Anatomy of Male Reproductive System Flashcards
What is the function of the ductus (vas) deferens in the male reproductive system?
The ductus deferens transports sperm from the epididymis to the urethra during ejaculation
Where does the ductus deferens begin and end?
The ductus deferens begins in the epididymis, passes through the inguinal canal, and ends at the ejaculatory duct, where it joins with the seminal vesicle.
What is the function of the scrotum in the male reproductive system?
The scrotum is a sac that contains the testes and spermatic cord, helping regulate the temperature of the testes for optimal sperm production.
How does the scrotum help regulate the temperature of the testes?
The scrotum adjusts its position (via the dartos and cremaster muscles) to maintain the testes at a cooler temperature, which is necessary for sperm production.
What is the function of the testes in the male reproductive system?
The testes are the biological male gonads responsible for producing sperm and secreting male sex hormones (e.g., testosterone).
What structures are found inside the testes and what are their functions?
The testes contain seminiferous tubules (where sperm are produced), interstitial cells (which secrete testosterone), and the rete testis (a network of tubules where sperm mature).
What is the role of the epididymis in the male reproductive system?
The epididymis stores and matures spermatozoa. It is where sperm gain motility and are stored until ejaculation.
What are the parts of the epididymis?
The epididymis consists of three parts: the head (where sperm enter), the body (where sperm mature), and the tail (where sperm are stored).
What are the accessory reproductive glands and their function in sperm production?
The accessory reproductive glands include the seminal vesicles, prostate glands, and bulbourethral glands. These glands produce seminal fluid, which nourishes, protects, and facilitates the movement of sperm
What is the function of the seminal vesicle in sperm production?
The seminal vesicle secretes a fluid that is rich in fructose, which provides energy to the sperm, and prostaglandins, which aid in sperm motility.
What role does the prostate gland play in the male reproductive system?
The prostate gland secretes an alkaline fluid that neutralizes the acidity of the vaginal environment, helping to protect sperm and enhance fertilization potential.
What is the function of the bulbourethral glands (Cowper’s glands)?
The bulbourethral glands produce a clear, viscous fluid that lubricates the urethra and neutralizes any acidic residues remaining from urine.
What is the role of the penis in the male reproductive system?
The penis is responsible for the ejaculation of sperm and the excretion of urine. It contains the urethra, which serves as the passage for both.
What are the parts of the penis and their functions?
The penis consists of three parts: the root (attached to the pubic symphysis), the body (shaft), and the glans (the tip). The corpora cavernosa and corpus spongiosum are the erectile tissues that enable erection.
What are the external and internal genital organs in the male reproductive system?
The external genital organs include the penis and scrotum, while the internal genital organs include the testes, epididymis, ductus deferens, seminal vesicles, prostate gland, and bulbourethral glands.
What role do the internal genital organs play in reproduction?
The internal genital organs are responsible for the production, maturation, storage, and transportation of sperm (testes, epididymis, ductus deferens) and the secretion of seminal fluid (seminal vesicles, prostate gland, bulbourethral glands).
What are the key components of the scrotum?
The scrotum consists of skin, dartos fascia, and the spermatic cord. The dartos fascia is responsible for wrinkling the skin to help regulate temperature.
How does the scrotum divide into two parts?
The scrotum is divided into left and right compartments by a septum, which is externally marked by the scrotal raphe.
What is the function of the scrotal raphe?
The scrotal raphe is the external marking of the internal septum that divides the scrotum into left and right halves, each containing one testis and its associated spermatic cord.
Why are the male gonads (testes) externalized from the abdominopelvic cavity?
The testes are externalized from the abdominopelvic cavity to maintain a lower temperature (about 2-3°C lower than the body temperature), which is optimal for spermatogenesis.
How does the scrotum adjust its position to regulate temperature?
The cremaster muscle raises or lowers the testes in response to temperature changes, bringing them closer to or farther from the body. The dartos muscle causes the scrotum to wrinkle or relax, which helps conserve or dissipate heat.
What could happen if the temperature of the scrotum is too high for an extended period?
If the scrotal temperature is too high, it can impair spermatogenesis, leading to reduced sperm count and potentially causing infertility.
What is the function of the seminiferous tubules in the testes?
The seminiferous tubules are responsible for the production of spermatozoa (sperm cells) through a process called spermatogenesis.
How many seminiferous tubules are typically found in each testis?
Each testis contains approximately 400-600 seminiferous tubules.
What cells within the seminiferous tubules are involved in the production of sperm?
Sertoli cells provide support and nourishment for developing sperm, while spermatogenic cells undergo mitosis and meiosis to produce spermatozoa.
What is the overall shape and location of the testes?
The testes are paired, oval-shaped gonads suspended in the scrotum by the spermatic cord.
What is the thick outer capsule surrounding the testes called?
The tunica albuginea is a thick, fibrous capsule surrounding the testes that provides structural support.
What is the function of the tunica albuginea in the testes?
The tunica albuginea protects the testes and provides a barrier, maintaining the integrity of the testicular structure.
What role do Leydig cells play in the testes?
Leydig cells (also known as interstitial cells) are located between the seminiferous tubules and are responsible for producing androgens, primarily testosterone.
Why is testosterone important for male reproductive health?
Testosterone is crucial for the development of male secondary sexual characteristics, spermatogenesis, and libido.
What is the role of the epididymis in the male reproductive system?
The epididymis stores and matures spermatozoa. It is where sperm gain motility and are stored until ejaculation.
How is the epididymis anatomically related to the testes?
The epididymis is a coiled tube that lies on the posterior surface of each testis and connects to the ductus deferens.
What is the function of the rete testis?
The rete testis is a network of tubules within the testis that collects sperm from the seminiferous tubules and transports them to the efferent ductules
How is the rete testis connected to the rest of the male reproductive system?
:The rete testis connects to the efferent ductules, which then carry sperm to the epididymis.
What are the efferent ductules, and what is their function?
The efferent ductules are 12-20 small ducts that penetrate the tunica albuginea and connect the rete testis to the epididymis, facilitating sperm transport.
What is the role of the straight tubules in the testes?
The straight tubules (tubuli recti) carry sperm from the seminiferous tubules to the rete testis.
What structures are contained within the spermatic cord?
The spermatic cord contains the testicular artery, pampiniform plexus (venous network), ductus deferens, nerves, and lymphatic vessels.
What is the function of the spermatic cord?
The spermatic cord supports the testes, transmits blood supply, and connects the testes to the abdominal cavity via the inguinal canal.
Where do the gonads (testes or ovaries) initially develop in the body?
The gonads develop in the abdomen, near the posterior abdominal wall.
What happens to the gonads after they develop in the abdomen?
The gonads descend inferiorly towards the labioscrotal swelling.
How do the testes travel from their initial position in the abdomen to the scrotum?
The testes travel into the scrotum by moving through the abdominal wall, picking up layers of the wall as they descend.
Why do the testes need to descend into the scrotum?
The testes need to be outside the body at a cooler temperature to produce sperm properly.
Where do the ovaries remain during development?
The ovaries remain in the pelvis and do not descend like the testes.
What is the labioscrotal swelling?
The labioscrotal swelling is a structure towards which the gonads (testes or ovaries) move during development. In males, it eventually forms the scrotum.
What is the processus vaginalis?
The processus vaginalis is an invagination of the peritoneum that forms a tubular extension of the peritoneal cavity.
What does the processus vaginalis do during testicular descent?
The testes, along with the neurovasculature, herniate through the layers of the abdominal wall along the path formed by the gubernaculum and the processus vaginalis.
What anatomical structure is formed by the processus vaginalis?
The inguinal canal is formed as the testes descend through the abdominal wall.
What is the function of the gubernaculum?
The gubernaculum is a cord-like structure that guides the gonads (testes) from the posterior abdominal wall towards the labioscrotal swelling.
What surrounds the testes and spermatic cord after descent?
After descent, the testes and spermatic cord are surrounded by musculofascial layers from the abdominal wall.
What layers form the scrotum, and how are they derived from abdominal structures?
- Skin
- Dartos fascia (continuous with Colles’ fascia and derived from Scarpa’s fascia)
- External spermatic fascia (from external oblique aponeurosis)
- Cremasteric muscle and fascia (from internal oblique muscle and fascia)
- Internal spermatic fascia (from transversalis fascia)
What is the vascular supply of the scrotum?
- Arterial supply: Anterior scrotal arteries (from external pudendal artery) and posterior scrotal arteries (from internal pudendal artery).
- Venous drainage: Scrotal veins correspond to the arteries.
What is the innervation of the Scrotum?
Innervation:
- Anterior: Ilioinguinal nerve and genital branch of the genitofemoral nerve (L1-L2).
- Posterior: Posterior scrotal nerves (from pudendal nerve).
What is the lymphatic drainage of the scrotum?
Superficial inguinal lymph nodes.
Describe the layers surrounding the testis.
- External: Tunica vaginalis (parietal and visceral layers).
- Deep: Tunica albuginea (dense connective tissue).
What is the blood supply, venous and lymphatic drainage of the testis?
- Arterial supply: Testicular artery (from abdominal aorta).
- Venous drainage: Pampiniform venous plexus → Testicular vein → Left renal vein (left side) or IVC (right side).
- Lymphatic drainage: Para-aortic (lumbar) lymph nodes.
What are the clinical features of the testis on examination?
Smooth, firm, and oval. Normal size: ~4-5 cm long.
What zones make up the prostate, and which is most prone to BPH and carcinoma?
- Zones: Peripheral, central, transitional, and anterior fibromuscular zone.
- BPH: Transitional zone.
- Carcinoma: Peripheral zone.
What is the lymphatic drainage of the prostate?
Internal iliac and sacral lymph nodes.
What is the blood supply and venous drainage of the penis?
Arterial supply: Deep arteries of the penis, dorsal arteries of the penis (branches of internal pudendal artery).
Venous drainage: Deep dorsal vein → Prostatic venous plexus.
What are the components of the spermatic cord?
-Ductus deferens
-Testicular artery
-Pampiniform plexus
-Genital branch of the genitofemoral nerve
-Lymphatics
-Cremasteric artery
Describe the course of the ductus deferens.
Passes through the inguinal canal, crosses the external iliac vessels, and enters the pelvic cavity to join the seminal vesicle and form the ejaculatory duct.
How is erection of the penis mediated?
Innervation: Parasympathetic fibers (S2-S4) via pelvic splanchnic nerves.
Mechanism: Release of nitric oxide → Smooth muscle relaxation in cavernous tissue → Blood engorgement.
What mechanisms control emission and ejaculation?
- Emission: Sympathetic fibers (T10-L2).
- Ejaculation: Combination of somatic (pudendal nerve) and autonomic control.
Clinical Significance: What is testicular torsion, and why is it an emergency?
Twisting of the spermatic cord compromises blood supply, leading to ischemia and potential testicular necrosis.
What is a varicocele, and how does it form?
Dilatation of the pampiniform plexus, often on the left due to venous drainage into the left renal vein under higher pressure.
Why is lymphatic drainage significant in testicular tumors?
Tumors spread to para-aortic lymph nodes, following testicular embryological origin.
What are the layers of the tunica vaginalis?
Parietal layer
Cavity of tunica vaginalis
Visceral layer
What muscle elevates the testes, and what is its innervation?
Cremasteric muscle, supplied by the genital branch of the genitofemoral nerve (L1-L2).
What is the function of the cremasteric muscle?
Contraction of the cremasteric muscle elevates the testes for thermoregulation, helping to maintain optimal temperature for spermatogenesis.
What nerve supplies the cremasteric muscle?
The genital branch of the genitofemoral nerve (L1-L2).
What triggers contraction of the cremasteric muscle?
Reflex actions (e.g., cold temperature or light stroking of the inner thigh) can stimulate the contraction as part of the cremasteric reflex.
Clinical Significance: What is a hydrocele?
A hydrocele is the accumulation of excess serous fluid within the tunica vaginalis or spermatic cord.
What causes a hydrocele in the spermatic cord?
Excess fluid in a persistent processus vaginalis.
What causes a hydrocele in the testis?
Increased fluid secretion from the visceral layer of the tunica vaginalis.
How is a hydrocele detected during a clinical examination?
Positive transillumination test — light shines through the excess serous fluid when a light source is applied to the scrotum.
What are the layers of the scrotum and Testis?
“Some Damn Englishman Called It The Testis”:
Skin
Dartos fascia and muscle
External spermatic fascia
Cremasteric fascia
Internal spermatic fascia
Tunica vaginalis
Tunica albuginea
What are the three main parts of the epididymis?
Head (caput), body (corpus), and tail (cauda).
Which part of the epididymis receives spermatozoa from the testes?
The head (caput) receives spermatozoa from the efferent ductules of the testes.
What is the primary function of the epididymis?
To store and mature spermatozoa.
Describe the shape and structure of the epididymis.
It is an elongated, comma-shaped structure formed by a long, highly coiled tube.
How does spermatozoa move from the epididymis to the ductus deferens?
Spermatozoa pass from the tail (cauda) of the epididymis into the ductus (vas) deferens.
What type of epithelium lines the epididymis, and what unique feature does it possess?
The epididymis is lined with pseudostratified columnar epithelium with stereocilia, which increase surface area for absorption and secretion.
What is the function of the ductus deferens?
To transport mature spermatozoa from the epididymis to the ejaculatory ducts in anticipation of ejaculation.
Describe the course of the ductus deferens from the epididymis to the ejaculatory duct.
It ascends within the spermatic cord, passes through the inguinal canal, crosses over the external iliac vessels into the pelvic cavity, and joins the duct of the seminal vesicle to form the ejaculatory duct.
What is the relationship between the ductus deferens and the spermatic cord?
The ductus deferens is a component of the spermatic cord.
What type of muscle comprises the wall of the ductus deferens, and what is its role?
It is composed of smooth muscle, which contracts to propel spermatozoa during ejaculation.
How does the ductus deferens contribute to the formation of the ejaculatory duct?
It merges with the duct of the seminal vesicle to form the ejaculatory duct.
What structures are contained within the spermatic cord?
The ductus deferens, testicular artery, pampiniform plexus of veins, lymphatic vessels, autonomic nerves, and the cremasteric muscle fibers.
Through which anatomical passage does the spermatic cord travel?
The inguinal canal.
What is the function of the pampiniform plexus within the spermatic cord?
To cool the arterial blood entering the testes, aiding in temperature regulation essential for spermatogenesis.
Which muscle associated with the spermatic cord aids in elevating the testes for thermoregulation?
The cremaster muscle.
What is the significance of the spermatic cord in relation to testicular torsion?
Twisting of the spermatic cord can lead to testicular torsion, cutting off blood supply to the testis and constituting a surgical emergency.
What are the main components contained within the spermatic cord?
The spermatic cord contains:
- 3 Arteries: Testicular artery, Cremasteric artery, Artery to the ductus deferens
- 3 Nerves: Autonomic nerves (sympathetic and parasympathetic fibers), Genital branch of the genitofemoral nerve (L1–L2), Ilioinguinal nerve (L1)
- 3 Other Structures: Ductus (vas) deferens, Lymphatic vessels, Pampiniform plexus of veins
Into which veins do the right and left testicular veins drain?
- The right testicular vein drains into the inferior vena cava (IVC).
- The left testicular vein drains into the left renal vein.
From which major artery do the testicular arteries arise?
The testicular arteries arise from the abdominal aorta.
Through which anatomical structure does the spermatic cord travel to connect the scrotum to the abdomen?
The spermatic cord travels through the inguinal canal.
How does the cremaster muscle contribute to testicular thermoregulation?
Contraction of the cremaster muscle elevates the testes, bringing them closer to the body to increase temperature; relaxation lowers the testes away from the body to decrease temperature, thus maintaining optimal conditions for spermatogenesis.
hat are the three fascial layers surrounding the spermatic cord, and from which abdominal wall layers are they derived?
- External spermatic fascia: Derived from the external oblique aponeurosis.
- Cremasteric fascia and muscle: Derived from the internal oblique muscle and fascia.
- Internal spermatic fascia: Derived from the transversalis fascia.
What is the role of the pampiniform plexus within the spermatic cord?
The pampiniform plexus is a network of veins that surrounds the testicular artery, functioning to cool the arterial blood before it reaches the testes, thereby aiding in the regulation of testicular temperature essential for sperm production.
What is the primary function of the ductus (vas) deferens?
The ductus deferens transports mature spermatozoa from the epididymis to the ejaculatory ducts in anticipation of ejaculation.
What is the function of the genital branch of the genitofemoral nerve within the spermatic cord?
It provides motor innervation to the cremaster muscle and sensory innervation to parts of the scrotum.
Why is the spermatic cord clinically significant in conditions like testicular torsion?
- In testicular torsion, the spermatic cord twists, cutting off blood supply to the testis, which can lead to ischemia and necrosis if not promptly treated.
- Understanding the anatomy of the spermatic cord is crucial for diagnosing and managing such conditions.
What is testicular torsion, and how does it affect blood flow to the testicle?
Testicular torsion occurs when the spermatic cord twists, leading to compromised blood flow to the affected testicle. This can result in severe pain and potential tissue damage if not promptly treated.
What are the typical symptoms of testicular torsion?
Severe, sudden-onset testicular pain, swelling, tenderness, and absence of the cremasteric reflex.
Which diagnostic imaging is commonly used to confirm testicular torsion?
Scrotal ultrasound with Doppler to assess blood flow
What is the definitive treatment for testicular torsion?
Surgical detorsion and fixation (orchiopexy) to prevent recurrence.
Why is prompt treatment crucial in testicular torsion?
Delayed treatment can lead to testicular ischemia and necrosis, reducing the chance of testicular salvage.
What is a varicocele, and which veins are involved?
A varicocele is an enlargement of the veins within the scrotum, specifically the pampiniform plexus.
How does a varicocele typically present on physical examination?
As a “bag of worms” appearance upon palpation of the scrotum.
On which side is a varicocele more commonly found, and why?
More common on the left side due to the left testicular vein draining into the left renal vein at a right angle, causing turbulent flow.
What symptoms might a patient with a varicocele experience?
Dull ache in the scrotum, feeling of heaviness, or may be asymptomatic.
What potential complication is associated with varicocele?
Infertility due to impaired spermatogenesis.
Which imaging modality is used to confirm a varicocele?
Scrotal ultrasound showing dilated veins in the pampiniform plexus.
When is treatment indicated for a varicocele?
Treatment is indicated if the varicocele is symptomatic or associated with infertility.
Describe the course of the vas deferens from its origin to its termination.
- The vas deferens originates from the tail of the epididymis, ascends within the spermatic cord
- Passes through the inguinal canal into the pelvic cavity, travels over the bladder, and joins the duct of the seminal vesicle to form the ejaculatory duct
What is the primary function of the vas deferens?
The vas deferens transports mature sperm from the epididymis to the urethra in preparation for ejaculation.
Which structures accompany the vas deferens within the spermatic cord?
The spermatic cord contains the vas deferens, testicular artery, pampiniform plexus of veins, lymphatic vessels, autonomic nerves, and the cremasteric muscle.
Clinical Relevance: What is a vasectomy, and how does it affect male fertility?
A vasectomy is a surgical procedure involving the cutting and sealing of the vas deferens to prevent sperm from reaching the ejaculatory duct, thereby rendering a male infertile.
Explain the mnemonic “Water under the bridge” in relation to the vas deferens.
The mnemonic “Water under the bridge” refers to the ureter (“water”) passing underneath the vas deferens (“bridge”) as the latter crosses over it near the bladder.
What type of epithelium lines the vas deferens?
The vas deferens is lined with pseudostratified columnar epithelium
How many muscular layers are present in the vas deferens, and what are their orientations?
The vas deferens has three muscular layers: an inner longitudinal layer, a middle circular layer, and an outer longitudinal layer.
From which embryological structure does the vas deferens develop?
The vas deferens develops from the mesonephric (Wolffian) ducts.
Which artery primarily supplies blood to the vas deferens?
The vas deferens is primarily supplied by a branch of the superior vesical artery.
Into which veins does the venous blood from the vas deferens drain?
Venous blood from the vas deferens drains into the testicular veins.
Where are the seminal vesicles located in relation to the bladder and rectum?
The seminal vesicles are located posterior to the bladder and anterior to the rectum.
What type of fluid do the seminal vesicles secrete, and what are its main components?
The seminal vesicles secrete an alkaline fluid rich in fructose and coagulating enzymes.
Approximately what percentage of the total volume of seminal fluid is contributed by the seminal vesicles?
The seminal vesicles contribute about 70% to 85% of the total volume of seminal fluid.
What is the significance of the fructose present in the secretion of the seminal vesicles?
Fructose provides an energy source for spermatozoa, aiding in their motility and survival.
How does the alkaline nature of the seminal vesicle secretion benefit sperm?
The alkaline fluid helps neutralize the acidic environment of the female reproductive tract, enhancing sperm viability.
What role do the coagulating enzymes in the seminal vesicle secretion play?
Coagulating enzymes help in the formation of the seminal coagulum, which aids in sperm motility and protection.
Through which duct do the seminal vesicles secrete their fluid into the ejaculatory pathway?
The seminal vesicles secrete their fluid into the ejaculatory ducts, which then merge with the vas deferens.
What structures unite to form the ejaculatory duct?
The duct of the seminal vesicle joins the ampulla of the ductus (vas) deferens to form the ejaculatory duct.
Into which part of the urethra does the ejaculatory duct transport semen?
The ejaculatory duct transports semen into the prostatic urethra.
Where are the ejaculatory ducts located within the male reproductive system?
The ejaculatory ducts are located within the prostate gland.
What is the primary function of the ejaculatory ducts?
The primary function of the ejaculatory ducts is to transport semen from the vas deferens and seminal vesicles into the prostatic urethra during ejaculation.
What percentage of the total volume of seminal fluid is contributed by prostatic fluid?
The prostate gland contributes approximately 20–30% of the total volume of seminal fluid.
What surrounds the prostate gland?
The prostate gland is surrounded by a thick fibrous capsule.
What is a common condition affecting the prostate gland characterized by enlargement?
The prostate gland is prone to hypertrophy, commonly referred to as benign prostatic hyperplasia (BPH).
Which female glands are homologous to the male prostate gland?
The female paraurethral (Skene’s) glands are homologous to the male prostate gland.
Through which examination can the prostate be assessed via the rectum?
The prostate can be examined via a digital rectal exam (DRE).
What is the prostatic utricle, and what is its embryological origin?
The prostatic utricle is a blind-ended pouch located at the apex of the seminal colliculus. It is a remnant of the mesonephric duct and is considered the male homologue of the uterus.
What is the seminal colliculus, and what is its clinical significance?
The seminal colliculus, also known as the verumontanum, is a circular elevation of the urethral crest within the prostatic urethra. It serves as a landmark during transurethral resection of the prostate.
Where do the ducts of the prostate gland open, and what is their function?
The ducts of the prostate gland open into the prostatic sinuses, located on either side of the seminal colliculus. These ducts secrete prostatic fluid, contributing to the seminal fluid.
What is the urethral crest, and what structures are associated with it?
The urethral crest is a midline fold of mucosa in the prostatic urethra. It enlarges to form the seminal colliculus, which houses the prostatic utricle and the openings of the ejaculatory ducts.
What is the function of the internal urethral sphincter, and what type of muscle is it composed of?
The internal urethral sphincter is composed of smooth muscle and prevents retrograde travel of semen into the bladder during ejaculation.
Where is the external urethral sphincter located, and what type of muscle is it composed of?
The external urethral sphincter is composed of skeletal muscle and is located within the deep perineal pouch, alongside the bulbourethral glands.
EQ: Compare and contrast the internal and external urethral sphincters in terms of location, muscle type, and function within the male urethra.
Answer:
EQ: Explain the role of the seminal colliculus in the male reproductive system and its clinical significance during prostate surgery.
Describe the anatomical location and embryological origin of the prostatic utricle.
Which zone of the prostate surrounds the urethra and is most commonly affected by benign prostatic hyperplasia (BPH)?
The transitional zone surrounds the urethra and is the most common site for benign prostatic hyperplasia (BPH).
What are the common symptoms of benign prostatic hyperplasia (BPH), and how can it be detected during a rectal examination?
BPH commonly causes obstruction of urine flow. During a rectal examination, the prostate may feel “bulky.
Which zone of the prostate surrounds the ejaculatory ducts, and what is its significance in prostate cancer?
The central zone surrounds the ejaculatory ducts. It is responsible for only 2% of prostate cancers, but these are typically more aggressive.
What is the most common site for prostate cancer, and how does it typically present in terms of symptoms?
The peripheral zone is the most common site for prostate cancer, which is often relatively asymptomatic. During a rectal examination, it may feel “rock hard.”
What is the anterior region of the prostate made of, and why is it not considered a functional zone?
The anterior region of the prostate consists mainly of fibromuscular tissue and is not considered a functional zone due to the minimal glandular tissue present.
What structures are located in the central zone of the prostate?
The central zone surrounds the ejaculatory ducts as they enter the prostate.
EQ: Describe the anatomical zones of the prostate, and explain which zones are most commonly associated with benign prostatic hyperplasia and prostate cancer
EQ: Discuss the clinical findings of benign prostatic hyperplasia (BPH) and prostate cancer, and how these conditions can be identified during a rectal examination.
EQ: Why is the anterior region of the prostate not considered a functional zone, and what is its composition?
What is the anatomical relationship between the puboprostatic ligament and the prostate gland?
The puboprostatic ligament wraps around the prostate gland and attaches to the pubic symphysis, providing support to the prostate.
What is the function of the bulbourethral glands (Cowper’s glands) in the male reproductive system?
The bulbourethral glands secrete a clear fluid that lubricates the urethra and neutralizes residual acidity, preparing the urethra for the passage of sperm during ejaculation.
Where are the bulbourethral glands located anatomically?
The bulbourethral glands are embedded within the external urethral sphincter muscle in the deep perineal pouch, posterior to the membranous urethra.
What is the embryological homologue of the bulbourethral glands in females?
The bulbourethral glands are homologous to the greater vestibular (Bartholin’s) glands in females
What is the ductal pathway of the bulbourethral glands?
The ducts of the bulbourethral glands drain into the penile (spongy) urethra, releasing their secretion during sexual arousal.
What is the size and structure of the bulbourethral glands?
Each bulbourethral gland is approximately the size of a pea and is composed of several lobules enclosed within a fibrous capsule.
What is the role of the secretion from the bulbourethral glands during sexual arousal?
The secretion from the bulbourethral glands serves as a lubrication medium for the urethra and the tip of the penis, expels any residual urine or mucus, and neutralizes residual acidity in the male urethra.
EQ: Explain the role of the bulbourethral glands in the male reproductive system, including their embryological origin and ductal pathway.
EQ: Compare and contrast the bulbourethral glands and the greater vestibular glands in terms of their anatomical location, function, and embryological origin.
Describe the anatomical location and function of the puboprostatic ligament in the male pelvis.
What is the average length of the male urethra?
The male urethra is approximately 18 to 20 centimeters in length.
What are the three parts of the male urethra?
The male urethra consists of three parts:
Prostatic Urethra: Passes through the prostate gland.
Membranous Urethra: Passes through the external urethral sphincter.
Spongy (Penile) Urethra: Runs along the length of the penis.
What is the function of the internal urethral sphincter?
The internal urethral sphincter prevents retrograde ejaculation by preventing semen from entering the bladder during ejaculation.
Where is the external urethral sphincter located, and what is its function?
The external urethral sphincter is located within the deep perineal pouch and is responsible for voluntary control over urination.
What is the navicular fossa, and where is it located?
The navicular fossa is a slight dilation of the spongy urethra located at the tip of the glans penis.
What is the least dilatable part of the male urethra?
The membranous urethra is the least dilatable part of the male urethra.
What is the function of the bulbourethral glands?
The bulbourethral glands secrete a clear fluid that lubricates the urethra and neutralizes residual acidity, preparing the urethra for the passage of sperm during ejaculation.
What is the average length of the male urethra?
The male urethra is approximately 18 to 20 centimeters in length.
EQ: Describe the anatomical structure and function of the male urethra, including its three parts and associated sphincters.
What is the purpose of inflating the balloon in a transurethral catheter?
To maintain the catheter’s position in the bladder.
How can the external urethral meatus be located in biological females?
By using the clitoris as an anatomical landmark.
Why is catheterization generally easier in biological females compared to males?
The female urethra is shorter and has a straight passage.
What should be considered about the male urethra when performing catheterization?
It has two bends when the penis is flaccid, and the penis should be held at a right angle to the abdomen to straighten the urethra during the procedure.
What condition in biological males may make catheterization more difficult?
Benign prostatic hyperplasia (enlarged prostate).
What can excessive force during male catheterization cause?
Creation of a “false passage” by damaging the urethra.
Which part of the male urethra is most likely to be damaged during catheterization?
The membranous urethra.
Why is care essential when catheterizing males with benign prostatic hyperplasia?
The enlarged prostate may obstruct the urethral passage, increasing the risk of trauma or false passage formation.
What are the landmarks used to guide catheter insertion in biological males?
The bends of the urethra and the position of the penis at a right angle to the abdomen.
What are the two primary functions of the penis?
Outlet for semen and urine
In which position is the penis described as erect in anatomy?
The anatomical position.
How many cylindrical bodies of erectile tissue are present in the penis?
Three cylindrical bodies.
What are the paired cylindrical bodies of erectile tissue called, and where do they arise from?
The corpora cavernosa, which arise from the left and right crus (plural: crura).
What is the name of the single cylindrical body of erectile tissue in the penis?
The corpus spongiosum.
What structure does the corpus spongiosum contain?
The spongy urethra.
How does the corpus spongiosum expand distally and proximally?
It expands distally as the glans of the penis and proximally as the bulb of the penis.
What is the function of the corpora cavernosa in the body of the penis?
These are the primary erectile tissues in the body of the penis.
What is the anatomical significance of the left and right crus?
They are erectile tissues attached to the pubic bone and continue distally as the free corpus cavernosum.
What happens to the spongy urethra as it travels through the corpus spongiosum?
It remains surrounded by erectile tissue and exits at the external urethral meatus in the glans.
What are the three main parts of the penis?
The root, body (shaft), and glans.
Which muscles cover the root of the penis?
The bulbospongiosus and ischiocavernosus muscles.
What are the functions of the bulbospongiosus muscle?
It stabilizes the perineal body, assists in the expulsion of urine and semen, and aids in erection by increasing pressure in the bulb of the penis.
How does the ischiocavernosus muscle contribute to penile function?
It surrounds the left and right crura of the penis and contracts to force blood from the cavernous spaces in the crura into the corpora cavernosa, helping to maintain erection.
From where does the fundiform ligament arise, and what is its role?
It arises from the linea alba of the abdomen and supports the penis.
What is the origin and function of the suspensory ligament of the penis?
It arises from the pubic symphysis and supports the penis.
Which nerve provides innervation to the penis?
The perineal nerve, a branch of the pudendal nerve (S2 - S4).
What structures comprise the body (shaft) of the penis?
Paired corpora cavernosa and a single corpus spongiosum.
What are the components of the root of the penis?
The left and right crura (proximal parts of the corpora cavernosa) and the bulb (proximal part of the corpus spongiosum).
What is the glans of the penis, and what covers it?
The glans is the distal part of the corpus spongiosum, covered by the prepuce (foreskin).
Where is the external urethral orifice located, and what is its significance?
It is located at the tip of the glans penis and is the narrowest part of the urethra, serving as the exit point for urine and semen.
What are the three main parts of the penis?
The penis consists of three main parts:
Root: The base of the penis, attached to the pelvic bones.
Shaft (Body): The elongated portion extending from the root to the glans.
Glans: The conical tip of the penis, also known as the head
What are the two types of erectile tissue found in the penis?
Answer: The penis contains two types of erectile tissue:
Corpora Cavernosa: Two paired columns of erectile tissue located dorsally (on the top side) of the penis.
Corpus Spongiosum: A single column of erectile tissue located ventrally (on the underside) of the penis, which surrounds the spongy urethra.
What is the function of the corpus spongiosum?
Answer: The corpus spongiosum surrounds the spongy urethra and expands distally to form the glans. Its primary function is to prevent the urethra from collapsing during erection, allowing for the passage of semen and urine.
What are the crura of the penis, and what is their role?
The crura are the proximal (root) portions of the corpora cavernosa.
They are attached to the pubic bones and play a crucial role in anchoring the penis to the pelvic floor, contributing to the rigidity during erection.
What is the function of the bulbospongiosus muscle?
The bulbospongiosus muscle stabilizes the perineal body, assists in the expulsion of urine and semen, and contributes to the rigidity of the penis during erection.
How does the ischiocavernosus muscle contribute to erection?
The ischiocavernosus muscle assists in erection by compressing the veins and nerves of the penis, thereby increasing blood flow into the erectile tissues and maintaining rigidity.
What is the role of the fundiform ligament in penile anatomy?
The fundiform ligament arises from the linea alba (white line) of the abdomen and supports the penis, helping to maintain its position and orientation.
What is the function of the suspensory ligament of the penis?
The suspensory ligament arises from the pubic symphysis and supports the penis, anchoring it to the pubic bone and aiding in its stability during erection.
Which nerve innervates the muscles of the perineum, including those involved in penile function?
The perineal nerve, a branch of the pudendal nerve (S2 – S4), innervates the muscles of the perineum, including those involved in penile function.
What are the dorsal veins of the penis, and what is their function?
The penis has both superficial and deep dorsal veins. The deep dorsal vein runs along the dorsum of the penis between the dorsal nerve and deep dorsal artery, draining blood from the erectile tissues.
What is the role of the dorsal artery in penile anatomy?
The dorsal artery travels along the dorsum of the penis, providing blood supply to the skin and fascia of the penis, including the foreskin, and the erectile tissues.
What is the function of the dorsal nerve of the penis?
A branch of the pudendal nerve, the dorsal nerve of the penis is responsible for sensory innervation, including touch, temperature, and pain sensations.
What is the deep artery’s role in penile erection?
The deep artery of the penis supplies blood to the corpora cavernosa, playing a crucial role in achieving and maintaining an erection.
What is the spongy urethra, and where is it located?
The spongy urethra is the portion of the urethra that passes through the penis, allowing for the passage of urine and semen. It is located within the corpus spongiosum.
What are the cavernous nerves, and what is their function?
The cavernous nerves, originating from the pelvic splanchnic nerves (S2 – S4), are responsible for the parasympathetic innervation of the penis, facilitating erection.
What is the process of erection, and which nervous system is involved?
During sexual arousal, parasympathetic stimulation causes the corpora cavernosa and corpus spongiosum to engorge with blood, leading to an erection.
What is emission, and which nervous system controls it?
Emission involves the movement of semen into the prostatic urethra. This process is under sympathetic control and includes the contraction of the internal urethral sphincter to prevent retrograde ejaculation.
What is ejaculation, and how is it achieved?
Ejaculation is the expulsion of semen from the penis. It involves the contraction of the urethral muscles (parasympathetic) and the bulbospongiosus muscle (somatic), leading to the release of semen through the external urethral meatus.
