Male Reproductive System and Vasectomy
by Robert Tallitsch, PhD | May 5, 2022
Real Male Reproductive Anatomy visualized in 3D with an explanation of a Vasectomy procedure!
Written by: Robert Tallitsch, PhD
The functions of the male reproductive organs are:
- the production and maturation of the male gametes, termed sperm,
2. the transportation of sperm to the exterior, and
3. the production of seminal fluid, which activates the spermatozoa, provides nutrients for the spermatozoa, and produces buffers to counteract the acidity of the male urethra and female vagina.
This Brain Builder will discuss the anatomy of the male reproductive system and the surgical procedure termed a vasectomy, which is one form of male birth control.
Male Reproductive System
Scrotum
The scrotum is a pouch of pigmented pelvic skin containing the testes and the proximal segments of the male reproductive tract. It also contains nerves, the arterial vessels supplying the testes with blood, and the venous pampiniform plexus, which drains the testes and forms the testicular vein.
The scrotum is subdivided into right and left compartments by a connective tissue septum. Each compartment contains one testis. The left testis hangs at a lower level within the scrotum than does the right testis.
Testes
Each testis is covered with a tough connective capsule, the tunica albuginea. Deep to the tunica albuginea are the 400-600 tightly coiled seminiferous tubules of the testis, which are the site of sperm formation. The seminiferous tubules empty into a collecting chamber termed the rete testis. The rete testis unite to form 12-20 efferent ductules, which ultimately exit the testis and join with the epididymis.
Male Reproductive Tract
The male reproductive tract is responsible for transporting the sperm to the exterior of the body.
The epididymis is the site of sperm maturation and activation. In this process the spermatozoa develop the abilities to move and fertilize the female ova.
The epididymis is a long, coiled, single duct. The most proximal part, termed the head of the epididymis, lies on the posterior, superior portion of the testis. This leads to the body of epididymis, which travels inferiorly along the posterolateral border of the testis, where it empties into the ductus deferens (also termed the vas deferens) within the scrotum.
The ductus deferens is a muscular tube that passes from the scrotum into the pelvic cavity by passing through the inguinal canal of the anterior pelvic wall. There the ductus deferens descends on the interior surface of the pelvic wall, passing medially and crossing the ureter posterior to the bladder and anterior to the rectum. At this location the ductus deferens joins with the duct of the seminal gland, forming the ejaculatory duct. The ejaculatory duct passes through the prostate gland and empties into the prostatic urethra.
The three accessory glands of the male reproductive system are the prostate, seminal glands (seminal vesicles), and the bulbo-urethral glands.
Each seminal gland, which lies between the bladder and rectum, is a coiled gland that develops as a blind-ended outgrowth from the ductus deferens. The duct from each seminal gland joins with the ductus deferens, forming the ejaculatory duct.
The prostate surrounds the initial segment of the urethra within the pelvic cavity, lying inferior to the bladder, posterior to the pubic symphysis, and anterior to the rectum.
There are two bulbo-urethral glands. Each lies on either side of the membranous urethra, the second segment of the male urethra.
These three types of accessory glands produce a significant proportion of the ejaculatory fluid. This fluid activates the spermatozoa, provides nutrients for the spermatozoa, and produces buffers to counteract the acidity of the male urethra and female vagina.
There are three segments to the male urethra: prostatic, membranous, and penile. The prostatic urethra starts at the urinary bladder and passes inferiorly through the prostate, and becomes the membranous urethra upon exiting the prostate gland. The membranous urethra then enters the penis and becomes the penile (spongy) urethra.
Penis
The penis is composed of two parts: the root and the body. The root of the penis is palpable posterior to the scrotum. The body of the penis (also termed the pendulous part) is covered with skin. The distal tip of the body of the penis is covered with the glans penis.
Vasectomy
A vasectomy is a form of male birth control that has a very low risk of complications. It is typically performed as an outpatient in the physician’s office under local anesthesia, and the procedure typically takes less than 30 minutes and is more than 99% effective.
The typical procedure involves:
- Numbing the surgical area by injecting a local anesthetic into the skin of the scrotum.
- A small incision is made on the superior, anterior portion of each side of the scrotum in order to locate the right and left ductus deferens within the scrotum.
- Small segments of each (right and left) ductus deferens are externalized through each corresponding incision of the scrotum.
- Each ductus deferens is then cut and the proximal and distal segments are either permanently sampled, cauterized, or tied to prevent the passage of sperm through the cut segments.
- The cut ends of each ductus deferens are then repositioned within their respective sides of the scrotum, and the incisions are sutured closed.
Following the procedure the patient is advised to ice the affected area of the scrotum for 1 to 2 days, wear tight fitting underwear for approximately 2 days, and to refrain from any sexual activity for approximately 10 days after the procedure.
The male will ejaculate some seminal fluid during sexual activity following a vasectomy, but the fluid will no longer contain sperm. However, the physician typically requests a sperm sample 12 or more weeks following the vasectomy to ensure that no sperm are present within the ejaculate.
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Key Terms:
Scrotum - A pouch of pigmented pelvic skin that contains the testes.
Ductus deferens - A muscular tube that connects the epididymis to the duct of the seminal gland, forming the ejaculatory duct.
Seminal glands - A pair of accessory glands of the male reproductive system that develop as blind-ended segments of the ductus deferens.
Bulbo-urethral glands - Paired accessory glands of the male reproductive system which are found to lie on either side of the membranous urethra.
Membranous urethra - The second segment of the male urethra, which connects the prostatic urethra to the penile urethra.
Epididymis - The portion of the male reproductive tract where sperm activate and mature.
Prostatic urethra - The portion of the male urethra that passes through the prostate gland.
Vasectomy - A form of male birth control that involves the cutting of each ductus deferens (vas deferens).
Questions:
- True or False? The seminiferous tubules are the site of sperm formation and maturation.
A: False. The seminiferous tubules are the site of sperm formation but not sperm maturation.
- True or False? A vasectomy is a major surgical procedure that must be done in a surgical room of the hospital.
A: False. The procedure is routinely done in the physician’s office as an outpatient.
- List the three functions of the male reproductive system.
A: The three functions of the male reproductive system are:
a) production and maturation of the male gametes, termed sperm;
b) transport of sperm to the exterior; and
c) the production of seminal fluid, which activates the spermatozoa, provides nutrients for the spermatozoa, and produces buffers to counteract the acidity of the male urethra and female vagina.
- List the three segments of the male urethra, moving from distally to proximally.
A: Penile urethra, membranous urethra, and prostatic urethra
- True or False? Following a vasectomy the male is unable to ejaculate.
A: False
- True or False? The epididymis passes from the scrotum into the pelvic cavity of the male through the inguinal canal.
A: False. The ductus deferens passes from the scrotum into the pelvic cavity of the male via the inguinal canal.
- True or False? The left testis typically hangs lower than the right within the scrotum.
A: True
- True or False? There are two pairs of bulbo-urethral glands, and each pair lies on either side of the membranous urethra.
A: False. There are only two bulbo-urethral glands, each of which lies on either side of the membranous urethra.
- List the three accessory glands of the male reproductive system.
A: The three accessory glands of the male reproductive system are the prostate, bulbo-urethral gland, and the seminal glands.
- True or False? During a vasectomy a small incision is made on the superior, anterior portion of each side of the scrotum in order to locate the right and left ductus deferens within the scrotum.
A: True
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