Growth and Development Prenatal  old age

Prenatal Period Time before birth Gametes are joined together during fertilization As sperm are exposed to uterine fluid capacitation occurs allowing them to whiplashing movement Enzymes on the sperm break down the wall of the oocyte and only one is allowed to enter

Fertilization Fertilization takes place in fallopian tubes Zygote travels to uterus where implantation takes place 10 days after fertilization

In Vitro”within glass” Fertilization Eggs are harvested from female and sperm from male Egg is fertilized in petri dish and implanted into uterus

Prenatal Period Placenta grows attached to the uterine wall Placenta provides nutrients, removes wastes and secretes hormones

Prenatal Period Umbilical cord forms out of placenta and connect to fetus Mother and fetal blood rarely mix Many toxins, chemicals(caffeine, alcohol, drugs) and some microorganisms can cross barrier

Gestation Pregnancy last 39 weeks Divided into 3 (3 month) trimesters Embryo up to 8 weeks Fetus 8 weeks until delivery Baby after delivery

Delivery “en caul”

Full Term Pregnancy

Multiple Births

Parturition Baby drops down into birth canal and causes a stretching of uterus Uterus stretching causes release of oxytocin and via a positive feedback loop increases until child is expelled from uterus After birth the placenta must also be expelled

Post Natal Period Infancy Childhood Adolescence Adulthood Older Adulthood (old age)

Effects of Aging Decrease in skeletal and muscle mass By age 80 there is 50% reduction in muscle mass Skin becomes dry, sagging Number of nephrons decrease by 50% Ribs cartialge hardens resulting in “barrel chest” Atherosclerosis(narrowing) and arteriosclerosis(hardening) Presbyopia, hardening of lens causes loss in near vision Cataract occurs when lens becomes cloudy

Progeria Rare genetic condition where children age very rapidly Tissues fail to regenerate They usually die in first or second decade of life