Chapter 5
Tissues
Tissues
 Cells are arranged in tissues that provide specific
functions for the body
 Cells of different tissues are structured differently,
which leads to their differences in function.
 The Tissues of the body include four major types:
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Epithelial
Connective
Muscular
Nervous
Epithelial Tissues
 Widespread throughout the body – Covers organs and
lines body surfaces
 Anchored to a basement membrane
 Made up of tightly packed cells containing little
intercellular material
 Generally lack blood vessels
 Are frequently replaced
 Function in protection, secretion, absorption, excretion
and sensory reception.
 There are 9 types of Epithelial Tissues
Structure of Epithelial Tissues
Simple Squamous Epithelium
 Made up of a single
layer of thin,
flattened cells
 Functions in the
exchange of gases
in the lungs
 Lines blood and
lymph vessels as
well as body cavities
Simple Cuboidal Epithelium
 Consists of a single
layer of cube-shaped
cells with centrally
located nuclei
 Functions in
secretion and
absorption in the
kidneys and in
secretion in glands
Simple Columnar Epithelium
 Made up of rows of
elongated cells whose
nuclei are all located near
the basement membrane
 Lines the uterus, stomach
and intestines where it
protects underlying
tissues, secretes
digestive fluids and
absorbs nutrients
 In the intestine, these
cells possess microvilli
that increase the surface
area available for
absorption.
Pseudostratified Columnar
Epithelium
 Appeared layered due
to the varying positions
of their nuclei within
the rows of cells, but
are not truly layered.
 Cilia may be present
 Cilia on these cells aid
in moving eggs through
oviducts to the uterus
in the female
reproductive system
Stratified Squamous Epithelium
 Made up of layers of
flattened cells that are
designed to protect
underlying layers
 Makes up the outer
layer of skin
 Lines the mouth,
throat, vagina and
anal canal
Stratified Cuboidal Epithelium
 Consists of two to
three layers of
cuboidal cells lining a
lumen (opening) of
the mammary glands,
sweat glands and
pancreas.
 Several layers of cells
provide greater
protection than a
single layer.
Stratified Columnar Epithelium
 Consists of several
layers of cells
 Found in part of the
male urethra and
parts of the pharynx
Transitional Epithelium
 Designed to distend and return to its normal size
 Found in the urinary bladder
 Design provides distensibility (stretching) and keeps
urine from diffusing back into the internal cavity
Glandular Epithelium
 Made up of cells designed to produce and secrete
substances into ducts or into body fluids
 Exocrine glands – glands that secrete products into
ducts
 Endocrine glands – glands that secrete products
directly into body fluids and blood.
Glandular Epithelium
Connective Tissues
 Bind, support, protect, serve as frameworks, fill
spaces, store fat, produce blood cells, protect
against infection and repair tissue damage
 Unlike epithelial tissues, connective tissues have
abundant intercellular material and have good
blood supplies (except in cartilage)
 There are 6 types of connective tissues
Loose Connective Tissue
 Forms delicate, thin
membranes
throughout the body
that bind body parts
together.
 Binds the skin to
underlying organs
and fills spaces
within muscle.
Adipose Tissue
 Designed to store fat
 Found beneath the
skin, around joints,
padding the kidneys
and other internal
organs, and in
certain abdominal
membranes.
Dense Connective Tissue
 Consists of densely
packed fibers and is
very strong, but lacks
a good blood supply.
 Is found as part of
tendons and
ligaments
Cartilage
 Provides a supportive framework for various structures.
 Hyaline Cartilage – is white with abundant fine collagen
fibers
 Is found at the end of bones and supports respiratory
passages
 Elastic Cartilage
 Provides a framework for the external ears and parts of the
larynx
 Fibrocartilage
 Tough tissue that provides a shock-absorbing function in
intervertebral disks and in the knees and pelvic girdle
Cartilage
Bone
 The most rigid
connective tissue
 Bone cells are called
osteocytes
 Has a good blood
supply, enabling
rapid recovery after
an injury.
Blood
 Composed of red
and white cells
suspended in
plasma
 Formed in the red
bone marrow
 Functions to
transport
substances
throughout the body.
Muscular Tissue
 Muscle cells or fibers can contract
 Muscular tissue consists of three main types:
 Skeletal
 Smooth
 Cardiac
Skeletal Muscle Tissue
 Attached to bone
 Voluntary – can be
controlled by
conscious effort
 Cells (muscle fibers)
are long and
cylindrical, striated
(striped) and have
many nuclei
 Contract from nervous
impulse and then
relaxes
Smooth Muscle Tissue
 Lacks striations, only
has one nucleus, and
consists of spindle
shaped cells
 Involuntary – is not
controlled consciously
 Found in the walls of
internal organs and in
the digestive tract,
blood vessels and
urinary bladder
Cardiac Muscle Tissue
 Found only in the
heart
 Consists of
branching fibers that
are connected to
each other
 Has a single nucleus
in each cell, but
appears stretched
Nervous Tissue
 Found in the brain,
spinal cord and
nerves
 Neurons or nerve
cells conduct
nervous impulses
 Neuroglia (helper
cells) support and
nourish the neurons