Tissues of the Human Body
Key Terms
• Histology:
– the study of tissues.
• Tissues:
– groups of cells which are similar in
structure and which perform common or
related functions.
4 primary types of tissues
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Epithelial
Connective
Nervous
Muscle
Epithelial Tissue
• Epithelial Tissue Locations:
– Covers the body
– Lines the cavities, tubes, ducts and blood vessels inside
the body
– Covers the organs inside body cavities
Epithelial Tissue
• Epithelial Tissue Functions:
– Protection from physical & chemical injury,
Epithelial Tissue
• Epithelial Tissue Functions:
– Protection against microbial invasion,
Epithelial Tissue
• Epithelial Tissue Functions:
– Contains receptors which respond to stimuli,
Epithelial Tissue
• Epithelial Tissue Functions:
– Filters, secretes & reabsorbs materials and
– Secretes serous fluids to lubricate structures.
Epithelial
• Fit closely together to form sheets and bound
together by cell junctions
• Have free surface
Epithelial
• Lower surface rests on
basement membrane,
an unstructured
material secreted by
cells
• Avascular and depend
on diffusion from
capillaries in
underlying tissues for
nutrients
Epithelial
• Simple=one layer cells
• Stratified=multiple layers of cells
• Shape= squamous, cuboidal, columnar
Muscle Tissue
• Muscle Tissue:
– Associated with the
bones of the skeleton,
the heart and in the
walls of the hollow
organs of the body.
Muscle Tissue
• Muscle Tissue Functions:
–
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–
–
–
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Movement
Locomotion
Maintains posture
Produces heat
Facial expressions
Pumps blood
Peristalsis
Muscle Tissue Types
• Smooth
• Cardiac
• Skeletal
Smooth Muscle
• Given name
b/c no
stripes
Smooth Muscle
• Have single nucleus and are spindle-like
(pointed ends)
Smooth Muscle
• Found in walls of hollow organs like stomach,
bladder, uterus and blood vessels
Smooth Muscle
• Peristalsis (wave like motion) created to
propel food through digestive tract.
Cardiac
• Found only in heart
• Has stripes (striations)
Cardiac
• Uni-nucleate
• Branching cells that fit together tightly at
intercalated disks (think clasped fingers)
Skeletal
• Controlled voluntarily
Skeletal
• Cells are long and cylindrical
• Multi-nucleate
• Striped (striations)
Connective Tissue
• Connective Tissue:
– Most abundant & widely distributed tissue
Connective Tissue Functions
• Connects, binds and supports structures,
• Tendons, ligaments, etc.
Connective Tissue Functions
• Protects & cushions organs and tissues,
Connective Tissue Functions
• Insulates (fat)
Connective Tissue Functions
• Transports substances (blood).
Connective Tissue
Variations in blood supply
• Well vascularized
• Exceptions: tendons and ligaments have poor
blood supply and cartilage is avascular
Connective Tissue
• Extracellular matrix -varying amounts of
nonliving substances secreted to outside of
cells
Extracellular Matrix
• Produced by the cells involved and then
secreted
• Its what makes the connective tissues
different
Extracellular Matrix
• Composed of nonstructured ground substance
and fibers
Types of Connective Tissue
• Bone
• Cartilage
• Dense fibrous (tendons and ligaments)
Types of Connective Tissue
• Areolar (loose, many fibers)
Types of Connective Tissue
• Adipose (fat tissue)
Types of Connective Tissue
• Reticular: lymph nodes, spleen, and bone
marrow
Types of Connective Tissue
• Blood
Nervous Tissue
• Nervous Tissue:
– Main component of
the nervous system,
i.e., brain, spinal cord &
nerves.
Nervous Tissue Functions
– Regulates & controls body functions
– Generates & transmits nerve impulses
Nervous Tissue Functions
– Supports, insulates and protects impulse
generating neurons.
• Specific tissue types & representative cell types we
will review:
– epithelial
• Squamous
• Cuboidal
• Columnar
– connective
• Adipose
• Bone
• Hyalaine cartilage
– muscle
– nervous
Squamous Epithelium
• Simple – one cell thick
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Forms solid layer of
cells which line blood
vessels, body cavities &
cover organs in body
cavities
Stratified – multiple
layers
Forms epidermis
Cuboidal Epithelium
Cuboid Cells
Duct
Cuboid Cells
Duct
• Simple – one cell thick
• Roughly cube shaped
 Line ducts in kidneys,
etc, where reabsorption
and secretory activities
take place.
Columnar Epithelium
• Simple – one cell thick
• Column shaped (long &
narrow)
• Line digestive tract
where reabsorption &
secretion occurs.

Pseudostratified – gives
the appearance of more
than one layer of
columnar epithelial cells
• Specific Connective Tissue Types:
• Adipose
• Bone
• Hyalaine cartilage
Connective - Adipose
• Honeycomb or
chickenwire appearance
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Stores energy (fat)
Insulates
Supports & protects
organs
Connective - Bone
• Tree ring-like
appearance
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Supports & protects
Mineral storage
Fat storage
Blood cell production
Connective – Hyaline Cartilage
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Supports while
providing flexibility
Absorbs compression
between bones in joints
(articular cartilage)
Holds open respiratory
passages
Most abundant type of
cartilage in body
• Specific Muscle Tissue Types:
– muscle (skeletal)
Muscle - Skeletal
• Muscle fibers (cells)
long, parallel &
cylindrical
• With many nuclei
(multinucleate)
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Striations (cross stripes
run perpendicular to the
cells
Produce voluntary
movement
Locomotion
Heat
Specific Nervous Tissue Types
Nervous – Neuron
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Branching cells with
many long processes
Large central nucleus
Transmit impulses from
one area of the body to
other areas
Regulate activities
through neuron
impulses