Human Reproductive Biology: Fertilization and Contraception (VOCAB)

Vocabulary flashcards covering the key terms and concepts related to the sexual response, fertilization, zygote formation, implantation, pregnancy, and contraception as discussed in the video.

Four phases of the human sexual response (Masters and Johnson)

Excitement, plateau, orgasm, and resolution.

Excitement phase

Initial arousal; parasympathetic reflex causes arterioles in external genitalia to dilate and fill with blood.

Plateau phase

Increased muscle tension, heart rate, blood pressure, and breathing; male urethral sphincter contracts to prevent urine mixing with semen.

Orgasm

Rhythmic muscular contractions; ejaculation in males; uterine contractions and increased lubrication in females; female orgasm is not required for conception.

Resolution phase

Body returns to baseline after arousal; leads toward rest; in males, progress to refractory period; some females may have serial orgasms.

Refractory period

Post-orgasm interval in males during which another orgasm is unlikely; lasts minutes to days.

Serial orgasms

Some females can experience multiple orgasms in succession.

Ovulation

Release of a secondary oocyte from the ovary about once a month; oocyte viable for about a day; sperm can live 3–5 days.

Secondary oocyte

Egg released at ovulation; completes meiosis II upon fertilization.

Sperm viability window

Sperm can persist in the female tract for 3–5 days, creating a fertilization window.

Fertilization

Union of sperm and egg to form a zygote; triggers completion of meiosis II and fusion of male and female pronuclei.

Capacitation

Changes the sperm undergo in the female tract that enable fertilization; involves remodeling of protective proteins and acrosome activation.

Corona radiata

Outer layer of granulosa cells surrounding the oocyte; must be penetrated by sperm.

Zona pellucida

Glycoprotein layer around the oocyte with sperm receptors; binding triggers calcium influx and acrosomal reaction.

Acrosome

Cap on the tip of the sperm head containing enzymes for penetrating the zona pellucida.

Acrosomal reaction

Release of enzymes that allow sperm to digest through the zona pellucida.

Meiosis II (oocyte completion)

Upon fertilization, the secondary oocyte completes meiosis II, producing an ovum and a polar body.

Male pronucleus

Swollen sperm nucleus after fertilization; one of the two haploid nuclei before fusion.

Female pronucleus

Nucleus formed from the ovum after fertilization; combines with the male pronucleus.

Zygote

Diploid cell formed when the pronuclei fuse; begins mitosis to develop.

Implantation

Fertilized egg attaches to the uterine lining; endometrium must be receptive for gestation to begin.

Endometrium

Functional uterine lining that supports implantation and pregnancy and is hormonally regulated.

Gestation

Period of development inside the uterus after implantation, leading to birth.

Sterilization

Permanent contraception via tubal ligation (female) or vasectomy (male).