1. Animal Reproduction

2. Purpose of Reproduction?

3. Types of Reproduction Asexual Fission Budding Regeneration
PARTHANOGENESIS
Egg develops without fertilization; haploid or diploid
Male worker bees; ants & wasps
Komodo dragons
Some sharks

5. Asexual vs. Sexual Reproduction
Many offspring fast
Each individual is capable of having their own “kids” w/o a partner
No genders necessary
Variation comes only from mutations, therefore slow to adapt to environment
Occurs when environment is favorable
Successful genotypes continuously passed on
Takes longer to increase population size
Need males & females
Genetic variation
Enhanced reproductive success
Faster adaptation to environment
Occurs when environment is unstable, rapidly changing

6. Hermaphrodites Each individual has male and female parts
Any two individuals can mate
Some can self-fertilize
Allows sessile organisms to mate

7. Types of Fertilization
Internal
External
Sperm deposited near female reproductive tract; fertilization occurs within tract
Few zygotes (fertilized eggs) produced
More protection for developing embryo
Female releases eggs into environment, male fertilizes them externally
Many zygotes produced
Less protection for developing embryo
More likely that damage will happen to them, so the more you have, the more offspring will actually survive

8. External Fertilization
Spawning
Male and female gametes released at the same time
Can be in response to:
Chemicals
Lunar cycles
Temperature
Day length

9. Embryo Protection Methods
Internal
External
Soft – shelled eggs
Ingestion of eggs
Gluing of eggs to a mate for protection
Hard – shelled eggs
Protective womb for internal embryo development

10. Explain how the renin - angiotensin – aldosterone system works
Explain how the renin - angiotensin – aldosterone system works. What is its stimulus and how does it respond?

11. Human Reproduction

12. Male Reproductive Anatomy
Testes (testicles) – male gonads
SEMINIFEROUS TUBULES – sperm maturation site
Surrounded by Leydig cells that produce hormones
EPIDIDYMIS
Tubule where sperm mature
VAS DEFERENS
Muscular duct which sperm are sent through to reach the urethra during ejaculation

14. Male Reproductive System
Semen - ejaculated sperm + secretions
SEMINAL VESCICLES - secretion contains mucus, fructose, coagulating enzymes, and prostaglandins
PROSTATE GLAND – secretion has anticoagulant and citrate
BULBOURETHRAL GLAND – secretes mucus to neutralize acidity of urine

16. Male Reproductive Organs
Penis
delivers semen to female reproductive tract
Fills with blood when stimulated and closes off veins, preventing blood from leaving
Viagra – acts like NO (nitric oxide) and causes relaxation of arteries enhancing blood flow

18. Female Reproductive Organs
Ovaries – female gonads
Contain hundreds of eggs (OOCYTES) that are surrounded by FOLLICLES
Oviduct - Fallopian tube
Oocyte is expelled from follicle and travels down oviduct to the UTERUS
Lined with cilia to help propel the egg
Uterus has thick inner lining to nourish the egg called the ENDOMETRIUM

20. Female Reproductive Organs
Vagina – canal leading to the uterus
Site of sperm deposition
CERVIX – narrow opening of the uterus that connect to vagina
LABIA – folds of skin protecting external vagina

22. Spermatogenesis & Oogenesis

24. What is in the acrosome? Why Why the mitochondrial sheath?

25. Hormones of the Spermatogenesis
Gonadotropin Releasing Hormone released from hypothalamus
GnRH causes relase of follicle-stimulating hormone and luteinizing hormone
FSH causes production of Sertoli cells
Nourish developing sperm
LH stimulates Leydig cells
Leydig cells then secrete testosterone & other androgens
Increases spermatogenesis

26. FSH from anterior pituitary
Before birth
At puberty
Many follicles stimulated, one matures
Secondary oocyte is released and finishes division if fertilized

27. Spermatogenesis vs. Oogenesis
All 4 meiotic cells become sperm
Occurs from adolesence through all of adulthood
Produces millions of functional sperm
Continuous process
Only 1 of 4 meiotic cells become an egg; the rest a polar bodies
Starts before birth; ends around 50 yrs old
Produces hundreds of functional eggs
Many long interrupted pauses in production

28. Female Reproductive Cycle

29. The Ovarian Cycle GnRH causes release of small amounts of FSH and LH
FSH causes follicle growth
LH causes estradiol production by follicle cells
Low estradiol production inhibits FSH and LH levels

30. The Ovarian Cycle Estradiol levels begin to greatly increase
Causes FSH and LH levels to go up
Positive feedback – more estradiol = more LH
Increase in LH causes follicle to grow and burst, releasing oocyte into fallopian tubes

32. The Ovarian Cycle
LH causes left over follicular tissue to become the corpus luteum
Glandular tissue that secretes progesterone and estradiol
Promote thickening of uterine wall
Levels cause negative feedback on hypothalamus and causes decrease of LH & FSH
Low levels of LH & FSH cause corpus luteum to disintegrate

35. The Uterine Cycle

36. The Uterine (Menstral) Cycle
Uterus must prepare to support a developing embyo
Wall must be thick and vascularized
Estradiol & progesterone cause thickening after follicle rupture

37. The Uterine Cycle As corpus luteum disintegrates, hormone levels drop
Causes vasoconstriction
Uterine lining disintegrates
Endometrium is shed and blood is lost during MENSTRUAL PHASE