Transcript CH 3 P3 Lecture

Anatomy & Physiology
Chapter 3 – Part 3
Tissues
Body Tissues
• Tissues
– Groups of cells with similar structure and
function
– 4 primary types:
•
•
•
•
Epithelium
Connective
Nervous
Muscle
Epithelial Tissues
• Found in different areas:
– Body Coverings
– Body Linings
– Glandular Tissue
• Functions:
–
–
–
–
Protection
Absorption
Filtration
Secretion
Epithelial Tissues
• Epithelium Characteristics:
– Cells fit closely together
– Have no blood supply of their own
Classification of Epithelium
• Number of Cell
Layers:
– Simple = one layer
– Stratified = more than
one layer
• Shape of Cells:
– Squamous = flattened
– Cuboidal = cube
shaped
– Columnar = column
like
Classification of Epithelium
Connective Tissue
• Includes the most abundant tissues
• Functions:
– Binds body tissues together
– Supports the body
– Provides protection
Connective Tissue
• Extracellular Matrix:
– Non-living material that surrounds living cells
– Two main elements:
• Ground substance = mostly water along with
proteins and polysaccharides
• Fibers
Muscle Tissue
• Function is to produce movement
• Three types:
– Skeletal Muscle
– Cardiac Muscle
– Smooth Muscle
Nervous Tissue
• Comprised of neurons
and nerve support
cells
• Function is to send
impulses to other
areas of the body
Tissue Repair
• Regeneration
– Replacement of destroyed tissue by the same
kind of cells
• Fibrosis
– Repair by dense fibrous connective tissue
(scar tissue)
Events in Tissue Repair
• Capillaries become very permeable
• Regeneration of surface epithelium
Regeneration of Tissues
• Tissues that regenerate easily:
– Epithelial
– Fibrous Connective
– Bone
• Tissues that regenerate poorly:
– Skeletal Muscle
• Tissues that are replace largely with scar tissue:
– Cardiac Muscle
– Nervous tissue within the brain and spinal cord
Developmental Aspects of
Tissues
• With old age there is a decrease in mass
and viability in most tissues.
Developmental Aspects of
Tissues
• Some cells lose their ability to divide when they
are fully mature.
– This is called AMITOTIC
– For example: heart muscle and nervous tissue
– However, if these tissues are injured, the lost cells
cannot be replaced by the same type of cells but by
scar tissue.
• If a cell multiplies wildly, the abnormal cell mass
is known as NEOPLASM.
– May be benign or malignant (cancerous)
Simple Epithelium
• Simple Squamous
– GD: Single layer of flat
cells
– Location: Lines body
cavities
– Location: Lines lungs
and capillaries
Simple Epithelium
• Simple Cuboidal
– GD: Single layer of
cube-like cells
– Location: Covers the
ovaries
Simple Epithelium
• Simple Columnar
– GD: Single layer of tall
cells
– GD: Includes GOBLET
CELLS – produce
mucus for secretion
– Location: Lines the
digestive tract
Simple Epithelium
• Pseudostratified
– GD: Single layer, but
some cells are shorter
than others
– Location: Found in the
respiratory tract – has
cilia
Stratified Epithelium
• Stratified Squamous
– GD: Several layers of
flat cells
– Location:
• Skin
• Mouth
• Esophagus
Stratified Epithelium
• Transitional Epithelium
– GD: Shape of cells
depends upon the
amount of stretching
– Location: Lines organs of
the urinary system to
help stretch the bladder
Glandular Epithelium
• Gland = one or more cells that secretes a
particular product
• Two major gland types:
– Endocrine Glands
• Ductless
• Secretions hormones directly into the blood
– Exocrine Glands
• Have ducts
• Include sweat and oil glands
Connective Tissue Types
• Dense Connective
– Made up of collagen
fibers
– Examples: tendons
and ligaments
Connective Tissue Types
• Adipose
– Made of areolar tissue
with fat globules
– Functions:
• Insulates the body
• Protects organs
• Serves as a site of fuel
storage
Connective Tissue Types
• Areolar
– Most widely distributed
connective tissue
– Soft tissue
– Contains all fiber types
Connective Tissue Types
• Hyaline Cartilage
– Most common
cartilage
– Entire fetal skeleton is
hyaline cartilage
Connective Tissue Types
• Elastic Cartilage
– Made of elastic fibers
– Provides elasticity
– Example: supports the external ear
Connective Tissue Types
• Fibrocartilage
– Highly compressible
– Example: forms
cushion-like discs
between vertebrae
Connective Tissue Types
• Bone
– Composed of a hard
matrix of calcium salts
– Used to protect and
support the body
Connective Tissue Types
• Blood
– Blood cells are
surrounded by fluid
matrix
– Functions as the
transport vehicle for
materials
Connective Tissue Types
• Reticular
– Delicate network of
interwoven fibers
– Forms internal support
for the lymph nodes,
spleen, and bone
marrow
Muscle Tissue Types
• Skeletal Muscle
– GD: Can be controlled
voluntarily
– GD: Cells are striated
– GD: Cells have more
than one nucleus
– Location: Attached to
the bones
– Function: Movement
Muscle Tissue Types
• Smooth Muscle
– GD: Involuntary
– GD: No visible
striations
– GD: One nucleus per
cell
– Location: Surrounds
hollow organs
– Function: movement
Muscle Tissue Types
Cardiac Muscle
– GD: Cells are striated
– GD: One nucleus per
cell
– GD: Involuntary
– Location: ONLY in the
HEART
– Function: pump blood