Adrenal Gland

Question 1

Stress

Answer 1

Reaction of an organism to a threatening situation

Real or perceived disruption of homeostasis

Question 2

Stress resp

Answer 2

Resp is a combo of autonom NS and neuroendo
Symp NS, adr medulla, ant pit - adr cortex axis
Optimise survival chance
CNS centres coord and integrate (hindbrain hypot limbic)
Vol or invol

Question 3

Stressors

Answer 3

Physical or emotional
Social
Fear or novelty
Infection
Phys injury or restriction
Internal disturbance

Question 4

Invol stress resp

Answer 4

Similar regardless of stressor
Last longer
More intense with incr stress

Question 5

Hs used

Answer 5

Catechols NA and adr from adr medulla contolled by symp nn

GCs cortisol from adr cortex controlled by acth from ant pit corticotrophs

Question 6

Synth GC use

Answer 6

Allow patient to survive stress or suppress fatal imm over recation

Question 7

Synth catechol use

Answer 7

Help critical patients maintain BP

Question 8

Adr gland loc

Answer 8

Beneath peritoneum
Surrounded by adr capsule
Substatial blood supply and drainage so h secr into blood with rapid distrib

Question 9

Blood supply

Answer 9

Suprarenal aa supply adr gland
Cortical aa and arterioles branch into cap beds within cortex that coalesce into vv at the corticomedullary jctn
Medullary aa and arterioles penetrate cortex without branching and form capillary beds within the medulla

Question 10

Blood drainage

Answer 10

Cortico and med vv empty through 1 large central v leave adr and anastomoses with vc or renal v
Cortex has no vv so must deain through medulla so secr from cortex can influence medulla

Question 11

Gland org

Answer 11

Cortex from mesoderm
Med from neural crest (ectoderm)
Avian has med islands
Amphib and some fish have sep

Question 12

Zona glom

Answer 12

Outermost layer
Thun
Rum cells in clusters
Carn horse and pig in columnar arches aka zona arcuata. Prod aldosterone
Stim by AII and incr K plasma

Question 13

Zona intermedia

Answer 13

Vv thin
Cont mostly undiff cells
2nd layer in

Question 14

Zona fasciculata

Answer 14

Thick
Large round foamy appearing cells in cords radiate from zg to med
Foamy as lipid droplets (chol) as precursor for most steroid hs
Prod GCs
Stim by acth

Question 15

Zona reticularis

Answer 15

Thin
Network of cords but no longer parallel
Prod androgens/ss

Question 16

Medulla cell content

Answer 16

Chromaffin cells most abundant - columnar basophilic granular cyt due to h cont granules
Areanged in clusters round med vv
Richly innerv by pre gang symp with small no of symp ganglion cells
Gang cells- round or polygonal with prominent nuclei

Question 17

NA/adr balance of medulla

Answer 17

Foetal mostly NA, adult mostly adr
Each chromaffin cell only prod 1 h stored in e- dense granules
NA cont- more e- dense smaller more centrally loc
Adr- opposite

Question 18

Catechol ratio in species

Answer 18

Most mammals have more adr

Question 19

Catechol synth and control

Answer 19

Synth with tyrosine take. Up by chrom cells
Adr cortical activity enhance synth
Control pts:
Tyrosine hydroxylase enz
PNMT enz

Question 20

a1 rec

Answer 20

Adr stim
NA v stim
Cause gut and skin arteriolar and veno constriction

Question 21

a2 rec

Answer 21

Stim adr
V stim NA
Activate ventr of heart
Large incr in heart contractility

Question 22

B1 rec

Answer 22

Adr v stim
NA stim
Activ of renin release cause incr agiotensin cause more vasoconstr

Question 23

B2 recs

Answer 23

Adr c stim
NA not
Striated m vasodil
Large blood shift to mm coronary a and brain

Question 24

Adr blood flow change

Answer 24

Incr to liver esp, skel m and a bit to brain

Decr to kid

Question 25

NA blood flow change

Answer 25

Decr to kid and brain | No effect on skel m and liver

Question 26

Carechol secr

Answer 26

Stim by Ach release from pregang symp fibres innerv med Granules release by exocyt Post secr into blood carried by albumin and other pros and bind adrenergic rec with same effect as direct symp NS stim

Question 27

Cause of sympathomedullary act

Answer 27

Higher centres | Eg limbic and hypot

Question 28

CV effects

Answer 28

Incr rate and force of contr of heart m mainly adr on B2 | Constr blood vessels NA cause widespread so incr BP

Question 29

Metab effects

Answer 29

Incr BMR Stim lipolysis in adupocytes Basically incr blood gluc Usually B rec so adr more effective

Question 30

Other effects

Answer 30

Dilate bronchioles and pupils | Inhib non essential processes

Question 31

Liver effects

Answer 31

Incr glycogenolysis via B2 | Gng incr via a

Question 32

Muscle effects

Answer 32

Incr glycogenolysis to give gluc for E prod

Question 33

Adipose effects

Answer 33

Lipolysis in adupocytes by lipase cause incr FFA aid conserv of gluc

Question 34

Endo effects

Answer 34

Block release and periph effects of insulin Incr efficiency of gluc circ and preserve for brain Adr incr BMR so incr heat gen Most metab effects insep from adrenocortical hs

Question 35

Cortex h fxs

Answer 35

GC gluc reg and stress resp MC mineral balance and BP reg SS many fx

Question 36

Adr h prod

Answer 36

From chol from series of enz mediated conversions only in adr cortex Differ due to side chain struct and other changes

Question 37

Steroid prod control pt

Answer 37

Rate lting step is chol to pregnenolone via enz 20,22 desmolose Step is activated by acth

Question 38

Aldosterone fx

Answer 38

Incr Na and water reabs and k secr in DCT and CD so incr BP

Question 39

Conns syndrome

Answer 39

Incr aldosterone prod due to thmour of adr cortex cause hypertension hypokal metab alkalosis (as incr H secr due to H/K pump action)

Question 40

Adr androgens

Answer 40

DHEA and androstenedione have weak adrenergic activity and are of little signif in M as in testis convert to testosterone (more potent) In F cortex is main source

Question 41

Adr oestrogen

Answer 41

Androstendione converted to oestrogen via aromatase | Cortex main source in M and post menopausal F

Question 42

GC in rodents and birds

Answer 42

Corticosterone main one secr formed from pregnenolone too