Review Session "Must Knows" Flashcards Preview

FHB - Endocrinology (by Richie) > Review Session "Must Knows" > Flashcards

Flashcards in Review Session "Must Knows" Deck (107)
1

TH functions like

steroid hormone

2

Steroid hormones act via

transcriptional effects

3

GHRH produced in what nuclei?

Arcuate nucleus

4

GnRH produced in what nuclei?

POA

5

CRH produced in what nuclei?

PVN (parvocellular division)

6

TRH produced in what nuclei?

PVN

7

Somatostatin produced in what nuclei?

PeVN

8

Name 2 hypothalamic releasing hormones manufactured in the PVN

CRH and TRH

9

Does prolactin have a hypothalamic releasing factor?

No. It's under tonic inhibitory control of dopamine.

10

Under pathological conditions, excessive TRH can stimulate

Prolactin

11

Prolactin is a potent inhibitor of

GnRH

12

SS inhibits GH release at the

anterior pituitary

13

SS inhibits GHRH pulsatility at the

hypothalamus

14

Name 2 hormones produced by acidophiles

Prolactin, Growth Hormone

15

Name 4 hormones produced by basophiles

FSH
LH
ACTH
TSH

16

AVP-secreting magnocellular neurons are derived from what brain nuclei?

SON and PVN

17

AVP-secreting parvocellular neurons are derived from what brain nucleus?

PVN

18

What are the two divisions of the PVN?

Magnocellular and parvocellular

19

AVP-secreting magnocellular neurons regulate

Water balance

20

AVP-secreting parvocellular neurons regulate

stress

21

What happens to the zona fasciulata under exogenous corticosteroid treatment (long-term)

atrophy

22

What's the precursor gene for ACTH and alpha-MSH

POMC

23

Small cell lung carcinomas can secrete

excess ACTH

24

Kd refers to hormone affinity or specificity to receptor?

Affinity

25

Receptor kinases versus receptor linked kinases

Receptor kinases have intrinsic kinase activity; linked don't.

26

Name hormones that bind receptor-linked kinases (3)

GH
Prolactin
EPO

27

Name hormones that bind regular receptor kinases (3)

Insulin
IGF-1
ANP

28

Recite the melatonin synthesis pathway

Tryptophan to 5-HTP via tryptophan hydroxylase (RLS). 5-HTP to 5HT. 5HT to melatonin through N-acetyltransferase (RLS for melatonin, in PINEAL gland).

29

Recite the dopamine synthesis pathway

1. Tyrosine

...tyrosine hydroxylase (RLS)....

2. X-Dopa (L-Dopa is active)

3. Dopamine

...dopamine B-hydroxylase (ACTH promotes)...

4. Norepinephrine

...PMNT (cortisol promotes)...

5. Epinephrine

30

Where is melatonin synthesized

pineal gland

31

PRIMARY lesion in thyroid gland will show up as...

High basal TSH, since no T3/4 to negatively feedback on a. pit

Responsive to TRH challenge

32

SECONDARY lesion in pituitary gland will show up as what, on the TRH test?

Low baseline TSH, unresponsive to TRH challenge

33

High GnRH pulse releases

LH at ant. pit

34

Low GnRH pulse releases

FSH at ant. pit

35

Where is the hypophyseal portal system? Whats the blood supply?

Ant. pit, superior hypophysial artery.

36

Kallman's

GnRH can't migrate

37

Lesion to adenohypophysis. What kind of hormones impaired?

FLAT (basophile 10%) PiG (acidophile 40%)

38

2 main causes of central diabetes insipidus?

Etiology: 2 main causes

1. Decreased AVP release – most common defect
Hypothalamic or pituitary defect due to trauma, cancer, or infectious disease.

2. Decreased renal responsiveness to AVP
Genetic: X-linked mutation in AVP type-2 receptor – 90% males Acquired: lithium treatment, hypokalemia AVP levels are normal in these cases.

39

The secretion of which hormones is suppressed by somatostatin?

GH and TSH!

Note: TH promotes GH release. They're connected.

40

SS14 is made where?

Brain. This is the one that suppresses GH and TSH.

41

SS28 is made where?

Intestines.

42

What are burin, PC1, PC2?

The endopeptidases Furin, PC1, and PC2 aid in processing of the mature SS28 and SS14.

43

GH acts on effectors cells through what pathway?

JAK-STAT

44

Name 4 inhibitors of GH release

SS28, IGF1, Free fatty acids, Glucose

45

Name 4 promoters of GH release

GHRH
Hypoglycemia
Catecholamines (exercise)
Amino acids
Thyroid hormone

46

GH effect on adipose?

Via Jak/STAT:
Decrease glucose uptake (keeps GLUT4 intracellular), increase lipolysis

47

GH effect on muscle cells?

Via Jak/STAT:

Decrease glucose uptake (keeps GLUT4 intracellular)

48

GH effect on liver?

Via JAK/STAT:

Increase RNA synthesis
Increase protein synthesis
Increase gluconeogenesis
Increase IGF BP
Increase IGF

49

IGF-1 effect on bone, heart, lung, chondrocytes?

Increase protein synthesis
Increase RNA/DNA synthesis
Increase cell size/number
GROWTH

50

IGF-1 effect on muscle? ****

Increase amino acid uptake
Increase protein synthesis

(it acts like insulin at muscle)....but it is INSULIN DEPENDENT...glut 4...need energy to power the growth of muscle!

51

Diabetes type 1 eats a steak. What will happen?

GH is released (free AA's) but no insulin, so no IGF-1. So starvation amidst plenty.

52

What is the rate limiting step of steroid hormone synthesis? What hormone regulates this step?

Steroidogenic regulatory protein (StAR), which transfers the free cholesterol from the outer to the inner mitochondria. This is RLS. This is promoted by ACTH.

53

What does does p450cc catalyze?

p450cc is desmolase.
Free cholesterol to pregnenalone.

54

Prednisone

More potent GC effect, than MR effect.

55

Why does prednisone not increase blood pressure?

Because it acts on GC receptors not MR.

56

Cortisol: MR or GR potency?

1:1

Equal potency for both! That's why we need 11-Beta-HSD2 to convert it to cortisone, lest it activates the MR receptor!

57

Which has a stronger GR activity: prednisone or methylprednisone?

Methylprednisone

58

What drug has zero MR relative potency?

Dexamethasone

59

What drug has more MR potency than GC potency?

Fludrocortisone

60

Fludrocortisone. 1st thought?

MR>>>>>>GR

61

Dexamethasone. 1st thought?

No MR potency! All MR!

62

Prednisone and methylprednisone. 1st thought?

GR>>>>MR. Methylprednisone is stronger than regular prednisone.

63

Which of the following will raise your BP the most?
A. Cortisol
B. Prednisone
C. Methylprednisone
D. Dexamethasone
E. Flurdocortisone

E

64

11BHSD2 is blocked by carbenoxolone. Or too much licorice. Effect?

Excess MR activation. High BP, high Na and H20 retention.

65

Local cortisol production by what enzyme?

11-beta-HSD1
(Novel DMT2 target)

66

Blood from capsular artery sees steroid hormones in what order?

Mineralocorticoids, glucocorticoids, androgens, catecholamines (not a steroid hormone)

67

What are the direct and indirect ways that cortisol suppresses inflammation?

Direct: cortisol-GR directly sequesters NFK-B so it can't transcribe TNF-alpha

Indirect: Cortisol-GR increases transcription of IkB, which then sequesters NFK-B so it can't enter nucleus

68

Cortisol increases transcription of proteolysis via what factors?

E3 ubiquitin ligase
MuRF-1

69

How do BOTH hypo and hyperthyroidism lead to goiter?

Hypothyroidism: low T3/T4 due to lack of iodine, or TPO defect, or hashimotos. Results in lack of negative feedback on TSH secretion from basophils in ant. pituitary, thus lots of TSH.

Hyperthyroidism: high T3/T4 due to too much stimulation by TSH or autoantibodies to TSH-R (grave's disease).

70

Why don't you want to use aspirin for thyroid storm?

Aspirin suppresses thyroid binding globulin, increasing T3/4 levels

71

2 types of parathyroid cells

Chief cells - make PTH
Oxyphil cells - unknown function

72

Hashimoto's

Auto-antibodies destructive to thyroid tissue

73

KEY OBESITY STATISTICS

BMI>30 (at least 20% of population)
Waist:hip > 0.95 in men
Waist:hip > 0.85 in women

74

Metabolic syndrome X statistics

4 requirements

1. Dyslipidemia (TG>150mg/dl, HDL135/80)

3. Visceral obesity
(waist>40in in men, >35in women)

4. Insulin resistance (fasting glucose > 100mg/dl)

75

PPAR-gamma agonists

TZD - used for insulin resistance and T2DM

(aka avandia)

Induces differentiation of adipocytes, increase fat storage, and weight gain side effect.

76

Hypothalamic appetite modulators

Stimulators: Neuropeptide Y, AGRP

Inhibitors: aMSH, CART

77

Best measure for diabetes

HbA1C (glycosylated RBC)

78

In the follicular phase, what two hormones are inhibiting anterior pituitary release of FSH/LH?

Inhibin and estrogen from ovary

79

In the ovulatory phase, something special happens with estrogen

Surpasses threshold amount and switches from negative to positive feedback to ant. pituitary, promoting LH/FSH surge.

80

In the Luteal phase, the follicle reorganizes into the corpus luteum, which begins making...

E2 and progesterone. Strong negative feedback to anterior pituitary (LH/FSH) and hypothalamus (GnRH)

81

What marks the beginning of a new menstrual cycle?

absent hCG, and LH, E2, and progesterone, promotes sloughing of endometrium (bleeding/menses)

82

Theca cells (female) come from same progenitor as their male counterpart....

Leydig cells (spermeogenesis support)

Theca cells don't have aromatase...they help granulosa cells make estrogen.

83

Granulosa cells (female) come from the same progenitor as their male counterpart...

Sertoli cells

Granulosa cells make the estradiol because they have aromatase.

84

Female phenotype, no uterus

XXY klinefelters.

MIF from sertoli cells degraded mullein ducts.

85

Give an example of male pseudohermaphroditism

Phenotypically female, with testes.

86

If T too low in development

excess gonoadotropic signalling promotes scar tissue formation on testes

87

Larynx enlargement is due to action of

Testosterone

88

Where does in the seminiferous tubule does spermatogenesis occur, anatomically?

BASAL COMPARTMENT of seminiferous tubule --> blood testes barrier --> inner seminiferous tubule --> lumen of tubules

89

Are spermatogonia inside or outside the blood-testes barrier?

Outside! Once the first meiotic division starts, the spermatogonium turns into a "primary spermatocyte" that crosses the blood-testes barrier!

90

Leading cause of female infertility

Female infertility quadruples between 20 and 40 years old. Also:

PCOS (polycystic ovarian syndrome). Root cause of PCOS is insulin resistance and androgen production (causing infertility)...and increased conversion to estrogens (weight gain)....sleep apnea, hirsuitism...

91

Leading cause of male infertility

androgen deficiency: inadequate production or action of T, promotes poor spermatogenesis. Or defects in seminal tract. Idiopathic oligospermia.

Note: infertility doesn't mean impotence (erectile dysfunction)

92

What is the role of CRH during parturition?

CRH potentiates contracture response to prostaglandins and oxytocin.

93

Decrease in Progesterone/E2 ratio

promotes contractions

94

Increase in E2/Progesterone ratio

promotes contractions

95

Increase in Progesterone/E2 ratio

promotes quiescence

96

Decrease in E2/progesterone ratio

promotes quiescence

97

Inhibin B

secreted by follicular cells. negative regulation of LH/FSH

98

Inhibin A

secreted by corpus luteum. negative regulation of LH/FSH

99

Paracrine effect of inhibin, on theca cells

PROMOTES androgen production in inhibin cells. remember that inhibin lacks aromatase, which is why it makes androgens (androstenedione) for later aromatization at the granulosa cell

100

What is TCF72?

most highly associated genetic polymorphism...T2DM

101

what does insulin do to serum K and Pi levels?

Decreases K and Pi (increases uptake into the cell; indirect stimulation of Na/K pump)

102

Effect of insulin on HCO3- and pH?

increases HCO3-
Increases pH

103

Effect of insulin on lipolysis and ketone bodies

Stops lipolysis, so no more substrates for ketone body synthesis, so no ketoacidosis and thus no left shift in equilibrium towards CO2,

104

AVP potentiates the effect of

CRH (think AVP pertains to stress)

105

Insulin counter-regulatory hormones

GH
Cortisol
Glucagon
Catecholamines

106

PCB

competes with thyroid hormone binding to TBG. Increases TH production

107

DES

Non-steroidal estrogen
DES daughter tragedy