Human male reproductive system

Human male produces sperm for sexual intercourse. They transfer these sperms into the vagina ( female sex organ) of the female. For this function following structures are required.

Testes


Two testes produce male sex hormone testosterone & sperm.

Accessory glands


These glands produce fluid. This fluid help in transport of sperm to the penis.

Semen


The fluid with sperms is called semen.

Penis


A penis play's a vital role to deposit seamen into the vagina of female during sexual intercourse.

Production and Transport of Sperm:-


1; Testes


The male reproductive organs have two testes ( paired testes). These testes produce sperm cells. Testes are present outside the body. The temperature of testes remains 34 degree centigrade. The lower temperature is necessary for the survival & production of sperms. Muscles can lower the temperature of testes according to external temperature. These testes contains two types of tissues.

Seminiferous Tubules


Every testis is composed of 800 tightly coiled seminiferous tubules. They produce more than thousands of sperm in healthy young man. There are two other types of cells present on the wall of the seminiferous tubules.

♦Spermatogenic cells:


They give rise to sperm cells.

♦Sustentacular cells:


These cells secrets hormone inhibin. They also nourishes the sperms cells.

Interstitial cells


These cells secrets male sex hormone testosterone. They are clusters of endocrine tissues. Interstitial cells are present between the seminiferous tubules.

2. Epididymis


Rete testes


The seminiferous tubules merged into a network of tiny tubules called the rete testis.

These rete testis merged into a coiled tube called epididymis.

It's a system of tubes that carries the sperm to penis.

The epididymis has three main functions

⇒It contains smooth muscle. By peristaltic contractions,  these muscles transmit the sperm cells toward the penis.

⇒It stores sperm until they become mature & ready to be ejaculated.

⇒It acts duct system for sperm to pass into the ductus deferens.

3. Ductus deferens


It is the dilated portion of the epididymis. These ductus move upward after the scrotum. They pass through the lower part of the abdominal wall through the inguinal canal. Inguinal hernia is caused,  when abdominal wall weakened at inguinal canal. Sperms are stored in ampulla untill they are ejaculated.

4. Accessory glands


Accessory glands add their secretions to the sperm.

The accessory glands are

♦Prostate glands:


These glands secretes water, phospholipids, buffering salts, cholesterol and enzymes.

♦Seminal vesicle:


Paired seminal vesicles secrete Vitamin C , Prostaglandin, fructose and water.

This secretion provide energy to the motile sperm.

In females, it neutralizes the acidity of the vagina. The normal pH of human females vagina is about 3 to 4. But sperm fertility & motility increases it to about 6.

♦Bulbourethral glands:


It helps in ejaculation of sperms during sexual intercourse. These glands secrete a clear alkaline fluid. The average human ejaculation produces 3 ml to 4 ml of semen. It contains 300 to 400 millions sperms.

The fluid containing sperms is called semen.

5. Penis


It has two functions. During urination, it carries urine through the urethra to the outside of body. During sexual intercourse, it also transports semen through urethra. It contains three cylindrical strands of erectile tissue; two corpora cavernosa and the corpus spongiosum.

♦Corpus spongiosum:


Glans penis:- It extends beyond the corpora cavernosa and becomes the expanded tip of the penis.  This tip of the penis is called glans penis. Penis has loosely fitting skin.

Circumcision سنت کرنا


The removal of prepuce for religious or health reasons is called circumcision.

Circumcision also prevent the cancer of penis.


6. Sperm


A mature human sperm consists of a

♦Head

It contains haploid nucleus. This nucleus has mostly DNA. Acrosome is a cap over the head of sperms. Acrosome contains an enzyme called acrosin. This enzyme helps the semen in rupturing and penetrating the outermost layer of secondary oocytes.

♦Midpiece

It has spiral mitochondria. These mitochondria supply energy to sperm.

♦Tail

Tail benda to produce whip like movements.

The sperm tail contains microtubules.

 

 

 

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