epithelium

Question 1

What are the 4 types of tissue ?

Answer 1

epitheilium

muscles

connective

nervous

Question 2

what are avascular tissues? (epithelium is avascular )

Answer 2

tissues that do not have blood vessels .

Question 3

how are epithilium tissues supplied with blood if they are avascular?

Answer 3

through the underlying connective tissue .

Question 4

what parts of the body can epithelium cover ?

Answer 4

exterior body surfaces

line internal closed surfaces ( cascular system , pericardial cavity , pleural cavity , peritoneal cavity)

body tubes that communicate with the exterior 9such as gastrointestinal tact , resparatory , and genitourinary tracts )

forms secratory part of glands (glandular epithelium )

specialized epithelial cells functions as receptors for special senses

Question 5

what are the three germ layers that all cells ( including epithelial cells ) are derived from ?

Answer 5

ectoderm : facing the outside of the body

endoderm: facing inside of the body

mesoderm special type of epithelium produced from the mesoderm is endothelial lining of circulatory system and the mesothelium of body cavity

Question 6

what are some structures that are derived from only ectoderm germ layer?

Answer 6

nervous tissue

Question 7

what are some structures derived from only mesoderm germ layer?

Answer 7

muscle ,connective tissue

Question 8

what germ layers is epithelium derived from?

Answer 8

all 3

Question 9

what is the endothelial ?

Answer 9

lining of the circulatory system

Question 10

what is the mesothelial?

Answer 10

lining of the interior body cavity .

Question 11

epithelial cells must have polarity , what does polarity mean .

Answer 11

having apical(apex) , lateral and basal domains that are sometimes associated with specific functions .

Question 12

what are all epithelial cells connected to and where are they in relation to eachother?

Answer 12

all epithelial cells are connected to a basement membrane and are fused together by junctions .

Question 13

what is a tight junction?

Answer 13

complete seal between epithelial cells .

Question 14

what is a adherance junction ?

Answer 14

a typer of cell-cell anchoring that connects the actin of one cell to the actin of another cell ( remember that actin is a microfilament )

Question 15

what are desosome junctions ?

Answer 15

a type of cell-cell junction that connects the intermediate filaments of one cell to another .

Question 16

what are gap junctions ?

Answer 16

junctions that act as channels between cells , transporting small water molecules and ions from one cell top another .

Question 17

what are hemidesmosome junctions ?

Answer 17

junctions that anchor intermediate filaments to extracellular matrix(type of cell-matrix junction )

Question 18

what are actin-matrix junctions

Answer 18

junctions that anchor the actin of the cell to the intracellular matrix

Question 19

what is the basment membrane made of ?

Answer 19

basal lamina (20-100mm)(contains type 4 collagen )

and

reticular lamina (thick , formed by reticular fibers )

Question 20

what is the basal lamina made of?

Answer 20

lamina lucida (clear) 
and 
 lamina densa (contains condensed \_\_)

Question 21

what does the epithelium cover ?

Answer 21

exterior body surfaces

closed cavities

body tubes that communicate with exterior

Question 22

what are the secretory portion of the gland made of ?

Answer 22

epithelial tissue

Question 23

what epithelium is derived from ectoderm germ layer ?

Answer 23

anything facing the exterior environment .

nervous tissue

oral and nasal mucosa , epidermis , glands of the skin and mammary glands

Question 24

what epithelium is derived from endoderm germ layer?

Answer 24

anything facing the interior

lining of respiratory and GIT

Question 25

what epithelium is derived from mesoderm ?

Answer 25

endothelial lining of circulatory system and mesothelium of the body cavity

muscles and connective tissue

Question 26

what are the major characteristics of epithelial tissue

Answer 26

Avascular

have polarity

closely packed

has junctions

basal surface attached to basement membrane

Question 27

actin is microfillament and is 5-7 nm

Answer 27

..

Question 28

what type of collagen is present in basal lamina ‘?

Answer 28

type 4 collagen

Question 29

what is transitional epithelium ?

Answer 29

type of stratified squamous epithelium that can relax and contact depending on the needs of the body . ex: epithelium in bladder is relaxed when bladder is empty but is contracted when it is full of urine

Question 30

where is simple squamous epithelium located and what is its function ?

Answer 30

lungs and blood vessels . it allows materials to pass through by diffusion

Question 31

where is simple cuboidal epithelium present and what is its function ?

Answer 31

in ducts in secretory portions of small glands and kidneys .

its function is to secrete and absorb

Question 32

where is simple columnar epithelium present and what is its function ?

Answer 32

ciliated tissue In the bronchi , uterine tubes and ureters . they are also in the digestive tract .

it absorbs ; it also secretes mucous and enzymes

Question 33

where is pseudostartfied columnar epithelium present and what is its function

Answer 33

lines the trachea and much of the upper respiratory tract . it secretes mucus , ciliated tissue moves mucous ( coughing is a result of this )

Question 34

where is stratified squamous epithelium located and what is its function ?

Answer 34

skin and oral epithelium

protection

Question 35

where is stratified cuboidal epithelium present and what is its function ?

Answer 35

sweat gland , salivary gland , and mammery gland

its is a protective tissue