endocrine - repro Flashcards

0
Q

isoform of 5a-reductase:

Expression starts at puberty

A

Type 1

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1
Q

Testosterone and DHT synthesis

A

Aldrostenedione to testosterone (17B-HSD) to DHT (5a-reductase)

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2
Q

isoform of 5a-reductase:

Found in skin - contributes to sebaceous gland activity and acne formation

A

Type 1

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3
Q

isoform of 5a-reductase:
Found in male urogenital tract, skin, hair follicles and Liver
For masculinization of ext genitalia in utero

A

Type 2

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4
Q

Leydig cell produces estrogen peripherally. Effects…

A

Bone maturation
Insulin sensitivity
Improves lipoprotein profile (increase HDL)

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5
Q

60% of androgen is bound to

A

sex hormone binding globulin SHBG

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6
Q

Androgen negative feedback effect on FSH and LH ..more on

A

LH

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7
Q

Regulation of Sertoli cell function

A

Stimulated by both testosterone and FSH
Expresses FSH receptor
FSH stimulates synthesis of inhibin

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8
Q

Loophole in male repro axis..

A

Intratesticular T level should be >100x more than circulating T level to maintain normal spermatogenesis

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9
Q

Exogenous T level increases circulating T only

A

True

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10
Q

Regulation of development of internal genitalia in male

A

Wolffian duct-Testosterone and presence of MIS

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11
Q

Regulation of development of internal genitalia in female

A

Mullerian duct - absence of MIS

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12
Q

Regulation of development of external genitalia in male

A

Presence of DHT

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13
Q

Regulation of development of external genitalia in female

A

Absence of DHT

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14
Q

GnRH neurons have been demonstrated in the feral hypothalamus by

A

9wks gestation

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15
Q

Functional connections are established between GnRH neurons and portal system by

A

16wks AOG

16
Q

Characterized by low amplitude GnRH secretionas mirrored by LH secretion

A

Childhood period

17
Q

Characterized by a striking increase in amplitude of LH pulses with a lesser change in frequency

A

Puberty

18
Q

In adult male, LH is secreted in pluses approx every

A

2 hrs

19
Q

Seminiferous tubular dysgenesis

A

Klinefelter syndrome

20
Q

Genetic disorder in men with extra X chromosome.

Phenotypically male but with small testis and decreased germ cell

A

Klinefelter syndrome

21
Q

Results from hereditary defect of X chromosome gene controlling androgen receptor expression
Phenotypically female but male internal genitalia
Male pseudo hermaphroditism

A

Androgen insensitivity syndrome

22
Q

Due to decreased DHT formation

A

5a reductase deficiency

23
Q

Normal internal genitalia but incomplete masculinized external genitalia - ambiguous genitalia. Mistaken for females at birth

A

5a reductase deficiency

24
Q

Primary isolated gonadotropin deficiency due to inability of GnRH neurons to migrate to medico basal hypothalamus from nasal placode. With undescended testes (CRYPTORCHIDISM) and microphallus. Asso with anosmia

A

Kallmann syndrome

25
Q

Female repro cell which expresses LH receptor

A

Theca cells

26
Q

Female repro cell which produces androgen (primarily androstenedione)

A

Theca cells

27
Q

Theca cells expresses what enzyme

A

Cyp11a1, 3b-HSD, cyp17

28
Q

Female repro cell which expresses FSH receptor

A

Granulosa cells

29
Q

Granulosa cells expresses what enzymes

A

17b-HSD, cyp19

30
Q

Regulation of menstrual cycle when there is high freq GnRH pulses

A

LH production

31
Q

Regulation of menstrual cycle when there is low freq GnRH pulses

A

FSH production

32
Q

Most common cause of congenital hypogonadism

A

Gonadal dysgenesis or Turner syndrome

33
Q

Short stature, webbed neck, low se tears, shield-shaped chest, short 4th metacarpals and sexual infantilism

A

Turner syndrome

34
Q

Chronically a ovulation women with high androgen, estrogen, and LH levels

A

PCOS

35
Q

Diagnosis of PCOS requires 2 out of 3 of

A
  1. Amenorrhea
  2. Evidence of excess androgen secretion (acne, hirsutism)
  3. Polycystic ovaries by ultrasound
36
Q

Primary defect of PCOS

A

Inappropriate signals between HP axis and ovary