1. Human Development-Notes

2. Human Development sex cells have 23 chromosomes
-begins with 2 parents (male & female) who each produce a sex cell
sex cells have 23 chromosomes

3. the result of fertilization is a zygote(fertilization until 3 weeks of gestation)
-3 weeks later the offspring is referred to as an embryo

4. Growth & Development of the Embryo-weeks 3-8 of gestation
3rd week after fertilization: different types of cells form
Ex- cells that will form muscles & cells that will form skin

5. Growth & development of the embryo con’d
-4th week after fertilization: heart begins to beat & body organs begin to form
-5th week: blood begins to circulate, hands & legs start forming

6. Growth & Dev of Embryo con’d
6th week: lungs start to form, finger & toes form
8th week: face begins to look human

7. Growth & Dev of the Fetus (8 weeks gest until birth)
15 weeks-baby moves amniotic fluid through its nose & respiratory system which helps lungs develop

8. 20 weeks Reproductive organs show gender of baby
Fetus has started moving around in uterus; mom feels baby move

9. 20 weeks (con’d)
Baby (fetus) can hear & recognize the sound of mom’s voice

10. Most obvious change during fetal (8 wks gest until birth) development period is increase in body size
Baby gains weight & body fat

11. 28th week Baby (fetus) has eyelashes & eye brows
Can blink eyes & detect bright light filtering into womb (uterus)

12. Babies born before the 28th week will need considerable medical help to survive.
This improves all the time-able to save babies with smaller birth weight & earlier gestation.

13. Only deliver before 28th week if absolutely necessary
Babies born after 28th week are usually able to survive with medical help-esp breathing

14. Premature birth-baby born before week 37.
(Not 38th-please correct in your notes)

15. In uterus with baby:
Amniotic sac- fluid (water & amniotic fluid) filled membrane surrounding baby
-protects & cushions baby; lets it move freely inside uterus
(imagine a water filled balloon with a small plastic toy inside)

16. Also in uterus: (con’d)
2. Placenta- spongy mass of blood vessels from mom & child attached to mom’s uterus -helps nourish baby with food & oxygen -connected to baby by umbilical cord (New notes)

18. Also in uterus
3. umbilical cord- contains arteries & veins; allows oxygen to pass from mom to baby
-carbon dioxide passes from baby to mom

19. How does baby breathe in womb(uterus)?
Fetus doesn’t actually breathe in womb with its lungs
Baby does make breathing like movements as practice for after birth & lung development
*remember baby gets oxygen from mom through umbilical cord

20. Childbirth Usually starts when amniotic sac breaks; “my water broke”
Muscles of uterus (womb) start contracting-get stronger & closer together

21. Childbirth (con’d)
Eventually baby leaves mom’s body & umbilical cord is cut (usually by daddy)
*placenta leaves mom’s body also-the “after birth” after baby

22. A few Notes on Puberty!!
Boys: Pituitary gland (in brain) triggers secretion (releasing) of a hormone (regulates) called testosterone.
(Pi two i tary )

24. Puberty in boys (con’d)
Testosterone causes-sperm production, hair growth(face, armpits etc), shoulders broaden(widen), voice deepens

25. Puberty in Girls!!!!
Pituitary gland triggers release of hormone called estrogen

27. Puberty in girls(con’d)
Hormone estrogen causes-ovaries start releasing eggs, hips widen, begin menstruating (periods), breasts develop

28. Adolescence Kids/teens try to establish themselves as individuals
More independent from parents
Spend less time w/parents & more w/peers
Emotional ups & downs

31. Adulthood Greater freedom & greater responsibilities
Legal adult-age 18, can vote

32. Early Adulthood Approx ages 18-mid 30’s Peak health
Stage where most complete education, begin career
Many marry & start a family

34. Middle Adulthood Mid 30’s –mid 60’s Start to show signs of aging
Gray hair, wrinkles
More health problems-diabetes, cancer, heart disease
Kids grow up & leave home

36. Late Adulthood Begins in mid 60’s-death
People retire from work; reflect on life
Focus on grandchildren
Not as physically able-slower reflexes, less muscle

37. Late Adulthood (con’d)
Weaker immune system-risk of developing disease rises
Arthritis (joints wear out & become stiff & painful) is common

38. Late Adulthood (con’d)
As many as 1 in 4 adults may develop Alzheimer’s disease (brain changes cause mental abilities to decrease)

40. Kind of sounds depressing but…
On the bright side: many people remain healthy & active into their 80’s or 90’s
Adopt a healthy lifestyle now to increase your chances of staying healthy & active in old age

41. Bright Side:
Exercising the body & brain help prevent physical & mental effects of aging