27.4 Reproductive anatomy of the male

Semen

The sperm and glandular secretions make up the semen. The semen is is the fluid ejaculated from the penis during orgasm. Includes sperm, alkaline and fructose

Ejaculation stage 2

The sphincter at the base of the penis relaxes, admitting semen into the penis. Simultaneously, a series of strong muscle contractions around the base of the penis and along the urethra expels the semen from the body.

Circumcision

The surgical removal of the prepuce, arose from religions traditions. Majority of American males are circumcised. It reduces the chance of a a man to pass STD and AIDS

Androgens

stimulate sperm production

Male gonads (testes or testis for singular)

Each housed outside the abdominal cavity in a sac called the scrotum

Ejaculation stage 1

1.At the peak of sexual arousal, the muscles in the epididymis, seminal vesicles prostate gland and vas deferens contract. This forces secretions from the glands into urethra and propel sperm from epididymis. Sphincter muscle at the base of the bladder contracts preventing urine from leaking into the urethra from the bladder. Another sphincters also contracts closing off the entrance of the urethra into the penis. The section of the urethra between the two sphincters fills with semen and expands

Orgasm

A series of rhythmic involuntary contractions of the reproductive structures.

epididymis

Coild tube which stores the sperm while they continue to develop.

Penis

Consists mainly of erectile tissue that can fill with blood to cause an erection (getting bigger) during sexual arousal. Like the clitoris, the penis has a shaft that supports the glans

follicle stimulating hormone

FSH increases sperm production by the testes

Hormones control sperm production by the testes

Influenced by signals from brain, the hypothalamus secretes a releasing hormone that regulates release of follicle stimulating hormone (FSH) and luteinizing hormone (LH) by the anterior pituitary.

Scrotum

Keeps the sperm-forming cells cool enough to function normally

luteinizing hormone

LH promotes the secretion of androgens, mainly testerone

vas deferens

Muscular contractions propel the sperm from the epididymis to the vas deferns. The vas deferns passes upward in to the abdomen and loops around the urinary bladder. Next to the bladder, the vas deferens joins a short duct from a gland, the seminal vesicle.

Prostate gland

Secretes a thin fluid that nourishes the sperm

Three glands of human male's reproductive system

Seminal vesicles, the prostate gland, and the bulbourethral glands.

Ejaculation

Sperm leaves the epidymis, the expulsion of sperm-containing fluid from the penis.

Acidity

The alkalinity of the semen balances the acidity of any traces of urine in the urethra and neutralizes the acidic environment of the vagina protecting the sperm and increasing their motility.

Seminal vesicle

The two seminal vesicles secrete a thick fluid that has fructose which provides most of the energy used by the sperm as they swim through the female's reproductive tract

Ejaculatory duct

Two ducts unite to form a short ejaculatory duct, which joins its counterpart conveying sperm from the other testis. They empty into the urethra, which conveys both urine and sperm out through the penis at different times.

Differences between female and male reproductive system.

Unlike the female, the male has a direct connection between the reproductive and urinary system.

Amount of sperm discharged during ejaculation

about 2-5 ml of semen are discharged during ejaculation. 95% of the fluid consists of glandular secretions. The other 5% is made up of millions of sperm.

gonad

organ that makes gametes

Bulbourethral glands

secretes a clear alkaline fluid that is basic to neutralize the womans vagina or neutralize traces of acidic urine that could still be left in the urethra