Human Growth and Reproduction

1. Human Growth and Reproduction

5. Female System Terms • Vagina/birth canal • Cervix • Ovary • Egg (ovum/ova) • Fallopian tubes (oviduct) • Uterus • follicle

6. Menstration - release of tissue & blood through the vagina; usually occurs each month two weeks after ovulation and lasts 3 to 7 days • Hypothalamus - small portion of the brain that controls hormone release • Pituitary - "The Master Gland“; located in brain and responsible for the functioning of all other glands including thyroid, adrenals, and sex glands

8. Follicle Stimulating Hormone (FSH) – a hormone secreted in the pituitary that Stimulates growth & development of the ovarian follicle in females • FSH in males stimulates the production of sperm • Follicle - small sac near the surface of the ovary that contains the developing egg cell • Luteinizing Hormone (LH) - hormone produced in the pituitary gland that stimulates the development of the corpus luteum

9. Estrogen – female hormone that regulates development of secondary sex characteristics • Progesterone – secreted by corpus luteum; regulates the build up of endometrial tissue in the uterus • Testosterone – male hormone that regulates the development of secondary sex characteristics

10. Ovulation - release of mature egg cell from its follicle in the ovary • corpus luteum - yellow mass that forms in the cavity of a ruptured follicle that releases progesterone • Fertilization - union of the egg and the sperm which results in conception (formation of a zygote)

11. cell division – (Cleavage/Mitosis) - shortly after fertilization the egg, now called a zygote, starts to divide into 2 cells, then 4, 8, etc. • Implantation - the zygote attaches to the uterine lining and starts to draw nutrition from the blood supply (occurs between 6th & 11th days after fertilization) • Endometrium – lining of the uterus; where zygote implants

12. Oviduct – passageways where egg is released form ovaries; site of fertilization; also called “fallopian tubes” • Cervix – opening at lower end of uterus • Vagina – muscular organ that receives the penis and sperm

21. Male System terms: • Penis • Testicles • Scrotum • Epididymis • Urethra • Vas Deferens • Prostate Gland • Seminal Vesicles • Cowper’s (Bulburethral) Glands • Seminiferous Tubules

22. Penis – delivers sperm to female reproductive tract • Testicle – produces sperm & testosterone • Epididymus – sperm is stored in this tightly coiled tube • Scrotum – sac containing the testes; extension of abdomen; functions to keep the testes at a temperature slightly lower than that of the rest of the body. (for human beings, the temperature should be 1 or 2 degrees lower)

23. Vas Deferens – thin muscular tube that transports sperm from epididymus to the urethra • Seminal Vesicle - a pair of simple glands inferior to the urinary bladder; secretes alkaline fluid that adds to semen & neutralizes acidity of vagina • Bulbourethral (Cowpers) glands – produce a clear secretion known as pre-ejaculate which helps to lubricate the urethra so sperm can easily pass through; also neutralizes traces of acidic urine in urethra

24. Prostate Gland – walnut-sized gland encircling urethra that stores & produces seminal fluid • Urethra – tubes that connects urinary bladder to outside of body; travels through penis and carries semen as well as urine • Seminiferous tubules – located in testicles; location of meiosis (creation of sperm)

37. A new study conducted by Chicago researchers shows that internal mucosal layers of foreskin are more susceptible to HIV infection than cervical tissue or the external layers of foreskin, which explains why uncircumcised men seem to be at much higher risk for HIV acquisition than men who are circumcised…this is not proven beyond a reasonable doubt…more testing is needed!

40. A fertile man makes around 1000 new sperm persecond, in the testes. Each sperm carries half the chromosomes (n or haploid) packed into its head. The rest of the cell is a long tail, which propels the sperm towards the egg at about three millimeters per minute. The neck is crammed with mitochondria, which help make the energy needed for the journey. Once they're released, sperm usually survive for 48 hours.

43. A human egg (oocyte) is about 100 micrometers in diameter, which is large for a cell. A fertile woman usually releases one egg a month, from one of her two ovaries. Unless the egg is fertilized within the next 24 hours, it dies. At its center, the egg contains half the chromosomes (n or haploid) number for its species. The rest of the cell is a rich food store for the fertilized egg during the first few days of its life. A baby girl is born with around .5-1.5 million eggs already formed in her undeveloped ovaries. However, only about 500 are released in her lifetime, between puberty (15) and menopause (55).

44. Ovulation • An egg (orange), almost ready to be released by a woman's ovary. • During a healthy cycle, a woman will release one or perhaps two eggs which should slowly travel down, hopefully meeting sperm on the way so it can be fertilized.

46. Fertilization