Lecture 22 - Male Reproduction

Question 1

each lobule of the testes has loops of

Answer 1

seminiferous tubules where spermatozoa mature

Question 2

in the testes, sperm move through

Answer 2

rete testis and efferent ductules to reach the epididymis for packaging

Question 3

the seminiferous tubules are composed of

Answer 3

sertoli cells which nurture sperm and the developing sperm are in this location

Question 4

in the space around the seminiferous tubules in the testes

Answer 4

are leydig cells which produce testosterone

Question 5

what are the 3 stages of spermatogenesis

Answer 5

mitosis & meiosis
packaging

Question 6

where does mitotis and meiosis occur

Answer 6

in seminiferous tubules

Question 7

when do mitosis and meiosis start

Answer 7

at puberty: testosterone dependent

Question 8

what happens during packaging?

Answer 8

final maturation of sperm: acquisition of motility

Question 9

where does packaging occur

Answer 9

epididymis

Question 10

mitosis of male reproduction results in

Answer 10

2 diploid cells

Question 11

meiosis of male reproduction results in

Answer 11

4 haploid cells

Question 12

the midpiece of sperm contain

Answer 12

mitochondria

Question 13

the head of the sperm contain

Answer 13

nucleus

Question 14

mitosis occus in the

Answer 14

outer/basal compartment of the seminiferous tubules

Question 15

meiosis occurs in the

Answer 15

inner/adluminal compartment of seminiferous tubule

Question 16

what separates the outer/basal compartment and the inner/adluminal compartment

Answer 16

tight junctions aka blood-testes barrier

Question 17

function of sertoli cells

Answer 17

nurture sperm
phagocyte defective sperm
secrete luminal fluid
during the embryonic life secrete muellerian inhibiting substance
secrete inhibin
secrete paracrine agents modulating release of T from leydig cells
respond to T and FSH
produce androgen binding protein
contain aromatase

Question 18

steps of packaging

Answer 18

1. pressure of luminal fluid within ST moves sperm towards epididymis
2. in the E. most the ST fluid is reabsorbed and high T favors maturation
3. 90% of semen volume derives from accessory glands

Question 19

edididymis

Answer 19

tube of SM lined with secretory epithelium
* site of final maturation; extensive remodeling
* spermatozoa become motile
* seminiferous fluid absorbed; concentrations sperm 100 fold
* requires high T in epididymal fluids
* stored for a few days
* packaging takes about 14 days

Question 20

vas deferens

Answer 20

• delivers sperm to abdominal cavity
• sperm stored in ampulla of vas deferens until ejaculation

Question 21

accessory glands: seminal vesicles

Answer 21

seminal vesicles:
* empty in vas deferens
* contribute to 60% of total sperm volume
* function: dilutes sperm, provide nutrients and buffering
* composition: vit C, prostaglandins, fibrinogen, fructose buffering agents

Question 22

accessory glands: prostate

Answer 22

prostate
* surrounds ejaculatory duct and urethra
* function: provides enzymes and factors that favor the motility, contribute to buffering
* composition: Zn, prostatic acid phosphataase, prostatic specific agents (PSA) -> indicate health of prostate

Question 23

accessory glands: bulbourethral glands

Answer 23

bulbourethral glands
* at basis of penis
* produce a mucus-like substance prior to ejaculation
* function: clean up urethra and lubrication

Question 24

FSH receptors are restricted to

Answer 24

sertoli cells

Question 25

FSH sensitizes Sertoli cells to

Answer 25

testosterone

Question 26

FSH also stimulates

Answer 26

* inhibin and ABP synthesis * formation of tight junctions * synthesis of seminiferous fluid

Question 27

androgen synthesis occurs in

Answer 27

testes and adrenal gland

Question 28

80% of estrogens in males derives from

Answer 28

T. conversion in peripheral tissues

Question 29

20% of T. is converted in

Answer 29

E2 in testes

Question 30

estrogen is involved in

Answer 30

formation-breakdown of bones

Question 31

estrogens together with androgens mgith play a role in the growth of

Answer 31

prostate -> benign prostate hypertrophy | w/age, male body makes more E and more receptors for androgens in prosta

Question 32

prolactin functions in males

Answer 32

* permissive of LH-stimulated T synthesis * increases # of androgen receptors on accessory glands, favoring their development

Question 33

high prolactin inhibits

Answer 33

GnRH release which then decreaes FSH/LH secretion and decreases T

Question 34

andropause

Answer 34

reduction in testicular fxn related to age. * decrease T * increase LH/FSH * decrease spermatogenesis * starts at age 60-70

Question 35

symptoms of androgen deficiency

Answer 35

* decreased hemoglobin * decreased hematocrit * muscle weakness * decreased libido * decreased sperm count and energy * altered mood * hot flashes

Question 36

testosterone replacement therapy AE

Answer 36

* increased hematocrit/hemoglobin * fluid retention * prostatic enlargement * gynecomastia * heart attack * obstructive sleep apnea * possibly liver toxicity