Human Development Ch3

corpus luteum - secretes progesterone to support early pregnancy or menstruation if fertilization does not occur. 

amniotic fluid - protective liquid surrounding a developing fetus in the amniotic sac, providing cushioning, temperature regulation, and essential nutrients for growth. 

Amnion, ectoderm, mesoderm, endoderm 

Amnion – a thin membrane that surrounds and protects a baby in the womb. 

Ectoderm is the outer layer of cells in an embryo that forms the skin, brain, and nerves. 

Mesoderm is the middle layer of cells in an embryo that forms muscles, bones, and blood vessels. 

Endoderm is the inner layer of cells in an embryo that forms the lungs, liver, and digestive system. 

Vernix is a white, creamy coating on a baby's skin that protects it in the womb. 

Lanugo is soft, fine hair that covers a baby's body before birth to help keep it warm. 

Teratogen factors- (All cause some type of harm) 

prescription drugs- Prescription drugs can harm a fetus by causing birth defects or developmental issues, so pregnant women should consult their doctor before taking any medications. 

tobacco- can lead to premature birth, low birth weight, and developmental issues, so avoiding smoking and secondhand smoke is essential for a healthy pregnancy. 

rubella- Rubella can cause serious birth defects like deafness, heart problems, and developmental delays, so women should get vaccinated before pregnancy to prevent infection. 

Toxoplasmosis- Toxoplasmosis can cause brain damage, vision problems, and other birth defects in the fetus, so pregnant women should avoid handling cat litter and eat properly cooked meat to reduce the risk. 

what determines if a teratogen will harm a fetus? 

A teratogen's harm to a fetus depends on the timing, dose, type, genetics, and the mother's health. 

Nutrition and vitamins (recommended during pregnancy) 

Nutrition: Proper nutrition and vitamins are crucial for fetal growth and development, so pregnant women should eat a balanced diet and take prenatal 

Vitamins: including folic acid, to support a healthy pregnancy. 

Rh Factor Incompatibility 

why is this important 

Rh factor incompatibility occurs when a Rh-negative mother carries a Rh-positive baby, which can lead to complications, 

what can be done and under what circumstances? 

receiving an injection of Rh immunoglobulin (RhIg) during pregnancy can prevent problems. 

Stages of Childbirth (define) 

First Stage: Labor – This stage begins with contractions and ends when the cervix is fully dilated (10 cm). It has three phases: 

• Early labor: Mild contractions, cervix dilates up to 3-4 cm. 

• Active labor: Stronger contractions, cervix dilates from 4 to 7 cm. 

• Transition phase: Intense contractions, cervix dilates from 8 to 10 cm. 

Second Stage: Delivery of the Baby – The mother pushes, and the baby moves through the birth canal and is born. 

Third Stage: Delivery of the Placenta – The placenta is expelled after the baby is born, usually within 5-30 minutes. 

The Baby’s adaptation to Labor & Delivery what do hormones do 

During labor and delivery, the baby undergoes several adaptations to prepare for life outside the womb, with hormones playing a key role: 

1. Stress Hormones (Catecholamines - Adrenaline & Noradrenaline) – These help the baby cope with the stress of birth, increase heart rate, and improve blood flow to vital organs like the brain and heart. 

2. Cortisol (Stress Hormone) – Supports lung development and helps clear fluid from the lungs to prepare for breathing air. 

3. Surfactant Production – Hormones stimulate surfactant release, which prevents lung collapse and allows easier breathing. 

1. Glucose Regulation – Hormones help the baby mobilize stored energy for the transition from the placenta to independent feeding. 

2. Thermoregulation – Hormones help activate brown fat stores to generate heat and keep the baby warm after birth. 

These adaptations ensure the baby can breathe, regulate temperature, and sustain itself outside the womb 

Apgar (what do the numbers tell us?) 

The Apgar score (0-10) assesses a newborn’s health based on skin color, heart rate, reflexes, muscle tone, and breathing, with higher scores indicating better condition and lower scores requiring medical attention. 

Preterm and Low-birth-weight infants (what can either mean for a newborn?) 

Preterm and low-birth-weight infants may face challenges such as breathing difficulties, weak immune systems, trouble feeding, and developmental delays, often requiring specialized medical care to support growth and survival.