MCAT reproductive system

Male

XY

Female

XX

Pathway of sperm

seminiferous tubules→ epididymis→ vas deferens → ejaculatory duct → urethra → penis

testes contain

seminiferous tubules and interstitial cells of leydig

seminiferous tubules

sperm is produced here

cells of Leydig

produce testosterone

epididymis

place where sperm gain motility through their flagella and are stored before ejaculation

ejaculation

sperm pass through vas deferens and ejaculatory duct

urethra

two ejaculatory ducts fuse here and the sperm is carried through the penis

seminal fluid

sperm is mixed with this to pass through. seminal vesicles contribute fructose and nourish sperm. prostate gland gives fluid an alkaline environment

Cowper’s glands

produce a clear viscous fluid

semen

sperm + seminal fluid

stages of sperm development spermatogenesis

spermatogonia (2n) → primary spermatocytes (S phase) → secondary spermatocytes (after meiosis 1 ) → spermatid (n, after meiosis 2) → spermatozoa (after maturation)

ovaries

female reproductive organ that produces estrogen and progesterone

follicles

membranous sacs in ovaries that nourish ova( eggs)

fallopian tube

• lined with cilia

• propels egg during ovulation

uterus

site of fetal development

cervix

lower end of uterus that connected to vaginal canal

oogenesis

production of female gametes

All oogonia are formed during

fetal development

primary oocytes

arrested in prophase I

secondary oocyte

produced once a month

a primary oocyte undergoes meiosis I

also produces a POLAR body that is arrested

zona pelludia

necessary environment around oocyte for nourishment and sperm bin ding

when sperm penetrates zona pelludia

meiosis II of oocyte is triggered

prior to puberty

gonadotropin releasing hormone is restricted

GnRH triggers

anterior pituitary gland to produce FSH and LH

FSH stimulates production of

estrogen

Estrogen leads to thickening of

endometrium

progesterone

hormone that helps to maintain health of endometrium

menstrual cycle

follicular phase → ovulation → luteal phase → menstrual phase

follicular phase

GnRH increases which stimulates FH and LH from pituitary and signals follicles to produce estrogen

ovulation

LH surges, ovum are released into abdominal cavity

luteal phase

• progesterone increases

• estrogen stays high

• LH drops off

menstruation

corpus luteum turns into corpus albicans

• estrogen and progesterone decline