Pregnancy and Childbirth

Sperm Capacitation

period of sperm condition in female repro tract. prepares the acrosome for fertilization. increases sperm motility

Fertilization

occurs in the uterine tube, creates a zygote

3 phases of fertilization

1. Corona radiata penetration

2. Acrosome reaction and zona pellucida penetration

3. fusion of sperm and oocyte plasma membranes and pronuclei

Placenta

exchange of nutrients, respiratory gases, waste products, and antibodies. production of estrogen and progesterone.

Formed from maternal tissues (stratum functionalis) and fetal tissues (chorion). Chorionic villi immersed in a pool of maternal blood. mother and baby’s blood do not mix

Sexual differentiation

no diff in males and females before week 5. embryos initially contain indifferent gonads and 2 duct systems (paramesonephric ducts (F) and mesonephric ducts (M))

Internal Female Development

gonads differentiate into ovaries. paramesonephric ducts form uterine tubes and uterus. mesonephric ducts degenerate

Internal male development

gonads differentiate into testes. paramesonephric ducts degenerate. mesonephric ducts form male duct system and seminal vesicles. testes descend into scrotum

Late pregnancy

uterus expands (20x!!!). uterus myometrium becomes more active during last trimester, mild contractions may occur. Hormone relaxin softens the cervix and loosens the pubic symphysis.

Stages of labor

cervical dilation- begins with first regular contractions and ends when cervix is fully dilated. longest stage

expulsion- lasts from full dilation to delivery of baby

placental- eliminates the placenta, accomplished withing 15-30 min after birth of infant