(Epithelial Tissue) (Pt.1) What is Epithelial tissue

Question 1

What is Epithelial Tissue

Answer 1

• Sheet of cells that cover the body surface or lines a body cavity
• Most substances recieved/given off by the body must past through the epithelial tissue

Question 2

What are the forms of epithelial tissue and define

Answer 2

• Covering and lining epithelium: form outer layer of skin, dips into and lines open cavities of the urogenital, digestive and respiratory system
• glandular epithelium: fashions the glands of the body

Question 3

What are functions of epithelial tissue

Answer 3

• Absorption, Secretion, filtration, sensory reception, and excretion

Question 4

What are special characteristics of epithelial tissue

Answer 4

• Polarity, specialized contacts, regeneration, avascular but innervated, supported by connective tissue

Question 5

Explain the polarity characteristic

Answer 5

Consist of apical surface &

basal surface

Question 6

Explain specialized contact characteristic

Answer 6

• epithelial cells fit closely together to form continuous sheets, except glandular epithelium
• tight junctions and desmosomes tie sides of adjacent cells together

Question 7

Explain the supported by Connective Tissue characteristic

Answer 7

• All epithelial cells rest upon and are supported by connective tissue
• Basement Membrane

Question 8

(Pt of supported by CT, character) What is the basement Membrane/ how many layers does it contain, explain

Answer 8

Basement Membrane:
- reinforces epithelial sheet, help resist stretching/tearing, defines epithelial boundary

consist of two layers
basal lamina:
- large glycoproteins secreted by epithelial cells & fine collagen fibers
-selective filter
- decide who repair wound

reticular lamina:

• deeper than basal lamina
• layer of extracellular material tht have collagen fibers frm underlying CT

Question 9

Explain avascular but innervated characteristic

Answer 9

• Epithelial is avascular meaning it has no blood vessel, but innervated meaning supplied by nerve fibers
• epithelial cells are nourished by substances diffusing frm blood vessels in the underlying CT

Question 10

Explain the Regeneration characteristic

Answer 10

• epithelial is highly regenerative
• if destroyed, they can reproduce themselves
• some cells are exposed to friction & surface cells rub off
• adequate nutrition = replacement (cell division)

Question 11

Explain the Apical Surface (Polarity, character)

Answer 11

• not touching any surrounding tissue
• exposed to either outside of body or cavity of internal organ
• surface is smooth slick, but most have microvilli

Question 12

Explain the basal surface (Polarity, character)

Answer 12

• adjacent to basal lamina

- attached to underlying Connective Tissue