Male Genitalia

Scrotum: It's a cutaneous bag containing the right & left testis, the epididymis & the lower parts of the spermatic cords.

Layers of scrotum :

1. Skin
2. Dartos muscle
3. External spermatic fascia
4. Cremasteric muscle & fascia
5. Internal spermatic fascia
6. Parietal layer of tunica vaginalis

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Blood supply of scrotum:

Arterial supply by -

1. I) superficial ext. pudendal artery
2. II) deep ext. pudendal artery,

III) scrotal

1. IV) Cremasteric

 

Penis:

The penis has a fixed root and a body that hangs free.

Root of the penis:

The root of the penis is made up of three masses of erectile tissue called the bulb of the penis and the right and left crura of the penis. The bulb is situated in the midline and is attached to the undersurface of the urogenital diaphragm. Each crush is attached to the side of the pubic arch.

Body of the penis:

Body of the penis is essentially composed of three cylinders of erectile tissue enclosed in a tubular sheath of fascia. The erectile tissue is made up of two dorsally placed corpora cavernosa and a single corpus spongiosum applied to their ventral surface. On the tip of the glans penis is the slit-like orifice of the urethra, called the external urethral meatus.

The erectile tissues of the penis are the corpus cavernous and corpus spongiosum.

Supports of the penis:
The body of the penis is supported by two condensations of deep fascia that extend downward from the linea alba and sympysis pubis to be attached to the fascia of the penis.

Arterial supply of Penis:

Deep arteries of the penis: Corpora cavernosa

Dorsal artery of the penis: Glans penis and the corpus spongiosum

The artery of the bulb of the penis: Bulb and proximal part of corpus spongiosum

Venous Drainage of Penis:

Superficial dorsal vein drain into the superficial external pudendal veins.

Deep dorsal vein drains into prostatic plexus of veins.

Other veins draining the penis correspond to the arteries.

Nerve Supply of Penis :

The sensory nerve supply to the penis is derived from the dorsal nerve of the penis and the ilioinguinal nerve.

The muscles of the penis are supplied by the perineal branch of the pudendal nerve.

The autonomic nerves are derived from the pelvic plexus via the prostatic plexus. The sympathetic nerves are vasoconstrictors and the parasympathetic are vasodilators.

 

Clinical of Penis:

Hypospadias: It is a condition when the male urethra opens anywhere on the undersurface of the penis or in the perineum instead of the tip of the glans penis.

Epispadias: When the external meatus of the urethra opens on the dorsal surface of the penis is called epispadias.

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Seminal vesicles

The seminal vesicles (also called vesicular glands, or seminal glands), are a pair of two convoluted tubular glands that lie behind the urinary bladder of some male mammals. They secrete fluid that partly composes the semen.

The seminal glands are a pair of 5cm long tubular glands. They are located between the bladder fundus and the rectum (separated from the latter by the rectovesical pouch and the recto-prostatic fascia).

Their most important anatomical relation is with the vas deferens, which combine with the duct of the seminal vesicles to form the ejaculatory duct, which subsequently drains into the prostatic urethra.

Internally the gland has a honeycombed, lobulated structure with a mucosa lined by pseudostratified columnar epithelium. These columnar cells are highly influenced by testosterone, growing taller with higher levels, and are responsible for the production of seminal secretions.

Location

The anterior aspect of each seminal vesicle is in contact with the posterior wall of the bladder.

Medial to the seminal vesicles are the ampulla of the vas deferens, whereas the veins of the prostatic venous plexus lie lateral to them.

Arterial supply

The arteries that supply the seminal vesicles are branches of the inferior vesical and middle rectal arteries.

 

Ejaculatory Duct

The ejaculatory ducts (ductus ejaculatorii) are paired structures in male anatomy.Each ejaculatory duct is formed by the union of the vas deferens with the duct of the seminal vesicle.They pass through the prostate, and open into the urethra at the seminal colliculus. During ejaculation, semen passes through the prostate gland, enters the urethra and exits the body via the urinary meatus.

In general, an ejaculation has different steps:

-Excitation.

-Plateau phase, like an inflexion point.

-Orgasm.

Ejaculatory duct function

Ejaculatory duct function is to mix the sperm stored in the ampulla with fluids secreted by the seminal vesicles and to transport these substances to the prostate.

 

The vas deferens

The vas deferens is a thick cord like tubular structure .

45 cm long organ vas deferens,spinal cord,femur, sartorius muscle.

The vas deferens begins from the tail of the epididymis as a continution of the canal of epididymis.

Structure of vas deferens

Presents three coats from outside inwards: areolar,muscular, mucous

The muscular coat consist of outer longitudinal, middle circular,inner longitudinal.

The mucous membrane is lined by nonciliated simple columnar secretory epithelium.

Blood Supply of vas deferens :It is supplied by Superior and inferior vesical artery.

Development :

It is developed from the mesonephric duct.

Spermatic cord: It's a soft, rounded cord consisting of a tubular sheath

Length : 7.5cm

Extension: from the deep inguinal ring to the upper part of the post. border of the testis.

Contents of spermatic cords :

1. Ductus deferens
2. Testicular artery
3. Cremasteric artery
4. Artery of ductus deferens
5. Lymph vessels from the testis
6. Genital branch of genitofemoral nerve 7. Parnpiniform plexus of veins
7. Plexus of sympathetic nerves
8. Remains of processus vaginalis

Coverings of the spermatic cord: from inwards to outwards -

1. Internal spermatic fascia
2. Cremasteric muscle & fascia
3. Ext. spermatic fascia

Prostrate: It's a conical fibro musculo glandular organ that surrounds the proximal part of the male urethra

It has an apex, base

four surfaces - anterior, posterior & two inferolateral surfaces.

Anatomically it's divided into 3 lobes- median & 2 lateral.

Surgically 5 lobes - Anterior, posterior, median, right & left lobes.

Blood supply of prostate :

Arterial supply -

1. Inferior vesical
2. Middle rectal
3. Internal pudendal arteries

 

 

 

 

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Male reproductive organs/genital oragns:

1. External genitalia
2. Internal genitalia

 

External genitalia:

1. Penis and
2. Scrotum

Penis: It's a sexual organ as well as a urinary organ.

Parts: It consists of 2 parts

1. a) Root or radix (attached portion) : it comprises three masses of erectile tissue, two crura(rt and left) and the bulb of the penis
2. b) Body or corpus (free pendulous portion): The body of penis is further divided into three parts; body proper, neck, and glans penis. It is composed of three elongated masses of erectile tissue- two corpora cavernosa and one corpus spongiosum.

Developmental anomalies of penis :

1.Phimosis

2. Hypospadias
3. Bifid penis

Scrotum: The scrotum is a cutaneous bag containing the right and left testis, the epididymis and the lower parts of the spermatic cord.

Layers of scrotum: From outside to inwards

1. Skin
2. Dartos muscle
3. External spermatic fascia
4. Cremasteric muscle and fascia
5. Internal spermatic fascia
6. Parietal layer of tunica veginalis.

Functions of scrotum:

1. It protects the test is from external violence.
2. Maintains a temperature which is lower than that of the abdomen.

Homologus structure : Labia majora (in female)

Development : The scrotum is developed by the fusion of two genital swellings. The fusion is represented by a median raphe.

Clinical importance of scrotum :

1. Due to laxity of skin and its dependant position, the scrotum is a common site for edema.

2.Abundance of hair and of sebaceous glands also makes it a site for sebaceous cysts.

3. Hydrocele is a condition in which fluid accumulates in the processus vaginalis of peritoneum.
4. Some common abnormalities of scrotal contents are:

? tumor of the testes

?hydrocele

?Eppadidymitis

?varicocele

?spermatocele

Contents of scrotum :

1. Testes

2.Epididymis

3. Lower part of spermatic cord.

Testes:

?Coverings of testis: From outside to inwards

1. Visceral layer of tunica vaginalis

2.Tunica albuginea

3.Tunica vasculosa

?Cells within the testes :

1. Spermatogenic cells: Produce spermatozoa.
2. Sertoli cell:

support, protection and nutrition of the developing spermatogenic cells.

Phagocytosis of the residual cytoplasm during spermiogenesis.

The tight junctions of sertoli cells form the blood testis barrier.

3. Interstitial cells of leydig:

The Secret testosterone.

after puberty they stimulate the growth of secondary sexual characteristics of male.

they initiate a heterosexual drive and increase the height of the epithelial cells of the prostate and seminal vesicles.

Artery supply of testes:

It is mostly supplied by right and left testicular artery which is the branch of abdominal aorta.

Partly supplied by the artery to the vas deferens a branch of superior or inferior vesical artey

sometimes it is supplied by cremasteric artery, is a branch of inferior epigastric artery.

Venous drainage: About 15 to 20 veins appear from the posterior border of testis and epididymis and unite to form a pampiniform plexus. At the superficial inguinal ring the plexus unites to form four veins and at the deep ring they further join to form two veins. Finally a single vein is formed in the posterior abdominal wall. Right testicular vein drains into Inferior Vena cava at an acute angle; left testicular vein drains into left renal vein almost at a right angle.

Factors responsible for Descent of testis :

1. Differential growth of the body.
2. Gubernaculam testis.
3. Intra-abdominal pressure
4. Intra-abdominal temperature

4.Testosterone

5. Contraction of the arched fibres of internal oblique muscle.

Cryptorchidism:

Cryptorchidism means imperfect in descent of testis.

?Complications of criptorchydism:

1. it may fail to produce spermatozoa.
2. it is prone to undergo malignant change.

Epididymis: It is a coma shaped body. it has three parts head

body and tail.

Function: 1. It stores the spermatozoa.

2. it provides the maturity of spermatozoa.

Lining Ep: Pseudostratified columnar ep. with deep sterio-cilia.

Contents of spermatic cord:

1. Ductus deferens.
2. Artery to the ductus deferens.
3. testicular artery
4. cremasteric artery
5. pampiniform plexus of veins
6. lymph vessels from the testis

7.genital branch of genitofemoral nerve

8.plexus of sympathetic nerves around the artery to the ductus deferens.

9. Remains of the processus vaginalis.

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