Week 3

Question 1

Zygote

Answer 1

fertilized egg: during germinal period (first 14 days) it begins duplication and division within hours of conception
​​- Development of the placenta
- Implantation (about 10 days after conception)
- Organism grows rapidly

Question 1

Embryo

Answer 1

third through eighth week: Primitive streak becomes the neural tube and later forms the brain and spine of the CNS.
- Head takes shape.
- Eyes, ears, nose, and mouth form.
- Heart begins to pulsate.
- Extremities develop and webbed fingers and toes separate.

Question 2

Fetus

Answer 2

9th week until birth
- Genitals form and sex hormones cause differences in fetal brain organization.
- By three months, the fetus weighs about 3 ounces.
- Experiences the period of greatest brain growth during the fourth, fifth, and sixth months

Question 3

Teratogen

Answer 3

These include any agent or condition, including viruses, chemicals, and drugs, resulting in birth defects or even death (some only cause harm during critical periods, like heart formation at 3-4 weeks)
- Many teratogens are virtually harmless until exposure reaches a certain level.
*Fetal alcohol syndrome (FAS)

Question 4

Know the major causes and consequences of low birth weight

Answer 4

Higher risk in heart disease, mental illness, cancer, diabetes

Question 5

Most common reasons for LBW

Answer 5

Maternal malnutrition and behavior
Hunger; poor nutrition
Drug use
Multiple births