Pregnancy and Human Development

Flashcards covering key vocabulary and definitions related to pregnancy and human development.

Fertilization

The fusion of sperm chromosomes with oocyte chromosomes to form a zygote.

Monospermy

A process where only one sperm successfully fertilizes an oocyte.

Zona Pellucida

A glycoprotein-rich extracellular matrix surrounding the oocyte.

Acrosomal Reaction

The release of enzymes from the sperm's acrosome to digest the zona pellucida.

Embryonic Period

The first 8 weeks post-fertilization during which major organs begin to form.

Fetal Period

The period from weeks 9 to 38, during which the fetus develops further.

Gastrulation

The process that transforms the two-layered embryonic disc into three germ layers: ectoderm, mesoderm, and endoderm.

Neurulation

The formation of the neural tube from the ectoderm, which will develop into the central nervous system.

HCG (Human Chorionic Gonadotropin)

A hormone produced by the placenta that maintains the endometrium during pregnancy.

Placenta

The organ that exchanges nutrients and wastes between maternal and fetal blood without direct blood exchange.

Umbilical Cord

The structure that contains two umbilical arteries and one umbilical vein, connecting the fetus to the placenta.

Teratogens

Substances that may cause congenital abnormalities or fetal death by crossing placental barriers.

Dilation (Stage of Labor)

The first stage of labor where the cervix opens to allow the baby to pass through.

Acrosome

The cap-like structure on the head of sperm that contains enzymes for penetrating the oocyte.

Blastocyst

A hollow ball of cells formed from a morula that implants in the uterine wall.

Ectoderm

The outermost germ layer, which develops into the skin and nervous system.

Mesoderm

The middle germ layer, which develops into muscles, bones, and the circulatory system.

Endoderm

The innermost germ layer, which forms the gut and associated organs.

Foramen Ovale

A flap-covered hole between the right and left atria that shunts blood from right to left in fetal circulation.

Ductus Arteriosus

A vessel that directs blood from the pulmonary artery to the aorta, bypassing the lungs in fetal circulation.

Cortical Reaction

The reaction that occurs when sperm enters the oocyte, preventing other sperm from binding.

Fetal Oxygen Exchange

Process through which oxygen and nutrients are exchanged between maternal and fetal blood via the placenta.

Breech Presentation

A delivery position where the baby is positioned feet or buttocks first.