Parts of male reproductive organs and their functions
The male genital organs are divided into two groups -
External male genital organ
Internal male genital organ
Male External Genital Organ
The male external genital organs include the following structures:
1- Penis
2- Scrotum
3- Testes
4- Epididymes
5- Spermatic cords
1- Penis
The penis is the male organ of copulation and is traversed by the urethra, which provides passage for both urine and semen. It is capable of becoming hard and erect due to its engorgement with blood, a requirement for its intromission into the vagina.
Parts
The penis consists of the following two parts-
1- Root or radix - The root of the penis is situated in the superficial perineal pouch and is attached to the inferior aspects of the urogenital diaphragm.
2- Body or corpus - the body of the penis is the free pendulous portion and lies in front of scrotum.
Blood supply of Penis
Arterial supply
The penis is supplied by the following four pairs of arteries :
1- Deep arteries of the penis
2- Dorsal arteries of the penis
3- Arteries of the bulb
4- Superficial dorsal arteries of penis
Venous drainage
The following two veins mainly drain the venous blood from the penis :
1- Superficial dorsal vein of the penis
2- Deep dorsal vein of the penis
Nerve supply
1- Sensory innervation - sensory supply to the penis is derived from following :
Dorsal nerve of penis
Illoinguinal nerve
2- Motor innervation : the muscle of penis are supplied by the perineal branch of pudendal nerve
3 - Autonomic innervation : the autonomic nerves of the penis are derived from the pelvic plexus via prostatic plexus.
Scrotum
The scrotum is a large pendulous sac of skin located below and behind the penis. It is considered as an out-pouching of the lower part of the anterior abdominal wall.
It contains the following structures:
1- Testes
2- Epididymes
3- Lower part of the spermatic cords
It consists of the five layers -
1- Skin
2- Dartos muscle
3- External spermatic fascia
4- Cremasteric muscle and fascia
5- Internal spermatic fascia
Blood supply
The following arteries supply the scrotum
1- Superficial external pudendal artery
2- Deep external pudendal artery
3- Scrotum branches of the internal pudendal artery
4- Cremasteric artery, a branch of the inferior epigastric artery
Nerve supply
1- Anterior one-third of the scrotum is supplied by ilioinguinal nerve and genital branch of genitofemoral nerve
2- Posterior two-third of the scrotum is supplied by posterior scrotal branches of the perineal nerve and perineal branch of the posterior cutaneous nerve of the thigh
3- Testis
The testis is a male gonad. It is homologous with the ovary in the female. It is a mobile organ and lies in each half of the scrotal sac. It is oval in shape, it measures approximately length 4 cm, breadth 2.5 cm , anteroposterior diameter 3 cm and weight 10-15 g .
It consists of the two poles, two borders and two surfaces.
It has three coats cover the testis. From superficial to deep these are :
1- Tunica vaginalis
2- Tunica albuginea
3- Tunica vasculosa
Blood supply
Arterial supply
It is supplied by the testicular artery
Venous drainage
The pampiniform plexus of veins.
4- Epididymes
The epididymis is a comma-shaped structure, which lies on to the superior and posterolateral surface of the testis. It is made up of highly coiled tubes.
Parts
The epididymis from above downward is divided into three parts:
Head
Body
Tail
Functions.
The functions of epididymis are :
1- Storage and maturation of spermatozoa
2- Absorption of the fluid
3- Addition of substances to the seminal fluid to nourish the maturating spermatozoa
The internal genital organs include :
1- Tastes
2- Prostate
3- Seminal vesicles
4- Ejaculatory ducts and penis
1— Testis
The testis is a male gonad. It is homologous with the ovary in the female. It is a mobile organ and lies in each half of the scrotal sac. It is oval in shape, it measures approximately length 4 cm, breadth 2.5 cm , anteroposterior diameter 3 cm and weight 10-15 g .
It consists of the two poles, two borders and two surfaces.
It has three coats cover the testis. From superficial to deep these are :
1- Tunica vaginalis
2- Tunica albuginea
3- Tunica vasculosa
Blood supply
Arterial supply
It is supplied by the testicular artery
Venous drainage
The pampiniform plexus of veins.
Prostate
The prostate is a pyramidal-shaped , fibromuscular glandular organ which surrounds the prostatic urethra, the prostate glands secretes acid phosphatase, fibrinolysin, citric acid ,amylase, prostate-specific antigen, and prostaglandins. Its secretions form the bulk of the seminal fluid. Its female homologue is paraurethral glans.
It is located by the lesser pelvis below the neck of the urinary bladder and above the urogenital diaphragm.it is like a cone shape and resembles a chestnut in appearance. It presents the following measuremets:
Weight - 3 g
Width - 4 cm
Length - 3 cm
Thickness - 2 cm
Prostate consists of the four lobes -
1- Anterior lobe
2- Posterior lobe
3- Median lobe
4- Two lateral lobes
Blood supply
Arterial supply
The prostate gland is supplied by the branches of inferior vesical, middle rectal and internal pudendal arteries
Venous drainage
The veins from the prostate form a rich venous plexus around the sides and base of the gland and occupy the space between the true and false capsules.
It has two pathways-
1- internal iliac vein
2- internal and external vertebral venous plexus through veins passing through anterior sacral foramina
Nerve supply
It consists of the following sources -
1- sympathetic supply is provided by the superior hypogastric plexus
2- parasympathetic supply is provided by the pelvic splanchnic nerves
Seminal vesicles
The seminal vesicle are two coiled sacculated tubes about 2 inches long which can be unraveled to three times of this length. They lie extraperitoneally on each side, at the base of the urinary bladder, lateral to the termination of the vas and in deferens
of the rectum. The lower narrow end of seminal vesicle joins the ductus deferens to form the ejaculatory duct.
Ejaculatory ducts
There are two ejaculatory ducts one on each side of the median plane at the lower part of the bladder base. Each duct traverses anteroinferiorly through the upper posterior half of the prostate and along the side of prostatic utricle to open in the posterior wall of prostatic urethra on the seminal colliculus on either side of the opening of prostatic utricle.
Vasa deferentis
These are two in number. Each vas deferenes is a thick-walled muscular tube which transports spermatozoa from the epididymis to the ejaculatory duct. The vas deferens is about 18 inches long and has a narrow lumen except in the terminal part which is sacculated - the ampulla of vas deferens.
Arterial supply
It is supplied by following arteries-
1- artery to vas vas deferens, a branch of superior vesical artery
2- artery to vas deferens, a branch of inferior vesical artery
3- artery to vas deferens , a branch of middle rectal artery
Venous drainage
The veins from deferens join the vesical venous plexus which in turn drains into the internal iliac veins.
Nerve supply
It is primarily by the parasympathetic fibres from the pelvic splanchnic nerves.
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