The Reproductive system (exam 2)

Function of the reproductive system

reproduction, fusion of gametes (sperm/ova) to produce offspring (23 chromosomes)

What does the reproductive system include

gonads, reproductive tract, accessory glands

Sex hormones

testosterone, estrogen, and progesterone

Hormone pathway for reproductive system

Hypothalamus releases Gonadotropin releasing hormone, anterior pituitary, gonadotropes, LH and FSH

where are Testes developed

gonadal ridge in the embryo

why are the testes positioned lower

cooler environment for spermatogenesis

function of leydig cells

secrete masculinizing testosterone

Effects of testosterone

• masculinizes the reproductive tract

• promotes descent of testes into the scrotum

• promotes growth and maturation of the R system at puberty

• essential for spermatogenesis

• develops sex drive

• controls gonadotropin hormone secretion

• induces male patterns of hair growth

• deep voice

• muscle growth

non reproductive effects of testosterone

• exerts a protein anabolic effect

• promotes bone growth at puberty

• closes the epiphyseal plates after being converted to estrogen by aromatase

• may induce aggressive behavior

what does spermatogenesis yeild

abundance of highly specialized mobile sperm

pathway of spermatogenesis

1. Spermatogonium (46)

2. mitosis

3. Spermatogonia (46)

4. Mitosis

5. Primary spermatocytes (46)

6. Meiotic division

7. Secondary spermatocytes (23, doubled strands)

8. Second meiotic division

9. Spermatids (23, single strand)

10. packaged into Spermatozoa

When does GnRH activity increase in males

puberty

feedbakc control of testicular function

testosterone and inhibin differentially influence the secretory rate of LH and FSH

role of testosterone in spermatogenesis

germ cell mitosis and meiosis

role of FSH in spermatogenesis

Spermatid remodeling /packaging

what makes up semen

• accessory gland secretions

• sperm (only small part of ejaculated fluid)

• mucus

testis

Produce sperm, located in the scrotum

3 function of epididymis and ductus deferens

serve as sperms exit route from the testis, site of maturation for motility and fertility, concentrate and store sperm

Seminal vesicle

empties into the last portion of the ductus deferens, one on each side and they supply fructose to nourish the ejaculated sperm, stimulate motility provide the bulk of the semen

Prostate gland

single gland, surrounds the urethra at the neck of the bladder, secretes alkaline fluid that neutralizes acidity in the vagina, triggers clotting of sperm to keep the sperm in the vagina during penis withdrawal

Bulbourethral gland

pair, both emoty into the urethra, secrete mucus for lubrication