Human Development and Heredity

Flashcards covering key concepts of human development and heredity, including fertilization, prenatal development stages, and labor.

What is fertilization?

Fertilization is the union of the nuclei of the egg and sperm, resulting in the formation of a zygote.

When does fertilization typically occur?

Fertilization typically occurs during ovulation, around day 14 of the menstrual cycle.

How long do sperm survive in the female reproductive tract?

Sperm can survive for approximately 12 to 72 hours after ejaculation.

Where does fertilization commonly occur?

Fertilization most commonly occurs in the first third of the fallopian tube.

What is the process that occurs after sexual intercourse?

Millions of sperm are deposited in the vagina, with around 100,000 surviving to swim toward the egg.

What happens during cleavage in prenatal development?

Cleavage is the process of cell division that increases the number of cells.

What are the four main processes involved in prenatal development?

Cleavage, growth, morphogenesis, and differentiation.

What is the early embryonic period?

The early embryonic period lasts for the first two weeks post-fertilization, starting from the formation of a zygote.

What key structure forms after fertilization and before implantation?

The blastocyst forms after fertilization and before implantation.

What is the role of the trophoblast in the blastocyst?

The trophoblast is the outer layer of cells that will form the placenta.

What is the significance of hCG in early pregnancy?

hCG prevents the deterioration of the corpus luteum, signaling pregnancy and maintaining hormone supply.

What is organogenesis?

Organogenesis is the formation of organs and structures during the embryonic period.

What occurs during the fetal period?

The fetal period focuses on growth and maturation of tissues, organs, and systems, starting from week 9 until birth.

What is labor?

Labor is defined as the rhythmic contractions of the myometrium to expel the fetus and placenta during childbirth.

What triggers the onset of labor?

The onset of labor is triggered by hormonal changes, especially between estrogen and progesterone.

What is the typical presentation for childbirth?

The standard birth presentation is head-first, known as vertex position.

What complications may arise from breech presentation during birth?

Breech presentations may lead to complications that require medical intervention for safe delivery.