Transcript Epithelial Tissues

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“Epi”= upon
“Pseudo”= false
“Squam” = scale
“Strat”= layer
Simple- one layer
Stratified- multiple layers
Cuboidal- cube shaped
Columnar- rectangle shape- column
Squamous- flat shape
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* a group of cells with specialized functions
Types:
1)
 2)
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Epithelial
Connective
Muscle
Nerve
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Covers all free body surfaces
Characteristics:
Lacks blood vessels, attached to a basement
membrane, replaced continuously
 Functions: protects, secretes, absorbs, excretes
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Simple Squamous- single layer of flat cells
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Found: lungs, lines blood vessels, body cavities
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Simple cuboidal- single layer of cube shaped
cells
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Found: kidneys and other glands
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Simple columnar- single layer of elongated
cells, nucleus is located near bottom of cell
Contains microvilli- helps with absorption
 Contains goblet cells- secretes mucus
 Found: uterus, digestive tract
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Pseudostratified columnar- single layer of cells
that look layered due to nuclei placement
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cilia- to move mucus or sex cells
Found: reproductive system, respiratory system
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Stratified Squamous- many flat layers of cells,
protects
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Found: skin, mouth, throat, vagina, anal canal
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Stratified cuboidal- layers of cube shaped cells,
protects
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Found: mammary glands, sweat glands, salivary
glands, pancreas
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Stratified columnar- top layer is elongated,
bottom layers are cube shaped, protects
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Found: male urethra, pharynx
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Transitional- specialized to change shape under
tension
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Found: Bladder
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General Characteristics:
Support
 Protection
 Fills spaces
 Stores fat
 Produce blood cells
 Protect against infection
 Helps repair damaged tissue
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Cells are separated by matrix (intercellular
material)
Types of cells:
Fibroblasts- produce collagenous and elastic fibers
 Macrophages- are phagocytes (eat other cells and
materials)
 Mast cells- help with blood clotting and immune
response
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Types of fibers in CT:
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Collagenous fibers- thick fibers made of collagen,
grouped in parallel bundles, holds tissues together,
found in tendons
Elastic fibers- thin fibers, stretch easily, build
networks, made of elastin
Reticular fibers- very thin fibers, delicate support
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Forms delicate, thin membranes
Has many fibroblasts
Has a lot of collagenous and elastic fibers
Function: Binds skin to tissue beneath and
provides nourishment to epithelial tissue, fills
space between muscle
Type of loose connective tissue, Fat
 Function- protection, traps heat, and energy
stores in the body
 Found: beneath skin, around vital organs,
around joints.
 Note how nucleus is
pushed to the side.
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Made of tightly packed collagenous fibers
Function: Rigid structure, connects tissues
Found: tendons, ligaments, white of eyes, deep
layer of skin
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Cartilage- rigid yet partially flexible
Function: provides support, protects, forms
structure for developing bones
3 types of Cartilage
Hyaline:
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Fine collagenous fibers, chondrocytes, intercellular
matrix- looks like white plastic
Found : ends of bone in joints, soft part of nose, rings
of respiratory passage
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Elastic cartilage
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Made of dense network of elastic cartilage- flexible
Found: makes framework for ears, and parts of
larynx
Fibrocartilage
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Very tough tissue, contains many collagenous fibers
Shock absorbers
Found between disks in vertebral column
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Osteocytes, Intercellular matrix contains
mineral salts and collagen, which makes bone
rigid and collagen reinforces the mineral
components
Function: structure, protection, provides
framework
Found throughout whole body in Skelton
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Cells suspended in fluid matrix (plasma), red
blood cells, white blood cells, platelets
Blood forms in red marrow of long bones
Function: Transports, helps maintain stable
internal environment
Found: throughout body in blood vessels and
heart chambers
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Characteristics: contract, move structures
attached to them
3 Types:
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Skeletal, Smooth, cardiac
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Structure: Long cells (muscle fibers), striations
Function: attached to bones and helps with
movement, can move by voluntary action
Muscle fibers contract when stimulated by
nerves, then relax immediately.
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Structure: cells lack striations, short, spindle
shaped
Function: muscle that works involuntary,
constricts/ contracts to move things
Found: digestive system, bladder, blood
vessels
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Structure: cells are striated and joined end to
end, has an intercalated disk between muscle
fibers
Function: involuntary contractions in pumping
blood
Found only in heart
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Structure: neuron (basic cell) has axons and
dendrites, neuroglial cells (supports and binds
nervous tissue)
Function: Sensitivity and conduction of nerve
impulses
Found: Brain, spinal cord, peripheral nerves