Human Biology - Prenatal Development and Birth chapter 18

These flashcards cover key concepts related to prenatal development and the birth process as outlined in the lecture notes.

What are the three stages of prenatal development?

Pre-embryonic, Embryonic, Fetal

What is cleavage in the context of prenatal development?

Cleavage is the rapid mitosis of a zygote without size increase.

Define gastrulation.

Gastrulation is the process during embryonic development that forms primary germ layers.

What is allometric growth?

Allometric growth refers to differential rates of growth of various parts of an organism.

What occurs at implantation?

The blastocyst attaches to the endometrium and the trophoblast invades the endometrium.

What hormone does the trophoblast release during implantation?

Human chorionic gonadotropin (HCG).

What are the primary germ layers formed during gastrulation?

Endoderm, Ectoderm, and Mesoderm.

What does the inner cell mass of the blastocyst become?

The body of the developing embryo.

What is the function of the placenta?

To provide nutrients and oxygen to the fetus and remove waste products.

How does labor initiate according to the lecture?

Labor is driven by positive feedback involving oxytocin which leads to contractions.

What marks the beginning of differentiation in embryonic development?

The end of cleavage.

When does the fetal period begin and end?

The fetal period is from week 9 to birth.

What happens to the uterus during birth?

The cervix dilates to allow the fetus to be pushed out.

What happens to the placenta after birth?

The placenta is expelled as afterbirth.

What is the significance of the embryonic stage in relation to the fetal stage?

The embryonic stage lays the foundations for the fetal stage, where organs and organ systems grow.