gametes
sex cells
gametes (sex cells) combine their genes to form ?
fertilized egg - zygote
Primary Sex Organs
produce gametes (testes & ovaries)
Secondary Sex Organs
male - ducts, glands, penis delivers sperm cells
female - uterine tubes, uterus & vagina recieve sperm & nourish developing fetus
secondary sex characteristics
develop at puberty to attract a mate
Chromosomes
our cells contain 23 pairs of chromosomes
22 pairs of autosomes - non-sex chromosomes
1 pair of sex chromosomes
XY males - XX females
sex of child determined by?
type of sperm that fertilizes mother's eff
Gonads begin to develop at __ weeks
(2) sets of ducts
6 weeks
mesonephric - develop into male reproductive system
paramesonephric - develop into female reproductive tract
SRY gene
in males, codes for?
sex-determining region of Y gene
in males, codes for protein that causes developement of testes → secrete testosterone → mullerian-inhibiting factor → degenerates paramesonephric ducts
Female development occurs in absence of?
SRY
External genitals of male & female embryos remain undifferentiated until about ___ weeks
both have same (3) structures
8
1) urogenital folds
2) genital tubercle
3) labitoscrotal swelling
1) urogenital folds
2) genital tubercle
3) labitoscrotal swelling
1) MALE - enclose urethra
FEMALE - form labia minora
2) M: glans of penis
F: clitoris
3) scrotum or labia majora
Gonads of male - testes
produce sperm & secrete hormones
System of ducts in male testes
transport & store sperm. assist in their maturation, convey them to exterior
Sperm:
Seminiferous tubules → ?...
straight tubules → rete testis → efferent ducts in epididymis → ductus epididymis
Function of Epididymis
sperm maturation & storage
From epididymis, sperm travels to...
Vas deferens (ductus deferens) (part of spermatic cord) → ejaculatory ducts → urethra
Accessory sex glands (3)
add secretions to semen
seminal vesicles, prostate & bulbourethral glands
Accessory sex glands
- seminal vesicles
help neutralize acidic environment of male urethra & female reproductive tract by secreting alkaline fluid
- fructose for ATP production
60% of sperm volume
Accessory sex glands
- Prostate
slightly acidic fluid
for ATP production, proteolytic enzymes to break down clotting (eventually) from seminal vesicle
antibiotic to destroy bacteria
Accessory sex glands
- bulbourethral glands
alkaline fluid
protects sperm by neutralizing acids from urine in urethra
secrete mucus - lubricates end of penis & urethra lining,
Scrotum
supporting structure for testes
raphe of scrotum
external median ridge
1) Scrotal septum
2) Cremaster muscle
1) internally divides scrotum into two sacs, each containing a single testis
made up of subQ layer & muscle tissue - dartos muscle (smooth muscle)
2) series of skeletal muscle bands associated with each testis in scrotum
Testes
1) tunica vaginalis
2) tunica albuginea
1) serous membrane partially covering testes
2) internal - white fibrous capsule
extends inward & divides testis into lobules which contain seminiferous tubules that produce sperm
(2) types of cells in seminiferous tubules
1) spermatogenic cells - sperm-forming cells
2) sertoli cells- functions in supporting spermatogenesis
Spermatagonia ( __ ___) develop from __ ___ cells that arise in ___ __ and enter testes in __ week of developement
(sperm cells)
primordial germ cells
yolk sac
5th
toward lumen of seminiferous tubule are layers of progressively more mature cells.
In order of advancing maturity:
primary spermatocytes → 2ndary spermatocytes →spermatids →sperm cells
Sertoli cells
embedded among spermatogenic cells
extend from basement membrane to lumen
- nourish, phagocytize xs cytoplasm, control movements, & release of sperm into lumen
produce fluid for sperm transport
secrete inhibin & regulate effects of testosterone & FSH
Leydig (interstitial) cells
found in spaces between seminiferous tubules
secrete testosterone
