Spermatozoon, Semen, Flow of Sperm, and Male Sexual Response

What are the three main parts of a spermatozoon (sperm)?

Head, mid-piece, tail.

What does the nucleus in the sperm head contain?

Chromosomes.

What is the function of the acrosome in the sperm head?

Contains enzymes that help the sperm penetrate the egg.

What is found in the mid-piece of the sperm and what does it do?

Mitochondria; produce ATP for movement.

What is the function of the sperm tail (flagellum)?

Propels the sperm for motility.

What percentage of semen is from the seminal vesicles?

60%.

What percentage of semen is from the prostate gland?

30%.

What makes up the remaining 10% of semen?

Sperm, spermatic duct secretions, and bulbourethral fluid.

What is the normal sperm count per mL?

50 to 120 million sperm/mL.

At what sperm count is a male considered infertile (sterile)?

20–25 million sperm/mL.

What are the components of semen?

Spermatozoa, fructose, clotting enzymes, clot dissolving enzymes, prostaglandins, buffers, antibodies.

What is the flow of sperm/semen from production to ejaculation?

Seminiferous tubules → straight tubules → rete testis → efferent ductules → epididymis → vas deferens → ejaculatory duct → urethra (prostatic → membranous → spongy) → external urethral orifice.

Which glands add fluids during the flow of semen?

Seminal vesicle, prostate gland, bulbourethral gland.

Why can semen and urine not be passed simultaneously?

The urethra is shared by both systems but only allows one function at a time.

What artery supplies blood to the penis during sexual response?

Internal pudendal artery.

What nerve carries sensory information from the penis?

Internal pudendal nerve.