pregnancy

The pre-embryonic period lasts for:
A. One month
B. One week
C. Three months
D. Two weeks

D. Two weeks

The embryonic cells that develop into all muscles of the body are the:
A. Mesoderm
B. Endoderm
C. Ectoderm
D. Chorion

A. Mesoderm

Inhibition of the secretion of which hormone allows for milk production?
A. Oxytocin
B. Dopamine
C. Prolactin
D. Estrogen

B. Dopamine

What are the major developments of each trimester?

• 1st trimester: Major organs begin forming; heart starts beating.

• 2nd trimester: Baby grows, moves, and develops more.

• 3rd trimester: Baby gains weight, organs mature, and prepares for birth.

How long does the pre-embryonic period last? Embryonic period?

• Pre-embryonic: First 2 weeks after fertilization.

• Embryonic: Weeks 3–8 after fertilization.

How do sperm know where to swim to find the egg?

They follow chemical signals released by the egg and surrounding cells (chemotaxis).

When is the morula stage of development?

• Around day 3–4 after fertilization.

• It's a solid ball of about 16–32 cells.

What is the difference between trophoblast and embryoblast cells?

• Trophoblast: Outer cells that help form the placenta.

• Embryoblast: Inner cells that develop into the embryo.

What do chorion cells become?

The fetal portion of the placenta (chorionic villi).

Be able to explain the ectoderm, endoderm, and mesoderm.

• Ectoderm (outer): Skin, brain, and nervous system.

• Mesoderm (middle): Muscles, bones, heart, blood, and kidneys.

• Endoderm (inner): Lining of digestive and respiratory tracts, liver, and pancreas.

Explain the positive feedback loops of both labor and milk letdown

Baby pushes on cervix → Oxytocin released → Stronger contractions → More pressure on cervix → More oxytocin.

What do prostaglandins do in labor?

• Soften and dilate the cervix.

• Help strengthen uterine contractions.