Endocrine - Physiology

Question 1

Hormone Structure:

Which amino acid derivatives are derivatives of tyrosine?

Answer 1

Adrenaline
Noradrenaline
Dopamine
Thyroid hormones

Question 2

Hormone Structure:

Which amino acid derivatives are derivatives of tryptophan?

Answer 2

Melatonin

Question 3

Hormones:

Which SHORT polypeptides does the pituitary make?

Answer 3

ACTH, GH and PRL

Question 4

Hormones:

Which LONG polypeptides does the pituitary make?

Answer 4

TSH, LH, FSH

Question 5

Hormones:

Which SHORT polypeptides does the hypothalamus make?

Answer 5

ADH, Oxytocin, regulatory hormones

Question 6

Hormones:

Which SHORT polypeptides does the pancreas make?

Answer 6

Insulin and glucagon

Question 7

Hormones:

Which SHORT polypeptides does the parathyroid make?

Answer 7

PTH

Question 8

Hormones:

Which SHORT polypeptides does the C-cells of Thyroid make?

Answer 8

Calcitonin

Question 9

Hormones:

Which SHORT polypeptides does the heart make?

Answer 9

ANP and BNP

Question 10

Hormones:

Which SHORT polypeptides does the adipose make?

Answer 10

Leptin and resistin

Question 11

Hormones:

Which LONG polypeptides does the kidney make?

Answer 11

EPO

Question 12

Hormones:

Which LONG polypeptides does the reproductive system make?

Answer 12

Inhibin

Question 13

Second Messengers: cAMP

How is cAMP activated?

Answer 13

Hormone binding to its receptor activates G PROTEIN
G Protein then activates ADENYLYL CYCLASE
Adenylyl cyclase then converts ATP to cAMP

Question 14

Second Messengers: cAMP

What does cAMP do?

Answer 14

cAMP then activates kinase which phosphorylates

Question 15

Second Messengers: cAMP

What does phosphodiesterase (PDE) do?

Answer 15

Phosphodiesterase (PDE) is also activated by G PROTEIN and reduces cAMP to AMP

Question 16

Second Messengers: cGMP

How is cGMP activated?

Answer 16

GUANYLYL CYCLASE converts to GTP to cGMP in response to NITRIC OXIDE

Question 17

Second Messengers: cGMP

What does cGMP do?

Answer 17

cGMP exerts effects by stimulating PKG (Protein Kinase G)

Question 18

Second Messengers: Phospholipid Derived

How is Phospholipase C (PLC) activated?

Answer 18

Hormone binds to its receptor to activate G PROTEIN which then activates PHOSPHOLIPASE C (PLC)

Question 19

Second Messengers: PLC

What does PLC (Phospholipase C) do?

Answer 19

PLC hydrolyses PIP2 in membrane into DAG and IP3

Question 20

Second Messengers:

What does DAG do?

Answer 20

DAG = diacylglycerol

Increases affinity of protein kinase C for calcium

Question 21

Second Messengers:

What does IP3 do?

Answer 21

IP3 = inositol triphosphate

Binds to endoplasmic reticulum to trigger release of calcium

Question 22

What does calmodulin do?

Answer 22

Calmodulin binds to calcium (acting as a second messenger) then activates enzymes (ie smooth muscle contraction via alpha 1 receptors)

Question 23

How do G Protein Coupled Receptors work?

Answer 23

Composed of alpha and beta subunits.

Alpha subunit binds to GTP and hydrolyses to GDP then mediates signals via second messenger systems

Question 24

How do Tyrosine Kinase Receptors work?

Name some examples

Answer 24

For signals from insulin and growth factors

After ligand binding the receptor autophosphorylates to interact with intercellular adaptor proteins

ie: insulin receptor activates Raf-Ras-MAPK and the Akt/protein kinase B pathway

Question 25

How do Cytokine receptors work? | Name some examples

Answer 25

After ligand binding the receptor activates intracellular kinases. ie Janus kinases (JAKs) STAT family Ras

Question 26

How do Serine Kinase Receptors work?

Answer 26

Mediate action of activins, transforming growth factor beta, and mullerian inhibiting substance and bone morphogenic proteins Signal via "smad" proteins

Question 27

Where is the hypothalamus located?

Answer 27

Located ventral part of the diencephalon on either side of the 3rd ventricle extending from the optic chiasm to the mamillary bodies

Question 28

What nuclei are in the supraoptic region of the hypothalamus?

Answer 28

Supraoptic nucleus | Paraventricular nucleus

Question 29

What do BOTH the nuclei in the supraoptic region of the hypothalamus secrete?

Answer 29

The supraoptic nucleus and paraventricular nucleus secrete ADH and Oxytocin down the infundibulum to the POSTERIOR pituitary

Question 30

Paraventricular nucleus secretes WHAT in addition to ADH and oxytoxin?

Answer 30

The paraventricular nucleus of the supraoptic region secretes CRH into the portal system to the ANTERIOR pituitary

Question 31

What nuclei are in the TUBERAL region of the hypothalamus?

Answer 31

The MEDIAL section: - ventromedial nucleus - arcuate nucleus The LATERAL section

Question 32

What is the role of the ventromedial nucleus?

Answer 32

The ventromedial nucleus of the hypothalamus = "Satiety Centre" - control of eating - Irritability and aggression

Question 33

A lesion in the ventromedial nucleus of the hypothalamus will result in what?

Answer 33

Overeating

Question 34

What is the role of the arcuate nucleus?

Answer 34

The arcuate nucleus of the hypothalamus = "infundibular/periventricular nucleus" - secrete releasing hormones: CRH, GHRH, GNRH, TSH

Question 35

What is the role of the lateral hypothalamic area?

Answer 35

= "Feeding Centre" | - control of eating

Question 36

A lesion in the lateral hypothalamic area of the hypothalamus will result in what?

Answer 36

Anorexia

Question 37

What is the role of the mamillary region of the hypothalamus?

Answer 37

Contains the 'Posterior Hypothalamic Nucleus' = Thermoregulatory centre Contains the Mamillary Nuclei = Memory Centre

Question 38

What is the memory centre?

Answer 38

Mamillary nuclei

Question 39

Where is the Thermoregulatory Centre?

Answer 39

Mamillary region posterior hypothalamic nucleus

Question 40

A lesion in the ANTERIOR posterior hypothalamic nucleus results in what?

Answer 40

Hyperthermia

Question 41

A lesion in POSTERIOR posterior hypothalamic nucleus results in what?

Answer 41

Hypothermia