MALE REPRO

Spermatogonium

A male germ cell that is always in contact with the seminiferous tubule basement membrane.

Primary spermatocyte

A diploid cell resulting from the mitotic division of spermatogonium, which divides via meiosis I.

Secondary spermatocyte

A haploid cell that divides via meiosis II.

Spermatid

The cell formed after the second meiotic division that differentiates into sperm cells through spermiogenesis.

Spermatozoa

Mature sperm cells consisting of a head, midpiece, and tail.

Dartos muscle

A thin layer of muscle in connective tissue surrounding the scrotum responsible for wrinkling the skin.

Cremaster muscle

An extension of the abdominal muscles that raises or lowers the testes in response to temperature.

Erection

Result of parasympathetic activation causing vasodilation of penile arteries (smooth muscle relaxation in their tunica media)

Increased blood flow in the arteries results in an engorgement of the corpora cavernosa and the corpus spongiosum due to an increase in the blood volume within their sinusoids.

Corpora cavernosa

Two columns of erectile tissue in the penis that become engorged with blood during erection.

Pampiniform plexus

A network of veins surrounding the testicular artery that helps in thermoregulation of the testes.

• counter-current heat exchange system

  • so that warm blood in arteries leaving the body heats cooler blood in the veins leaving the testes.

  • The arterial blood entering the testis is now less than 37⁰C.

GnRH

Hormone originating in the hypothalamus that targets the anterior pituitary.

FSH

Hormone from the anterior pituitary that stimulates Sertoli cells to produce androgen-binding protein (ABP).

LH

Hormone from the anterior pituitary that stimulates interstitial cells to produce testosterone.

Testosterone

Hormone that stimulates spermatogenesis and regulates secondary sexual characteristics.

ABP (Androgen Binding Protein)

Binds to testosterone to increase its levels, made by Sertoli cells.

Inhibin

• origin: Sertoli cells

• inhibits GnRH and FSH when sperm count is high.

Bulbourethral gland (Cowper's)

• 5% of semen

• Produces alkaline mucus that acts as lubricant and neutralises the urethra's pH during intercourse.

Seminal vesicles

• 60% of semen.

• fructose, citric acid etc to nourish sperm

• fibrinogen (fibrin) to coagulate semen

• prostaglandins = uterine contractions to transport sperm

Prostate gland

• Gland that produces 30% of semen

• containing fibrinolysin that help dissolve coagulated sperm.

• seminal plasmin = antimicrobial

Spermatogenesis

The entire process that forms spermatozoa.

Spermiogenesis

The differentiation of a spermatid into a mature spermatozoon.

Spongy urethra

The section of the urethra that travels through the penis.

Path of sperm to the vas deferens

1. Seminiferous tubules

2. Straight tubules (tubulus rectus)

3. Rete testis

4. Efferent ductules

5. Head of epididymis

6. Body of epididymis

7. Tail of epididymis

8. Vas deferens

A and B cells of spermatogonia

A replenishes stem cell pool, while B becomes primary spermatocyte.

Erection stimulation

parasympathetic nervous system.

Emission/ejaculation stimulation

sympathetic nervous system.

Tunica albuginea

Thickened layer of fibrous tissue surrounding the corpora cavernosa; allows for compression of veins during erection.

location of sperm cells

Spermatocytes are located closer to the middle as they mature; spermatogonium is always in contact with the basement membrane while sperm are within the lumen.

epithelium of epididymis

pseudostraified, columnar with stereocilia

• stereocilia increases surface area

ejaculatory duct location

Duct which is located at the ampulla of the ductus deferens. This duct projects into the prostate gland and ends at the opening into the urethra.