Endocrinology III Flashcards Preview

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Flashcards in Endocrinology III Deck (83):
1

Where does Insulin act?

Muscle and fat

GLUT4 transporters

2

T/F
Insulin inhibits lipolysis

True

3

What becomes dominant when insulin decreases?

Glucagon - liver
Epinepherine - muscle

4

Why can't insulin be given orally?

Peptide hormone

5

Type I diabetes is due to insulin _______.
Type II diabetes is due to insulin _______.

Deficiency
Resistance

6

What 3 requirements are there for a random plasma glucose Diabetes diagnosis?

Glucose > 200 mg/dl
polyuria
polydipsia

(and/or weight loss)

7

Why is there still high blood glucose in a diabetic in the fasting state?

There's not enough insulin to get glucose from GNG and glycogenolysis into the cell.

8

Hemoglobin A1c glucose level above _____ suggests diabetes.

6.5%

9

T/F
Pre-diabetes always progresses to diabetes.

False

10

Define:
polyuria
polydipsia
polyphagia

(excessive)
urination
thirst
food intake

11

What contributes to diabetic hyperglycemia in the intestine and the kidney?

Intestine: decreases GLP-1
Kidney: SGLT-2 (glc transporter) over-expressed

12

What are some tests to confirm Type I diabetes?

GAD (glutamic acid decarboxylase antibody)

ICA (islet cell cytoplasmic autoantibodies)

*GAD long-lasting

13

There are many environmental factors leading to Type II diabetes. What are the 2 most important?

Obesity
Aging

14

What most often breaks in type II Diabetes?

Post-receptor actions

(pre-receptor is rare and receptor defects not often)

15

Ketones suggest...

Type I

16

What is a non-insulin treatment for Type II diabetes that decreases liver glc production and fasting glc?

Biguanide
metformin

17

What is an effective therapy for diabetes that stimulates beta cells, inhibits alpha cells, and decreases appetite?

Incretins

GLP-1

*expensive and effective

18

What do SGL2T2 inhibitors do?

inhibit excretion of glc

*newest drugs

19

What are the 2 background insulins?

(long lasting, no peak)

Glargine and Detemir

20

What does it mean if blood glucose is high before a meal in a diabetic?

The previous meal wasn't covered enough by insulin

21

What can too much insulin cause?

Hypoglycemia
loss of consciousness
death

22

What are 2 hormonal causes of hypoglycemia?

GH or Cortisol deficiency

*these cause insulin resistance. With no insulin resistance, glucose is taken up by muscle and fat and not enough for the brain

23

What is a better treatment than snickers for hypoglycemia?

Glucagon injection

24

What leads to lipolysis in type I diabetes?

unopposed Glucagon

*ketoacidosis

25

What enzyme, suppressed by insulin, is over-active in response to epinephrine in type I diabetics?

Hormone Sensitive Lipase

*fat pours out of adipose tissue=ketoacidosis

26

Why does ketoacidosis not occur in Type 2 diabetes?

insulin deficient but not completely absent

27

What does high blood glucose, high urine glucose, and salt/water loss lead to?

Dehydration and High Serum Osmolality

28

What happens to tissues freely permeable to glucose in long-term diabetes?

They break down

Microangiopathies (retinopathy, neuropathy, nephropathy)
Macroangiopathy (cerebral, coronary, peripheral)

29

What are AGE's?

Advanced Glycation Endproducts

*highly reactive consequence of too much glc
free radicals , cross linked proteins, etc.

30

What is ischemia?

Low oxygen to tissues

(consequence of chronic hyperglycemia)

31

What reduces inflammation in treatment for diabetic retinopathy?

Glucocorticoid

32

What risk factor goes way up in diabetic nephropathy?

heart disease

(mortality 20-40 times higher)

33

What is the mechanism of the slowed neural conduction in diabetic neuropathy?

semental demyelination

*distal first - which is why problems with feet

34

What are the conditions that comprise metabolic syndrome?
(need 3 of these)

Hyperinsulinemia
Hyperglycemia
Hypertriglyceridemia
Low HDL cholesterol
Hypertension
Central obesity

35

What causes foot problems in diabetics?

Loss of feeling
Poor blood supply
Poor wound healing

(combined microvascular neuropathy and macrovascular disease)

36

Does intensive treatment of type I diabetes slow the onset of progression of disease?

Yes

*bigtime

37

Does intensive glucose control prevent macrovascular complications in Type II diabetes?

No.

*macrovascular disease outcomes the same

38

What two factors, if controlled, can benefit type II diabetes?

Blood pressure and Lipid control

39

How often should the feet be examined with a Diabetic patient?
What common drug can be useful in preventing other complications?

Daily

Aspirin

40

What do Leydig cells do?

Produce testosterone in presence of LH

*in testes

41

What is the function of Sertoli cells?

secrete mullerian inhibiting substance

"nurse" spermatogenisis process

42

When do gonads differentiate?

6 weeks

43

Describe the differentiation process at about 7 weeks.

Testosterone stimulates Wolffian ducts

Mullerian inhibiting substance degenerates Female (mullerian) ducts

44

What do the formation of the penis, scrotum, and prostate require?
What enzyme is involved?

DHT - dihydrotestosterone

5-alpha-reductase

*undervirillization usually defect in process (usually amount of DHT)

45

review:
Male gonad feedback loops

GnRH > LH/FSH > Testosterone

46

What stimulates the testes to make testosterone before and after 12 weeks?

Before 12 weeks: HCG (human chorionic gonadotropin) from placenta

After 12 weeks: FSH/LH from fetal pituitary

47

What does micropenis suggest?

Fetal pituitary failure

*low LH = low testosterone = low DHT = micropenis
**must screen for other pituitary deficiencies

48

Testosterone effects the development of the ______ genitalia and dihydrotestosterone effects the development of the _____ genitalia.

Internal (vas defrens, etc)
External (scrotum, prostate, etc)

49

What does the maintenance of testicular germinal structures depend on?

Local testosterone

(intra-testicular)

50

What hormone stimulates the testes to produce testosterone?

LH

51

How are GnRH and LH/FSH secreted?

pulses

52

What type of cells are stimulated by LH?
FSH?
(in men)

LH - Leydig cells (testosterone)
(this diffuses to Sertoli cells)

FSH - Sertoli cells (Inhibin B)
*androgen binding protein

53

GnRH >
(complete feedback)

LH > Leydig cells > Testosterone

FSH > Sertoli cells > Inhibin

54

What can convert testosterone to estradiol?

Aromatase
(found mostly in fat)

55

What is the abnormal migration of GnRH-producing neurons and (bundled with) olfactory neurons called?

Kallman syndrome

*hypogonadism and no sense of smell

56

How are tertiary (hypothalamic) defects in sex hormones treated?

At primary level with testosterone

(if fertility is the issue requires FSH/LH or GnRH via pump)

57

HCG act in place of...

LH

58

If there is trouble at the testes what are hormone levels?

high GnRH, FSH, LH

low Testosterone

59

If someone is born without testes, what is the external genitalia?

female (internal and external)

60

When do testes fail in Klinefelter Syndrome?

After puberty

61

What are some target tissue defects in sexual differentiation?

Defective androgen receptor, 5-alpha-reductase (no DHT), aromatase (no estrogen)

62

If the testes are present but there are defective androgen receptors what would the hormone levels be?

high GnRH, FSH/LH, Testosterone, DHT, Estrogen

63

Why would androgen insensitivity syndrome produce no internal male or female genitalia?

Testosterone has no effect to produce male genitalia

Mullerian inhibiting hormone gets rid of internal female genitalia

64

Androgens refer to what 2 molecules?

Testosterone and DHT

65

What are the hormone levels in 5-alpha-reductase deficiency?

Normal everything.

*internal genitalia male, external female until puberty

66

What causes gynecomastia (excess breast tissue in males)?

excess Estrogen
(E/T ration high)

*common in aging

67

What condition includes the following: tall, epiphyses not closed, osteoporosis, normal genitalia, and abnormal semen?

No aromatase (so no estrogen)
No estrogen receptors

68

Why would a continuous GnRH treatment be appropriate for prostate cancer?

GnRH that NOT in pulses down-regulates FSH and LH receptors

also, 5-alpha reductase inhibitors (no DHT) is a treatment for prostate cancer

69

What developmental indicators are affected by hormones?

height
(length at birth, bone growth)

70

Is brain size (head circumference) affected by hormones?

NO

*genetics, nutrition, environment

71

What 3 hormones affect length before birth?

insulin
IGF-1
IGF-2

72

T/F
Endocrine causes of childhood obesity is common

False

0.1%

73

T/F
Height after birth isn't affected by hormones

FALSE

*GH and IGF-1

74

Describe the growth feedback loop

GHRH > GH > IGF-1

75

What does thyroid hormone do developmentally?

Height (acts in concert with GH)

Full fetal/child brain development

76

What are the 4 main hormones for growth?

GH
IGF-1
Thyroid hormone
Estrogen/testosterone (added at puberty)

*remember - estrogen closes epiphyses

77

What are some endocrine causes of short stature?

hypothyroidism
abnormal GH secretion
excess Cortisol
Precocious puberty

78

Thyroid hormone and GH both affect ____ more than _____.

height
weight

79

What effect does GH deficiency have on teeth?

gaps
small mandible

80

What does GH excess cause?

Gigantism or acromegaly

81

What is the difference between central and peripheral precocious puberty?

early puberty brought on by increases GnRH in Central

brought on by abnormal hormone source in Peripheral

82

How is central precocious puberty treated?

peripheral?

continuous GnRH

treat underlying cause

83

T/F
Hypothyroidism and GH deficiency can present similarly.

True

*fatigue, no growth in height, slow pulse, delayed deep tendon relaxation

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