L2 Anatomy and Physiology Reproduction

The testes and ovaries (AKA [blank_start]gonads[blank_end]) are primary sex organs which create sperm and eggs (AKA [blank_start]gametes[blank_end]). Secondary sex organs (essential to reproduction) in males are the [blank_start]glands, ducts[blank_end], and penis, and in females are the [blank_start]uterine tubes, uterus[blank_end], and vagina.

Testes: - produce sperm cells ([blank_start]gametogenesis[blank_end]) - secret testosterone by interstitial ([blank_start]Leydig[blank_end]) cells Sertoli cells: – extend from [blank_start]basement[blank_end] membrane to [blank_start]lumen[blank_end] in the testes – form blood-testis barrier, support [blank_start]developing[blank_end] sperm cells – produce [blank_start]fluid[blank_end] & control [blank_start]release[blank_end] of sperm into lumen – secrete [blank_start]inhibin[blank_end] which slows sperm production Scrotum: - Sac of loose skin, fascia & [blank_start]smooth[blank_end] muscle divided by a septum - Protect and maintain the temperature of the testes [blank_start]2[blank_end] degrees lower than body temperature Epididymus: - [blank_start]storage[blank_end] site of sperm cells. - absorbs about [blank_start]90%[blank_end] of the fluid secreted by the testis - sperm remain stored here for [blank_start]40-60[blank_end] days and are absorbed if not ejaculated prior to that time

Semen is a mixture of secretions from epididymis, seminal vesicle, prostate, and bulbourethral gland. Major constituents of semen: • Sperm - [blank_start]acrosome[blank_end] over head are enzymes used to dissolve a path to penetrate the egg, nucleus with genes in body, tail powered by [blank_start]mitochondria[blank_end]. 50-120 million sperm/mL. • Fructose - energy for the sperm. • Clotting and anticoagulant factors - semen clots like [blank_start]blood[blank_end]. About 15-30 minutes later, anticoagulant factors dissolve the clot. • Prostaglandins - stimulate [blank_start]peristaltic contractions[blank_end] of the female reproductive tract that may help draw semen into the uterus • Spermine - is a [blank_start]base[blank_end] that reduces acidity of the female vagina, increasing the survival rate of sperm.

Ejactulation: • Initiated by [blank_start]sympathetic[blank_end] nerve impulses • The ducts and accessory glands contract, emptying their contents into the [blank_start]urethra[blank_end]. • The urethral [blank_start]sphincters[blank_end] constrict. • The [blank_start]bulbospongiosus[blank_end] muscles of the penis contract rapidly and rhythmically, propelling semen from the urethra.

Sperm is viable for 2 days (egg: 12-24 hr).

Choose the incorrect statement.

Hypothalamus-pituitary axes to target gonads: 1. Hypothalamus makes [blank_start]GnRH or LHRH[blank_end] (gonadotrophins) 2. Pituitary makes [blank_start]FSH and LH[blank_end] 3. FSH and LH target [blank_start]gonads[blank_end] 4. Gonads make estrogen, progesterone, or testosterone

Hypothalamus-pituitary axes to target breasts: 1. Hypothalamus makes [blank_start]PRH[blank_end] 2. AP makes [blank_start]prolaction[blank_end] 3. Breasts make malk

GRH is naturally released in a [blank_start]pulsatile[blank_end] manner. Clinical uses: • Continuous gonadotrophin-releasing hormone agonist or antagonist: - [blank_start]Reduces[blank_end] the release of FSH & LH - Used to treat various sex-hormone dependent [blank_start]conditions[blank_end] such as breast and prostate cancer, endometriosis • Pulsatile gonadotrophin-releasing hormone agonist: - [blank_start]Fertility[blank_end] treatment

Testosterone releases in a pulse-like manner in 1-3 hr intervals.