hypothalamus and pituitary

Question 1

what is the pituitary gland is composed of?

Answer 1

anterior pituitary and posterior pituitary

Question 2

where is vasopressin/ADH produced?

Answer 2

supraoptic nuclei of the hypothalamus

Question 3

where is oxytocin produced?

Answer 3

magnocellular neurones of the PVN in the hypothalamus

Question 4

what do the parvocellular neurones of PVN produce?

Answer 4

many releasing hormones such as gonadotropin releasing hormone (GnRH), growth hormone releasing hormone (GHRH), corticotropin releasing hormone (CRH), thyroid releasing hormone (TRH), dopamine and somatostatin

Question 5

what do herring bodies do?

Answer 5

store vasopressin and oxytocin in posterior pituitary

Question 6

what does the hypothalamic- hypophyseal portal system ensure?

Answer 6

that hypothalamic hormones reach endocrine cells of anterior pituitary with very little delay

Question 7

what does the small blood flow in portal veins allow?

Answer 7

very small amounts of hypothalamic hormones from relatively few hypothalamic neurones to control secretion of anterior pituitary hormones without causing dilution in general circulation

Question 8

what hormone does dopamine inhibit?

Answer 8

prolactin

Question 9

what is the target organ of adrenocorticotropic hormone (ACTH)?

Answer 9

adrenal cortex

Question 10

what hormone do somatotrophs produce?

Answer 10

growth hormone

Question 11

what hormone inhibits growth hormone?

Answer 11

somatostatin

Question 12

which is the most abundant anterior pituitary hormone?

Answer 12

growth hormone

Question 13

what is the relationship between growth hormone levels and blood glucose levels?

Answer 13

increased blood glucose, decreased GH levels

Question 14

what is involved in negative feedback of GH?

Answer 14

IGF-1 produced by liver in response to GH feedbacks to hypothalamus and anterior pituitary to shut off stimulus

Question 15

what enhances growth hormone secretion?

Answer 15

1. sleep
2. exercise
3. fasting (postprandial hypoglycaemia)
4. increase in amino acids
5. stress

Question 16

what pathways do growth hormone receptor binding activate?

Answer 16

JAK2 and Src pathways

Question 17

what kind of tissue is the anterior pituitary composed of?

Answer 17

glandular tissue

Question 18

what kind of tissue is the posterior pituitary composed of?

Answer 18

neural tissue

Question 19

where is the pituitary gland located?

Answer 19

1. base of hypothalamus, sitting in sella turcica of sphenoid bone
2. between cavernous sinuses

Question 20

what are the 3 main cell types of the anterior pituitary?

Answer 20

1. chromophobes (clear)
2. chromophils (50%)
   - acidophils (lightly stained) - 40%
   - basophils (darkly stained) - 10%

Question 21

what is the embryological origin of anterior pituitary?

Answer 21

oral ectoderm

Question 22

what is the embryological origin of posterior pituitary?

Answer 22

nervous tissue from diencephalon from developing CNS

Question 23

what are the other names for anterior pituitary?

Answer 23

pars distalis, adenohypophysis

Question 24

what are the other names for posterior pituitary?

Answer 24

pars nervosa, neurohypophysis

Question 25

which pituitary hormones share a common alpha-subunit?

Answer 25

FSH, LH, TSH