Ch. 7: The Biology of Sex and Gender

Chapter 7 of Garrett 6e Brain and Behavior

Activating Effects

Hormonal effects on sexual development that can occur at any time in an individual’s life; their duration depends on the presence of the hormone.

Androgen Insensitivity Syndrome

A form of 46,XY intersex involving insensitivity to androgen due to a genetic absence of androgen receptors.

Androgens

A class of hormones responsible for a number of male characteristics and functions.

Castration

Removal of the gonads (testes or ovaries).

Central Subdivision of the Bed Nucleus of the Stria Terminalis (BSTC)

A structure larger in males than in females, involved in pheromone signaling.

Congenital Adrenal Hyperplasia (CAH)

A form of 46,XX intersex characterized by excess androgen production.

Coolidge Effect

An increase in sexual activity when the variety of sexual partners increases.

Dihydrotestosterone

A derivative of testosterone that masculinizes the genitals of males.

Estrogens

A class of hormones responsible for female characteristics; produced by ovaries.

Estrus

A period when a nonhuman female animal is ovulating.

46,XX Intersex

Possession of ambiguous or male external genitalia with two X chromosomes.

46,XY Intersex

Possession of ambiguous or female external genitalia with one X and one Y chromosome.

Gender

The behavioral characteristics associated with being male or female.

Gender Dysphoria

Distress caused when a person's gender identity does not match their birth sex.

Gender Identity

A person’s subjective feeling of being male, female, or genderless.

Gender Role

A set of behaviors society considers appropriate for a given biological sex.

Gonads

The primary reproductive organs: testes in males or ovaries in females.

Hypogonadism

A disorder where gonads fail to produce normal levels of sexual hormones.

Medial Amygdala

Part of the amygdala that responds to sexually exciting stimuli.

Medial Preoptic Area (MPOA)

Part of the hypothalamus important for sexual performance.

Müllerian Ducts

Early structures that develop into female reproductive organs.

Müllerian Inhibiting Hormone

Hormone that causes the Müllerian ducts to degenerate in males.

Organizing Effects

Hormonal effects of sexual development occurring during the prenatal period.

Ovaries

The female gonads where ova develop.

Oxytocin

A hormone involved in lactation, sexual arousal, and bonding.

Pheromones

Airborne chemicals that have physiological effects on other animals of the same species.

Progesterone

A hormone that controls reproductive functions in females and is needed for testosterone production in males.

Sex

The biological characteristics that divide organisms into male and female.

Sexually Dimorphic Nucleus (SDN)

A part of the MPOA important to male sexual behavior.

Testes

The male gonads that produce sperm.

Testosterone

The major sex hormone in males; a member of the class of androgens.

Third Interstitial Nucleus of the Anterior Hypothalamus (INAH3)

A nucleus found to differ in size between gay men, heterosexual women, and heterosexual men.

Transgender

An individual whose gender identity differs from their sex assigned at birth.

Ventromedial Hypothalamus (VMH)

An area in the hypothalamus important for female sexual receptivity.

Vomeronasal Organ (VNO)

A cluster of receptors in the nasal cavity that detect pheromones.

Wolffian Ducts

Early structures that develop into male reproductive organs.