PARTS OF MALE REPRODUCTIVE SYSTEM

 STD-12      UNIT-6     CHA-3

HUMAN REPRODUCTION

PARTS OF MALE REPRODUCTIVE SYSTEM 

All parts of male reproductive system are listed below 

1. SCROTUM 
2. TESTES 
3. EPIDIDYMES 
4. VASA DEFERENTIA 
5. EJECULATORY DUCT 
6. URETHRA 
7. PENIS 
8. MALE ACCESSORY GLANDS 

For Scrotum & Testes read previous article Human male reproductive system- Scrotum & Testes

EPIDIDYMES 

• The epididymis is a mass of long narrow closely coiled tubule which lies along the inner side of each testis . 
• At the anterior end of the testis it is called caput epididymis , in which the vasa effer entia open . 
• The middle part of the eipdidymis is known as corpus epididymis .
• The poste rior end of the epididymis is called as cauda epididymis . 
• The epididymis stores the sperms and also secretes a fluid which is considered to nourish the sperms . 

VASA DEFERENTIA 

• A vas deferens emerges from the cauda epididymis on each side and leaves the scrotal sac and en ters the abdominal cavity through the inguinal canal . 
• The vas deferens loops over the uri nary bladder where it is joined by duct from the seminal vesicle to form the ejaculatory duct 
• Vasa deferentia carry sperms . Rete testis , vasa efferentia , epididymes and vasa deferentia are called the male sex accessory ducts . 
• These ducts store and transport the sperms from the testis to the outside through urethra . 

EJECULATORY DUCT 

• The ejaculatory ducts are two short tubes each formed by the union of the duct from a seminal vesicle and a vas deferens . 
• They pass through the prostate gland and join the prostatic part of theurethra .
• The ejaculatory ducts are composed of the fibrous , muscular and columnar epithelial tissue . 
• Ejaculatory ducts carry sperms and secre tion of seminal vesicles . 

URETHRA

• The male urethra provides a common pathway for the flow of urine called Semen . 
• It is much longer in male than in the female , measuring about 20 cm . The urethra includes three parts 
• The first part is surrounded by the prostate gland and is called the prostatic urethra which arises from the urinary bladder and carries urine only . 
• The second part is the membranous urethra which is situated behind the lower part of the pubic symphysis . The membranous urethra is the smallest urethra . 
• The third part is the penile urethra which is situated in the penis . 
• There are two urethral sphincters . 
• The internal sphincter consists of smooth muscle fibers situated at the neck of the bladder above the prostate gland . 
• The external sphincter consists of striated muscle fibers surrounding the membranous part of the urethra . 
• Membranous urethra and penile urethra carry both urine and semen . External opening of the urethra is called urethral meatus . 

PENIS 

• The penis is male genitalia ( male copulatory or gan ) . 
• At the tip of the glans penis is the slit like opening called the external urethral orifice or urinogenital aperture . 
• The penis in addition to conducting urine from the body , transfers semen into reproductive tract of the female during sexual intercourse .
• The penis contains three cylindrical masses of erectile tissue two dorsal corpora cavernosa and one ventral corpus spongiosum . 
• These bodies are surrounded by fibrous tissue . 
• The corpus spongiosum which contains the penile urethra , is enlarged end of the penis to form the glans penis . 

• The glans penis is covered by loose fold of skin , the prepuce or foreskin . 
• During sexual arousal the three bundles of tissue in the penis become engorged with blood . 
• The penis carries both urine and semen . 

MALE ACCESSORY GLANDS 

• The seminal vesicles are one pair of sac like structures near the base of the bladder . 
• Their ducts join the vasa deferentia to form the ejaculatory ducts . 
• They produce an alkaline secretion which forms 60 % of the volume of semen . 
• Seminal fluid pH is 7.4 . The secretion of the seminal vesicles con tains fructose , hormone like prostaglandins , and clotting proteins that are different from those in blood . 
• The fructose is a source of energy for the sperm. 
• The prostaglandins stimulate uterine contractions and thus may help the sperm to be moved towards the female's oviducts , where fertilization takes place . 
• The clotting proteins help semen coagulate after ejacu lation . 
• Alkaline nature of the seminal fluid helps to neutralize the acidic environment of the and kill sperms . 
• male urethra as well as that of female reproductive tract which otherwise would inactivate and kill sperms

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Manish Mevada

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