Structure and Function of the Male Genitourinary System Flashcards Preview

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1. First ____ days after conception the gonads of males and females are similar in appearance.

2. Cells that will give rise to spermatogonia and oogonia migrate from where to where?

3. What promotes the conversion to testes?

4. Seminiferous tubules appear within _____ days following conception.

5. What do they Produce?

6. What appears around day 65?

1. 40

2. yolk sac to developing embryonic gonads.

3. Testis-determining factor (TDF)

4. 43-50

-Germinal cells: sperm.
-Nongerminal cells: Sertoli cells.

6. Leydig cells:
Appear about day 65.


1. Leydig cells secrete what?

2. When does this begin and when does it peak?

3. Masculinizes _________ structures.

4. [Testosterone] then does what until puberty?

5. Testes descend into scrotum shortly when?

6. Functions? 2

1. testosterone.

2. Begins at the 8th week and peaks at 12-14th week.

3. embryonic

4. declines to very low levels

5. before birth.

6. spermatogenesis and testosterone production


1. Testes, or male gonads, are what?

2. Testes develop in the what?

3. and then descend through the inguinal canal into what?

4. ___% spermatogenesis and ___% testosterone production

Arteries, Veins, and Nerves

1. two egg-shaped structures outside the abdominal cavity in the scrotum.

2. abdominal cavity

3. pouch of peritoneum (tunica vaginalis)

4. 80, 20


Testicular Descent
1. How mant stages?

2. When are they? 2

3. Why is this important?

1. Two stages

-7-12 weeks fetal life (AMH)- so they dont turn into ovarian
-and 7-9 months fetal life (Testosterone)- actual descent

3. Increased risk for testicular cancer


What structures are the scrotum?

1. Houses Testes

2. Dartos Muscle (wrinkles em)- changes in temperature modifies surface area

3. Cremaster Muscle (elevates em)- and layers of fascia = spermaticord
(3 degrees lower generally)


Genital Duct System:
1. Testes are composed of several hundred what?

2. Each contains one or more what?

3. These tubules are the site of what?

4. Tubules lead into the efferent ducts, and become the what?

5. 10,000 to 20,000 efferent ducts emerge to join the ________ (sperm finishing school)

6. Sperm still can’t swim, so they rely on the what?

1. lobules

2. coiled seminiferous tubules (sperm factories)

3. sperm production!!!

4. rete testis

5. epididymis

6. peristaltic movements of the ductal walls of the epididymis


Genital Duct System:
1. Spermatozoa continue their migration through the what?

2. The ampulla of the vas deferens serves as a what?

3. They camp out here happily awaiting what?

4. Vasectomy? How long can they live here?

1. vas deferens

2. storage reservoir for sperm

3. ejaculation

4. 42 days they are present. So you can still maintain your fertility for 42 days!


Accessory Organs? 3

1. Seminal Vesicles (adds fructose)

2. Prostate Gland (adds alkaline fluid to semen so it can protect them in cervical/vaginal secretion and urine)

3. Bulbourethral Glands (Cowper Glands)- also secrete the alkaline agent


1. Shaft that ends in a tip called the _____?

2. What is the foreskin?
-Foreskin removed with circumcision

3. What are the tissues types in the penis? 2

1. glans

2. Loose skin of the penis shaft folds to cover the glans (foreskin)

-Corpora cavernosa (lateral mass)
-Corpus spongiosum (ventral mass- engorged with blood in erection)


Endocrine Regulation
Negative feedback? 3

1. Inhibits GnRH from hypothalamus.

2. Inhibits anterior pituitary response to GnRH.

3. Inhibin secretion inhibits anterior pituitary release of FSH.


Female sex steroids? 2

Male sex steriods? 1

1. Female:
Estrogen and progesterone.

2. Male:


Control of LH and FSH Secretion:
1. Negative feedback:
Testosterone inhibits what?

2. Maintain relatively constant secretion of what?

3. Declines gradually in men over ___ years of age.

4. Testosterone converted to ____, which inhibits LH.

5. What inhibits FSH secretion?

6. Aromatization reaction producing _______ in the brain, is required for the negative feedback effects.

1. LH and GnRH production.

2. LH and FSH.

3. 50

4. DHT

5. Inhibin

6. estradiol


Endocrine Function of the Testes:
1. Testosterone and its derivatives are responsible for what?

2. Stimulate growth of what? 3

3. Promote ________ synthesis.

4. Act in paracrine fashion, responsible for what?

1. initiation and maintenance of body changes in puberty.

-larynx, and
-bone growth until sealing of the epiphyseal discs.

3. hemoglobin

4. spermatogenesis.


1. Seminiferous tubules:
Contain receptor proteins for what? and where is it?

2. ____ stimulates spermatogenesis to occur.

3. Leydig cells:
___ stimulates secretion of testosterone.

4. Contain receptor proteins for ____.

1. FSH in Sertoli cells.

2. FSH

3. LH, LH


Male Sex Hormones
1. Androgens: secreted by the what? (20% of the mass of the testes)
2. under the influence of ___ from anterior pituitary.

3. Leydig cells not fully mature until after approximately ___yo

4. ___________ is the significant hormone responsible for the male hormonal effects!

1. interstitial cells of Leydig

2. LH

3. 10

4. Testosterone


Embryonically what is THE determining factor in the development of male or female genital organs and characteristics?



1. Injection of large quantities of testosterone into gravid animal causes development of what?

2. Removal of fetal testes in a male fetus causes development of what?

3. If the Leydig cells aren’t mature till after the age of 10, how does this differentiation occur?

1. male sexual organs in the fetus even when the fetus is genetically female

2. female sexual organs

3.Human Chorionic Gonadotropin (or hCG, which is produced by the placenta) from mom stimulates testosterone secretion in the fetal testes


1. Stimulus for descent of the testes during the last what of pregnancy?

2. If a male child is born with undescended testicles, what can cause testes to descend in usual manner if inguinal canals large enough?

(not usually done, 80-90% of undescended testes will descend by one year of age)

1. 2-3 months

2. administration of testosterone or LH (a gonadotropin)


Primary sexual characteristics:
Causes what? 3

1. penis,
2. scrotum, and
3. testes to all enlarge during puberty


Testosterone: Secondary sexual characteristics
1. Molecularly almost all of these effects occur because of increased what?

2. What are they? 6

1. rate of protein formation (PP)

-Distribution of body hair
-Baldness (a man without functional testes does not become bald)
-Deepened Voice
-Skin: increases thickness, more prone to acne
-Muscular development
-Bone growth, bone density, calcium retention


Disorders of Embryonic Sexual Development
1. What does intersex mean?

2. Individual with either what?

3. Have accessory sex organs and external genitalia that are what?

4. Most common cause of female pseudohemaphroditism is what?

5. In the male, one cause is testicular feminizing syndrome: Which is what?

1. Both ovarian and testicular tissue is present in the body.

2. testes or ovaries but not both.

3. incompletely developed or inappropriate.

4. congenital adrenal hyperplasia.

5. Normal functioning testes, but lack receptors for testosterone.


Low testosterone etiologies? 7

1. Hypogonadism
2. Trauma to Leydig cells
3. Mumps
4. RX/Chemo
5. Testicular tumors
7. ETOH (beer)

(primary from testicles, secondary from pituitary, tertiary from hypothalamus)


What are the products of mitosis in spermiogensis? 5

1. Germ cells
2. Primary spermatocyte (2n)
3. Secondary spermatocyte (n)
4. Spermatid (n)
5. Spermatozoa(n)

Continuously happening in sertoli cells in the seminiferous tubules


1. Spermatocytes divide in two stages, one of which is by the process of meiosis to form what?
-How many chromosomes do they have?

2. Spermatids mature for how long until they become spermatozoa?

3. Function of Sertoli Cells?

1. four spermatids, each containing 23 unpaired chromosomes

2. two months

3. Actually envelope spermatids for processing before release into lumen (protect and nurse sperm)


Sertoli Cells:
1. They form what?

2. What is the function of this? 2
3. Secrete? 2
4. Phagocytize what?
-What does this do?

1. Form blood-testes barrier:

-Prevents autoimmune destruction of sperm.
-Produce FAS ligand which binds to the FAS receptor on surface to T lymphocytes, triggering apoptosis of T lymphocytes.(Prevents immune attack.)

-Secrete inhibin.
-Secrete androgen-binding protein (ABP):

4. Phagocytize residual bodies:
-May transmit information molecules from germ cells to Sertoli cells.


Function of Secrete androgen-binding protein (ABP)?

Binds to testosterone and concentrates testosterone in the tubules.


Hormonal Control of Spermatogenesis
1. Formation of primary spermatocytes and entry into early prophase I, begin during when?

2. Spermatogenesis arrested until when?

3. Testosterone required for completion of what? 2

4. Secrete paracrine regulators:
such as? 3

5. ____ necessary in the later stages of spermatid maturation.

1. embryonic development.

2. puberty.

-spermatid maturation.

-Transforming growth factor.

5. FSH


1. Sperm formed in the where?

2. Sperm emptied into where?(maturation)

3. Then where until the urethra where it exits through the meatus? 2

1. seminiferous tubules (900 seminiferous tubules make up the testis

2. epididymis

-Vas Deferens
-Prostate Gland (Seminal vesicle empties at this point)


1. Once in the epididymis, sperm become what?
-Why not before this?

2. and go through final maturation and become capable of what?

3. Most of the mature sperm is stored in the where?
-For how long?

1. fully motile
-(inhibitory proteins in epididymal fluid prevent motility until after ejaculation)

2. fertilizing ovum

3. Vas Deferens
-can maintain fertility for at least a month


Seminiferous tubules contain? 6

1. Spermatogonia>
2. Primary Spermatocyte>
3. Secondary Spermatocyte>
4. Spermatid>
5. Spermatozoa (Sperm cell)
6. Also Sertoli Cells