Hypothalamus and Pituitary Hormones

Question 1

What are the alternative names for the anterior and posterior pituitary glands?

Answer 1

Anterior pituitary- adenohypophysis

Posterior pituitary- neurohypophysis

Question 2

What do the following cell types release:
Somatotrophs		
Lactotrophs/ mammotrophs 
Corticotrophs		
Thyrotrophs		
Gonadotrophs

Answer 2

Somatotropin (GH)
Prolactin
Corticotropin (ACTH)
Thyrotropin (TSH)
Gonadotropins (LH, FSH)

Question 3

Which hormones does the anterior pituitary gland release?

Answer 3

Somatotropin (GH), prolactin, corticotropin (ACTH), thyrotropin (TSH), gonadotropins (LH, FSH)

Question 4

What does growth hormone do?

Answer 4

Growth (especially linear growth) and metabolism

Question 5

What does prolactin do?

Answer 5

Lactation, growth and development of breasts, high levels of prolactin inhibit GnRH

Question 6

What is ACTH synthesised from and what does it do?

Answer 6

Synthesised from POMC, stimulates synthesis and release of cortisol

Question 7

What does TSH do?

Answer 7

Stimulates synthesis and release of thyroid hormones

Question 8

What does LH do?

Answer 8

Stimulates Leydig cells in testes to produce testosterone in men, stimulates ovulation/formation of corpus luteum in women

Question 9

What does FSH do?

Answer 9

Stimulates follicular development in ovaries, spermatogenesis in Sertoli cells in testes

Question 10

What are tropic hormones?

Answer 10

Hormones released from hypothalamus and anterior pituitary, affect endocrine glands

Question 11

What are trophic hormones?

Answer 11

Hormones that promote growth and tissue integrity

Question 12

Describe the effect of the release gonadotropin releasing hormone (GnRH)

Answer 12

. Hypothalamus releases GnRH
. Anterior pituitary produces more FSH and LH
. Gonads produce sex hormones (testes produce testosterone, ovaries produce oestrogen)

Question 13

Describe the effect of the release of GHRH and somatostatin

Answer 13

Hypothalamus releases GHRH
Ant pit releases GH
Liver produces IGF-1 (insulin-like growth factor)

Hypothalamus releases somatostatin (GHIH)
Ant pit stops releasing GH
Liver stops producing IGF-1

Question 14

Describe the effect of the release of TRH

Answer 14

Hypothalamus releases TRH
Ant pit releases TSH
Thyroid produces thyroid hormones (T3, T4)

Question 15

Describe the effect of the release of dopamine

Answer 15

Hypothalamus releases dopamine
Inhibits ant pit from releasing prolactin
(Prolactin stimulates breast tissue growth and dev, lactation)

Question 16

Describe the effect of the release of CRH

Answer 16

Hypothalamus releases CRH
Ant pit releases ACTH
Adrenal cortex releases cortisol

Question 17

How are oxytocin and ADH similar in structure?

Answer 17

Both are nonapeptides (9 amino acids)

Question 18

Which factors stimulate the release of ADH?

Answer 18

Decrease in blood pressure, blood volume

Increase in blood osmolality, stress

Question 19

How does ADH act and what is its effect?

Answer 19

Binds to V1 receptors on blood vessels= vasoconstriction
Binds to V2 receptors on kidneys (DCT and CD)= increase permeability (re-absorb more water)
ACTH release

Question 20

Which factors stimulate the release of oxytocin?

Answer 20

Suckling and parturition

Question 21

By which feedback mechanism does oxytocin act?

Answer 21

Positive feedback

Question 22

By which feedback mechanism are the hypothalamus and anterior pituitary inhibited?

Answer 22

Negative feedback

Question 23

Name the 2 gonadotropins

Answer 23

FSH and LH (stimulate gonads)