Epithelial Tissue

Question 1

list the five functions of epithelial tissue

Answer 1

1. protection of underlying tissue
2. absorption
3. secretion
4. excretion
5. sensation

Question 2

what are the five characteristics of epithelial tissue?

Answer 2

1. distinct cell surfaces
2. mostly comprised of cells
3. covers body surfaces, lines openings, lines inside of body, inside of heart, lungs, and cavities
4. nonvascular
5. capable of regeneration

Question 3

what are the three types of distinct epithelial cell surfaces?

Answer 3

1. apical (free) surfaces
2. lateral surfaces
3. surfaces attached to basement membranes

Question 4

what are apical or free surfaces?

Answer 4

not attached to any other cells

Question 5

what are lateral surfaces?

Answer 5

attached to other epithelial cells

Question 6

what is the basement membrane?

Answer 6

attaches epithelial cells to underlying tissue, produced by epithelium and underlying tissue (usually connective)

Question 7

are there a lot of extracellular components in epithelial tissue?

Answer 7

not really, it is mostly tightly packed cells

Question 8

what are the two ways of classifying epithelial tissue?

Answer 8

1. by arrangement of layers

2. by cell shape

Question 9

list and describe the three categories of epithelial classification based on arrangement of layers?

Answer 9

1. simple: just one layer of cells, nuclei line up
2. pseudostratified: one layer of cells but LOOKS like more than one layer, all cells attached to basement membrane, different heights, always columnar
3. stratified: 2 or more cell layers, nuclei stack up

Question 10

list and describe the three categories of epithelial tissue based on cell shape

Answer 10

1. squamous: very thin and plate-like
2. cuboidal: square-like, all sides fairly even
3. columnar: longer than they are wide

Question 11

describe simple squamous epithelial tissue

Answer 11

thin layer, not adapted to withstand wear and tear

Question 12

where is simple squamous epithelial tissue found?

Answer 12

lining blood vessels, the heart, parietal and visceral pleura and peritoneum, the alveoli of the lungs

Question 13

where is simple cuboidal epithelial tissue found?

Answer 13

in renal tubules, thyroid gland, and ovary surfaces

Question 14

describe the shape and list the two types of simple columnar epithelial tissue

Answer 14

taller than it is wide, ciliated and non ciliated

Question 15

state and describe the specialized cells that are found in simple columnar epithelial tissue

Answer 15

goblet cells: secretes mucus for lubrication/moisture/ maintenance/protective function

Question 16

what are cilia?

Answer 16

hair-like extensions of the apical surface, move particles along in a unidirectional manner in the oviduct and respiratory tract

Question 17

where is simple columnar epithelial tissue found?

Answer 17

in the uterus, oviduct, lining stomach, small and large intestines, and gallbladder

Question 18

where is ciliated pseudostratified columnar epithelial tissue found?

Answer 18

nasal cavity, pahrynx, trachea, and bronchi

Question 19

where is nonciliated pseudostratified columnar epithelial tissue found?

Answer 19

parathryoid

Question 20

is stratified squamous epithelial tissue thick or thin?

Answer 20

it is typically the thickest epithelial layer

Question 21

where is stratified squamous epi tissue found?

Answer 21

lining places open to the outside: epidermis (outer layer) of skin, mouth, esophagus, vagina, anus

Question 22

what is stratified cuboidal and stratified columnar epi associated with?

Answer 22

glands

Question 23

where is stratified cuboidal epi tissue found?

Answer 23

esophageal glands, sweat glands, salivary glands

Question 24

where is stratified columnar epi tissue found?

Answer 24

lining mammary glands, lining glands of pharynx and larynx

Question 25

what is transitional epi tissue?

Answer 25

stratified and highly specialized for stretching and expansion

Question 26

where is transitional epithelium found?

Answer 26

in urinary tract, lining bladder and ureters

Question 27

what two things is glandular epi specialized for?

Answer 27

secretion and excretion

Question 28

define excretion

Answer 28

expulsion of waste products

Question 29

define secretion, give two examples

Answer 29

release of a substance from a cell that has been synthesized by that cell, and the substance typically affects other cells in the body (hormones, mucus)

Question 30

what are the two classifications of glandular epithelium?

Answer 30

endocrine and exocrine

Question 31

define endocrine glandular epi

Answer 31

gland secretes its products into bloodstream for travel around the body

Question 32

define exocrine glandular epi

Answer 32

empty their products onto an epithelial surface (not the bloodstream) via a duct

Question 33

how do goblet cells relate to exocrine glandular epi?

Answer 33

they are unicellular glandular epi, that don't use a duct

Question 34

how do endocrine and exocrine glandular epi develop

Answer 34

the same until the end stages of development

Question 35

how does endocrine glandular epi develop at the end stages?

Answer 35

connection to epithelial surface disappears, must secrete into bloodstream

Question 36

how does exocrine glandular epi develop at the end stages?

Answer 36

connection to epithelial surface remains, forms ducts

Question 37

list the 3 types of exocrine glands as defined by how the products leaves the cell

Answer 37

merocrine, apocrine, holocrine

Question 38

describe merocrine cells, give examples

Answer 38

none of the cell is damaged or lost when the product is secreted or excreted, the most common (salivary glands, pancreas in exocrine fashion)

Question 39

describe apocrine cells, give example

Answer 39

products are released as fragments of gland cells, product accumulates at free end of cell, then pinched off, and any organelles in free end are released, regeneration required (mammary glands)

Question 40

describe holocrine glands, give example

Answer 40

entire cell is lost with product, least common, needs regeneration (sebacious glands of skin and eyes)