Crash Course :Reproductive System part 3

Human Sexual Response Cycle

The four-stage model of physiological responses during sexual activity: Excitement, Plateau, Orgasm, Resolution.

Vasocongestion

The swelling of genital tissues due to increased blood flow; causes erection and lubrication.

Emission

The first stage of male orgasm where semen is moved into the urethra from the vas deferens.

Expulsion

The second stage of male orgasm involving rhythmic muscular contractions that force semen out of the body (ejaculation).

Refractory Period

A time after orgasm when a person, typically male, cannot be stimulated to another orgasm.

Capacitation

The final functional maturation of sperm that occurs in the female reproductive tract, enabling fertilization

Acrosome

A cap-like structure on the sperm head containing enzymes needed to penetrate an egg.

Acrosomal Reaction

The release of digestive enzymes from the sperm's acrosome to break down the egg's outer layers

Zona Pellucida

The thick, glycoprotein layer surrounding the egg that the sperm must penetrate.

Cortical Reaction

The release of cortical granules from the egg after sperm fusion, creating the slow block to polyspermy.

Polyspermy

The pathological fertilization of one egg by multiple sperm, leading to a nonviable zygote.

Zygote

The diploid cell formed by the union of a sperm nucleus and an egg nucleus; the first cell of a new organism.

Contraception

The intentional prevention of pregnancy through various methods, devices, or agents.

Hormonal Contraception

Methods (pill, patch, implant) that use synthetic hormones to primarily suppress ovulation.

Barrier Methods

Contraceptives (condoms, diaphragms) that physically block sperm from entering the uterus.

Intrauterine Device (IUD)

A small, T-shaped device inserted into the uterus to prevent pregnancy (copper or hormonal).

Vasectomy

A surgical sterilization procedure for males involving the cutting and sealing of the vas deferens.

Tubal Ligation

A surgical sterilization procedure for females involving the cutting or blocking of the uterine tubes.