Male Reproductive System Flashcards
Wollfian duct
Will form the vas deferens in males
Mullerian duct
Will form the oviduct/uterus in females
Male reproductive system consists of ______
testes, genital ducts, accessory glands, and penis
Testes
Have different cell types that (1) produce sperm and (2) secrete hormones
such as testosterone, which drives male reproductive physiology.
Cryptorchidism
The failure of one or both
testes to descend from the abdomen
Tunica albuginea
A dense connective tissue capsule that surrounds each testis
Testicular lobules
The testis is subdivided into about 250 compartments or testicular lobules. Each contains:
1-4 highly convoluted seminiferous tubules in which sperm production occurs.
Connective tissue, in the space between the tubules, with endocrine interstitial
cells (Leydig cells) secreting testosterone.
Seminiferous tubules
Produce sperm by spermatogenesis and spermiogenesis.
Each tubule is a loop linked by a short segment, the straight tubule, to the
rete testis, a maze of epithelium-lined channels.
Each seminiferous tubule is lined with a stratified epithelium called germinal or spermatogenic epithelium
“Germ cells” or spermatogenic cells
Develop into spermatozoa.
Sertoli cells
Form the epithelial walls; these nourish developing sperm cells.
Myoid cells
Contract the seminiferous tubules.
Spermatogenesis
Germ cells undergo a series of changes,
including reduction of chromosomes from 46 (diploid) to 23 (haploid), up to the spermatid stage.
Involves mitosis and meiosis.
Spermiogenesis
Spermatids transform to spermatozoa.
Follows spermatogenesis; it is the final differentiation
process.
Interstitial cells (Leydig cells)
Interstitial tissue between the tubules is sparse connective tissue containing interstitial cells (Leydig cells), which
produce testosterone.
Sertoli cells functions
Support, protection, and nutrition of the developing spermatogenic cells
Exocrine and endocrine secretion
Phagocytosis
Blood-testis barrier
Tight occluding junctions between the basolateral membranes of Sertoli cells form a blood-testis barrier. This prevents autoimmune
attacks against the unique spermatogenic cells, which appear after the immune system is mature and central self-tolerance is established.
Spermatogenesis &
Spermiogenesis Process
Type A spermatogonia
Type B spermatogonia
1° spermatocytes
2° spermatocytes
Spermatids
Spermatozoa
Testicular cancer
Most (95%) testicular cancer involves germ cell tumors, which only appear after puberty and are much more likely to develop in men
with untreated cryptorchidism.
Straight tubules
Function: Convey sperm into the rete testis
The seminiferous tubules drain into short, much narrower straight tubules, which connect to the rete testis
Rete testis
Function: Channels with sperm from all seminiferous tubules
A network of channels embedded along with blood vessels in the connective tissue of the mediastinum testis.
Efferent ductule
Function: Absorb most fluid form seminiferous tubules; convey sperm into the epididymis
Epididymal duct (Epididymis)
Function: Site for sperm maturation and short-term storage; expels sperm at ejaculation
Ductus (vas) deferens
Function: Carries sperm by rapid peristalsis from the epididymis to the ejaculatory ducts
Ejaculatory ducts
Function: Mix sperm and seminal fluid; deliver semen to urethra, where prostatic secretion is added
Vasectomy
A very small incision is made through the scrotal skin near the two ducts and each vas deferens is exposed, cut, and the ends are cauterized and tied.
Semen
The mixture of spermatozoa and the secretions of seminal vesicles, prostate, and bulbourethral glands
Seminal Vesicles
Exocrine glands in which
production of their yellowish secretion depends on
testosterone. Seminal vesicle fluid typically makes up about 70% of the ejaculate. Its components include:
Fructose, a major energy source for sperm
Prostaglandins, which stimulate activity in the female reproductive tract
Fibrinogen, which allows semen to coagulate after ejaculation.
Prostate Gland
A collection of 30-50 tubuloacinar glands
embedded smooth muscle which contracts at ejaculation.
A contributor to the volume of seme
Common prostate gland problems
Chronic prostatitis, usually involving bacteria.
Nodular hyperplasia or benign prostatic hypertrophy,
occurring mainly in the mucosal glands where it often leads to compression of the urethra and problems with urination.
Prostate cancer (an adenocarcinoma), the most common cancer in nonsmoking men, occurring mainly in glands.
Bulbourethral Glands (Cowper glands)
Each gland has tubuloacinar secretory units surrounded by smooth muscle cells and lined by a mucus-secreting epithelium.
During erection, release a clear mucus-like secretion
that coats and lubricates the urethra for the imminent passage of semen.
Three erectile bodies
corpus spongiosum and two corpora cavernosa
Penile erection
Parasympathetic stimulation:
relaxes the smooth muscle and dilates the tiny arteries, this enlarges the corpora cavernosa and causes them to compress the dorsal veins against the tunica albuginea, which blocks the venous outflow and produces tumescence (swelling) and rigidity in the erectile tissue.
Sympathetic stimulation:
Beginning at ejaculation, constricts the tiny arteries and trabecular muscle, decreasing blood flow into the spaces, lowering the pressure there, and allowing the veins to drain most blood from the erectile tissue.
Erectile dysfunction
At the beginning of an erection, acetylcholine from
parasympathetic nerves causes the helicine
arteries (tiny arteries) and erectile tissue to release
a signaling molecule (cyclic GMP) that causes vasodilation. This molecule is degraded eventually
by enzyme, relaxing the vasodilation.
The drug sildenafil (Viagra) may alleviate the
problem by inhibiting the enzyme that degrades
cyclic GMP in the smooth muscle cells of the
erectile tissue. This promotes relaxation of these cells to maintain an erection.
What is the main effect of benign prostatic hypertrophy?
Difficulty with urination.
What is the important function of the blood-testis barrier?
It prevents autoimmune attacks against the spermatogenic cells. These attacks occur because the innate immune system is established before spermatozoa begin to develop.
Which mass of erectile tissue surrounds the penile urethra?
Corpus spongiosum
The pathway of a spermatozoon from the seminiferous tubules to the urethra is:
Straight tubule, rete testis, efferent ductules, epididymis, vas deferens
The dense connective tissue capsule that surrounds each testis is called the
Tunica albuginea
Why is a male child with undescended testes likely to be come infertile?
The temperature within the body is too warm for sperm to develop properly.
Reversed prompt
Will form the vas deferens in males
Wollfian duct
Reversed prompt
Will form the oviduct/uterus in females
Mullerian duct
Reversed prompt
testes, genital ducts, accessory glands, and penis
Male reproductive system consists of ______
Reversed prompt
Have different cell types that (1) produce sperm and (2) secrete hormones
such as testosterone, which drives male reproductive physiology.
Testes
Reversed prompt
The failure of one or both
testes to descend from the abdomen
Cryptorchidism
Reversed prompt
A dense connective tissue capsule that surrounds each testis
Tunica albuginea
Reversed prompt
The testis is subdivided into about 250 compartments or testicular lobules. Each contains:
1-4 highly convoluted seminiferous tubules in which sperm production occurs.
Connective tissue, in the space between the tubules, with endocrine interstitial
cells (Leydig cells) secreting testosterone.
Testicular lobules
Reversed prompt
Produce sperm by spermatogenesis and spermiogenesis.
Each tubule is a loop linked by a short segment, the straight tubule, to the
rete testis, a maze of epithelium-lined channels.
Each seminiferous tubule is lined with a stratified epithelium called germinal or spermatogenic epithelium
Seminiferous tubules
Reversed prompt
Develop into spermatozoa.
“Germ cells” or spermatogenic cells
Reversed prompt
Form the epithelial walls; these nourish developing sperm cells.
Sertoli cells
Reversed prompt
Contract the seminiferous tubules.
Myoid cells
Reversed prompt
Germ cells undergo a series of changes,
including reduction of chromosomes from 46 (diploid) to 23 (haploid), up to the spermatid stage.
Involves mitosis and meiosis.
Spermatogenesis
Reversed prompt
Spermatids transform to spermatozoa.
Follows spermatogenesis; it is the final differentiation
process.
Spermiogenesis
Reversed prompt
Interstitial tissue between the tubules is sparse connective tissue containing interstitial cells (Leydig cells), which
produce testosterone.
Interstitial cells (Leydig cells)
Reversed prompt
Support, protection, and nutrition of the developing spermatogenic cells
Exocrine and endocrine secretion
Phagocytosis
Sertoli cells functions
Reversed prompt
Tight occluding junctions between the basolateral membranes of Sertoli cells form a blood-testis barrier. This prevents autoimmune
attacks against the unique spermatogenic cells, which appear after the immune system is mature and central self-tolerance is established.
Blood-testis barrier
Reversed prompt
Type A spermatogonia
Type B spermatogonia
1° spermatocytes
2° spermatocytes
Spermatids
Spermatozoa
Spermatogenesis &
Spermiogenesis Process
Reversed prompt
Most (95%) testicular cancer involves germ cell tumors, which only appear after puberty and are much more likely to develop in men
with untreated cryptorchidism.
Testicular cancer
Reversed prompt
Function: Convey sperm into the rete testis
The seminiferous tubules drain into short, much narrower straight tubules, which connect to the rete testis
Straight tubules
Reversed prompt
Function: Channels with sperm from all seminiferous tubules
A network of channels embedded along with blood vessels in the connective tissue of the mediastinum testis.
Rete testis
Reversed prompt
Function: Absorb most fluid form seminiferous tubules; convey sperm into the epididymis
Efferent ductule
Reversed prompt
Function: Site for sperm maturation and short-term storage; expels sperm at ejaculation
Epididymal duct (Epididymis)
Reversed prompt
Function: Carries sperm by rapid peristalsis from the epididymis to the ejaculatory ducts
Ductus (vas) deferens
Reversed prompt
Function: Mix sperm and seminal fluid; deliver semen to urethra, where prostatic secretion is added
Ejaculatory ducts
Reversed prompt
A very small incision is made through the scrotal skin near the two ducts and each vas deferens is exposed, cut, and the ends are cauterized and tied.
Vasectomy
Reversed prompt
The mixture of spermatozoa and the secretions of seminal vesicles, prostate, and bulbourethral glands
Semen
Reversed prompt
Exocrine glands in which
production of their yellowish secretion depends on
testosterone. Seminal vesicle fluid typically makes up about 70% of the ejaculate. Its components include:
Fructose, a major energy source for sperm
Prostaglandins, which stimulate activity in the female reproductive tract
Fibrinogen, which allows semen to coagulate after ejaculation.
Seminal Vesicles
Reversed prompt
A collection of 30-50 tubuloacinar glands
embedded smooth muscle which contracts at ejaculation.
A contributor to the volume of seme
Prostate Gland
Reversed prompt
Chronic prostatitis, usually involving bacteria.
Nodular hyperplasia or benign prostatic hypertrophy,
occurring mainly in the mucosal glands where it often leads to compression of the urethra and problems with urination.
Prostate cancer (an adenocarcinoma), the most common cancer in nonsmoking men, occurring mainly in glands.
Common prostate gland problems
Reversed prompt
Each gland has tubuloacinar secretory units surrounded by smooth muscle cells and lined by a mucus-secreting epithelium.
During erection, release a clear mucus-like secretion
that coats and lubricates the urethra for the imminent passage of semen.
Bulbourethral Glands (Cowper glands)
Reversed prompt
corpus spongiosum and two corpora cavernosa
Three erectile bodies
Reversed prompt
Parasympathetic stimulation:
relaxes the smooth muscle and dilates the tiny arteries, this enlarges the corpora cavernosa and causes them to compress the dorsal veins against the tunica albuginea, which blocks the venous outflow and produces tumescence (swelling) and rigidity in the erectile tissue.
Sympathetic stimulation:
Beginning at ejaculation, constricts the tiny arteries and trabecular muscle, decreasing blood flow into the spaces, lowering the pressure there, and allowing the veins to drain most blood from the erectile tissue.
Penile erection
Reversed prompt
At the beginning of an erection, acetylcholine from
parasympathetic nerves causes the helicine
arteries (tiny arteries) and erectile tissue to release
a signaling molecule (cyclic GMP) that causes vasodilation. This molecule is degraded eventually
by enzyme, relaxing the vasodilation.
The drug sildenafil (Viagra) may alleviate the
problem by inhibiting the enzyme that degrades
cyclic GMP in the smooth muscle cells of the
erectile tissue. This promotes relaxation of these cells to maintain an erection.
Erectile dysfunction
