CH. 29 - DEVELOPMENT, GROWTH & AGING
I. PRENATAL = Conception è Parturition, 3 phases
A. GERMINAL - 1st 2 weeks
1. Fertilized egg è Uterus
2. Steps: (Fig. 29.2, p. 1078)
a. ZYGOTE - Fertilized egg
b. CLEAVAGE – days 1-4, mitosis
é in cell #, not size
PLURIPOTENT - any cell can develop into anything
c. MORULA - solid ball, 12 cells, day 5
d. BLASTOCYST - hollow, 32 cells, day 6
- implants into endometrium (Fig. 29.3, p. 1080)
e. GERMINATION - 3 embryonic layers, 13-14 days (p.1082-83)
i. ECTODERM - outer, skin, nervous sys, senses
(Tab. 29.1, p. 1083) ii. MESODERM - middle, circ, musc, c.t., bones
iii. ENDODERM - inner, G.I. lining, lungs, liver, gland
B. EMBRYONIC - 2nd - 8th week (14-56 days) (Tab. 29.2, p. 1094-1095)
1. DETERMINATION è DIFFERENTIATION è MORPHOGENESIS
2. Nourishment from endometrium - PLACENTA developing
3. MOST SENSITIVE TO OUTSIDE INFLUENCE!
C. FETUS - Nourishment from blood
1. 8-14 weeks
a. Recognize as human
b. Face present, all digits separated, skeleton ossifying
c. Movement present
2. 14-24 weeks
a. Normal human proportions
b. Sex determined
c. Refinement & growth
3. 24-36 weeks - good chance of survival outside uterus
4. 280 days = normal gestation, PARTURITION = BIRTH
5. é in size = predominant element in fetus
II. NEWBORN/NEONATE
A. CIRCULATORY (Fig. 29.20, p. 1101-1102)
1. Foramen ovale closes è fossa ovalis (between L & R atria)
2. Ductus arteriosus è ligamentum arteriosum (PDA if not closed)
3. Umbilical vessels è ligamentum teres
(round ligament of liver)
B. DIGESTIVE
1. MECONIUM - Anal dishcarge @ birth
2. é Stomach acid è ê pH , 30 days
3. Liver function - 2 weeks
C. APGAR 0-10 (Tab. 29.3, p. 1103) - 9 is normal
1. Appearance
2. Pulse
3. Grimace
4. Activity
5. Respiration
III. LIFE STAGES
GERMINAL èEMBRYO èFETUS èNEONATE èINFANT èCHILD è
ADOLESCENT è YOUNG ADULT è MIDDLE ADULT è OLDER ADULT
IV. AGING
A. CAUSES
1. Loss of cells not replaced
a. Neurons & muscle
2. Loss of tissue plasticity
a. é collagen cross-linkage, ê hyaluronic acid
3. ê efficiency of systems/immunity - can’t adjust to stress
4. Habits - smoking, drinking, drugs
5. Environment - toxics, radiation
6. Genetics !
7. Spouses, children, in-laws, boyfriends/girlfriends, (professors?)
V. DEATH
A. Absence of respiration & heart beat
B. Absence of response to stimuli
C. CEREBRAL DEATH - Flat EEG for 30 minutes