Male Anatomy and Physiology

1. Male Anatomy and Physiology

2. Testicles • Testicles – • One testicle is usually larger than the other, and also usually will tend to hang lower. • The testicles make the hormone testosterone which causes a boy’s body to change during puberty. • It is divided into sections and with tightly coiled tubes called seminiferous tubules that produce the sperm. Between the tubes special cells make the testosterone.

3. Sperm • Sperm: • Refers to the male reproductive cells. • The human sperm cell is haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid cell. • The sperm cell consists of a head, a midpiece and a tail.

4. Scrotum • Scrotum • The scrotum is a dual-chambered protuberance of skin and muscle containing the testicles and divided by a septum. It is an extension of the abdomen, and is located between the penis and anus. • Since testicles are temperature sensitive, the sac will hang low when warm and contract or pull closer to the body when cold to keep warm. • This is also important during fertility since sperm need to be produced a few degree cooler than normal body temperature.

5. Epididymis • Epididymis – • A tightly coiled tube also the sperm tend to spend 6 weeks here. • This is where sperm mature and develop the ability to swim. • The epididymis can be divided into three main regions • The head - The head of the epididymis receives sperm from the teste. The concentration of the sperm here is dilute. • The body • The tail - as it is involved in absorbing fluid to make the sperm more concentrated. • Sperm formed in the testeenter the head epididymis, progress to the body and finally reach the tail region, where they are stored. Sperm entering the head epididymis are incomplete - they lack the ability to swim forward and to fertilize an egg. During their transit in the epididymis, sperm undergo maturation processes necessary for them to acquire these functions.

6. Vas Deferens • Vas Deferens – • There are two tubes, one from each testicle, that lead out from the epididymis. • Sperm stay in this tube which runs up to the urethra in the prostate gland until ejaculation. • This is when this fluid leaves the body. • During ejaculation the smooth muscle in the walls of the vas deferens contracts reflexively, thus propelling the sperm forward. • The sperm is transferred from the vas deferens into the urethra, collecting secretions from the male accessory sex glands such as the seminal vesicles, prostate gland and Cowper’s gland, which form the bulk of semen.

7. Seminal Vesicles • Seminal Vesicles – • Produces 60% of the seminal fluid. The fluid gives the energy to the sperm to help them move. • They are located in two pouches just above the prostate gland, on either side of the Vas Deferens

8. Cowper’s Gland • Cowper’s gland- • Produces 10% of the seminal fluid, and secretes lubrication and pre-ejaculatory fluids • Neutralizes the urethra for semen to pass through • Are located on either side of the urethra at the base of the penis

9. Prostate Gland • Prostate gland – • Produces 30% of the seminal fluid, is where semen is completed and helps protect the sperm from the acidity in the vagina. • White, milky substance • Surrounds the urethra, just below the bladder • The prostate starts at birth really small, but grows larger during puberty. The urethra and vas deferens join together in the prostrate gland.

10. Semen • The force and amount of semen that will be ejected during an ejaculation will vary widely between men and may contain between 0.1 and 10 milliliters. • (By way of comparison, note that a teaspoon is 5 ml and a tablespoon holds 15 ml.) • There are 20-100 million sperm cells per milliliter • 2 - 6 milliliter per ejaculation • Equals to 50 - 500 million sperm per ejaculation. • Men with less than 20 million sperm cells per milliliter are considered sub-fertile.

11. Urethra • Urethra - • Ss a tube that connects the urinary bladder to the genitals for removal out of the body. • Where both urine and semen travel through the penis and are expelled from the body

12. Penis • Penis - • The penis is an external sexual organ. It is a part of reproductive system and additionally serves as the urinal duct • There are 3 chambers in the penis • The penis is made up of nerves , blood vessels, and tissue. • The tip of the penis, called the glans, has a raised ridge that separates it from the middle section, and the root is attached to the pelvic bone.

13. Ejaculation • Ejaculation: • Ejaculation is the ejecting of semen from the penis • A series of muscular contractions delivers semen • Ejaculation may occur spontaneously during sleep (known as a nocturnal emission or wet dream).

14. Complication of the Male Anatomy • Testicular injury • Mild injuries can cause swelling, pain, or brusing • Testicular Torsion • When one of the testicles twists around, cutting off the blood supply, killing the teste • Hernia • When a portion of the intestines pushes through an abnormal opening in the abdominal wall into the groin or scrotum • Epididymitis • Inflammation of the epididymis, usually caused by an infection such as an STI. Results in pain and swelling of the testicle

15. Prostate Problems • For men under 50, the most common prostate problem is prostatitis. • For men over 50, the most common prostate problem is prostate enlargement. • Enlarged due to an infection, tumor, or age problems • Presses on the urethra, resulting in frequent or difficult urination • Inflammation of the penis • Redness, itching, swelling, pain, from bacterial infection • Testicular Cancer • Occurs most often in males between 14-40 • Signs include – painless lump, testicular swelling, or pain • Prostate, Penile Cancer • Sterility • Too few sperm produced and found in semen