Download Connective Tissue

4
Tissues
PowerPoint® Lecture Presentations prepared by
Leslie Hendon
University of Alabama, Birmingham
© 2014 Pearson Education, Inc.
I. Tissues
A. Cells work together in functionally related groups called tissues
B. Tissue - A group of closely associated cells that perform related
functions and are similar in structure
II. Four Basic Tissue Types and Basic Functions
► Epithelial tissues - covering
► Connective tissues - support
► Muscle tissues - movement
► Nervous tissue - control
III. Epithelial Tissue
A. Covers all body surfaces and lines all body cavities
B. Functions of epithelia
1. protection
2. secretion
3. absorption
4. diffusion
5. filtration
6. sensory reception
C. Special Characteristics of Epithelia
1. cellularity - cells separated by minimal extracellular material
2. specialized contacts - cells joined by special junctions
3. polarity - cell regions of the apical surface differ from the basal
surface
4. avascular (no blood vessels) - epithelia receive nutrients from
underlying connective tissue
5. regeneration - lost cells are quickly replaced by cell division
Cilia
Narrow
extracellular
space
Microvilli
Apical region of
an epithelial cell
Cell junctions
Tight junction
Adhesive belt
Desmosome
Gap junction
Epithelium
Basal region
Nerve ending
Connective
tissue
Capillary
Basal
lamina
Reticular
fibers
Basement
membrane
► First name of tissue indicates number of cell layers
Simple epithelia - single layer of cells attached to basement
membrane
Stratified epithelia - multiple layers of cells (basal cells
attached to basement membrane)
► Last name of tissue describes shape of cells
Squamous—cells are wider than tall (plate-like)
Cuboidal—cells are as wide as tall, like cubes
Columnar—cells are taller than they are wide, like columns
Apical surface
Basal
surface
Simple
Apical surface
Basal
surface
Stratified
Classification based on number
of cell layers
Squamous
Cuboidal
Columnar
Classification based on
cell shape
Simple Squamous Epithelium
Description
A. single layer; flat cells with disc-shaped nuclei
Functions
A. passage of materials by passive diffusion and filtration
B. secretes lubricating substances in serosae
Location
A. alveoli of lungs
B. renal corpuscles
C. lining of heart, blood, and lymphatic vessels
D. lining of ventral body cavity (serosae)
Simple squamous epithelium
Description: Single layer of
flattened cells with disc-shaped
central nuclei and sparse
cytoplasm; the simplest of the
epithelia.
Function: Allows passage of
materials by diffusion and
filtration in sites where protection
is not important; produces
lubricating fluid in serosae.
Air sacs
of lung
tissue
Nuclei of
squamous
epithelial
cells
Location: Kidney glomeruli; air
sacs of lungs; lining of heart,
blood vessels, and lymphatic
vessels; lining of ventral body
cavity (serosae).
Photomicrograph: Simple squamous epithelium
forming part of the alveolar (air sac) walls (140).
Simple squamous epithelium
Simple Cuboidal Epithelium
Description
A. single layer of cube-like cells; large, spherical central nuclei
Function
A. secretion and absorption
Location
A. kidney tubules, small glands, ovary surface
Simple cuboidal epithelium
Description: Single layer of
cubelike cells with large,
spherical central nuclei.
Simple
cuboidal
epithelial
cells
Function: Secretion and
absorption.
Basement
membrane
Location: Kidney tubules;
ducts and secretory portions of
small glands; ovary surface.
Connective
tissue
Photomicrograph: Simple cuboidal epithelium
in kidney tubules (430).
Simple Columnar Epithelium
Description—single layer of column-shaped (rectangular) cells
A. some bear cilia at their apical surface
B. may contain goblet cells
Function
A. absorption; secretion of mucus, enzymes, and other substances
B. ciliated type propels mucus or reproductive cells by ciliary action
Location
A. nonciliated- stomach, intestines, gall bladder
B. ciliated – bronchi, uterine tubes, uterus
Simple columnar epithelium
Description: Single layer of tall
cells with round to oval nuclei;
some cells bear cilia; layer may
contain mucus-secreting
unicellular glands (goblet cells).
Microvilli
Goblet
cell
Simple
columnar
epithelial
cell
Function: Absorption; secretion
of mucus, enzymes, and other
substances; ciliated type propels
mucus (or reproductive cells) by
ciliary action.
Location: Nonciliated type lines
most of the digestive tract
(stomach to anal canal),
gallbladder, and excretory ducts
of some glands; ciliated variety
lines small bronchi,
uterine tubes,
and some
regions of
the uterus.
Basement
membrane
Photomicrograph: Simple columnar epithelium
of the small intestine (650).
Pseudostratified Columnar Epithelium
Description
A.like simple columnar, but uneven surface
B. may contain goblet cells and bear cilia
C. nuclei lie at varying heights within cells
D. gives false impression of stratification
Function—secretion of mucus; propulsion of mucus by cilia
Locations
A. non-ciliated type
i. ducts of male reproductive tubes
ii. ducts of large glands
B. ciliated type
i. lines trachea and most of upper respiratory tract
Pseudostratified columnar epithelium
Description: Single layer of
cells of different heights, some
not reaching the free surface;
nuclei seen at different levels;
may contain mucus-secreting
goblet cells and bear cilia.
Cilia
Goblet
cell
Pseudostratified
epithelial
layer
Function: Secretion, particularly
of mucus; propulsion of mucus
by ciliary action.
Location: Nonciliated type in
male’s sperm-carrying ducts and
ducts of large glands; ciliated
variety lines the trachea,
most of the upper respiratory
tract.
Trachea
Basement
membrane
Photomicrograph: Pseudostratified ciliated
columnar epithelium lining the human trachea
(780).
Stratified Squamous Epithelium
Description
A. many layers of cells are squamous in shape
B. deeper layers of cells appear cuboidal or columnar
C. thickest epithelial tissue
D. adapted for protection from abrasion
1. Keratinized
a. Location - epidermis of the skin
b. contains the protective protein keratin
c. waterproof
d. surface cells are dead and full of keratin
2. Non-keratinized
a. Forms moist lining of body openings
Stratified squamous epithelium
Description: Thick membrane
composed of several cell layers;
basal cells are cuboidal or
columnar and metabolically
active; surface cells are flattened
(squamous); in the keratinized
type, the surface cells are full of
keratin and dead; basal cells are
active in mitosis and produce the
cells of the more superficial
layers.
Stratified
squamous
epithelium
Function: Protects underlying
tissues in areas subjected to
abrasion.
Nuclei
Basement
membrane
Location: Nonkeratinized type
forms the moist linings of the
esophagus, mouth, and vagina;
keratinized
variety
forms the
epidermis of
the skin, a
dry membrane.
Connective
tissue
Photomicrograph: Stratified squamous
epithelium lining the esophagus (280).
Stratified Cuboidal Epithelium (rare)
Description - generally two layers of cube-shaped cells
Function - protection
Location
A. Forms ducts of:
1. mammary glands
2. salivary glands
3. largest sweat glands
Stratified cuboidal epithelium
Description: Generally two
layers of cubelike cells.
Basement
membrane
Function: Protection.
Location: Largest ducts of
sweat glands, mammary glands,
and salivary glands.
Cuboidal
epithelial
cells
Duct
lumen
Photomicrograph: Stratified cuboidal epithelium
forming a salivary gland duct (290).
Stratified Columnar Epithelium (rare)
Description
A. several layers
B. basal cells usually cuboidal superficial cells elongated
Function - protection and secretion
Location
A. rare tissue type
B. found in male urethra and large ducts of some glands
Stratified columnar epithelium
Description: Several cell layers;
basal cells usually cuboidal;
superficial cells elongated
and columnar.
Stratified
columnar
epithelium
Function: Protection; secretion.
Location: Rare in the body;
small amounts in male urethra
and in large ducts of some
glands.
Urethra
Basement
membrane
Underlying
connective
tissue
Photomicrograph: Stratified columnar epithelium
lining the male urethra (360).
Transitional Epithelium
Description
A. characteristics of stratified cuboidal and stratified squamous
B. superficial cells dome-shaped when bladder is relaxed
C. squamous when full
Function
A. permits distension of urinary organs when filled with urine
Location - urinary bladder and ureters
Transitional epithelium
Description: Resembles both
stratified squamous and stratified
cuboidal; basal cells cuboidal or
columnar; surface cells dome
shaped or squamous-like,
depending on
degree of
organ
stretch.
Transitional
epithelium
Function: Stretches readily and
permits distension of urinary
organ by contained urine.
Location: Lines the ureters,
bladder, and part of the urethra.
Photomicrograph: Transitional epithelium
lining the bladder, relaxed state (365); note the
bulbous, or rounded, appearance of the cells at
the surface; these cells flatten and become
elongated when the bladder is filled with urine.
Basement
membrane
Connective
tissue
V. Glands
A. Endocrine glands (INTO the blood)
1. ductless glands
2. secrete directly into surrounding tissue fluid
3. produce messenger molecules called hormones
B. Exocrine glands (ONTO a surface)
1. ducts carry substances to epithelial surface
a. mucus-secreting glands
b. sweat and oil glands
c. salivary glands
d. liver and pancreas
C. Unicellular Exocrine Glands (The Goblet Cell)
1. goblet cells produce mucin
2. mucin  water  mucus
3. protects and lubricates many internal body surfaces
4. goblet cells are a unicellular exocrine gland (e.g. intestine)
D. Multicellular Exocrine Glands
1. have two basic parts
2. epithelium-walled duct
3. classified by structure of duct
a. simple
b. compound
c. tubular
d. alveolar
e. tubuloalveolar
Tubular
secretory
structure
Alveolar
secretory
structure
Simple duct structure
Compound duct structure
(duct does not branch)
(duct branches)
Simple
tubular
Simple branched
tubular
Example
Example
Compound tubular
Intestinal
glands
Stomach (gastric)
glands
Duodenal glands of small intestine
Simple
alveolar
Simple branched
alveolar
Example
No important
Example
Sebaceous (oil)
example in
humans
glands
Surface epithelium
Duct
Example
Compound alveolar
Example
Mammary glands
Compound
tubuloalveolar
Example
Salivary glands
Secretory epithelium
E. Cell Junctions
1. factors binding epithelial cells together
2. adhesion proteins link plasma membranes of adjacent cells
F. Special cell junctions
1. tight junctions - close off intercellular space
a. found at apical region of most epithelial tissues types
b. some proteins in plasma membrane of adjacent cells are fused
c. prevent molecules from passing between cells
2. adhesive belt junctions - anchoring junction
3. transmembrane linker proteins
a. attach to cytoskeleton and bind adjacent cells
4. desmosomes—main junctions for binding cells together
a. scattered along abutting sides of adjacent cells
b. intermediate filaments extend across the cytoplasm
c. and anchor at desmosomes on opposite side of the cell
d. are common in cardiac muscle and epithelial tissue
5. gap junctions - passageway between two adjacent cells
a. let small molecules move directly between cells
b. cells are connected by hollow protein channel
c. passage of small atoms (e.g. ions) or molecules
d. function in intercellular communication
Plasma membranes
of adjacent cells
Microvilli
Intercellular
space
Basement membrane
Intercellular
space
Plaque
Channel
between cells
(connexon)
Interlocking
junctional
proteins
Intercellular
space
Intercellular
space
Intermediate
filament
(keratin)
Tight junctions: Impermeable
junctions prevent molecules from
passing through the intercellular
space.
Linker
glycoproteins
(cadherins)
Desmosomes: Anchoring junctions
bind adjacent cells together and help
form an internal tension-reducing
network of fibers.
Gap junctions: Communicating
junctions allow ions and small
molecules to pass from one cell to the
next for intercellular communication.
G. The Basal Lamina
1. at boundary between the epithelium and connective tissue
2. non-cellular supporting sheet between the epithelial tissue
3. connective tissue deep to it
4. consists of proteins secreted by epithelial cells
5. Functions
a. determining which molecules from capillaries enter the
epithelium
b. scaffolding along which regenerating epithelial tissue
cells can migrate
c. underlying connective tissue deep to it form
the basement membrane
VI. Epithelial Surface Features
A. Microvilli—fingerlike extensions of plasma membrane
1. have a core of actin filaments that stiffen the microvillus
2. abundant in kidney tubules and small intestine
3. surface across which small molecules enter or leave cells
Microvilli
Microvillus
Actin
filaments
B. Cilia – whiplike extensions of apical surface membranes
1. microtubules held together by cross-linking proteins
2. microtubules arranged in pairs called doublets
3. movement is generated when adjacent doublets grip each
other with the motor protein dynein
4. cilia originate as microtubules assemble around centrioles
Cilia
Layer of mucus
Cell surface
VII. Connective Tissue
A. Most diverse and abundant tissue
B. Main classes of connective tissue
1. connective tissue proper
2. cartilage
3. bone tissue
4. blood
C. Important functions of connective tissue type
1. form basis of the skeleton
2. store and carry nutrients
3.surround blood vessels and nerves
4. support and binding of other tissues
5. holding body fluids (interstitial fluid  lymph)
6. defending body against infection
7. storing nutrients as fat and protection
D. Special Characteristics of Connective Tissue
1. few cells, abundant extracellular matrix
2. extracellular matrix is composed of ground substance
3. extracellular fibers
4. extracellular matrix produced by cells called fibroblasts
5. common embryonic origin is mesenchyme
E. Structural Elements of Connective Tissue
1. connective tissues differ in structural properties
2. differences in types of cells
3. differences in composition of extracellular matrix
4. however, connective tissues all share structural elements
F. Cells
1. fibroblasts - primary cell type of connective tissues produces
the extracellular matrix
2. chondroblasts secrete matrix in cartilage (chondro)
3. osteoblasts secrete matrix in bone (osteo)
G. Fibers
1. Extracellular matrix is composed of fibers and ground substance
2. Fibers function in support and also have unique properties
a. collagen fibers - strongest; resist tension
b. reticular fibers - bundles of special type of cartilage
c. elastic fibers - contain elastin
H. Ground substance
1. Is produced by primary cell type of the tissue
2. Is usually gel-like substance consisting of:
a. proteoglycans and glycosaminoglycans (arthritis)
b. cushions and protects body structures
c. holds tissue fluid
Connective Tissue
Extracellular
matrix
Ground substance
Macrophage
Fibers
Collagen fiber
Elastic fiber
Reticular fiber
Fibroblast
Lymphocyte
Fat cell
Mast cell
Neutrophil
Capillary
VIII. Embryonic Connective Tissue (Mesenchyme)
A. has gel-like ground substance
B. cells are star-shaped mesenchymal cells
C. connective tissues arise from mesenchyme in the embryo
Embryonic connective tissue: mesenchyme
Description: Embryonic
connective tissue; gel-like
ground substance containing
fibers; star-shaped
mesenchymal cells.
Mesenchymal
cells
Ground
substance
Function: Gives rise to all
other connective tissue types.
Fibers
Location: Primarily in embryo.
Photomicrograph: Mesenchyme, an embryonic
connective tissue (385). The matrix is composed
of the fluid ground substance (clear-appearing background)
and fine, sparse fibers.
IX. Areolar (Loose) Connective Tissue
A. underlies all epithelial tissues
B. between muscle and skin
C. surrounds small nerves and blood vessels
D. structures & functions shared by other connective tissues
E. fibers provide support
F. Three types of protein fibers in extracellular matrix
a. collagen fibers
b. reticular fibers
c. elastic fibers
► Fibroblasts produce these fibers
G. Tissue fluid (interstitial fluid)
1. watery fluid in extracellular matrix (comes from blood plasma)
K. Ground substance
1. made and secreted by fibroblasts
2. viscous, spongy part of extracellular matrix
a. Consists of sugar and protein molecules
Main battlefield in fight against infection
i. macrophages
ii. plasma cells
iii. mast cells
iv. white blood cells
v. neutrophils
Description
1. gel-like matrix with all three fiber types
2. cells of areolar connective tissue
3. fibroblasts, macrophages, mast cells, white blood cells
Function
1. wraps and cushions organs
2. holds and conveys tissue fluid (interstitial fluid)
3. Important role in inflammation
Locations
1. widely distributed under epithelia
2. ackages organs
3. surrounds capillaries
Connective tissue proper: loose connective tissue, areolar
Description: Gel-like matrix with
all three fiber types; cells:
fibroblasts, macrophages, mast
cells, and some white blood cells.
Elastic
fibers
Ground
substance
Function: Wraps and cushions
organs; its macrophages
phagocytize bacteria; plays
important role in inflammation;
holds and conveys tissue fluid.
Fibroblast
nuclei
Collagen
fibers
Location: Widely distributed
under epithelia of body, e.g.,
forms lamina propria of mucous
membranes; packages organs;
surrounds capillaries.
Photomicrograph: Areolar connective tissue,
a soft packaging tissue of the body (340).
Epithelium
Lamina
propria
X. Adipose Tissue
Description
1. closely packed adipocytes
2. have nucleus pushed to one side by fat droplet
3. highly vascularized
Function
1. provides reserve food fuel
2. insulates against heat loss
3. supports and protects organs
Location
1. under skin (hypodermis)
2. around kidneys
3. behind eyeballs, within abdomen, and in breasts
Connective tissue proper: loose connective tissue, adipose
Description: Matrix as in areolar
connective tissue, but very sparse;
closely packed adipocytes, or fat
cells, have nucleus pushed to the
side by large fat droplet.
Nucleus
of fat cell
Function: Provides reserve food
fuel; insulates against heat loss;
supports and protects organs.
Vacuole
containing
fat droplet
Location: Under skin in the
hypodermis; around kidneys and
eyeballs; within abdomen;
in breasts.
Adipose
tissue
Photomicrograph: Adipose tissue from the
subcutaneous layer under the skin (350).
Mammary
glands
XI. Reticular Connective Tissue
Description - network of reticular fibers in loose ground substance
Function
1. forms a soft, internal skeleton (stroma)
2. supports other cell types
Location - Lymph nodes, bone marrow, and spleen
Connective tissue proper: loose connective tissue, reticular
Description: Network of
reticular fibers in a typical loose
ground substance; reticular
cells lie on the network.
White
blood cell
(lymphocyte)
Function: Fibers form a soft
internal skeleton (stroma) that
supports other cell types
including white blood cells,
mast cells, and macrophages.
Reticular
fibers
Location: Lymphoid organs
(lymph nodes, bone marrow,
and spleen).
Spleen
Photomicrograph: Dark-staining network of
reticular connective tissue fibers forming the
internal skeleton of the spleen (350).
XII. Dense Connective Tissue
A. Two types of dense connective tissue
1. Dense irregular connective tissue
2. Dense regular connective tissue
(have more collagen than areolar connective tissue)
B. Dense Irregular Connective Tissue
Description
1. collagen fibers are thick and irregularly arranged
2. contains some elastic fibers and fibroblasts
Function
1. withstands tension
2. provides structural strength
Location
1. dermis of skin
2. submucosa of digestive tract
3. fibrous capsules of joints
4. capsules surrounding organs
(e.g. kidneys, bones, and lymph nodes )
Connective tissue proper: dense connective tissue, dense irregular
Description: Primarily
irregularly arranged collagen
fibers; some elastic fibers;
major cell type is the fibroblast;
defense cells and fat cells are
also present.
Nuclei of
fibroblasts
Function: Able to withstand
tension exerted in many
directions; provides structural
strength.
Collagen
fibers
Location: Fibrous capsules of
organs and of joints; dermis of
the skin; submucosa of
digestive tract.
Fibrous
layer of
joint
capsule
Photomicrograph: Dense irregular connective
tissue from the dermis of the skin (300).
C. Dense Regular Connective Tissue
Description
a. collagen fibers are parallel to the direction of pull
b. fibroblasts are located between collagen fibers
c. contains few elastic fibers
d. has great tensile strength
e. poorly vascularized
f. forms fascia (tissue around muscles and tedons)
Function
a. attaches muscle to bone
b. attaches bone to bone
c. withstands great stress in one direction
Location
a. tendons and ligaments
b. aponeuroses (broad sheet-like tendons)
c. fascia around muscles
Connective tissue proper: dense connective tissue, dense regular
Description: Primarily parallel
collagen fibers; a few elastic
fibers; major cell type is the
fibroblast.
Collagen
fibers
Function: Attaches muscles to
bones or to muscles; attaches
bones to bones; withstands great
tensile stress when pulling force
is applied in one direction.
Nuclei of
fibroblasts
Location: Tendons, most
ligaments, aponeuroses.
Shoulder
joint
Ligament
Tendon
Photomicrograph: Dense regular connective
tissue from a tendon (425).
D. Elastic Connective Tissue
Description - Elastic fibers predominate
Function - allows recoil after stretching
Location
a. within walls of arteries
b. in certain ligaments
c. surrounding bronchial tubes
Connective tissue proper: dense connective tissue, elastic
Description: Dense regular
connective tissue containing a
high proportion of elastic fibers.
Function: Allows recoil of tissue
following stretching; maintains
pulsatile flow of blood through
arteries; aids passive recoil of
lungs following inspiration.
Elastic
fibers
Location: Walls of large arteries;
within certain ligaments associated
with the vertebral column; within
the walls of the bronchial tubes.
Aorta
Heart
Photomicrograph: Elastic connective tissue in
the wall of the aorta (250).
Photomicrograph: Elastic connective tissue in
the wall of the aorta (250).
XIII. Cartilage
A. all cartilages have similar structural components
1. firm, flexible tissue
2. contains no blood vessels or nerves
3. matrix contains up to 80% water
4. chondrocytes – mature cells
5. chondroblasts - immature cells for growth and maintenance
a. secrete matrix of fibers during cartilage growth
B. Three types of cartilage
1. Hyaline cartilage
2. Elastic cartilage
3. Fibrocartilage
► Each cartilage has specialized functions
C. Hyaline Cartilage
Description
a. imperceptible collagen fibers (hyaline = glassy)
b. are mature cartilage cells
c. lie within lacunae
Function
a. supports and reinforces
b. resilient cushion
c. resists repetitive stress
Location
a. fetal skeleton
b. ends of long bones
c. costal cartilage of ribs
d. cartilages of nose, trachea, and larynx
Cartilage: hyaline
Description: Amorphous but
firm matrix; collagen fibers form
an imperceptible network;
chondroblasts produce the
matrix and, when mature
(chondrocytes), lie in lacunae.
Chondrocyte
in lacuna
Matrix
Function: Supports and
reinforces; serves as resilient
cushion; resists compressive
stress.
Location: Forms most of the
embryonic skeleton; covers the
ends of long bones in joint
cavities; forms costal cartilages
of the ribs; cartilages of the nose,
trachea, and
larynx.
Costal
cartilages
Photomicrograph: Hyaline cartilage from a
costal cartilage of a rib (470).
D. Elastic Cartilage
Description
a. similar to hyaline cartilage
b. more elastic fibers in matrix
Function
a. maintains shape of structure
b. allows great flexibility
Location
a. supports external ear
b. epiglottis
Cartilage: elastic
Description: Similar to hyaline
cartilage, but more elastic
fibers in matrix.
Chondrocyte
in lacuna
Function: Maintains the shape
of a structure while allowing
great flexibility.
Matrix
Location: Supports the
external ear (pinna); epiglottis.
Photomicrograph: Elastic cartilage from the
human ear pinna; forms the flexible skeleton of
the ear (510).
E. Fibrocartilage
Description
a. matrix similar but less firm than hyaline cartilage
b. thick collagen fibers predominate
Function - tensile strength and ability to absorb compressive shock
Location
a.intervertebral discs
b. pubic symphysis
c.discs of knee joint
Cartilage: fibrocartilage
Description: Matrix similar
to but less firm than that in
hyaline cartilage; thick
collagen fibers predominate.
Function: Tensile strength
with the ability to absorb
compressive shock.
Collagen
fibers
Location: Intervertebral
discs; pubic symphysis;
discs of knee joint.
Chondrocytes
in lacunae
Intervertebral
discs
Photomicrograph: Fibrocartilage from an
intervertebral disc (175).
XIV. Bone Tissue
Description
bone matrix contains:
1. inorganic Calcium salts
2. abundance of collagen fibers
3. well vascularized
► osteoblasts—secrete collagen fibers; create/maintain/remodel bone
► osteocytes—mature bone cells in lacunae
► (osteoclasts) – degrade bone during remodeling and repair
Function
1. supports and protects organs
2. provides levers and attachment site for muscles
3. stores calcium and other minerals
4. stores fat
5. bone marrow - site for blood cell formation
Location - Bones
Others: bone (osseous tissue)
Description: Hard, calcified
matrix containing many collagen
fibers; osteocytes lie in
lacunae. Very well vascularized.
Central
canal
Lacunae
Function: Supports and
protects (by enclosing); provides
levers for the muscles to act on;
stores calcium and other
minerals and fat; marrow inside
bones is the site for blood cell
formation (hematopoiesis).
Lamella
Location: Bones.
Photomicrograph: Cross-sectional view of bone
(175).
XV. Blood Tissue
Properties
1. an atypical connective tissue
2. develops from mesenchyme (embryonic tissue)
3. consists of cells surrounded by nonliving matrix
Description
1. Red blood cells, white blood cells and platelets
Function - Transport of respiratory gases, nutrients, and wastes
Location – within blood vessels and heart
Connective tissue: blood
Description: Red and
white blood cells in a fluid
matrix (plasma).
Red blood
cells
(erythrocytes)
White
blood cells:
• Lymphocyte
• Neutrophil
Function: Transport
respiratory gases, nutrients,
wastes, and other
substances.
Location: Contained within
blood vessels.
Plasma
Photomicrograph: Smear of human blood (1650);
shows two white blood cells surrounded by red
blood cells.
XVI. Covering and Lining Membranes
A. combine epithelial tissues and connective tissues
B. cover broad areas within body
C. epithelial sheet plus underlying connective tissue
D. Three Types of Membranes
1. cutaneous membrane
2. mucous membranes
3. serous membranes
1. Cutaneous membrane
a. skin
2. Mucous membranes
a. lines hollow organs that open to surface of body
b. epithelial sheet with layer of lamina propria
3. Serous membranes
a. simple squamous epithelium called mesothelium
b. produces serous fluid
c. lines closed cavities
i. visceral and parietal pleura (lungs)
ii. visceral and parietal peritoneum (intestines)
iii. visceral and parietal pericardium (heart)
Cutaneous membrane
The cutaneous membrane
(the skin) covers the body
surface.
Serous membranes
Serous membranes line body
cavities that are closed to the
exterior.
Cutaneous
membrane
(skin)
Parietal
pleura
Visceral
pleura
Mucous membranes
Visceral
Parietal
pericardium pericardium
Mucous membranes line body
cavities that are open to the
exterior.
Mucosa of
nasal cavity
Mucosa of
mouth
Esophagus
lining
Mucosa
of lung
bronchi
Parietal
peritoneum
Visceral
peritoneum
XVII. Muscle Tissue
A. is a composite tissue
B. contains areolar connective tissue and muscle tissue
C. muscle cells also called muscle fibers
D. cells contain myofilaments
1. myofilaments contain actin and myosin
E. Three types of muscle tissue
1. skeletal muscle tissue
2. cardiac muscle tissue
3. smooth muscle tissue
F. Skeletal Muscle Tissue (Striated muscle; Voluntary muscle)
Description
1. long, cylindrical cells
2. multinucleate
3. obvious striations
Function - voluntary movement
Location - skeletal muscles attached to bones (occasionally to skin)
Skeletal muscle
Description: Long,
cylindrical, multinucleate cells;
obvious striations.
Striations
Nuclei
Function: Voluntary
movement; locomotion;
manipulation of the
environment; facial expression.
Location: In skeletal muscles
attached to bones or
occasionally to skin.
Part of
muscle
fiber (cell)
Photomicrograph: Skeletal muscle (450).
Notice the obvious banding pattern and the
fact that these large cells are multinucleate.
G. Cardiac Muscle Tissue
Description
1. branching cells, striated
2. generally uninucleate
3. cells interdigitate at intercalated discs
Function - contracts to propel blood into circulatory system
Location - occurs in walls of heart
Cardiac muscle
Description: Branching,
striated, generally uninucleate
cells that interdigitate at
specialized junctions
(intercalated discs).
Striations
Intercalated
discs
Function: As it contracts,
it propels blood into the
circulation; involuntary
control.
Location: The walls of the
heart.
Nucleus
Photomicrograph: Cardiac muscle (355);
notice the striations, branching of cells, and
the intercalated discs.
Cardiac muscle
H. Smooth Muscle Tissue
Description
1. spindle-shaped cells with central nuclei
2. arranged closely to form sheets
3. no striations
Function
1. propels substances along internal passageways
2. involuntary control
Location - walls of blood vessels and GI tract
Smooth muscle
Description: Spindle-shaped cells
with central nuclei; no striations;
cells arranged closely to form
sheets.
Smooth
muscle
cell
Function: Propels substances or
objects (foodstuffs, urine, a baby)
along internal passageways;
involuntary control.
Nuclei
Location: Mostly in the walls of
hollow organs.
Photomicrograph: Sheet of smooth muscle from
the digestive tract (465).
XVIII. Nervous Tissue
Description
1. main components are brain, spinal cord, and nerves
2. contains two types of cells:
a. neurons (nerve cells)- conduct nerve impulses
b. neuroglial cells (supporting cells) - supporting cells
Function - transmit electrical signals
Location - brain, spinal cord, and nerves
Nervous tissue
Description: Neurons are
branching cells; cell processes
that may be quite long extend from
the nucleus-containing cell body;
also contributing to nervous tissue
are nonconducting supporting
cells, neuroglia (not illustrated).
Neuron processes
Cell body
of a
neuron
Neuron
processes
Cell body
Dendrites
Axon
Function: Transmit electrical
signals from sensory receptors
and to effectors (muscles and
glands) that control the activity
of the effector organs.
Location: Brain, spinal
cord, and nerves.
Nuclei of
neuroglia
Photomicrograph: Neurons (125).