Adrenal Cortex

Question 1

Control of GC secr

Answer 1

Hypot - CRH prod by neurones with cell bodies in the PVN
CRH axons terminate at median eminence. Pulsatile secr incr cause incr acth secr
Pit - acth released in resp to CRH by corticotrophs in ant pit
Adr- GC synth and secr by adr cortex cells in resp to acth

Question 2

GC -ve feedback

Answer 2

Most key on ant pit and hypot
Ant pit decr stim effect of CRH and so acth synth
Hypot inhib CRH release

Question 3

Prenatal GC rec

Answer 3

Expression in limbic system set early in life and permenantly modulate level of feedback

Question 4

Diurnal rhythms

Answer 4

Human and dog peak early am

Car early evening

Question 5

Corticosteroid binding globulin role

Answer 5

Aka transcortin
10% GC free 15 bound to albumjn 85 to CBG
Synthed by progesteron and oestrogen
Half life of 70min
Gc bind decr GC metab clearance rate by liver (bound means not bio active)
CBG act as buffer to prev GC fluctuation

Question 6

GC rec

Answer 6

T1 mineralocorticoid rec (aldosterone only work on this)

T2 glucocorticoid rec

Question 7

11B-HSD enz 2

Answer 7

Inact cortisol by oxidising to cortisone so prev MR activation

Question 8

11B-HSD enz 1

Answer 8

Reduce cortisone to cortisol and activate GCR expressed in metab tissues eg liver and adipose

Question 9

Acute GC resp

Answer 9

Promote recovery to normal
Incr gng
Incr escape behav and foraging for food
Suppress repro behav

Question 10

Chronic GC resp

Answer 10

Inhib repro and imm sust
Incr glycogen synth
Promote severe pro loss and neuronal cell death
Disrupt 2nd messenger systems
Suppress growth

Question 11

GC metab effects

Answer 11

When fasted incr and maintain normal blood gluc
Stim liver gng (gluc from aa and lipid)
Mobilise aa (incr proteolysis and block synth by extrahepatic tissue)
Inhib gluc uptake in m and adip tissue
Stim fat BD (FA use in m for E glycerol gng substrate

Question 12

Metab effects lead to chronic

Answer 12

M wasting
Incr CT fragility
Incr glycogen synth
Incr abdominal fat depos

Question 13

Bone effect

Answer 13

Resorp

Decr matrix synth and intest ca abs

Question 14

Kid effects

Answer 14

Req for normal resp to degyd and water loading

Na and k homeostasis

Question 15

Inflam and imm syst effects

Answer 15

Potent anti inflamm and imm suppr

Gen imm resp decr and incr infection risk

Question 16

Vasc effects

Answer 16

Req for normal BP maint
Art vasoconstr tone
Cap mem v leaky with out cortisol

Question 17

M effects

Answer 17

Cardiac m synth of B recskel m contractility decr without GC

Question 18

CNS effects

Answer 18

Inhib growth in immature animals
Incr Gc cause impaired memory and mood swings
Chronic incr cause incr appetite

Question 19

Repro effects

Answer 19

Delay puberty

Suppress repro/ovulation in F

Question 20

Tissue dam effects

Answer 20

Improve cell and IC mem stability

Question 21

Foetal effects

Answer 21

Prom lung maturationa dn incr lung surfactant prod necessary for after birth

Question 22

Integrated med and cortex stress resp

Answer 22

GC NA and adr incr gluc supply by liver, plasma gluc level and BP and improve CO
GC favour glycogen synth
Adr favour glycogenolysis

Question 23

Loss of GC secr

Answer 23

State of deranged metab

Inablility to deal with stressors

Question 24

Synthetic gC

Answer 24

Only act on GCR

40x potency of cortisol

Question 25

Cushings/hyperadrenocorticism acth dep

Answer 25

Incr acth secr by pit aka pit dep | Often excess acth cause cortical hyperplasia

Question 26

Cushings/hyperadrenocorticism acth indep

Answer 26

Due to adr gland defect Rare Aka adr dep

Question 27

Cushings/hyperadrenocorticism symptoms

Answer 27

``` Poly uria dipsia phagia Hypertension Central obesity Thin skin Bilat symmetrical alopecia Loss of tissue pro Immsuppre ```

Question 28

Cushings/hyperadrenocorticism PPID in horses

Answer 28

Adenoma/hypertrophy of PI Secondarg to loss of dopaminergic inhib of PI Have curly long coat that wont shed

Question 29

Cushings/hyperadrenocorticism PPID in horses mech

Answer 29

Hypertrophy and plasia of melanotroph cause incr pomc synth so incr acth amsh clip bend Msh and bens incr steroidofenic acth properties cause incr Gc prod and loss of circadian pattern Melanotrophs insens to Gcs so no feedback

Question 30

Addisons/ hypoadrenocorticism

Answer 30

Too little gc prod often with aldost deficit Due to infectious dis or autoimm destruction of adr cortex Haemorrhage or tumour Symptoms Cv dis fatigue lethargy weakness hypoglyc hyponatraemia Weight loss

Question 31

Stress effect on appetite

Answer 31

Acute cause appetite decr Chronic cause incr GC drive hedonic resp (desire and satisfaction from sweet/high fat food) cause intra abd fat send signal adiposity to brain to try to decr chronic stress via leptin

Question 32

Stress and depression

Answer 32

resp to inescapable stress Anxiety and give up Red GCR expression on hippocamp and incr CRH release cause anxiety disorder Also decr serotonin and NA activity in limbic syst

Question 33

Maternal stress/poor qual intrauterine enviro

Answer 33

Decr borth weight incr hPA axis activity incr obesity risk diabetes mellitus type 2 CV disease depression decr life expectancy

Question 34

Poor qual mothering or prolonged separation

Answer 34

More responsive to stress and offspring become poorer mothers