1. The Continuity of Life:
Reproduction 
Chapter 46
Campbell & Reece

2. Sexual reproduction Involves 2 events: Meiosis + Fertilization
Meiosis produces Haploid (1/2 Chromosomes) Gametes, specialized for:
1) Motility (sperm)
2) Nutrient storage (eggs)
Fertilization unites haploid gametes from two individuals
Restores diploid in offspring
New combinations of genes in offspring = unique

3. The Male Reproductive System
Testes: sperm and testosterone production
Epididymus: sperm maturation (~18 hrs.); motility
Vas Deferens: storage, Leads sperm from scrotum into abdominal cavity, thru glands, and around bladder
Glands: add seminal fluids
Cowper's Gland
Prostate- add fructose (carbohydrate)
Seminal vesicles- add alkaline fluids (semen)
Urethra
Penis
bulbourethral glands-lubricants

4. In the Testes: Spermatogenesis
each testis is divided into about 250 compartments, each packed with coiled seminiferous tubules which produce the sperm cells. Interstitial cells (between the tubules secrete testosterone)
Semeniferous tubules contain 2 types of cells:
1) Spermatogenic (sperm-producing) cells:
2) Sertoli cells (nourish & support developing cells)

5. 1st stage: "spermatogonia" (diploid): proliferate continuously by mitosis--> some differentiate into --> 2nd stage: "Primary Spermatocytes"
=> 1st meiotic division (Now Haploid)
3rd stage: "secondary spermatocytes"
=> 2nd meiotic division
4th stage: "spermatids“, mature into"spermatozoa" (sperm cell)

6. Sperm diagram Tail Neck Head axial filament Mitochondria (in sheath)
Nucleus
Acrosome (contains enzymes to penetrate egge membrane)
Axial filament contains 9+2 array of microtubules (typical of cilia and flagella)

7. Ejaculation a. Erection of the Penis b. Ejaculation erectile tissues:
2 Corpus Cavernosa
1 Corpus Spongiosum
fill with blood
b. Ejaculation
Mechanoreceptor stimulation causes reflexive nerve arc to smooth muscles which propels semen thru tract, up vas deferens, into urethra.
3-4 ml per ejaculation; only 10% is actually sperm cells ( billion)

8. The Role of Hormones in the Male
Androgens-produced in testes and adrenal cortex
Testosterone-
sperm production
secondary sex characteristics
aggression
Under control of Secretion from Pituitary:
LH -> testosterone
FSH -> acts on Sertoli cells

9. The Female Reproductive System
2 ovaries (3 cm each)
Outer layers form oocytes (immature egg cells)
2 oviducts (Fallopian tubes)
Uterus
Cervix
Vagina
outer stuctures: labia, clitoris

10. primary oocytes already forming in fetal female; reach prophase of 1st meiotic division
secondary oocytes continue meiosis at sexual maturity + polar body ("extra" cytoplasm-not fertile)
grow, mature
ovulation (released from ovary)
produces 2nd meiotic division (occurs after fertilization)
= OVUM and one additional polar body

11. Ovulation
Oocytes develop near surface of ovary and are surrounded by special cells
Called "ovarian follicle“, comprised of oocyte, follicular cells
During ovulation, the follicle ruptures and releases the 2nd degree oocyte
Follicle secretes Estrogens (grows Endometrium)
The follicle then enlarges and forms the Corpus Luteum "yellow body" which increases levels of progesterone to maintain pregnancy.

12. Fertilization
Secondary oocyte (egg) is "swept" into fallopian tubes by cilia.
Then, egg is propelled by waves of muscle contractions down the oviducts.
Oocyte breaks down after 72 hours.
Fertilization takes place in oviducts
The fertilized egg will reach uterus in 3 days.

13. Female Hormonal Controls
Controlled by Hypothalamus
GnRH, which triggers pituitary…
Pituitary Gland—releases-->LH, FSH which triggers…
Ovaries----> Estrogens + Progesterone
Under "feedback control system”