Male Reproductive System

Question 1

Which compartment of the seminiferous tubules contains the primary endocrine cell of the testis?

Answer 1

Peritubular compartment

Leydig cells

Question 2

Large cells with overflowing cytoplasmic envelopes that surround the developing spermatogonia all the way to the central lumen of the tubule.

Answer 2

Sertoli cells

Question 3

Which stage of spermatogenesis do the 46 chromosomes divide to produce haploid cells?

Answer 3

Secondary spermatocyte to spermatids

→ Thus, 23 chromosomes go to one spermatid and the other 23 go to the second spermatid.

Question 4

In mitotic spermatogenesis, stem cells called _______ reside at the basal level of the seminiferous epithelium

Answer 4

spermatogonia

Question 5

Thick cap located outside of the anterior two thirds of the head of the spermatozoon that is formed mainly from the Golgi apparatus

Answer 5

Acrosome

Question 6

Enzyme of the acrosome which can digest proteoglycan filaments of tissues

Answer 6

Hyaluronidase

Question 7

True or False:
Flagellar movement is a rhythmical transverse sliding motion between the anterior and posterior tubules that make up the axoneme

Answer 7

False: it’s a longitudinal sliding motion

Question 8

Essential hormone for spermiogenesis to occur

Answer 8

FSH
- stimulates the Sertoli cells; without this stimulation, the conversion of the spermatids to sperm (the process of spermiogenesis) will not occur.

Question 9

Hormone that stimulates Estrogen formation from testosterone by the Sertoli cells

Answer 9

FSH

Question 10

Hormone that promotes early division of the spermatogonia themselves

Answer 10

Growth Hormone

Question 11

True or False:
Once the sperm is matured, the activity is greatly enhanced in a neutral and slightly acidic medium as they exist in ejaculated semen

Answer 11

alkaline medium

Activity is greatly oppressed in slightly acidic medium

Question 12

Gland that secretes alkaline thin milky fluid containing calcium, citrate ion, phosphate ion, clotting enzyme, fibrinolysin.

Answer 12

Prostate gland
The slightly alkaline characteristic of the prostatic fluid is important for successful fertilization of the ovum since:
▪ The fluid of the vas deferens is relatively acidic due to the presence of citric acid.
▪ Vaginal secretions are acidic (pH 3.5 to 4.0).

Question 13

This content makes up the bulkiest portion of the seminal fluid
A. Sperm from the vas deferens
B. Fluid from the seminal vesicles
C. Fluid from the prostate gland
D. Fluid from mucous glands, especially the bulbourethral glands

Answer 13

B. Fluid from the seminal vesicles
▪ Sperm from the vas deferens (10%)
▪ Fluid from the seminal vesicles (60%, mucoid consistency)
▪ Fluid from the prostate gland (30%, alkalinity and milky appearance)
▪ Small amounts from the mucous glands, especially the bulbourethral glands

Question 14

This content of the prostatic fluid forms a weak fibrin coagulum that holds the semen in the deeper regions of vagina where the uterine cervix lies

Answer 14

Clotting enzymes

Question 15

Which of the following statements is TRUE?
A. Sperm removed from seminiferous tubules are motile and can fertilize the ovum immediately
B. The anterior 2/3 of the head is a thick cap called the axoneme which contains enzymes such as hyaluronidase and proteolytic enzymes
C. Capacitation is the process wherein the sperm mature inside the epididymis
D. The seminal vesicles produce prostaglandin which causes reverse peristaltic contractions in the uterus and fallopian tubes to move the ejaculated sperm toward the ovaries

Answer 15

D. The seminal vesicles produce prostaglandin which causes reverse peristaltic contractions in the uterus and fallopian tubes to move the ejaculated sperm toward the ovaries

• Prostaglandins are believed to aid fertilization in two ways:
→ By reacting with the female cervical mucus to make it more receptive to sperm movement.
→ By possibly causing backward, reverse peristaltic contractions in the uterus and fallopian tubes to move the ejaculated sperm toward the ovaries.

Question 16

While the spermatozoa remain in the fluid of the male genital ducts, they are continually exposed to large amounts of _______ which is continually added to the cellular membrane covering the sperm acrosome, toughening the membrane and preventing release of its enzymes.

Answer 16

Cholesterol

Question 17

Important ion to cause change in the activity of the flagellum – giving it a powerful whiplash motion, and in the cellular membrane that cover the leading edge of the acrosome making it possible for the acrosome to release its enzymes rapidly and easily as the sperm penetrate the granulosa cell mass surrounding the ovum – even more so as it attempts to penetrate the zona pellucida of the ovum.

Answer 17

Calcium

Question 18

Most important source of sensory nerve signals for initiating the male sexual act

Answer 18

Glans penis

Question 19

Which of the following statements is TRUE?
A. Lubrication is a sympathetic response wherein mucus flows from urethral and bulbourethral glands during intercourse
B. Nitric oxide activates the enzyme guanylyl cyclase, increasing cyclic GMP, which relaxes the arteries of the penis and the trabecular meshwork of smooth muscle fibers in erectile tissue
C. Ejaculation is the term used to describe the process of the contraction of the vas deferens and the ampulla to cause expulsion of sperm into the internal urethra
D. Erection is caused by parasympathetic impulses that pass from the lumbar portion of the spinal cord through the pelvic nerves to the penis

Answer 19

B. Nitric oxide activates the enzyme guanylyl cyclase, increasing cyclic GMP, which relaxes the arteries of the penis and the trabecular meshwork of smooth muscle fibers in erectile tissue

Penile erection
→ Believe to release NO and/or vasoactive intestinal peptide (VIP) in addition to acetylcholine (ACh)

Question 20

Filling of the internal urethra with semen elicits sensory signals during ejaculation is thru which nerves?

Answer 20

pudendal nerves to the sacral regions of the cord

Question 21

The entire period of ______ and ______ is called the male orgasm

Answer 21

emission and ejaculation

Question 22

Free cholesterol is transferred to the outer mitochondrial membrane and then to the inner mitochondrial membrane in a _________ protein-dependent manner

Answer 22

steroidogenic acute regulatory (StAr)

Question 23

A bifunctional enzyme with hydroxylase activity and lyase activity for gonads and adrenal glands

Answer 23

CYP17 is a bifunctional enzyme with 17-hydroxylase activity and 17,20-lyase activity

Question 24

Androstenedione → Testosterone is catalyzed by

Answer 24

17β-hydroxysteroid dehydrogenase (17β-HSD type 3)

Question 25

Gene that Encodes testis determining factor

Answer 25

SRY gene

Question 26

Stimulus for descent of the testes is ______

Answer 26

testosterone

Question 27

True or False:

Large quantities of androgenic hormones may cause baldness

Answer 27

True
Baldness is a result of two factors: genetic background for the development of baldness and superimposed in this genetic background, large quantities of androgenic hormones

A man who does not have functional testes does not become bald

Question 28

True or False:

Increased metabolic rate of testosterone is possibly an INDIRECT result its effect on protein anabolism

Answer 28

True

Question 29

True or False:

Testosterone directly increases erythropoietin levels and has a direct effect on red blood cell production.

Answer 29

False:
Testosterone does not appear to directly increase erythropoietin levels or have a direct effect on red blood cell production.

Question 30

Testosterone is secreted by the interstitial cells of Leydig in the testes, but only when they are stimulated by _____ from the anterior pituitary gland

Answer 30

LH

Question 31

Hormones necessary to initiate spermatogenesis

Answer 31

FSH and Testosterone

Question 32

ACTH produces GnRH, a 10-amino acid peptide secreted by the cell bodies located in the _____ nuclei of the hypothalamus

Answer 32

Arcuate