Lecture 5 - Epithelial Tissue

Question 1

where are epithelial tissue derived from

Answer 1

all three germ layers

Question 2

where is the epidermis derived from

Answer 2

ectoderm

Question 3

where is the lining of the GI tract and respiratory tract derived from

Answer 3

the endoderm

Question 4

where is the endothelium and mesothelium derived from

Answer 4

the mesoderm

Question 5

endothelium definition

Answer 5

lining of blood vessels, derived from mesoderm

Question 6

mesothelium definition

Answer 6

lining of pericardial and thoracic cavities, derived from mesoderm

Question 7

two types of epithelial tissue

Answer 7

membranous epithelia

glandular epithelia

Question 8

membranous epithelia

Answer 8

sheetlike tissues that cover or line surfaces, cavities and organs of the body

Question 9

glandular epithelia

Answer 9

perform secretory functions

Question 10

what do epithelial tissues cover

Answer 10

tubes (digestive and cardio tracts), cavities (thoracic), and all body surfaces (skin)

Question 11

functions of epithelial tissue (5)

Answer 11

protection and containment (skin)
absorption (intestines)
secretion (glands)
sensation (neuroepithelium) 
contractility (myoepithelium)

Question 12

characteristic of epithelial tissue

Answer 12

1. cells closely bound together by membrane specializations (junctions), form continuous sheets
2. supported by basement membrane (seperated from underlying supporting tissue)
3. Not penetrated by blood vessels (avascular)
4. Polar

Question 13

simple epithelial tissue

Answer 13

on a surface or facing a lumen 
single layer 
places where diffusion, absorption, or secretion occur 
squamous, cuboidal, or columnar 
have cilia or microvilli

Question 14

simple squamous

Answer 14

flat cells (scales)
diffusion of fluids or gas (very thin)

Question 15

location of simple squamous

Answer 15

lungs, blood and lymphatic vessels, cavities (pleural, peritoneal, pericardial)

Question 16

simple cuboidal

Answer 16

as tall as they are wide with prominent nucleus

excretion, secretion, absorption

Question 17

location of simple cuboidal

Answer 17

ducts of kidney, thyroid gland, salivary gland

Question 18

simple columnar

Answer 18

cells taller, eliptical nucleus located basally 
function in absorption

Question 19

location of simple columnar

Answer 19

intestines

Question 20

simple columnar ciliated

Answer 20

cilia at apical surface
propel ovum over cell surface to uterus
in the oviduct and respiratory tract

Question 21

pseudostratified columnar ciliated

Answer 21

nuclei at different positions but only one real layer
propel mucuous and entrapped particles
in trachea
Sometimes lymphocytes will have infiltrated

Question 22

stratified

Answer 22

two or more layers
protective function
classification is based on shape of cell at surface

Question 23

stratified squamous

Answer 23

top layer flattened
withstand chronic abrasion
in oral cavity, esophagus, cervix, vagina

Question 24

stratified squamous keratinized

Answer 24

surface layer of keratin, withstand chronic abrasion, epithelial surface of skin (epidermis)

Question 25

stratified cuboidal

Answer 25

1-2 layers of cuboidal provide thicker lining larger excretory ducts of exocrine glands (ex: salivary glands)

Question 26

transitional epithelium

Answer 26

many layers of cells, top is round and pillowed withstand toxicity of urine and accommodate stretch in urinary tract

Question 27

where are binucleated cells found

Answer 27

surface of transitional epithelium

Question 28

glandular epithelium

Answer 28

invagination of epithelial surfaces, formed during embryonic development, proliferation of epithelial cells into underlying connective tissue *NOBODY KNOWS TRIGGER*

Question 29

exocrine gland

Answer 29

maintain continuity with epithelial surface, discharge secretions via ducts

Question 30

endocrine gland

Answer 30

degenration of duct leaving islands of epithelial tissue, secretory products go right into blood

Question 31

modes of exocrine secretion

Answer 31

1. merocrine, most common, no loss of membrane (ex: goblet cell) 2. apocrine - secretory product in vesicles (ex: mammary gland) 3. holocrine - whole cell broken for discharge of products (ex: sebaceous gland)

Question 32

secretion into lumen is through what layer

Answer 32

apical (exocrine)

Question 33

secretion into blood vessel is through what layer

Answer 33

basal (endocrine)

Question 34

goblet cell is what type of gland

Answer 34

unicellular

Question 35

goblet cells use what type of secretion

Answer 35

merocrine

Question 36

synthesis of mucigen

Answer 36

protein component in RER, goes to golgi where a carb gets attached

Question 37

release of mucigen

Answer 37

secreted at steady basal rate, local irritation will cause release of entire mucigen content

Question 38

function of goblet cells

Answer 38

in upper GI tract, provide protection coat against autodigestion in lower GI tract, provide lubrication in respiratory tract, prevent drying and helps humidify inspired air and act as sticky surface to trap dust and microorganisms so they don't go to lungs