Male Reproductive System Flashcards
Which compartment of the seminiferous tubules contains the primary endocrine cell of the testis?
Peritubular compartment
Leydig cells
Large cells with overflowing cytoplasmic envelopes that surround the developing spermatogonia all the way to the central lumen of the tubule.
Sertoli cells
Which stage of spermatogenesis do the 46 chromosomes divide to produce haploid cells?
Secondary spermatocyte to spermatids
→ Thus, 23 chromosomes go to one spermatid and the other 23 go to the second spermatid.
In mitotic spermatogenesis, stem cells called _______ reside at the basal level of the seminiferous epithelium
spermatogonia
Thick cap located outside of the anterior two thirds of the head of the spermatozoon that is formed mainly from the Golgi apparatus
Acrosome
Enzyme of the acrosome which can digest proteoglycan filaments of tissues
Hyaluronidase
True or False:
Flagellar movement is a rhythmical transverse sliding motion between the anterior and posterior tubules that make up the axoneme
False: it’s a longitudinal sliding motion
Essential hormone for spermiogenesis to occur
FSH
- stimulates the Sertoli cells; without this stimulation, the conversion of the spermatids to sperm (the process of spermiogenesis) will not occur.
Hormone that stimulates Estrogen formation from testosterone by the Sertoli cells
FSH
Hormone that promotes early division of the spermatogonia themselves
Growth Hormone
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
alkaline medium
Activity is greatly oppressed in slightly acidic medium
Gland that secretes alkaline thin milky fluid containing calcium, citrate ion, phosphate ion, clotting enzyme, fibrinolysin.
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).
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
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
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
Clotting enzymes
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
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.
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.
Cholesterol
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.
Calcium
Most important source of sensory nerve signals for initiating the male sexual act
Glans penis
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
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)
Filling of the internal urethra with semen elicits sensory signals during ejaculation is thru which nerves?
pudendal nerves to the sacral regions of the cord
The entire period of ______ and ______ is called the male orgasm
emission and ejaculation
Free cholesterol is transferred to the outer mitochondrial membrane and then to the inner mitochondrial membrane in a _________ protein-dependent manner
steroidogenic acute regulatory (StAr)
A bifunctional enzyme with hydroxylase activity and lyase activity for gonads and adrenal glands
CYP17 is a bifunctional enzyme with 17-hydroxylase activity and 17,20-lyase activity
Androstenedione → Testosterone is catalyzed by
17β-hydroxysteroid dehydrogenase (17β-HSD type 3)
