Male Reproductive Endocrinology (2) Flashcards

0
Q

What makes someone a gonadal male?

A

SRY gene encodes testis determining factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

What makes someone genotypically a male?

A

Y chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is TDF?

A

A transcription factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What makes someone phenotypically male?

A

Hormones produced by the gonads determine the phenotypic sex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When can an XX male occur?

A

In rare cases when the SRY gene translocates to the X chromosome during male meiosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What determines the fate of primordial gonads?

A

Te genotype of the germ cells that the primordial gonads contain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

In males, what do mesonephors develop into?

A

Epididymis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is an indifferent gonad closely associated with?

A

Mesonephros and wolffian duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do leydig cells promote?

A

Androgens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do androgens help promote development of?

A
  1. Wollfian ducts and derived internal genitalia —> requires testosterone
  2. Prostate development —> requires DHT
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of external generalist develop in the absence of testosterone?

A

Female

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Is testosterone or DHT responsible for the development of mLe external genitalia?

A

Testosterone is converted to DHT….this then stimulates differentiation into male external genitalia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hat type of receptor does GnRH bind? What are its actions?

A

G protein coupled gonadotropin receptor and it then activates PLC to increase Ca++, DAG production and PKC activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe GnRH release and LH/ FSH release?

A

Pulsation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do constant levels of GnRH lead to? What are the clinical applications of this?

A

Inability to release LH and FSH…this is a treatment for prostate cancer in an effort to lower testosterone production.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In the prenatal stage, what is the source of sex-steroid production in the testes?

A

Leydig cells….which increase in number in a manner dependent on maternal chorionic gonadotropin or embryonic leutenizing hormone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Prior to puberty, describe GnRH/ LH/ FSH pulses and levels and describe the axis sensitivity to negative feedback?

A
  • Few GnRH pulses
  • Low LH and FSH levels
  • The axis is VERY sensitive to negative feedback inhibition by androgens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

During puberty, describe GnRH/ LH/ FSH pulses and levels and describe the axis sensitivity to negative feedback?

A

Frequency and amplitude of GnRH pulses increase

LH and FSH production increase

Sensitivity to negative feedback of testosterone decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What type of cells does FSH stimulate?

A

Sertoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What type of cells does LH stimulate?

A

Leydig cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which cells produce inhibit and where does inhibit act?

A

Sertoli cells produce inhibit which feeds back to the anterior pituitary to decrease release of FSH

21
Q

How does testosterone effect sertolic cells?

A

Activate Sertoli cells

22
Q

When LH stimulates it’s target cell, what are the transcriptional changes made?

A

Increased transcription of:

  • enzymes involved in testosterone synthesis
  • enzyme for RLS of steroid hormone synthesis
  • sterol carrier protein and sterol activating protein
23
Q

When FSH stimulates it’s target cell, what are the transcriptional changes made?

A

Increased transcription of:

  • androgen binding protein
  • aromatase enzyme
  • growth factors (to support production of sperm)
  • inhibits
24
True or false: inhibits suppress leydig cell proliferation
True
25
What do leydig cells produce that inhibits Sertoli cells?
Beta- endorphin
26
What do Sertoli cells produce that can stimulate leydig cells?
Estrogen
27
What is lacking in Kallmann syndrome?
Lack of pituitary hormones LH and FSH because lack GnRH
28
What is the explanation for why people with Kallmanns syndrome can't smell?
The olfactory receptors and the GnRH secreting cells both develop in the olfactory epithelium and then the GnRH secreting cells migrate into the brain
29
Name the enzyme and where it is found: Cholesterone --------------> Pregnenolone
Desmolase Leydig cells
30
Where is aromatase found? What does it do?
Sertoli cells Testosterone/ androstedione --------> estradiol/ estrone
31
Name the enzyme: Testosterone -------> DHT
5- alpha- reducatse
32
Name two causes of male psuedohermaphroditism:
5alpha reducatse deficiency and androgen insensitivity syndrome
33
What are some anabolic effects of androgens?
Promote protein synthesis, growth in muscle and strength, increased bone density/ strength/ linear growth
34
Are FSH levels higher in females?
No, they are 8x higher in males
35
Which androgen is responsible for the following: Sebum formation, beard growth, prostate development, external genitalia, sperm production, sex drive/ behavior, feedback inhibition to hypothalamus
DHT
36
Which androgen is responsible for: Increased RBC, increased muscle mass, increased upper body fat, increased VLDL, increased LDL, decreased HDL, sperm production
Testosterone
37
Which androgen is responsible for the following: Sperm production, skeleton maturation, sexual behavior
Estradiol
38
Describe the changes in male senescence:
NO abrupt loss of fertility Testosterone decreases starting at age 30 Quantity/ quality of sperm decreases FSH/ LH levels increase
39
What is used to treat male pattern baldness?
Finasteride, which blocks the production of DHT
40
What are the effects of anabolic steroid use:
Reduction in sperm count, shrunken testicles Damage to heart, liver, kidneys, psych problems Breast enlargement
41
What is defective in spinobulbsr muscular atrophy?
LMN disease caused by mutation in the androgen receptor because of a CAG repeat which leads to a polyglots mine expansion
42
What initiates spermatogenesis?
Initiated at puberty through the action of FSH and LH
43
Percentage of sperm in semen?
10%
44
After spermiation, where do spermatids move?
They move passively into rete testes and epididymis
45
What is maturation is sperm dependent on?
Testosterone
46
The flaccid penis is under SNS or PNS control?
SNS
47
Is the SNS or PNS responsible for erection?
PNS
48
What is the action of Viagra?
Inhibits a decrease in CAMP, keeping the levels high, by inhibiting cAMP specific phosphodiesterase
49
What NTs are involved in erection?
NO and ACh
50
Does SNS or PNs control emission?
SNS