary system consists of the kidneys, ureters, bladder and urethra and is responsible
for the important bodily function of soluble waste production, storage and elimination. The
waste substances are produced in the kidney as blood filtrates, transported via the ureters to the
bladder where it is stored and eventually eliminated through the urethra. This process also
results in the salvaging of large amounts of water, sugars and ions from the blood filtrate which
are returned to the blood. In addition, the kidneys play a role in controlling systemic blood
pressure by the secretion of renin.
Objectives
v Recognize and distinguish the various regions of the urinary system
v Understand the blood supply and significance of blood flow within the kidney
v Understand the structural and functional organization of the kidney and its nephrons
v Understand the structural basis and physiological basis of blood filtration in nephrons
v Distinguish the different regions of a nephron and their functional significance
Electron Micrographs
Study all of the EMs in Chapter 19 of Junqueira and compare the EMs to the LMs and to the
corresponding structures on your slides. In both Figure 19-5 and Figure 19-6 recognize and
understand the following terms.
Podocytes
Primary foot processes
Secondary foot processes
Filtration slits
Glomerular basement membrane
Endothelial fenestrations
What are the driving forces that cause fluid to move from the capillary to Bowman’s space?
The dialysis tubing in a kidney dialysis machine is analogous to what part of the renal corpuscle?
Terms
Kidney
Cortex
Renal Corpuscle
Glomerulus
Bowman’s Capsule
Bowman’s Space
Medullary Rays
Proximal Convoluted Tubule
Distal Convoluted Tubule
Juxtaglomerular Apparatus (only 64)
Macula Densa (only 64)
Afferent Arteriole
Medulla
Thin Limb of the Loop of Henle
Thick Limb of the Loop of Henle
Vasa Recta (capillaries)
Collecting Duct
Renal Papillae (only on 65)
Ducts of Bellini (only on 65)
Slide
Ø 64: Kidney https://vmicro.iusm.iu.edu/virtual_h/msci_144_5.html
Ø 65: Kidney trichrome (monkey) https://vmicro.iusm.iu.edu/virtual_h/msci_14_5.html
Ø Kidney Rat https://vmicro.iusm.iu.edu/virtual_h/msci_111_5.html
Junqueira
Ø Figs. 19-2 through 19-14
Name a simple squamous structure in the cortex.
How does the structure of the proximal convoluted tubule cells relate to their function?
Compare and contrast the cells of the proximal convoluted tubule and the distal convoluted
tubule.
What is the general function of the loop of Henle?
Ureter
Mucosa
Transitional Epithelium
Lamina Propria
Muscularis
Adventitia
Slide
Ø 69: Ureter https://vmicro.iusm.iu.edu/virtual_h/msci_16_5.html
Junqueira
Ø Fig. 19-15
What does the structure of the ureter’s muscularis suggest about this layer’s function?
Urinary Bladder
Mucosa
Transitional Epithelium
Lamina Propria
Muscularis
Adventitia (or serosa)
Examine
Slides
Ø 70: Urinary Bladder (distended) https://vmicro.iusm.iu.edu/virtual_h/464_70b.html
Ø 71: Urinary Bladder (empty) https://vmicro.iusm.iu.edu/virtual_h/464_71b.html
Ø Human Bladder https://vmicro.iusm.iu.edu/virtual_h/msci_118_5.html
Junqueira
Ø Figs. 19-16, 19-17
What is the function of this muscularis?
Notes
The Endocrine System
The organs usually grouped together as the endocrine system represent many structures
with a great deal of morphological and functional diversity. The fact that they are grouped
together reflects primarily the fact that they all secrete directly into the extracellular space for
uptake by the blood stream, rather than delivering their products into ducts for transport to other
sites, as in the exocrine glands. Endocrine glands may be large, distinct organs, such as those to
be studied here, or scattered groups of cells, such as the pancreatic islets, or individual cells, such
as those found in the mucosa of the digestive system. A structural feature common to all
endocrine tissues is a very rich vascular supply. Furthermore, in spite of having origins from
diverse kinds of tissues, almost all endocrine glands are structurally epithelial in appearance, i.e.,
they are composed of sheets, tubes, columns or clusters of closely contiguous cells. A less
universal feature of endocrine cells is a content of granules suggesting the secretory function of
the cells.
Objectives
v Understand the functional characteristics of endocrine cells and organs
v Be able to distinguish the major endocrine glands in LM
v Distinguish the regions, zones, and most important specific cells in the pituitary gland,
adrenal glands, thyroid gland, parathyroid gland, and the pancreatic islets.
Terms
Pituitary Gland (Hypophysis)
Anterior Pituitary
Pars Distalis
Basophils
Acidophils
Chromophobes
Pars Intermedia
Rathke’s Pouch (remnants)
Posterior Pituitary
Pars Nervosa
Pituicytes
Axons
Slide
Ø 10T: Pituitary Gland https://vmicro.iusm.iu.edu/virtual_h/msci_122_5.html
Ø 34: Pituitary Gland https://vmicro.iusm.iu.edu/virtual_h/128_bl_5.html
Ø Anterior Pituitary https://vmicro.iusm.iu.edu/virtual_h/msci_103_5.html
Ø
Junqueira
Ø Figs. 20-1 through 20-11
Name two basophils and two acidophils and give the target cells for their secretions.
The staining property of chromophobes is believed to have what functional significance?
Hormones stored in the axons of the pars nervosa are synthesized in cell bodies located where?
Adrenal Gland
Capsule
Cortex
Zona Glomerulosa
Zona Fasciculata
Zona Reticularis
Venous Sinuses
Medulla
Chromaffin Cells
Slide
Ø 33: Adrenal Gland https://vmicro.iusm.iu.edu/virtual_h/msci_63_5.html
Ø https://vmicro.iusm.iu.edu/virtual_h/msci_102_5.html
Ø adrenal rabbit: https://vmicro.iusm.iu.edu/virtual_h/msci_35_5.html
Junqueira
Ø Figs. 20-12 through 20-16
Compare and contrast the 3 zones of the adrenal cortex.
What is the embryological origin of the adrenal medulla?
Thyroid Gland
Follicles
Follicular Cell
Colloid
Parafollicular Cell
Slides
Ø 32: Thyroid Gland (Mallory stain) https://vmicro.iusm.iu.edu/virtual_h/msci_23_5.html
Ø Thyroid and Parathyroid https://vmicro.iusm.iu.edu/virtual_h_nw/nw_hist_1_195.html
Junqueira
Ø Figs. 20-18 through 20-21
In what sense can thyroid follicles be considered both exocrine and endocrine?
Parathyroid Gland
Capsule
Principal Cell (Chief)
Oxyphil Cell
Slide
Ø 90: Parathyroid Gland https://vmicro.iusm.iu.edu/virtual_h/msci_69_5.html
Ø
Junqueira
Ø Figs. 20-22, 20-23
Principal cells of this gland can be considered antagonists to what other cells?
Pancreas
Islets of Langerhans
Slide
Ø 53: Pancreas https://vmicro.iusm.iu.edu/virtual_h/044_bl_5.html
Junqueira
Ø Fig. 20-17
What are the two important pancreatic hormones with opposite effects on glucose metabolism?
The other hormones made in the islets are similar to those by what other endocrine cells?
Notes
The Male Reproductive System
The male reproductive system is responsible for the production, storage and delivery of
sperm, the male gametes. It consists of the testes, where gamete production occurs, a system of
ducts, the site of gamete maturation and passage to the exterior, and several associated glands
which provide the fluid medium for transport and nourishment for the gametes. It is important to
recognize and understand the cell types within the seminiferous tubules of the testes that
represent the different stages of meiosis and sperm production, as well as the secretory cells
outside and inside these tubules that support the process of spermatogenesis.
Objectives
v Recognize and understand the structure of the testis under the light microscope
v Understand the process of spermatogenesis and recognize the major stages of this process
v Understand the functions and structural features of the major regions of the male
reproductive ducts
v Recognize and know the function of the seminal vesicles and prostate gland
v Recognize structures in the penis and understand how these structures contribute to its
function
Electron Micrographs and diagram
-
Fig. 21-8
o Spermatozoan
-
Fig. 21-5
o Sertoli cell
• Spermatogonia
• Spermatocytes
• Spermatids
• Spermatozoa
Terms
Testis
Tunica Albuginea
Seminiferous Tubules
Spermatagonia
Primary Spermatocyte
Spermatids
Spermatozoa
Sertoli Cell (nuclei)
Leydig Cells (Interstitial)
Rete Testis (only on 72)
Epididymis (only on 72)
Stereocilia (only on 72)
Ductus Epididymis (only on 72)
Slide
Ø 11T: Testis https://vmicro.iusm.iu.edu/virtual_h/119_bl_5.html
Ø 72: Testis and Epididymis (Dog) https://vmicro.iusm.iu.edu/virtual_h/msci_155_5.html
Junqueira
Ø Figs. 21-3 through 21-11
Why are the secondary spermatocytes rare?
What is the longest stage of spermatogenesis?
Indicate three functions of Sertoli cells.
Ductus Deferens (Vas Deferens)
Pseudostratified Ciliated Columnar Epithelium
Lamina Propria
Muscularis
Note that the muscularis has three layers and is very thick.
Slide
Ø 73: Ductus Deferens https://vmicro.iusm.iu.edu/virtual_h/msci_53_5.html
Junqueira
Ø Fig. 21-12
What does the muscularis tell you about the function of the vas deferens?
Seminal Vesicle
Mucosa
Simple Columnar Epithelium
Muscularis
The mucosa is highly folded and the muscularis is very thick.
Slides
Ø 74: Seminal Vesicle https://vmicro.iusm.iu.edu/virtual_h/124_bl_5.html
Junqueira
Ø Figs. 21-13, 21-14
What components of semen do the seminal vesicles produce?
Prostate Gland
Prostatic Glands
Corpora Amylacea
The individual glands have a molded mucosa whose epithelium transition from cuboidal to
pseudostratified.
Slides
Ø 75: Prostate Gland https://vmicro.iusm.iu.edu/virtual_h/msci_47_5.html
Ø https://vmicro.iusm.iu.edu/virtual_h/95_bl_5.html
Junqueira
Ø Figs. 21-15, 21-16
How does benign prostate hyperplasia, BPH, which is common in older men, cause medical
problems?
Penis
Corpora Cavernosa
Helicine Arteries
Erectile Tissue (cavernous)
Corpus Spongiosum
Urethra
Slide
Ø 76: Penis https://vmicro.iusm.iu.edu/virtual_h/109_bl_5.html
Ø Penis https://vmicro.iusm.iu.edu/virtual_h_nw/nw_hist_1_170.html
Junqueira
Ø Figs. 21-17 through 21-19
What specific cell type(s) in the penis are acted on by “erectile dysfunction” drugs such as
Viagra?
Notes
The Female Reproductive System
Structures in the female reproductive system are specialized for the production,
movement, fertilization and maintenance of the female gamete, the egg or ovum, and for the
reception of sperm. In studying the system, one must keep in mind the major cyclical influence
of hormones on various parts of the female reproductive system, which results in a dynamic and
constantly changing morphology. Study the diagram in figure 19.7 of Junqueira for a useful
summary of the development of ovarian follicles and the hormones involved in this process.
Objectives
v Understand and recognize the overall organization of the ovary
v Recognize developing oocytes and their associated tissues in the ovary
v Understand the histological changes and their physiological significance during the
developmental process of oogenesis, ovulation, and corpus luteum formation
v Recognize and understand the functional significance of tissues in the fallopian tubes
(oviducts)
v Recognize the layers of the uterine wall and know how these change during the menstrual
cycle
Terms
Ovary
Tunica Albuginea
Germinal Epithelium (Serosa)
Primordial Follicle
Primary Oocyte
Follicular Cell (Granulosa)
Primary Follicle
Primary Oocyte
Follicular Cell (Granulosa)
Zona Pellucida
Basement Membrane
Thecae Folliculi
Secondary Follicle
Primary Oocyte
Follicular Cell (Granulosa)
Zona Pellucida
Basement Membrane
Theca Interna
Theca Externa
Antrum
Mature (Graafian) Follicle
Follicular Cell (Graafian)
Theca Interna
Theca Externa
Antrum
Cumulus Oophorus
Corona Radiata
Oocyte
Atretic Follicles
Slide
Ø 1: Ovary https://vmicro.iusm.iu.edu/virtual_h/61_bl_5.html
Ø 1a: Ovary rabbit https://vmicro.iusm.iu.edu/virtual_h/464_1b.html
Ø
Junqueira
Ø Figs. 22-1 through 22-9
How does the germinal epithelium differ from most mesothelia in the body?
When do primordial follicles develop?
What is the major function of granulosa cells and the significance of the zona pellucida?
What types of cells are present in the theca interna?
How exactly does the antrum relate to the process of ovulation?
What is the difference between the cumulus Oophorus and the corona radiata and what exactly is
released from the ovary at ovulation?
Ovary
Corpus Luteum
Theca Luteal Cell
Granulosa Luteal Cell
Slide
Ø 79: Corpus Luteum https://vmicro.iusm.iu.edu/virtual_h/058_bl_5.html
Ø
Junqueira
Ø Fig. 22-10
What two hormones do the two endocrine cell types in the corpus luteum synthesize?
Ovary (Postmenopausal)
Corpus Albicans
Slides
Ø 78: Postmenopausal Ovary https://vmicro.iusm.iu.edu/virtual_h/464_78b.html
Junqueira
Ø Fig. 22-11
Where did the corpus albicans come from?
Fallopian Tube (Oviduct, Fallopian Tube)
Mucosa
Simple Columnar Cells
Lamina Propria
Muscularis
Serosa
Slide
Ø 80: Fallopian Tube https://vmicro.iusm.iu.edu/virtual_h/msci_145_5.html
Junqueira
Ø Fig. 22-12
What two histological features of the oviduct relate to the movement of its contents?
Uterus
Endometrium
Stratum Functionalis
Stratum Basalis
Spiral Arteries
Myometrium
Perimetrium (Serosa)
Slide
Ø 81: Uterus monkey https://vmicro.iusm.iu.edu/virtual_h/001_bl_5.html
Ø Uterus endometrium proliferative
https://vmicro.iusm.iu.edu/virtual_h_nw/nw_hist_1_177.html
Ø Uterus endometrium secretory
https://vmicro.iusm.iu.edu/virtual_h_nw/nw_hist_1_178.html
Ø Uterus repair https://vmicro.iusm.iu.edu/virtual_h_nw/nw_hist_1_176.html
Junqueira
Ø Figs. 22-13 through 22-17
Describe the major changes in the endometrium during the menstrual cycle.
What exactly is lost during menstruation?
Notes