Histology
• Take home message:
–
–
–
–
Why an organism needs four tissue types
How they work together
How they aid in specific body processes.
Do NOT having memorize specific tissue types
with very little detail or understanding.
(Thanks to Jen Jost (USC Biology, Helmuth Lab) for
creating this Power Point Presentation)
Objectives of laboratory exercise
• To be able to explain the form and
function of the four types of tissues.
• To describe how these four tissues are
able to work together to form a
complete organism.
Introduction to Histology
• Four basic tissue types:
– Epithelial, connective, muscle, nervous
• All organisms are composed of ONLY
these four tissue types
• Tissue types are organized to form
organs, which form the functional
systems of the body
Epithelial tissue
Pg 154-155; slides 157-158
Cells are bound tightly together
Little extracellular material
Often control passage of material
Function: covers the internal and external
surfaces of the body
Four types: Squamous, cuboidal, columnar,
and transitional
Organized in layers: simple or stratified
Examples: Epithelial
• Transitional
epithelial: found in
the bladder
• Stretches as the
bladder becomes
full
Examples: Epithelial
• Simple squamous:
lines blood vessels
and lungs
• Allows for increased
blood flow and
increased oxygen
diffusion
Examples: Epithelial
• Stratified squamous:
lines the mouth,
esophagus, cervix
and skin
• Several layers offers
protection to outer
layers and
membranes of body.
Examples: Epithelial
• Simple columnar:
digestive tracts
• Cells mixed with
goblet cells that
secrete mucous to
aid in digestion
Example
Location
Shape (form)
Function
Transitional
epithelium
Bladder
Layer with no specific
shape,
Cells can stretch
Allow bladder to
stretch as it fills
Simple
squamous
Lungs, blood
vessels
Flat and thin layer
Increase flow and
absorption rate
through tubes
Stratified
squamous
Skin,
esophagus,
mouth cervix
Several layers of thin flat
cells
Provide protection
from abrasions
Simple
columnar
Digestive tract
One cell layer of
rectangular cells mixed with
goblet (mucous –
producing) cells
Aid in digestion
with mucous
production
Connective
• Function: Bind and support other
tissues
• Several types:
– Bone
– Blood
– CT proper: dense and loose
– Adipose
– Cartilage
Examples: Connective
• CT proper:
– Loose: ECM
– Dense: tendons and
ligaments
Examples: Connective
• Blood
– To circulate materials
throughout the
organism
– RBC’s: contain
hemoglobin to allow
for oxygen to be
carried to the
tissues.
Examples: Connective
• Cartilage: vary in #
of fibers
– Hyaline: ribs,
trachea
– Elastic: ears, larynx
– Fibro: spinal chord
Examples: Connective
• Adipose tissue:
– Insulation
– Storage
Muscle tissue
• Function: Able to contract for
locomotion.
• Three types: skeletal, cardiac and
smooth
Muscle tissue
• Skeletal:
– voluntary, striated,
multinucleate cells
• Muscles attached to
bones for voluntary
movement
Muscle tissue
• Smooth:
– Non-striated,
spindle-shaped, uninucleate involuntary
cells
• Muscles found in
digestive tract,
respiratory tract, etc.
Muscle tissue
• Cardiac:involuntary,
striated, branched,
uni-nucleate cells
• Only found in the
heart
Nervous tissue
• Function: Respond to
stimuli and transmit impulses.
• Cells are called neurons
• Composed of cell body, axon and
dendrites.
• Single cell may run up to several feet
long.
Test yourself!
• Work with another student (pairs)
• Note the location in the body
• Identify what type of tissue is in the slide
– Connective, epithelial, muscle, nervous
• Describe the structure (squamous, striated,
etc.) and Function (exchange of materials)
• Guess about what disease/injury is shown
• Healthy tissue is on left and
• Diseased/ Damaged tissue is on right.
Healthy
Mystery slide #1 Coronary artery
Diseased
Healthy
Mystery slide #2
Alveoli of lungs
Diseased
Healthy
Mystery slide #3
Alveoli of lungs
Diseased
Healthy
Diseased
Mystery slide #4
You should know this healthy tissue - no hints
Mystery slide #5
Brain
Healthy
Diseased
Mystery slide #6
Lining of the cervix
Healthy
Diseased
Mystery slide #7
Esophagus
Healthy
Diseased
Mystery slide #8
Bone
Healthy
Diseased
Healthy
Mystery slide #9
Mammary gland
Damaged
Mystery slide #10
Lining of the stomach
Healthy
Diseased
Mystery slide #11
You should recognize this healthy tissue too.
Healthy
Damaged
Healthy
Damaged
Mystery slide #12
You should recognize this healthy tissue too.