Epithelial Tissue

Question 1

Function of epithelial tissue

Answer 1

• cover external surface
• lines internal surfaces
• Glands are usually deprived from epithelium

Question 2

Describe features of epithelial tissue

Answer 2

• large sheets of cells

- covers exterior surface and lines organs

Question 3

Location of where epithelial tissue is found

Answer 3

• Lining of GI tract organs (glands)
• lines hollow organs
• skin surface (epidermis)
• airways
• digestive tract
• urinary and reproductive system
• blood vessels
• serous membranes

Question 4

Epithelial characteristics

Answer 4

• highly cellular
• polarity
• supported by connective tissue
• avascular
• innervated
• regeneration

Question 5

Polarity characteristics

Answer 5

• apical facing surface (external)

- basal surface (internal)

Question 6

Apical surface

Answer 6

• contains organelles and extensions

- cilia

Question 7

Basal surface

Answer 7

• contains organelles

Question 8

What is the basement membrane?

Answer 8

• combination of basal and reticular lamina
• connects epithelial tissue with connective tissue
• provides structural and functional support
• reticular lamina is secreted by connective tissue

Question 9

Avascular characteristic

Answer 9

• do not contain blood vessels

- materials that go through epithelial layer must go through diffusion or absorption

Question 10

Innervated characteristic

Answer 10

• supplied by nervous tissue

- allow interactions w/ external environment

Question 11

Regeneration characteristic

Answer 11

• quickly replaces damaged or dead cells

Question 12

key function of epithelial tissue

Answer 12

• first line of protection
• its cells are gatekeepers that control permeability
• everything must cross epithelium

Question 13

Epithelial cells

Answer 13

• secrete and release mucous and specific compounds on apical surface
• mucus can trap material

Question 14

Endocrine glands

Answer 14

• ductless
• releases secretions directing into surrounding tissues and fluid
• “inside”

Question 15

Exocrine glands

Answer 15

• secretions leave through a duct that opens to external environment

Question 16

What are the secretions of endocrine glands? and what happens to them?

Answer 16

• hormones

- released into interstitial fluid, into bloodstream, and delivered to cells

Question 17

examples of endocrine glands

Answer 17

• anterior pituitary
• thymus
• adrenal cortex
• gonads

Question 18

Secretions of exocrine glands, what happens to them?

Answer 18

• mucus
• sweat
• saliva
• breast milk
• they are released onto external environment (Apical surface)

Question 19

Simple epithelium and types

Answer 19

• single layer of cells
• simple squamous
• simple cuboidal
• simple columnar
• pseudostratified columnar

Question 20

Simple Squamous Epithelium

Answer 20

• flat and horizontal

- found in lungs, kidneys, and capillaries

Question 21

Special characteristic of simple squamous

Answer 21

• thin

- allows rapid passage

Question 22

Simple Cuboidal Epithelium

Answer 22

• boxlife cells
• nucleus located near center of cell
• in kidneys and gland ducts

Question 23

Special characteristic of simple cuboidal

Answer 23

• secretion and absorption of molecules

Question 24

Simple Columnar Epithelium

Answer 24

• tall, rectangular
• nucleus located in basal end of cells
• in digestive system and female reproductive tract

Question 25

Ciliated Columnar Epithelium

Answer 25

- composed of simple columnar epithelial cells - cilia on apical surface - in lining of uterine tubes and respiratory system

Question 26

Special characteristic of simple columnar

Answer 26

- absorption and secretion of molecules | - also has ciliated columnar epithelium

Question 27

Pseudostratified columnar epithelium

Answer 27

- looks stratified, but is single layer - different sizes of columnar cells - nuclei at different locations - found in respiratory tract

Question 28

Goblet cell

Answer 28

- mucus secreting unicellular gland | - found btwn columnar epithelial cells of mucous membranes

Question 29

Stratified Epithelium and types

Answer 29

- two or more layers of cells - found where protection against wear and tear is needed - stratified squamous, cuboidal, and columnar - transitional epithelium

Question 30

Stratified Squamous epithelium

Answer 30

- most common in body - apical layer are squamous - basal layer are columnar or cuboidal - top layer filled with dead cells filled w/ keratin

Question 31

Transitional Epithelium

Answer 31

- type of stratified epithelium - shape of apical cells can undergo changes in shape - only found in urinary system (ureters and bladder) - empty = folded, cuboidal apical cells (looks like more layers and thicker) - filled = unfolded, squamous cells