16 17 Male Reproductive

Question 1

What happens in the epididymis, ductus deferens, and urethra

Answer 1

system of ducts - Transport and stores sperm assists in their maturation, and conveys them to the exterior

Question 2

What are examples of accessory sex glands

Answer 2

Seminal vesicles, prostate, and bulbourethral glands

Question 3

What is the critical regulator of male reproductive function

Answer 3

androgens and other hormones

ALL functions & differentiation regulated by hormones

Question 4

The first fetal repro structure is female, male, or both

Answer 4

Both

Question 5

What does the Mullarian duct become? How is the process regulated?

Answer 5

Female repro organs - NOT under hormonal control
fallopian tube / oviduct
uterus
cranial 1/3 of vagina

Question 6

What does the Wolfian duct become

Answer 6

Male repro organs - require MIS/AMH stimulation
epididymis
vas deferens
seminal vesicle

Question 7

What do sertoli cells do to the male repro tract

Answer 7

secrete MIS/AMH to induce Mullerian duct regression

Question 8

What do leydig cells do to the male repro tract

Answer 8

secrete testosterone to induce Wolffian duct development

Question 9

What does MIS/AMH do?

Answer 9

Hormone produced by sertoli cells that causes Mullerian duct regression

Question 10

What are the 3 phases of spermatogenesis

Answer 10

Proliferation
meiotic
differentiation

Question 11

What drives spermatogenisis

Answer 11

Leydig cells and the androgens they produce

spermatogenesis is obligatory dependent on androgen

Question 12

What are the two populations of Leydig cells

Answer 12

1) Fetal leydig cells
- differentiate prenatally
- produce androgens that induce normal development of male internal and external reproductive organs
2) Mature leydig
- develop at puberty
- drive spermatogenesis and other events

Question 13

What do the testes do

Answer 13

produce androgen

produces sperm

Question 14

What species have a prostate

Answer 14

present in all species

Question 15

What species do not have seminal vesicles

Answer 15

absent in dogs and cats

Question 16

What species do not have bulbourethal glands

Answer 16

bears, dogs, aquatic animals

Question 17

What is the major producer of semen

Answer 17

seminal vesicles

Question 18

What is cryptorchidism

Answer 18

Testicle doesn’t descend properly
0.8-15% of dogs
can be treated surgically & medically
if untreated more prone to tumors

Question 19

What is Benign prostatic hyperplasia

Answer 19

begin NOT cancer
enlargement of the prostate gland
occurs only in dogs and humans

Question 20

What causes BPH symptoms? Treatment?

Answer 20

age and time
clinical symptom in dogs: incontinence

Treatment: castration

Question 21

gonads / testes

Answer 21

produces sperm

secretes hormones

Question 22

What is the function of the male reproductive system

Answer 22

produces androgens & other hormones
produces male gametes
conveys the gametes from their site of production into the female reproductive tract

Question 23

3 cells types in the testis that play critical roles in reproduction

Answer 23

germ cells 
 - spermatogonia > spermatozoa
sertoli cells 
 - regulate germ cell development
interstitial (leydig) cells 
 - secrete testosterone, the major androgen

Question 24

spermatogenesis

Answer 24

development of spermatids into sperm
65-75 days in humans - variable in species
sertoli cells important

Question 25

What drives androgen production by Leydig cells?

Answer 25

hypothalamus releases GnRH into the blood stream →

GnRH triggers the release of pituitary LH and FSH → stimulate the testes to secrete testosterone and produce sperm

Question 26

Hormonal control of the testes

Answer 26

a puberty > increased GnRH from hypothalamus > Anterior Pituitary increases secretion of LH and FSH

LH stimulates leydig cells to secrete testosterone
FSH acts indirectly on spermatogenesis

Question 27

What does lutenizing hormone (LH) regulate in male reproduction

Answer 27

stimulates Leydig cells to secrete testosterone

• testosterone stimulates spermatogenesis
• synthesized from cholesterol in testes
• suppresses secretion of LH and GnRH via negative feedback

Question 28

What does follicle stimulating hormone (FSH) regulate in male reproduction

Answer 28

acts on sertoli cells

• FSH & testosterone act on sertoli cells to promote spermatogenesis and stimulate secretion of androgen binding protein (APB)
• APB binds to testosterone keeping concentration high
• sertoli cells release inhibin which inhibits FSH

Question 29

How does androgen act to support and promote spermatogenesis?

Answer 29

sertoli cells are the ONLY cells in the seminiferous tubules that express androgen receptor

androgens from the leydig cells act on sertoli cells to drive spermatogenesis

androgenic regulation of spermatogenesis is INDIRECT; germ cells do not have androgen receptor and are not responding directly to androgens

Question 30

What are the functions of androgens produced in leydig cells?

Answer 30

• support spermatogenesis
• induce and maintain make accessory sex organs
• influence brain and sexual behavior
• promote protein anabolism, muscle mass, somatic and bone growth
• regulate secretion of gonadotropins
• induce secondary male sex characteristics (horns, mane, feathers, rooster comb, etc. )

Question 31

What are some clinically important male repro diseases and problems in vet med

Answer 31

cryptorchidism
infertility
benign prostatic hyperplasia (BPH)
testicular tumors

Question 32

testicular tumors

Answer 32

can occur in many diff cells in testes:
- sertoli cell tumors
- seminomas
- interstitial cell tumors
ALL can be malignant