#18 Reproductive Physiology.pptffsw hhhjkllpppppppp

qewqar3wrw3r3r3et4ewyreyhtryhSWsw

1. Human Reproductive System
Produces, stores, nourishes and transports
functional gametes (egg and sperm).

2. 2
o
Reproductive Organs = External Genitalia
Fertilization - union of sperm and egg = zygote.
1
o
Reproductive Organs = Gonads
Gonads make gametes (sex cells)
and the Sex Hormones.
Ducts, accessory organs and
glands assist gametes

3. •Male Gonads
–Testes produce sperm and testosterone.
•Female Gonads
–Ovaries produces eggs, estrogen and progesterone.

4. The Sex Chromosomes
XX or XY
Female Male
X chromosome has about 1,100 genes on it.
Y chromosome has about 80 genes on it.
22 pairs of autosomal chromosomes +
1 pair of sex chromosomes.

6. Platypus:
Researchers discovered it has 10 sex chromosomes,
some of them linked to mammals and some to birds.

7. Endocrine Regulation of Reproduction
Gonadotropin-releasing hormone (GnRH)
From Hypothalamus, stimulates FSH and LH release.
FSH:
↑ follicular development, ↑ estrogen (females).
Required for sperm production (males).
LH (ICSH in men):
Ovulation.
Regulates estrogen and progesterone (females).
↑ Testosterone (males)

8. Phenotypic Sex
Apparent anatomical sex of individual
Sexual differentiation
Male
Induced by Androgens
Mostly Testosterone
Female
Lack of Androgens

9. Mullerian
Inhibiting
Factor
Testosterone
+
Male

10. 2
o
Sexual Characteristic
Differences in anatomy and physiology between
males and females = sexual dimorphism.
Males Females
Pattern of hair growth
Characteristic
Voice (pitch)
Muscle mass
Bone growth/density
Sex drive
Distribution of body fat
Aggression

11. Genetic and Phenotypic Sex
If person with XY has testes that fail to
differentiate and secret hormones - Result?
= genetic male, anatomical female
If person with XY has normal testosterone
levels but target tissue lacks receptors -
Result?
= genetic male, anatomical female
(testicular feminization syndrome)

12. Sex Chromosome Abnormalities
Female
Genotype
Syndrome
Male
Genotype
Syndrome
XX Normal XY Normal
XO Turner
 
XXY Klinefelter
XXX Triple-X XYY XYY

13. •Klinefelters’s Syndrome
–Person has 47 chromosomes, the extra
one is a Y, genotype = XXY
•Turner’s Syndrome
–Person has 45 chromosomes, the X or Y is
missing, genotype = XO
= Male
= Female
Reduced fertility, small testicles, enlarged breast
Usually Infertile, short, immature sex organs at adolescence

14. Triple-X Syndrome
Women with 3X chromosomes - genotype is XXX
“Super-females" or “Meta-females”.
Taller, long legs, slender torsos, limited fertility.
 
XYY Syndrome
Males with extra Y chromosome - genotype is XYY.
 
“Super-males“ often tall, high testosterone levels.
 
Usually fertile.
 

Both often unaware of chromosomal abnormality

15. Male Reproductive Structures

16. •Held ‘outside’ body in the scrotum.
1
o
Reproductive organ: Testes
•Dartos muscle wrinkles skin of scrotum.
•Cremaster muscle pulls testes closer to body.
Male Reproductive Structures
•Cremaster Reflex.

17. Epididymis
~ 18 feet long
~ 3 weeks to travel through
- Head
- Body
- Tail
Stores sperm, recycles
damaged ones, site of
maturation of sperm
Ductus deferens – starts after tail of epididymis

18. The Accessory Glands

19. Accessory Organs of the Male
1. Seminal vesicles
2. Prostate gland
2. Bulbourethral glands
All secrete semen
1. Seminal Vesicles
•Paired glands - secretes 60% semen volume.
•Fibrinogen – converts to fibrin for clotting.
•Fructose – a monosacharide for energy.
•Prostaglandins – contract female tract.

20. 2. Prostate Gland
•Single gland - secretes 30% semen volume.
•Clotting proteins – to cause initial clots.
3. Bulbourethral Glands
•Lubricating properties.
•Fibrolysin – to liquefy clots.
•Paired glands (~5% semen volume).
•Alkaline mucus secretion (to neutralize).

21. Semen
•Typical ejaculation releases 2-5 ml.
•Sperm count typically 50 – 100 million per ml.
•Sperm count below 20 million per ml,
considered “infertile”.
•Sperm must be 2-3
o
F cooler than rest
of body, hence kept ‘outside’ in scrotum.

23. The Penis
•Erectile tissue (3 masses)
–Two corpora cavernosa
–One corpus spongiosum (surrounds urethra)
•Erection – dilation of arterial smooth muscles.
Erectile Dysfunction (ED)?

24. The Female Reproductive System
•Vaginal canal and vagina
•External genitalia
•Ovaries
•Uterus
•Uterine tubes

25. Female Reproductive System

27. Uterine Wall (Layers)
•Myometrium – muscular (thickest ~90%).
•Endometrium - innermost layer
•Perimetrium – outermost covering.
–Functional layer, top 1/3 (sheds).
–Basal Layer, bottom 2/3 (remains).

29. The Vagina – passage, connecting uterus to
external genitalia.
The External Genitalia:
Labia majora – outer (larger)
Labia minora – inner (smaller)
Lesser and greater vestibular glands.
Mons pubis
Clitoris – erectile tissue (spongiosum)
(prepuce = hood, foreskin of clitoris)