epithelial cells and surface specialisations

Question 1

mucous membrane consists of

Answer 1

epithelium lining, lamia propriety which is a connective tissue layer and a layer of smooth muscle called muscularis mucosae

Question 2

serous membranes consist of

Answer 2

a simple squamous epithelium that secretes serum and a thin layer of connective tissue

Question 3

where are serous membranes found

Answer 3

the peritoneum (abdominal organs), the pleural secs (lungs) and the pericardial sacs (heart)

Question 4

what is the parietal and visceral layer of a serous membrane

Answer 4

pariteal=outer edge
visceral= inner edge lining the organ
between this tis the lubricating serous cavity

Question 5

define epithelium

Answer 5

sheets of contiguous cells, of varied embryonic origin that cover the external surface of the body and line internal surfaces including the body vessels

Question 6

where doe the epithelium originate from

Answer 6

ectoderm=epidermis
endoderm= the lining of the GI tract (interior spaces opening to the exterior)
mesoderm= the inner linings of body cavities (interior spaces that don’t open to the exterior)

Question 7

4 types of simple epithelial cell types and draw their structure

Answer 7

squamous
cuboidal
columnar
pseudostratified

Question 8

4 types of stratified cells and draw their structure

Answer 8

squamous
cuboidal
columnar
transitional

Question 9

simple squamous epithelia- where they are found and its function

Answer 9

bowman capsule and its function is to provide fast material exchange and act as a barrier to fluid

Question 10

simple cuboidal function and where they are found

Answer 10

kindney collecting duct- absorption and secretion
thyroid - hormone synthesis, storage and mobilisation. thyroglobulin synthesised and stored at the centre of each focal (calloid)

Question 11

simple columnar function and where its found

Answer 11

in the mucosa of the colon and their function is for the absorption of nutrients

Question 12

what are microvilli

Answer 12

projections from cell which can only be seen under electron microscope which increase the surface area of a cell. DO NOT MOVE

Question 13

pseudostratified function and where its found

Answer 13

have nuclei at different levels so looks like multiple layer but it isn’t. found in the upper respiratory tract and contain goblet cells that secrete mucous and cilia which beat the mucous containing patines away form the lungs.
functions; prevent pathogens entering

Question 14

stratified squamous non keratinised function and where its found

Answer 14

oesophagus and vagina- needed where its moist and they are subject to abrasion. protect against abrasion and reduce water loss but remain moist

Question 15

stratified squamous keratinised function and where its found

Answer 15

keratinised means the have become squames and lost their nuclei. This is found at the epidermis of the skin. more keratinised = tougher the surface. protects against abrasion, protect from water loss, protect against V and prevent pathogens entering

Question 16

what is a melanocyte

Answer 16

produce melanin

Question 17

what is a langerhan cell

Answer 17

act as antigen presenting cells to T lymphocytes. Meditate immune reactions

Question 18

what are keratinocytes

Answer 18

cells that move to surface of skin losing their ability to divide and synthesising keratins which add to the strength of the epidermis. Once reach top are squames

Question 19

transitional function and where its found

Answer 19

found in urinary tract e.g bladder. Have the ability to change shape to extend and retract. and protect from toxic chemicals in urinary tract

Question 20

function of keratin

Answer 20

prevent water loss and prevent against abrasion

Question 21

function of cilia

Answer 21

controls movement of luminal contents

Question 22

goblet cells

Answer 22

secrete mucous by exocytosis to moisten, lubricate and trap pathogens. recognised by lack of cilia on surface

Question 23

Clara cells

Answer 23

act as stem cells for respiratory tract

Question 24

microfoldcells

Answer 24

found in small intestine near lymphatic nodules and trap pathogens and present them to lymphocytes and macrophages. look like mushroom.

Question 25

stereocillia

Answer 25

found in inner ear and responded to fluid motion for hearing and balance (may also be something to do with sperm and its movements

Question 26

cystic fibrosis

Answer 26

when mutation in CTFR gene meaning no chloride ions are related and therefore no water follows meaning mucous is much thicker than it should be

Question 27

renewal rate of airway epithelium from smoking

Answer 27

mucous thickens and cilia die off. Then Clara cells die, cells proliferate and mutations cause cancer. scar tissue layer down when aveoli die. 
trachea- 1-2 month 
alveoli- 8 days 
goblet cells - 10 days 
Clara cell- never

Question 28

name some respiratory related diseases x4

Answer 28

bronchitis- bronchi are inflamed = cough and mucous
emphysema- destruction of air sacs= shortness of breath
COPD (chronic obstructive pulmonary disease) = bot bronchitis and emphysema
asthma- bronchospasm (tightening of smooth muscle layer) = wheezing and shortness of breath