epithelia and connective tissues

Question 1

function of epithelia

Answer 1

have a free surface. -protect underlying tissues from the outside world

• protects/separates areas within the body.
• help told tissues together
• thermoregulation
• hormone release
• absorption

Question 2

epithelia

Answer 2

on surface

Question 3

endothelium

Answer 3

lining blood vessels

Question 4

mesothelium

Answer 4

lining body cavities

Question 5

simple

Answer 5

1 layer

Question 6

squamous

Answer 6

flat

to exchange functions eg alveoli, capillaries

Question 7

cuboidal

Answer 7

cube

for absorption and secretion eg, renal tubed, secretory glands

Question 8

columnar

Answer 8

taller than wide
large intracellular volume
potential for energy reserves and high organelle density.
motility, absorption and processing.
small intestine

Question 9

stratified

Answer 9

many layers

Question 10

pseudostratified

Answer 10

looks stratified but all cells connect to the basement membrane
respiratory tract

Question 11

transitional

Answer 11

many layers
waterproof and stretchy
bladder, urinary tract

Question 12

the basement membrane

Answer 12

sheets of matrix at interface of functional tissue [epithelium] and support tissue [connective tissue]. composed mainly of type IV collagen, glycoproteins and glycosaminoglycans

Question 13

structure of glands and ducts

Answer 13

epithelium folds and glands enable increased secretion. generally the secretory portion is columnar. ducts are cuboidal epithelium.

Question 14

epidermolysis bullosa

Answer 14

separation of epidermis and dermis- causes blistering

Question 15

carcinomas

Answer 15

cancers derived from epithelial cells

Question 16

adenocarcinoma

Answer 16

cancer in the glands

Question 17

exocrine glands

Answer 17

secrete their products onto the epithelial surface directly/ via a duct for local action eg, sweat glands, liver

Question 18

endocrine glands

Answer 18

release their secretions directly into the blood to act on different tissues eg, pituitary and thyroid glands

Question 19

connective tissue

Answer 19

the support tissue of the body. originated from embryonic mesoderm. abundance of matrix with few cells- cells[5%] and extracellular matrix [95%]- ECM

Question 20

what is the extracellular matrix composed of?

Answer 20

fibres (collagen and elastin), ground substance [glycoproteins ad glycosaminoglycans), cells- the fibroblast secretes ECM for most tissues.

Question 21

collagen

Answer 21

1) Procollagen- polypeptide chain synthesized on ribosome of rER and secreted into lumen, then modified by hydroxylation of certain proline and lysine residues and glycosylation before chain association and triple helix formation
2) Procollagen molecules secreted into extracellular space where the N and C propeptides are cleaved by specific proteases
3) The collagen molecules assemble into fibrils, stabilized by formation of covalent crosslinks.

Question 22

elhers danlos syndrome

Answer 22

type 1 collagen disorder- reduced tensile strength- tissue laxity, joint hypermobility and susceptibility to injury

Question 23

reticulin

Answer 23

type 3 collagen, branched

Question 24

elastin

Answer 24

provides elasticity. stretching and elastic recoil. Tropoelastin polymerises to elastin. requires fibrillin for assembly

Question 25

marfans syndrome

Answer 25

genes coding for fibrillin are defective- rupture of the aorta

Question 26

structural glycoproteins

Answer 26

• fibrillin- microfibrils-links to elastin.
• fibronectin- deposition and orientation of collagen and its links to cells via integrin.
• Laminin- major component of the basement membrane

Question 27

glycosaminoglycans

Answer 27

polysaccharide chain that attracts water