Beckett lecture: pituitary phgysiology

Question 1

Ventral hypothalamic neurons connect to what portal system?

Answer 1

Primary acpaillary plexus of the hypophyseal portal system

Question 2

Neons from which nuclei supply the neurohypophysis?

Answer 2

Suproptic and Paraventricular

Question 3

Which neutrons synthesis hormones for the post pituitary?

Answer 3

Mangocellular neurons

Question 4

What is the name of the neuronal tract between the hypothalamus and the post pituitary

Answer 4

hypothalamic-hypophyseal tract

Question 5

What 2 hormones are released by the posterior pituitary?

Answer 5

ADH and Oxytocin

Question 6

What cells comprise the posterior pituitary?

Answer 6

Pituicytes (glial-like cells) and magnocllular neurons

Question 7

Where does oxytocin originate?

Answer 7

Paraventricular and supraoptic nuclei

Question 8

What are the functions of oxytocin?

Answer 8

Milk ejection and uterine smooth muscle contraction

Question 9

What receptor does oxytocin act on?

Answer 9

GPCR

Question 10

Where is ADH synthesised?

Answer 10

Mainly in the supraoptic nucleus

Question 11

Name 3 functions of ADH

Answer 11

Reabsorption of water
Increase thirst
Vasoconstriction

Question 12

What activates the cells for eh ant pit?

Answer 12

Rleasing/inhibitory hormones released from the hypothalamus

Question 13

Outline the functions of FSH na LH

Answer 13

FSH: INCRASE Folliculogenesis and oestrogen/ sperm maturation
LH: increase ovulation, oestrogen and testosterone

Question 14

What is the nature of GnRH secretion?

Answer 14

Pulsatile and suppressed by lactation, diet, exercise and stress

Question 15

Which hormone suppresses GnRH

Answer 15

Corticotropin releasing hormone

Question 16

What can cause hyperprolactinaemia?

Answer 16

Prolactinoma and Dopamine antagonists (schizophrenia)

Question 17

What is the affect of prolactin on GnRH and therefore what ais the clinical presentation?

Answer 17

Prolactin inhibits GnRH causes an ovulation and amenoorhaoe in females and infertility in men/reducd libido

Question 18

How can pituitary insufficiency arise?

Answer 18

Pituitary tumour/ destruction pit gland (i.e. inflammation), SAH, radiotheral

Question 19

What are the secretions from the 2layers of the adrenal glands

Answer 19

medulla = catecholamines
Cortex= steroids

Question 20

Illustrate the correlation between site and secretion in the adrenal cortex

Answer 20

Zona reticularis: sex hormones
Zona fascicularis: glucocorticoids
Zone glomerulosa: aldosterone

Question 21

What cells release adrenaline/noradrenaline?

Answer 21

Chromaffin cells

Question 22

Effect of aacatecholamines?

Answer 22

Increase co, cerebral perfusion, pulmonary ventilation

Question 23

What are the effects of cortisol on the immune system, liver uncle and adipose tissue?

Answer 23

Suppression immune, gluconeogenesis in liver, protein catabolism in muscle and lipolysis in the adipose tissue

Question 24

What is the effect of cortisol on insulin?

Answer 24

Antagonist

Question 25

What is the affect of cortisol on the heart?

Answer 25

Increases sensitivity to adrenaline and noradrenaline

Question 26

How does cortisol affect the immune system?

Answer 26

Inhibits prostaglandin and leukotriene synthesis

Question 27

What is the therapeutic utility of cortisol?

Answer 27

Allergies, autoimmune disease

Question 28

How does cortisol levels vary?

Answer 28

In a diurnal variation

Question 29

Two major effects of aldosterone?

Answer 29

Increase K excretion and incase na reabsorption

Question 30

What are the manifestations of adrenocortical hyper secretion?

Answer 30

Cushing's sndreom, hyperaldosteronism, andrenogenital syndrome

Question 31

What can cause cushing's syndrome?

Answer 31

Hypersection of CRH or acth (Pituitary causes = Cushing's disease) Adrenal cortex adenomas Ectopic secretion Glucocorticoi dose

Question 32

Manifestations of cushing's syndrome?

Answer 32

Adrenal diabetes Fat redistribution muscle and bone weakness (breakdown of protein)

Question 33

What is conn's syndrome

Answer 33

Small, aldosterone-secreting tumor of the zona glomerulosa

Question 34

How does conn's syndrome manifest?

Answer 34

Muscle paralysis, hypertension and low plasma rennin

Question 35

What n cause adrenal androgen excess?

Answer 35

Tumours or congenital adrenal hyperplasia