Question

Describe the three glands: their secretions, composition of fluids, and volume of secretions, the functions, and the ducts traversed during male ejaculation.

Answer 1

The accessory glands of the male reproductive system are the seminal vesicles, prostate gland, and the bulbourethral glands that contribute to male ejaculations...

SEMINAL VESICLE -

• Secretion :- secretes significant fluid that ultimately becomes SEMEN..
• Composition of fluid:- The thick secretions from the seminal vesicles contain proteins, enzymes, fructose, mucus, vitaminC, flavins, phosphorylcholine and prostaglandins. The high fructose concentrations provide nutrient energy for the spermatozoa ... Also contain semenogelin, it is a protein that causes semen to become sticky and jelly-like after ejaculation.... The seminal fluid is alkaline in nature that renders semen alkaline...
• Volume of secretion:- the seminal fluid accounts for 70% of total semen secreted per ejaculation.. there are 20 – 100 million little spermies per mL of ejaculate. And because men produce anywhere from 2 – 6 mL of semen, some can shoot out 600 million spermatozoa in one single ejaculation...
• Function:- The alkalinity of semen helps neutralize the acidity of the vaginal tract prolonging the lifespan of sperm..Lipofuscin granules from dead epithelial cells give the secretion its yellowish color....motility, transportation, capacitation, and fertilising ability are its important function. Once in contact with females, seminal fluid may stimulate ovulation, modulate immune activity, provide nutrition, alter reproductive-tract pH, and form mating plugs...
• Duct:- seminal vesicle joins with vas deferens to form ejaculatory duct that runs 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....

PROSTATE GLAND

• Secretion:- it is called prostatic fluid..
• composition of fluids:- prostatic fluid is slightly alkaline, milky or white in appearance...Its protein content is less than 1%, and the contents are slightly acidic. Contents include proteolytic enzymes, prostatic acid phosphatase, fibrinolysin, and prostate-specific antigen. Zinc is present in 500-1000 times concentration than blood..
• Volume of secretion:- constitute the 30% of semen...
• function:- The prostate's primary function is to produce the fluid that nourishes and transports sperm (seminal fluid)... · The secretions produce lubrication and nutrition for the sperm. The prostatic urethra surrounded by prostatic s mooth muscle is a conduit for semen and prevents retrograde ejaculation (ie, ejaculation resulting in semen being forced backwards into the bladder) by closing off the bladder neck during sexual climax...
• duct:- The prostatic ducts (or prostatic ductules) open into the floor of the prostatic portion of the urethra.

BULBOURETHRAL GLANDS

• Secretion:- also known as Cowper's gland.They contribute to the final volume of semen by producing a lubricating mucus secretion..it is a  pre-ejaculate fluid called Cowper's Fluid (colloquially, pre-cum),
• composition:- clear fluid rich in mucoproteins...
• volume:- The bulbourethral gland contributes up to 4 ml of fluid during sexual arousal....
• function:- help to lubricate the distal urethra and neutralize acidic urine which remains in the urethra for passage of sperm.
• ducts:- it has single excretory duct. This duct is approximately 2.5 cm long and opens into the bulbar urethra at the base of the penis..