1. Structure and function of human reproductive structures
Human Reproduction
Structure and function of human reproductive structures

2. Sexual reproduction terms
Gametes--specialized reproductive cells
Ova (eggs)--female gamete
Sperm--male gametes
Zygote--formed from fusion of gametes’ nuclei (fertilization)--fertilization and birth brainpop animation
Result: offspring have genetic information from 2 parents
Brainpop intro to reproduction

3. Female Reproductive anatomy
Ovaries(2)--produce eggs (ova pl., ovum sing.)
produce sex hormones
At birth, female has all the eggs she will ever have (approximately 2 million)
At puberty (sexual maturity), ~400 eggs will mature
Each month, one ovary releases an egg into oviduct (fallopian tubes)--long tube that leads to the uterus
Fertilization normally takes place in oviduct

4. Female anatomy
•Uterus--muscular pear-shaped organ into which the egg travels (even in not fertilized)
If egg is fertilized, implants in wall of uterus-->pregnancy
If not fertilized, egg disintegrates within 24 hours after ovulation
Cervix--narrow portion at the bottom of uterus--provides opening to uterus from vagina
Vagina--muscular tube connects uterus to outside of body
Birth canal through which infants pass when born

9. Male reproductive anatomy
Testes(2)--found in the scrotum (pouch of skin) outside of body--keeps testes away from heat of body
Produce sperm in males at puberty (~13 years old) in seminiferous tubules
Produce sex hormones
Sperm require ~74 days to develop; millions mature each day. Many needed because few will survive / reach egg
Sperm contains:
Head--contains genetic material (DNA)
Midsection--has mitochondria for energy production
Tail--motility (movement) for travelling to egg

12. Male reproductive anatomy
Epididymis--long, coiled duct that stores sperm until ejaculation, which moves sperm out of the body
Vas deferens(2)--tubes that rapidly transport sperm from epididymis out of body

13. Male reproductive anatomy
Penis--male organ of sexual intercourse and urine excretion
Urethra--tube through which sperm (and urine) move out of the body
Semen--thick, white fluid that carries sperm
contains secretions
seminal vesicles (2)--fructose for sperm nourishment
prostate gland--basic solution to neutralize acidic environment of vagina
Cowper’s (bulbourethral) gland--provides lubricant; also helps to clean urethra
During ejaculation, ~5 mL of semen released with ~300 million sperm cells

16. Sexual intercourse
Penis becomes rigid with arousal due to increased blood flow
Vagina becomes lubricated with arousal
Ejaculation caused by involuntary muscle contractions
Sperm-containing semen released into vagina
Sperm travel toward oviduct, although only thousands survive the ~1 hour trip
Fertilization--sperm release enzymes that change the outer layer of egg so sperm can enter
Once one sperm enters, cell membrane of egg changes so no more sperm can enter--How do you get twins? (animation)
Zygote (fertilized egg) travels to uterus for implantation and is nourished by blood flow from mother during pregnancy

17. QUIZ--Hormones and Menstrual Cycle
1. Specifically, what body system deals with/controls hormones.
2. Name 3 organs in the human body that produce/control hormones
3. Name one of the sex hormones mentioned in the reading (other than estrogen, progesterone, and testosterone)

18. Hormones and their control
Endocrine system regulates hormones (chemical messengers)
Sexual development and secondary sex characteristics
Males--deeper voice, facial hair, etc.;
Females--widening hips, breast development
Effect is slow and long-lasting
Nervous system--response is quick and short
Feedback control of hormones
One hormone often stimulates organ, while another inhibits it
Negative feedback--product of process stops process
Positive feedback--product of process accelerated process
Insulin and glucagon from pancreas control blood sugar

19. Sites of hormonal control
Anterior pituitary (endocrine gland in brain)produces:
1. Luteinizing hormone (LH)
2. Follicle stimulating hormone (FSH)
Hypothalamus (in brain)
Regulates release of FSH and LH by acting on the pituitary
Controls blood pressure, body temp., emotions
Makes ADH and oxytocin

20. Hormones in males FSH stimulates maturation of the testes and sperm
LH stimulates release of testosterone (male sex hormone) from the testes
Testosterone stimulates:
Sperm production, erection, and ejaculation
Secondary sex characteristics

21. Hormones in females
Menstrual cycle-- ~monthly cycle that releases egg (ovum)
Ovulation--release of an egg (ovum)
Estrogen and progesterone--major female sex hormones
1. Produced by the ovaries
2. Stimulate sexual maturity
3. Regulate menstrual cycle (in part)

22. Menstrual cycle Approximately 28 days
Ovulation (release of egg at about day 14)
Sperm survive ~72 hours; egg survives ~24 hours-->Fertilization can occur within about a four-day window
If egg is not fertilized:
1. Hormone levels drop
2. Decreased blood flow to lining of uterus
3. Part of the lining of uterus disintegrates and passes to outside of body (menstruation)
loss of 50 mL to 150 mL of blood
Lasts 3 to 7 days

24. Specific menstrual hormones
FSH--causes maturation of egg inside a sac (follicle) on the surface of ovary
Estrogen--secreted by the developing follicle
1. Stimulates secretion of LH (stimulates ovulation and the production of estrogen)
2. Stimulates thickening of inner lining of uterus
Progesterone--maintains thickness of lining of uterus and promotes pregnancy (implantation of fertilized egg)
Corpus luteum formed after ovulation--releases estrogen and progesterone which together inhibit LH and maintain thick uterine lining

28. Menopause Profound hormonal changes in women
Signals end reproductive phase of life
Occurs ~ years old