Human REproduction

Gonadotropin-releasing hormone (GnRH)

A hormone from the hypothalamus that triggers puberty by stimulating the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

Luteinizing Hormone (LH)

A hormone released by the pituitary gland that stimulates increases in testosterone and plays a role in reproduction.

Follicle-Stimulating Hormone (FSH)

A hormone released by the pituitary gland that stimulates the production of eggs in ovaries and sperm in testes.

Leptin

A hormone secreted by adipose cells that is essential for the onset of puberty.

Tanner Stages of Puberty

A classification system that outlines the physical development stages of puberty in males and females.

Precocious Puberty

The onset of puberty before age 8 in girls or age 9 in boys.

Delayed Puberty

No development of secondary sexual characteristics by age 14; may resolve naturally or require medical intervention.

Andropause

A term referring to age-related hormonal changes in men, often characterized by a decrease in testosterone levels.

Ejaculation

A physiological process involving the expulsion of semen from the male reproductive tract.

Emission Phase

The preparatory stage of ejaculation where semen is moved into the urethra.

Expulsion Phase

The actual release of semen from the penis during ejaculation.

Masters and Johnson Model

A four-phase model of sexual response including excitement, plateau, orgasm, and resolution.

Kaplan’s Triphasic Model

A model highlighting sexual desire as a precondition for physiological responses, including excitement and orgasm phases.

Basson Model

A nonlinear model of sexual response emphasizing emotional intimacy and relationship satisfaction.

Vasocongestion

Increased blood flow to reproductive organs during arousal.

Myotonia

Muscle tension that occurs during sexual response phases.

Orgasmic Platform

Engorgement of the outer vaginal area during the plateau phase.

Clitoral Hood

The structure covering the clitoris; its stimulation often leads to orgasm.

Bartholin’s Glands

Glands that secrete lubrication during arousal, where blockage can lead to cyst formation.

Clitoral Orgasms

Orgasms that involve stimulation of the clitoris primarily through pudendal nerves.

Vaginal Orgasms

Orgasms that involve stimulation of the vagina primarily through pelvic nerves.

Blended Orgasms

Orgasms that combine clitoral and vaginal stimulation.

Reflection Phase

The phase following sexual experience where individuals reflect on its meaning and emotional impact.

Resolution Phase

The final phase of sexual response when the body returns to a pre-excitement state.

Female ejaculation

The expulsion of fluid by the Skene glands during sexual arousal or orgasm.

Refractory Period

A recovery phase after ejaculation during which a man cannot achieve another erection.

Seduction Phase

The initial phase of Reed's Erotic Stimulus Pathway where behaviors create desire.

Sensation Phase

The phase in Reed's model where sexual stimulation is experienced through the senses.

Surrender Phase

The phase in Reed's model corresponding to the experience of orgasm.

Sexual Response Cycle

The series of physiological changes that occur during sexual arousal and orgasm.

Criticisms of the Masters and Johnson Model

Includes research bias, lack of focus on emotional aspects, and an emphasis on genitals and heterosexual penetration.