View
224
Download
3
Category
Tags:
Preview:
Citation preview
Body Tissues
A. Tissues1. Groups of cells with similar structure and
function2. Four primary types
a. Epithelial tissue (epithelium)b. Connective tissuec. Muscle tissued. Nervous tissue
B. Epithelial Tissues
. 1. Locations– Body coverings– Body linings (structures
or organs)– Glandular tissue
2. Functions– Protection– Absorption– Filtration– Secretion
3. Epithelium Characteristics
a. Cells fit closely together and often form sheets
b. The apical surface is the free surface of the tissue
c. The lower surface of the epithelium rests on a basement membrane
d. A vascular (no blood supply)
e. Regenerate easily if well nourished
4. Classification of Epitheliaa. Number of cell layers
–Simple—one layer
–Stratified—more than one layer
5. Classification by shape
a. Shape of cells–Squamous•flattened
–Cuboidal• cube-shaped
–Columnar• column-like
6. Simple Epithelia
a. Simple squamous– Single layer of
flat cells– Usually forms
membranes• Lines body
cavities• Lines lungs and
capillaries
Simple Epithelia
b Simple cuboidal– Single layer of
cube-like cells– Common in
glands and their ducts
– Forms walls of kidney tubules
– Covers the ovaries
Simple Epithelia
c. Simple columnar– Single layer
of tall cells– Often
includes mucus-producing goblet cells
– Lines digestive tract
Stratified Epithelia
d. Stratified squamous– Cells at the apical
surface are flattened
– Found as a protective covering where friction is common
– Locations• Skin• Mouth• Esophagus
Stratified Epithelia
e. Stratified cuboidal• —two layers of cuboidal cells
–Both are •Rare in human body
f. Stratified columnar—• columnar—surface cells are
columnar, cells underneath vary in size and shape
C. Connective Tissue
1. Found everywhere in the body
2. Includes the most abundant and widely distributed tissues
3. Functions– Binds body tissues
together– Supports the body– Provides protection
5. Extracellular matrix– Non-living material that
surrounds living cells
D. Connective Tissue Types
• 1. bones• 2. Hyaline cartilage• 3. Elastic cartilage• 4. Fibro cartilage• 5. Dense connective tissue (dense fibrous
tissue)• 6. Loose connective tissue • 7. Blood (vascular tissue)
1. Bone (osseous tissue)
– Composed of• Bone cells in lacunae
(cavities)• Hard matrix of
calcium salts• Large numbers of
collagen fibers
– Used to protect and support the body
2. Hyaline cartilage
– Most common type of cartilage
– Composed of• Abundant
collagen fibers• Rubbery
matrix
– Locations• Larynx• Entire fetal
skeleton prior to birth
6. Dense connective tissue (dense fibrous tissue)
• Tendons—attach skeletal muscle to bone• Ligaments—
attach bone to bone at joints• Dermis—lower
layers of the skin
a. Areolar tissue
• Most widely distributed connective tissue
• Soft, pliable tissue like “cobwebs”
• Functions as a packing tissue
• Contains all fiber types• Can soak up excess fluid
(causes edema)
b. Adipose tissue
• Fat Cells• Functions– Insulates the
body–Protects some
organs–Serves as a site
of fuel storage
Blood (vascular tissue)
–Blood cells surrounded by fluid matrix called blood plasma– Fibers are visible
during clotting– Functions as the
transport vehicle for materials
10. Muscle Tissue
a. Function is to produce movementb. Three types– Skeletal muscle– Cardiac muscle– Smooth muscle
a. Skeletal muscle
– Under voluntary control– Contracts to pull on bones or skin– Produces gross body movements or facial
expressions
Characteristics of skeletal muscle cells
• Striated• Multinucleate(more
than one nucleus per cell)
• Long, cylindrical
b. Cardiac muscle
– Under involuntary control– Found only in the heart– Function is to pump blood– Characteristics of cardiac
muscle cells• Cells are attached to other
cardiac muscle cells at intercalated disks
• Striated• One nucleus per cell• Cells are branched
c. Smooth muscle
– Under involuntary control
– Found in walls of hollow organs such as stomach, uterus, and blood vessels
– Characteristics of smooth muscle cells• No visible striations• One nucleus per cell• Spindle-shaped cells
Recommended