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Download 1 19 HO-01LAB-059.wpd HUMAN HISTOLOGY IMPORTANT
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HUMAN HISTOLOGY
IMPORTANT THINGS TO ASK YOURSELF WHEN LOOKING AT &
STUDYING TISSUES
1. What does it look like?
2. What is the name (be specific)
3. Where is it found?
4. What is (are) the name(s) of any special cell(s)?
5. What is (are) the name(s) of any special structure(s)?
6. ALL of the above may not apply to ALL of the tissues studied.
CONNECTIVE TISSUES
1. Blood
2. Adipose
3. Areolar connective tissue
4. Reticular connective tissue
5. DWFCT (regular & irregular)
6. Cartilage
(hyaline, fibrocartilage. elastic)
7. Compact bone
EPITHELIAL TISSUES
1. Simple squamous epithelium
2. Simple cuboidal epithelium
3. Simple columnar epithelium
4. PSCCE
5. Transitional epithelium
6. Stratified squamous epithelium
a. keratinized (K)
b. non-keratinized (NK)
MUSCLE
1. Skeletal (teased & diseased)
2. Cardiac
3. Smooth
NERVE
1. Cerebral cortex
2. Giant multipolar neuron
3. Meissner's corpuscle (demo)
4. Pacinian corpuscle (demo)
5. Node of Ranvier (demo)
6. Neuromuscular junction (demo)
MITOSIS
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
SKIN (as an organ)
1. Epidermis
a. stratified squamous epidermis - K
b. stratum corneum
c. stratum basale {also s. germinativum}
2. Dermis
a. dermal papillae
b. DWFCT (main tissue present)
3. Hair Follicle
a. shaft
b. bulb
c. hair papilla
4. Arrector pili muscle
5. Sebaceous gland
6. Eccrine gland
7. Hypodermis
a. adipose
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HISTOLOGY
A tissue consists of a group of cells of similar structure and function, along with the nonliving
extracellular substance filling spaces between them. Histologists group all (mature, i.e. not embryonic)
human tissues into four major categories: EPITHELIAL, CONNECTIVE, MUSCULAR, and NERVOUS.
You will be expected to accomplish the following: (I) learn to recognize and name the specific types of
these four classes of tissues when viewed through a microscope; (ii) name any or all of the structures
associated with these tissues; (iii) identify and name the various cells; (iv) name examples of organs or
body parts in which these specific tissues may occur; and (v) in some cases describe the function and give
the names of specific structures found within the tissue(s).
Following is an outline of the tissues that we will examine through the microscope:
I. CONNECTIVE TISSUE
A. Areolar
B. Adipose
C. Reticular
D. Dense White Fibrous
1. Regular
2. Irregular
E. Cartilage
1. Hyaline Cartilage
2. Fibrocartilage
3. Elastic Cartilage
F. Vascular (blood)
G. Compact Bone
III. MUSCLE TISSUE
A. Skeletal
B. Cardiac
C. Smooth
I. CONNECTIVE TISSUE
II. EPITHELIAL TISSUE
A. Simple Squamous
B. Simple Cuboidal
C. Simple Columnar
D. Pseudostratified ciliated columnar {PSCCE}
E. Transitional
F. Stratified Squamous
1. Keratinized
2. Non-Keratinized
IV. NERVE TISSUE
A. Cerebral Cortex
B. Spinal Cord (Giant Multipolar Neuron)
C. Neuromuscular Junction {NMJ} (demo)
D. Sensory Nerve Endings (demo)
1. Meissner=s Corpuscles
2. Pacinian Corpuscles
E. Nodes of Ranvier (demo)
Connective tissue is one of the most abundant and varied of all types of tissues in the body. Most
connective tissues share the important feature of being composed mainly of MATRIX (extracellular
substance) with relatively few cells, whereas epithelial tissues are composed mainly of densely packed cells
with little matrix. In most cases, it is the matrix that characterizes connective tissues.
Connective tissue matrix includes fibers embedded in an amorphous GROUND SUBSTANCE. The
ground substance varies from a fluid consistency to a semisolid gel (solid in bone). Fibers are composed of
the structural proteins COLLAGEN and ELASTIN. Fibers of elastin are called ELASTIC FIBERS
(sometimes yellow fibers). Fibers of collagen are referred to as COLLAGEN FIBERS, RETICULAR
FIBERS, or OSSEIN FIBERS, depending on the tissue in which they occur.
Many different types of cells are associated with connective tissues: FIBROBLASTS {that produce
the fibers}, CHONDROBLASTS {immature cartilage cells}, CHONDROCYTES {mature cartilage cells},
OSTEOCYTES {bone cells}, ADIPOCYTES {fat cells}, ERYTHROCYTES {red blood cells}, and LEUKOCYTES
{white blood cells}. Other specialized types of cells may be found in connective tissues, but these are
beyond the scope of this class.
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A. AREOLAR CONNECTIVE TISSUE
Observe on low power a slide labeled AREOLAR TISSUE. This tissue
contains long, very thin, thread-like fibers of elastin, a structural protein,
called Elastic Fibers. They appear as dark hair-like fibers and provide
elasticity to this tissue. Thicker, very pink, non-elastic Collagen Fibers
may also be found. Collagen fibers are composed of the most common
structural protein in the body ... collagen. Both types of fibers extend in
all directions, very much as wind-blown hair appears.
Numerous cells may be seen composed of obvious dark Nuclei
surrounded by pale cytoplasm. Fibroblasts are the predominant cell
present and actually produce the non-living matrix of this tissue.
Macrophages {monocytes} are also present. Many different types of
blood cell may occur transiently in this tissue. We will make no attempt to
distinguish these cells. This tissue is found around organs, between
muscles, and in subcutaneous skin {hypodermis}. Areolar connective tissue can often be seen as a very
slimy, grayish film adhering to the underlying muscle of chicken (or any other vertebrate) when the skin is
removed.
B. ADIPOSE
Adipose should be observed on both low and high power. Adipocytes
{fat cells} appear as large, rather clear cells with very thin cell
membranes and a small dark nucleus. They contain only a tiny amount of
cytoplasm. Most of the space within the cell membrane is for the storage
of Lipids. Generally, when a person gains weight, the adipocytes do not
increase in number, but simply enlarge as more lipid is added within the
cell membrane. (Infants, if over-nourished, are an exception to increasing
the number of adipocytes.)
Adipose tissue has numerous Collagen Fibers running through it;
however, the slides used in this class are not prepared in a manner to
make these fibers visible. Adipose is found in the hypodermis, around
organs, (e.g., the heart and kidneys), within and between muscles, around
nerves, and in other places.
C. RETICULAR CONNECTIVE TISSUE
Reticular connective tissue consists of a network of finely branching
fibers of collagen called Reticular Fibers. View these on both low and
high power. Fibroblasts are the cells that form the reticular {net-like
pattern} fibers. This tissue forms the framework of the liver, lymph
nodes, spleen, and bone marrow. It is an important tissue of the
Reticuloendothelial System {Tissue Macrophage System}, which is
instrumental in the defense against microbial invasion.
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D. DENSE WHITE
{DWFCT}
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FIBROUS
CONNECTIVE
TISSUE
Dense white fibrous connective tissue {DWFCT} has a shining white
appearance when viewed grossly and is very tough when eaten. (There is
also a dense yellow fibrous connective tissue that we will not study).
DWFCT differs from areolar (loose) connective tissue in that it has
many more Collagen Fibers and fewer cells. Fibroblasts, although few in
number, are the most prevalent cell present. Two major types of this
tissue are found in the body. They are described as REGULAR DWFCT
and IRREGULAR DWFCT; the difference is determined by the
arrangement of the collagen fibers.
Regular DWFCT is found in tendons, ligaments, fasciae, aponeuroses (broad, flat sheet-like tendons),
periosteum, and the sclera and cornea of the eye.
You should examine a slide of tendon (the slide MAY be labeled white
fibrous tissue). Observe in longitudinal section the thick bundles of pinkstaining collagen fibers. The fibroblasts are compressed into thin, wavy
purple streaks. (Some slides have cross sections also that you are not
responsible for.)
Ligaments connect bone to bone across a moveable joint and are
similar to tendons except that they contain many more elastic fibers,
thereby exhibiting a greater ability to stretch without tearing.
Fasciae and aponeuroses have the bundles of DWFCT arranged in
multiple sheets. In the cornea, each sheet of regular DWFCT is at right
angles to the next sheet, as in the layers of plywood.
Irregular DWFCT occurs in the Dermis of the skin and sheaths of
nerves. Examine a slide labeled scalp. Look at the dermis and observe the
bands of collagen fibers. They appear to be short and extend in all directions, hence the term irregular.
This tissue has more elastic fibers than regular DWFCT; therefore, the skin is more elastic than tendons.
E. CARTILAGE
Three types of cartilage occur in the human organism: HYALINE, ELASTIC, and FIBROCARTILAGE.
They all share similar structures, but there are sufficient differences to make them recognizable.
Cartilage differs from other connective tissues in that it is avascular (no blood supply). It consists of
cells called Chondroblasts, Chondrocytes and extracellular fibers embedded in an amorphous, gel-like
matrix. The cavities within the matrix that contain the chondrocytes are called Lacunae.
1. HYALINE CARTILAGE
This is the most abundant type of cartilage. Costal Cartilages attach
ribs to the sternum; Articular Cartilages are found at the end of bones in
synovial joints. Tracheal Rings in the trachea ("wind pipe") and the Larynx
(voice box or "Adam's apple") are other examples of hyaline cartilage.
(The epiglottis, part of the larynx, is elastic cartilage.)
Examine a slide of trachea (may be labeled AHyaline Cartilage@ on both
low and high power. The trachea is a complex organ composed of many
tissues. The cartilage appears as a dense purple area with many cavities
(Lacunae) filled by cells (Chondrocytes).
Surrounding the cartilage is a layer called the Perichondrium. Note
the cells are very small, flattened, and arranged more closely together
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than the mature part of the cartilage. Some of these Chondroblasts are capable of becoming chondrocytes
and will do so when the cartilage grows. The perichondrium has a blood supply, although the major portion
of all cartilage is avascular.
2. ELASTIC CARTILAGE
Elastic cartilage is found in the Auricle or pinna, Eustachian Tube and
Epiglottis (part of the larynx). The slide you will examine is from the
auricle. The cartilage appears (on low power) as a band of tissue running as
a wavy strip through the slide. The same structures found in hyaline
cartilage may be seen here also: Perichondrium, Lacunae, Chondroblasts.
Chondrocytes, and Matrix.
Additionally, numerous thin threads of
ELASTIC FIBERS are visible. These fibers may appear as very dark,
densely packed threads or as very sparse and hard to distinguish fibers
depending on the manner in which the slides were stained. They are
responsible for giving this cartilage its pliable characteristic.
3. FIBROCARTILAGE:
This tissue occurs in amphiarthrodic (partially moveable) joints of
the vertebrae. These pads of cartilage are called intervertebral
discs. It is also present in the pubic symphysis and the sacroiliac
joints as well as other places.
This cartilage differs from elastic and hyaline: in that it has no
perichondrium; the chondrocytes tend to occur in horizontal rows
rather randomly placed; and there are numerous dense bundles of
collagen fibers between the rows of chondrocytes (rather like the
bundles of collagen fibers in regular DWFCT as in tendons).
F. BLOOD
Blood has all the criteria necessary for being classified as a tissue;
however, it has the unusual feature of lacking the intercellular cementing
substance that causes cells in conventional tissues to adhere to one
another. Hence, blood is a "liquid" tissue.
Blood cells are very small and must be viewed on high power. The most
predominant cell is the Erythrocyte {red blood cell}. It appears as an
enucleated reddish cell that seems to resemble a donut. The cell does not
actually have a hole in it. Its shape is a biconcave disc because it loses its
nucleus during development. The cell "caves in" much as the cheeks of a
person who has had all of their teeth pulled. RBC's contain hemoglobin and
are responsible for the transportation of oxygen to the tissues. This blood
slide is from a person with Sickle-cell Anemia. The occasional Sickled Cell
can be seen among the normal erythrocytes. They look somewhat like a
football.
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Leukocytes are the nucleated cells with a colorless cytoplasm that are
referred to as "white" blood cells. Actually, they are not white; they are
just not red. The nuclei of these cells stain dark blue or purple. There
are numerous types of leukocytes; however, at least 1000 power
magnification is necessary to positively identify the many different types.
All of these types may be classed in two major groups: Granular
Leukocytes
{GRANULOCYTES}
and
Agranular
leukocytes
{AGRANULOCYTES}.
The former have numerous granules in the
cytoplasm that are difficult to distinguish even at 430x. Granulocytes
are large cells with a three- to five-lobed nucleus. Agranulocytes have a
very large spherical nucleus that occupies most of the cell.
Upon very close inspection, numerous TINY purple dots interspersed
among the blood cells may be seen. They are Thrombocytes {blood
platelets} and are very important in blood clotting.
G. COMPACT BONE
Bone exists as two main types of tissue: Compact Bone, that is found
on the surface of bones; and Cancellous Bone, that may be seen as
spongy bone on the inner aspects of bones. Mature compact bone is
organized into Haversian Systems {Osteons}, each of which exhibits
these structures:
a. Haversian Canal: Canal that extends along the length of a bone
containing a blood vessel and a nerve.
b. Lacunae:
Spaces between the lamellae (layers of matrix)
within which the osteocytes occur (mature
bone cells).
c. Osteocytes:
Mature bone cells trapped in the matrix and
occupying the lacunae.
d. Canaliculi:
Cytoplasmic processes of osteocytes appearing
as tiny hair-like fibers extending from the cell
body.
Obtain a slide labeled GROUND BONE and identify the above
structures on low power. Note that numerous Haversian systems are
visible on the slide.
Occasionally, horizontal canals may be seen
connecting two Haversian canals. These are called Volkmann's Canals (Not all slides will have a Volkmann=s
canal ... be sure to look at your neighbor=s slide).
Bone matrix consists of Ossein Fibers (composed of collagen) embedded in mineralized (calcium salts)
ground substance. The protein fibers are not distinguishable on these slides.
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II. EPITHELIAL TISSUES
Epithelium covers body surfaces and organs and lines cavities. Each of the following is an example of
epithelial tissue: lining of vagina, outer surface of eardrum, outer surface of eye, covering of uterus,
epidermis, lining of aorta, lining of stomach, etc.
All epithelial tissues share certain characteristics: a free border or edge and a basement membrane.
They have numerous cells and very little extracellular matrix. An exception to this is the basement
membrane which is actually non-living ground substance formed by the underlying connective tissue. Most
epithelial tissues are attached to a basement membrane of an underlying connective tissue.
Epithelium is classified and often named according to the number of cell layers and the shape of the
cells. If the tissue is one cell thick, it is Simple; if it is more than one cell thick, it is Stratified. Squamous
epithelial tissues have flat cells that resemble fried eggs. Cuboidal tissues have cells shaped like a peach,
and Columnar tissues are shaped like columns (bananas). Hence, a single layer of flattened cells is called
Simple Squamous Epithelium. A single layer of column shaped cells is called Simple Columnar Epithelium,
etc.
Within each possible classification of epithelium, the cells may or may not have Cilia on their free
border. In human tissues these cilia are generally used to move mucus (and consequently anything trapped
in the mucus). Cilia are found, for example, lining the respiratory tract,
fallopian tubes, and vas deferens.
A. SIMPLE SQUAMOUS EPITHELIUM
This tissue is found in numerous places: Bowman's capsule of the
kidney, lining of alveoli in the lungs, capillary walls, etc. We will use the
kidney as an example of this tissue. You should refer to chapter 25 in your
textbook and learn the BASIC anatomy of the functional unit of the kidney,
namely the NEPHRON. The Glomerulus, Bowman's Capsule, and the Renal
Tubule must all be recognized and understood FIRST from diagrams, and only then should you attempt to
observe them on the microscope. Each of these nephrons (approx.
1,000,000 in each kidney) are all interwoven with each other. Therefore,
when a thin slice of kidney is placed on a microscope slide, one cannot
expect to see ANYTHING that resembles the diagram.
Place a prepared slide of KIDNEY on low power. The Glomeruli
resemble balls of tissue that are surrounded by a thin white space
(Bowman's Space). The glomeruli are numerous and more or less randomly
distributed in the Cortex of the kidney. Select a glomerulus and switch to
high power. Observe across the space (away from the glomerulus) a thin
membrane that is one cell thick. This is a Bowman's Capsule. It totally
surrounds the glomerulus but is often difficult to see in its entirety. You may have to look at several
glomeruli before you find a good example of a Bowman's capsule. The tissue of which Bowman's Capsule is
composed is SIMPLE SQUAMOUS EPITHELIUM.
B. SIMPLE CUBOIDAL EPITHELIUM
The Renal Tubule of the kidney is Simple Cuboidal Epithelium through
much of its length. Much of the thyroid gland and the outer covering of
the ovary are also Simple Cuboidal Epithelium. Most of the tissue on the
kidney slide (exclusive of the glomerulus and Bowman's capsule) is simple
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cuboidal epithelium. Observe on both low and high power the renal tubules cut in both cross & longitudinal
sections.
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C. SIMPLE COLUMNAR EPITHELIUM
The lining of the gall bladder, stomach, small intestine, and colon is
simple columnar epithelium. In the uterus and oviduct, this same tissue
occurs with cilia on the free edge. Notice the nuclei are all in neat rows
at the bottom of the cells.
D. PSEUDOSTRATIFIED CILIATED COLUMNAR EPITHELIUM (= PSCCE)
Look on the trachea slide (may also be labeled pseudostratified
ciliated columnar epithelium) at the edge of the tissue for PSCCE. The
Cilia are visible on high power. Goblet Cells may also be seen. The tissue
appears stratified because it has nuclei at various levels in the different
cells. Although the nuclei appear stratified, each column-shaped cell is
attached to the basement membrane; therefore, this is a tissue
exhibiting false stratification (hence the name).
E.
TRANSITIONAL EPITHELIUM
This tissue was once considered to represent a transitional form
between stratified squamous epithelium and stratified columnar
epithelium. The term transitional epithelium persists even though the
implication of a change from one type to another is no longer considered
appropriate. This type of epithelium is stratified and is most often
confused with stratified squamous epithelium non-keratinized (as in the
vagina). The distinguishing characteristic is the BALLOON SHAPE of the
cells on the free border. (In stratified squamous epithelium, they are
flat.) This tissue lines the Urinary Bladder.
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F. STRATIFIED SQUAMOUS EPITHELIUM
This tissue consists of multiple layers of cells. The layer next to the
underlying connective tissues is cuboidal cells; however, the outermost
layer of cells is squamous (flattened). Stratified tissues are always named
by the shape of the cell layer at the free border. Two types of this tissue
are common in humans:
1. STRATIFIED SQUAMOUS EPITHELIUM
NON-KERATINIZED
Found lining the vagina, esophagus, & oral cavity. The
epithelial layer is found at the top of the slide. Notice the cells at
the surface are flattened and that distinct nuclei are visible.
These cells are continuously shed into the oral cavity. The
presence of nuclei is a clear indication that keratinization does not
occur in this tissue and is useful in distinguishing from the next tissue you will observe (keratinized
stratified squamous epithelium). This lining is much thicker in the mature female than the
immature or menopausal adult because of the effect of estrogen.
The thicker layer of tissues below the epithelium consists mainly of connective tissues
organized into various structures, glands, blood and lymph vessels, nerves (very few), and two
unorganized layers of smooth muscle. Near the vaginal orifice the muscle is skeletal rather then
smooth.
2. STRATIFIED SQUAMOUS EPITHELIUM - KERATINIZED
The skin is the largest organ in the body and has three
layers: epidermis, dermis, and hypodermis. The Epidermis consists
entirely of keratinized stratified squamous epithelium over the
entire surface of the body with very little difference except on
the palms of the hands and soles of the feet where it is much
thicker and devoid of hair follicles. Because of this it is often
referred to as thick skin or thin skin.
Examine the scalp slide (thin skin) and note the Epidermis,
Dermis, and Hypodermis. The epidermis consists of four distinct
layers (five on the palms and soles). The bottom-most layer,
termed Stratum Basale, consists of a single row of cells next to the
dermis. These cells divide (by mitosis), giving rise to the cell layers
above. The outer layer of epidermis, the Stratum Corneum,
appears somewhat like flaky pie crust near the surface. The cells
formed below have all died and been converted into the protein Keratin. They are constantly shed
from all of the body surfaces. If excessive shedding occurs from the scalp, it is called dandruff.
People allergic to cats, dogs, horses, etc. are actually allergic to the protein in these cells shed by
the animal. The stratum corneum is thicker on the palms and soles, especially where a person has a
callus or corn.
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III. MUSCLE TISSUE
Three types of muscle tissue occur naturally in humans: Skeletal, Cardiac,
and Smooth. You must learn to recognize each type and know where it is
located in the body.
A. SKELETAL MUSCLE
Place a slide of Teased skeletal muscle on the microscope at 100X.
Teased means the muscle fibers have been separated much as in teasing
hair.
Look for the individual muscle fibers. Note the numerous Nuclei
that appear as dark "jelly beans" along the periphery of the fiber.
Alternating pale and dark bands called Striations are visible at both low
and high power (ADJUSTMENT of the iris diaphragm is critical to
maximize the visibility of this characteristic).
This tissue constitutes the ONLY tissue in the body over which you
have DIRECT conscious control. For this reason it is sometimes referred
to as VOLUNTARY MUSCLE.
Look also a the slide labeled trichinella. This is a worm (Trichinella spiralis) that is a parasite of
skeletal muscle tissue. Only animals that eat meat can have this parasite. How does one get the disease
called Trichinosis? What is its life cycle?
B. CARDIAC MUSCLE
This tissue is found only in the heart with a few fibers extending into
the ascending aorta. Cardiac muscle fibers extend in different directions
in the heart. SEARCH for fibers that have been cut LONGITUDINALLY
when looking at the slide on low power.
Note the branching of cardiac muscle fibers. This characteristic is
distinctly different from other types of muscle. Striations are difficult to
see in this tissue. Adjusting the iris diaphragm on high power may help.
Intercalated Discs may be seen as partition-like structures at various
intervals along the fibers. These discs may appear as a very clear "break"
in the fiber or as a dark band transecting it. (Not all slides show these
discs well; therefore, one will be on demonstration.)
C. SMOOTH MUSCLE
Smooth muscle, like cardiac, is involuntary (that is, not under
conscious nervous control). Its ubiquitous occurrence in the human body
includes the following: wall of the uterus, wall of blood vessels, iris of the
eye, muscular layer of the stomach & intestinal walls, skin (arrector pili),
etc.
Look at a teased smooth muscle slide to observe individual smooth
muscle cells. They are very pale and transparent and may be difficult to
locate on the slide. You should only use low power and reduce the light with
the iris diaphragm until you locate them. Only after viewing and focusing
on low power should you switch to high power.
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IV. NERVE TISSUE
We will observe only a few of the many examples of nerve tissue. Two main types of cells will be
visible: Neurons and Neuroglial Cells. The neurons conduct the nerve impulses and in a few cases produce
materials for secretion. The neuroglia serve many varied and important functions for the neurons.
A. CEREBRAL CORTEX
The Cerebral Cortex of the brain is the thin (approx. 1/4 inch) outer
layer of the cerebrum of the brain. The dark brown, pyramid-shaped
objects are Pyramidal Neurons.
They are important in thinking,
interpreting sensory data, and causing movement. Exactly what each
neuron does is in part related to its position in the brain.
B. GIANT MULTIPOLAR NEURONS
Giant Multipolar Neurons occur in the gray matter of the spinal cord.
They may be seen as large blue cells with a Nucleus that generally has a
small dark-staining Nucleolus prominently visible. The cell body of these
cells are referred to as the Soma. This slide is made by smearing the
tissue on the slide and is therefore very unorganized. (These are the cells
destroyed by the polio virus, resulting in paralysis.)
The long cytoplasmic extensions from these cell bodies are axons and
dendrites. (In these slides you cannot tell for sure which are axons & which
are dendrites, the noncommital term Neurite is often used).
Interspersed among these Giant Multipolar Neurons are small blue dots,
which are actually the nuclei of Neuroglial Cells. Neuroglia are the support cells of the nervous system.
C. NEUROMUSCULAR JUNCTION
The Neuromuscular Junction is the region between the Axon Terminal
of a motor nerve and a Skeletal (voluntary) muscle fiber. The Motor End
Plate is specialized are of the skeletal muscle fiber just opposite the axon
terminal. The neurotransmitter, acetylcholine (ACh), is released from the
axon terminal and thereby transmits the nerve stimulus to the muscle
chemically rather than electrically.
This is a very important physiological unit of the interface between
the nervous system and voluntary skeletal muscle. Many different poisons
(strychnine) and medicines (muscle relaxers) may affect its normal
function.
View this slide on demonstration only. Make certain you identify the
above structures and that you understand the difference between motor
end plate and neuromuscular junction. Similar structures are associated with autonomic nervous system and
smooth muscle but they are called Visceral Efferent Junctions.
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D. SENSORY NERVE ENDINGS:
1. MEISSNER'S CORPUSCLES
Respond to light touch and are located in the Dermal Papillae of the
skin. The number of receptors in different parts of the body varies.
Finger tips and eyelids have many while the skin on the elbow has few.
2. PACINIAN CORPUSCLES
Resembles a slice of onion (as you might place on a hamburger). These
are found DEEP in the Dermis and even in the upper hypodermis. They
respond to deep pressure. (They also occur deep within various areas
of the body.)
E. NODES OF RANVIER
Small gaps called Nodes of Ranvier occur in the Myelin Sheath, a fatty
covering of axons in both the CNS (central nervous system) & PNS
(peripheral nervous system). The slide you are viewing on demonstration is
taken from a peripheral nerve.
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V. Cell Cycle
Look at the whitefish blastula slide. At this early stage it doesn’t matter whether we are looking at fish tissue
or human tissue. The slide has several blastulas (balls of cells) on it. Focus on one blastula, then put it on high power so
that you can identify individual stages. You will need to be able to recognize the 5 stages of the cell cycle. Refer to p.
92 in the Rust book.
1. Interphase
This is a typical cell. All cells that you have observed so far have been in interphase.
a. The nucleus will have a well-defined nuclear membrane.
b. The nuclear material will be in the form of chromatin (the nucleus will look homogeneous)
2. Prophase
a. There is no nuclear membrane
b. The nuclear material is in the form of chromosomes. They look like little dark spots.
3. Metaphase
a. The chromosomes are lined up in the middle of the cell.
b. You can see spindle fibers stretching across the cell.
4. Anaphase
a. The double-stranded chromosomes have separated and each strand is moving toward the opposite
pole of the cell. They may be barely separated or almost to the other side of the cell.
5. Telophase
a. The chromosomes are at the poles.
b. The cleavage furrow is present.
c. The nuclear material is still in the form of chromosomes.
d. There is still no nuclear membrane.
VI. Skin as an Organ
Look at the scalp slide again as an example of the skin as an organ consisting of several types of tissue. You
will need to be able to recognize the 3 layers of the skin as well as the following structures. You will need to use high
power on the layers of the epidermis. Everything else on the skin you should observe on low power.
1. Epidermis- The epidermis is keratinized stratified squamous epithelium. It will look like a darker purple layer at the
top of the slide. Find these layers of the epidermis:
a. Stratum corneum- This is the outermost layer. It is the keratin layer and looks like flaky pie crust.
b. Stratum granulosum- This is a thin layer just under the stratum corneum. This is where keratinization
begins, and the cells look “grainy”. The nuclei will be flat.
c. Stratum spinosum- This is the thickest layer of the epidermis. The cells are rounded, but the DO NOT look
“spiny”. The nuclei will be rounded.
d. Stratum basale (stratum germinativum)- This is a single layer of cells at the base of the epidermis.
2. Dermis
The dermis is the thickest of the 3 layers of the skin. It consists of irregular dense white fibrous connective
tissue. There are also other structures present associated with the skin.
a. Dermal papillae- These are wavy “finger-like” projections of the dermis up into the epidermis.
b. DWFCT- irregular
c. Hair follicle- This is actually an epidermal structure that projects far down into the dermis.
d. Hair shaft- This will look like a non-cellular yellowish structure in the hair follicle.
e. Arrector pili muscle- This is a strip of smooth muscle. Look for a strip of slightly wavy tissue that runs at
an angle in the dermis
f. Sebaceous gland- This is an oil gland. The ducts open onto the hair follicle, so it will be close to the base of
the hair follicle.
g. Eccrine gland- This is a sweat gland. It is a coiled tubular gland. Look at about the level of the sebaceous
glands.
3. Hypodermis
This is the bottom layer of skin. It is made up of adipose and areolar tissue, but we will only see adipose
tissue.
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SUPERIOR APPENDAGES & PECTORAL GIRDLE
SCAPULA
acromioclavicular facet
acromion process
coracoid process
scapular notch
glenoid cavity
lateral border
superior angle
inferior angle
medial border
supraspinous fossa
transverse scapular spine
infraspinous fossa
HAND
navicular (scaphoid)
lunate
triangular (triquetrum)
pisiform
greater multangular (trapezium)
lesser multangular (trapezoid)
capitate
hamate
proximal phalanx
MIDDLE phalanx
distal phalanx (pl.= phalanges)
metacarpals (1-5)
RADIUS
head
neck
radial tuberosity
styloid process
navicular facet
lunate facet
ulnar notch (facet)
ULNA
olecranon process
semilunar notch
coronoid process
radial notch
head
styloid process
HUMERUS
greater tubercle
lesser tubercle
lateral tubercular crest
medial tubercular crest
intertubercular groove
head
lateral epicondyle
lateral supracondylar ridge
capitulum
trochlea
medial epicondyle
coronoid fossa
olecranon fossa
anatomical neck
surgical neck
CLAVICLE
acromial portion
sternal portion
INFERIOR APPENDAGES AND PELVIC GIRDLE
OS COXA
anterior superior iliac spine
anterior inferior iliac spine
posterior superior iliac spine
posterior inferior iliac spine
iliac crest
body of ilium
greater sciatic notch
lesser sciatic notch
arcuate line
acetabulum
acetabular fossa
ischium
ischial tuberosity
ischial spine
ramus of ischium
pubis
superior ramus of pubis
inferior ramus of pubis
pubic symphysis
obturator foramen
auricular surface
obturator groove
FEMUR
head
anatomical neck (same as surgical neck)
surgical neck (same as anatomical neck)
linea aspera {rough line}
fovea capitis {pit in head}
popliteal surface
greater trochanter
lesser trochanter
trochanteric fossa
lateral condyle
lateral epicondyle
medial condyle
medial epicondyle
intercondyloid notch
lateral supracondylar ridge
medial supracondylar ridge
patellar facet
FIBULA
lateral malleolus
TIBIA
lateral condyle
medial condyle
intercondylar tubercles
intercondylar eminence
anterior crest
medial malleolus
tibial tuberosity
FOOT
distal phalanx
MIDDLE phalanx
proximal phalanx
metatarsals (1-5)
talus
calcaneus
navicular
first cuneiform
second cuneiform
third cuneiform
cuboid
PATELLA
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Following is a list of the bones and their key characteristics. These are the only bones that you
must distinguish as right or left:
a. Humerus
capitulum
b. Radius
styloid process
c. Ulna
radial notch
d. Scapula
glenoid cavity
e. Os coxa
acetabulum
f. Femur
greater trochanter
g. Tibia
lateral condyle
VERTEBRAL COLUMN, STERNUM, RIBS
VERTEBRA
1. Centrum
2. Pedicle
3. Vertebral foramen
(spinal canal)
4. Vertebral arch (posterior arch)
5. Lamina
6. Superior articulating processes
7. Superior articulating facets
8. Inferior articulating processes
9. Inferior articulating facets
10. Transverse processes
11. Spinous process
12. Intervertebral foramen (notch?)
13. Demifacets
14. Foramen transversarium
15. Costal facet of transverse process
16. Atlas (C1)
a. lateral masses
b. anterior arch
17. Axis (C2)
a. odontoid process (= dens)
18. Cervical vertebrae (C1 - C7)
19. Thoracic vertebrae (T1 - T12)
20. Lumbar vertebrae (L1 - L5)
20. Sacral vertebrae (S1 - S5) (=sacrum)
21. Coccygeal vertebrae (=coccyx)
SACRUM
Sacral hiatus
Sacral cornu
Sacral foramen (1-4)
Medial sacral crest
Lateral sacral crest
RIBS
Costal tubercle & facet
Head
Neck
STERNUM
Manubrium
Gladiolus
Xiphoid process
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BONES OF THE CRANIUM AND FACE
MANDIBLE
body
mental foramen
mandibular foramen
angle
ramus
condyloid process
mandibular condyle
mandibular notch
coronoid process
alveolar process
MAXILLA
infraorbital foramen
anterior nasal spine
infraorbital margin
alveolar process
median palatine suture
transverse palatine suture
incisive foramen
FRONTAL
supraciliary ridge (arch)
supraorbital foramen
supraorbital margin
glabella
TEMPORAL
mastoid process
zygomatic process
external auditory meatus
mandibular fossa
internal auditory meatus
petrous portion of temporal
styloid process (often broken)
OCCIPITAL
external occipital protuberance
internal occipital protuberance
occipital condyles
fossa for cerebrum
fossa for cerebellum
SPHENOID
pterygoid processes
greater wing of sphenoid
lesser wing
sella turcica {Turk's saddle}
anterior & posterior clinoid processes
ETHMOID
crista galli
cribriform plate
perpendicular plate of ethmoid
nasal conchae (DO NOT TOUCH THEM!!)
ZYGOMATIC
temporal process
BONES W/O STRUCTURES
PALATINE
PARIETAL
NASAL
VOMER
LACRIMAL
HYOID
AUDITORY OSSICLES
MALLEUS
INCUS
STAPES
SUTURES
lambdoidal
squamosal
coronal
sagittal
ORBITAL STRUCTURES
supraorbital fissure
infraorbital fissure
optic foramen
lacrimal foramen
FORAMEN
*carotid
incisive
infraorbital
*jugular
*lacerum
lacrimal
magnum
mandibular
mental
optic
*ovale
rotundum
stylomastoid
supraorbital
* These foramen need
need to be found on the
INFERIOR view of the
skull only.
*Jesus Christ Loves Olives
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STRUCTURES OF THE SHEEP BRAIN
The brain is divided into three main regions. The FOREBRAIN includes the CEREBRUM,
THALAMUS, and HYPOTHALAMUS. The MIDBRAIN consists of the TECTUM and TEGMENTUM.
The HINDBRAIN is made up of the CEREBELLUM, PONS VAROLII, and MEDULLA OBLONGATA.
*
*
*
*
**
**
**
*
*
*
*
*
**
*
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
*
15.
*** 16.
*
*
**
***
17.
Sulcus (pl. = sulci)
Gyrus (pl. = gyri)
Longitudinal & Transverse fissures
Cerebrum (2 hemispheres; 4 lobes each)
Corpus Callosum
Lateral Ventricle
Fornix
CN I Olfactory (nerve)
Olfactory Tract(nerve vs tract??)
CN II Optic
Optic Chiasma
Optic Tract
Thalamus
Hypothalamus (the brain tissue
surrounding the 3rd ventricle)
Mammillary Body (part of the
hypothalamus
Midbrain
Tegmentum - floor of midbrain
Tectum - roof of midbrain
Corpora Quadrigemina:
Superior Colliculi - vision
Inferior Colliculi - hearing
Pineal Body - lies between the superior
colliculi
** 18. 3rd ventricle
** 19. 4th ventricle
***20. Cerebellum
Arbor Vitae
***21. Pons Varolii
***22. Medulla Oblongata
*
Trapezoid Bodies
*
Pyramids
These structures are not part of the
brain, but are associated with it:
***23.
**
** 24.
Spinal Cord
Spinal Canal
Meninges
Dura Mater (demo)
Arachnoid Mater
Pia Mater
Locate these structures on the whole brain only.
Locate these structures on the sagittal sectioned brain only.
Locate these structures on the whole brain and the sagittal section.
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STRUCTURES OF THE EAR
PINNA {AURICLE} Helix
TRAGUS
TYMPANIC MEMBRANE
EXTERNAL EAR
External Auditory Meatus
External Auditory Canal (cerumen)
MIDDLE EAR
AUDITORY OSSICLES = Malleus, Incus, & Stapes
EUSTACHIAN TUBE
INNER EAR
PETROUS PORTION OF TEMPORAL BONE
INTERNAL AUDITORY MEATUS
SEMICIRCULAR CANALS (DYNAMIC BALANCE)
VESTIBULE (STATIC BALANCE)
COCHLEA (Round window & Oval window)
COCHLEAR HISTOLOGY
SCALA VESTIBULI (perilymph)
SCALA MEDIA {=cochlear duct}
(contains endolymph)
SCALA TYMPANI (perilymph)
BASILAR MEMBRANE
VESTIBULAR MEMBRANE
ORGAN OF CORTI
* Hair Cells
* Tectorial Membrane
PHYSIOLOGY OF VISION
1. Extrinsic skeletal eye muscles associated with movement of the eyeball:
Superior Rectus
CN III - Oculomotor
Lateral Rectus
Inferior Rectus
CN III - Oculomotor
Superior Oblique
Medial Rectus
CN III - Oculomotor
Inferior Oblique
CN VI - Abducens
CN IV - Trochlear
CN III – Oculomotor
2. COW EYE DISSECTION: the following structures must be found on the cow eye:
Pupil
Blind spot
Anterior cavity
Iris
Lens
Anterior chamber
Sclera
CN II Optic nerve
Posterior chamber
Choroid layer
Ciliary body (muscle)
Posterior cavity
Tapetum lucidum
Retina
Vitreous humor
Bulbar conjunctiva
Postorbital adipose
Cornea
