HDE100A Chapter 4 Review

What are the three prenatal periods?

Germinal, embryonic, and fetal.

What occurs during the germinal period?

During the first two weeks after conception, cells divide rapidly and implantation occurs.

What occurs during the embryonic period?

During approximately weeks 3–8, basic body structures and organs begin to develop.

What occurs during the fetal period?

From about week 9 until birth, the fetus grows and organs mature.

What is cephalocaudal development?

Development proceeds from the head toward the tail or lower body.

What is proximodistal development?

Development proceeds from the center of the body outward toward the extremities.

Which major system begins developing early?

The central nervous system.

What is the age of viability?

Around 22 weeks after conception, survival outside the uterus may become possible with specialized care.

Why does viability vary among premature infants?

Outcomes depend on organ maturity, neurological and respiratory development, medical care, and individual circumstances.

What is a teratogen?

An agent or condition that can harm prenatal development, such as certain infections, drugs, chemicals, or alcohol.

What factors affect the impact of a teratogen?

Dose, timing, and the developing individual's susceptibility.

What is a threshold effect?

An effect that may occur when exposure passes a certain level; some risks increase with dose

Does exposure to a teratogen guarantee harm?

No. Effects depend on exposure, timing, dose, and other circumstances; risk is not certainty.

What does the Apgar scale measure?

A quick assessment of a newborn's condition using five signs: appearance, pulse, grimace, activity, and respiration.

What does each letter in APGAR stand for?

Appearance, Pulse, Grimace, Activity, and Respiration.

When is the Apgar score usually assessed?

At about one minute and five minutes after birth.