Introduction to Endocrinology

Question 1

Define Endocrinology

Answer 1

The study of hormones (and gland of origin), their receptors, intracellular signalling pathways and associated disease

Question 2

Define Paracrine

Answer 2

Acts on adjacent cells

Question 3

Define Autocrine

Answer 3

Feedback on same cell that secreted hormone

Question 4

What form of Iodotyrosine is most active

Answer 4

T3

Question 5

What are thyroid hormones bound to

Answer 5

TBG (Thyroid-Binding Globulin)

Question 6

Where are thyroid hormones stored

Answer 6

In colloids bound to thyroglobulin

Question 7

How does Dopamine effect the release of prolactin

Answer 7

Inhibits the release of prolactin

Question 8

What would happen to prolactin levels if the infundibulum of the pituitary gland was destroyed

Answer 8

Prolactin levels would increase

Question 9

Does the anterior pituitary gland have an arterial blood supply

Answer 9

Nope

Question 10

Blood supply of the anterior pituitary gland

Answer 10

Hypothalamus-hypophyseal portal veins

Question 11

What is the benefit of the hypothalamus-hypophyseal portal veins

Answer 11

Provides a mechanism for hormones of the hypothalamus to directly alter the activity of cells of the anterior pituitary gland by bypassing circulation

Question 12

What is the benefit of the hypothalamic-pituitary axis

Answer 12

Allows for an amplified response

Question 13

What cells produce FSH and LH

Answer 13

Gonadotrophs

Question 14

What cells produce ACTH

Answer 14

Corticotrophins

Question 15

What cell secrets TSH

Answer 15

Thyrotrophs

Question 16

Where is prolactin produced

Answer 16

Lactotrophs

Question 17

Where is GH produced

Answer 17

Somatotrophs

F: FSH
L: LH
A: ACTH
T: TSH
P: Prolactin 
I: Ignore
G: GH

Question 18

What does FSH and LH target

Answer 18

Gonads

Question 19

What does LH and FSH stimulate together

Answer 19

Germ cell development

Question 20

What does FSH exclusively stimulate

Answer 20

Release of oestrogen

Question 21

What does the release of oestrogen stimulate

Answer 21

Release of LH

Question 22

Role of LH

Answer 22

Stimulates the release of the egg which stimulates progesterone release

Question 23

Role of progesterone

Answer 23

Results in increased thickening of the uterine wall

Question 24

How does LH effect males

Answer 24

On leydig cells - testosterone release

Question 25

How does GH effect an individual

Answer 25

Growth and protein synthesis

Question 26

How does GH effect blood glucose levels

Answer 26

Increases: Causes gluconeogenesis Inhibits Insulin Lipolysis

Question 27

Role of GH on the liver

Answer 27

Increases protein synthesis and stimulates production of IGF-1 which acts on skeletons to increase cartilage proliferation

Question 28

What compound is IGF-1 similar to

Answer 28

Insulin

Question 29

Role of IGF-1

Answer 29

Basically GH's servant. It is produced by liver and stimulates body growth in every cell of the body

Question 30

Where is ACTH produced

Answer 30

Anterior Pituitary Gland

Question 31

Role of ACTH

Answer 31

Stimulates adrenal cortex to secrete cortisol from zona fasiculata , androgens from zona reticular and adrenaline from adrenal medulla

Question 32

Where is dopamine produced

Answer 32

Hypothalamus

Question 33

Does a negative feedback loop exist for prolactin

Answer 33

No, because of the role of Dopamine Prolactin acts on the hypothalamus to cause the release of dopamine

Question 34

What happens when GH binds to the hypothalamus

Answer 34

GH causes secretion of somatostatin which is inhibitory

Question 35

Where is Vasopressin produced

Answer 35

Supraoptic nucleus of the hypothalamus

Question 36

Where is Oxytocin produced

Answer 36

Paraventricular body

Question 37

Describe the pathway of from the supraoptic and paraventricular nuclei

Answer 37

Moves down the infundibulum and terminates in posterior pituitary gland

Question 38

Where are Vasopressin and oxytocin stored

Answer 38

In vesicles and accumulate in axon terminal in the posterior pituitary glands

Question 39

How does ACTH cause fluid retention

Answer 39

ACTH causes release of aldosterone which causes up regulation of Na+/K+ pumps (3 Na out for 2K in)

Question 40

Role of Oxytocin in breast milk

Answer 40

Needed for ejection of milk by myoepithelial cells

Question 41

Role of oxytocin during pregnancy

Answer 41

Stimulates contraction of uterine smooth muscles until baby is born and labour

Question 42

What is the consequence of oxytocin having a short half-life

Answer 42

More has to be produced on a minute-by-minute basis

Question 43

What type of receptors do ALL pituitary and hypothalamic hormones act on

Answer 43

G-protein couples receptors