Chapter 9 Flashcards
Menarche
A girl’s first menstrual period, signaling that she has begun ovulation. Pregnancy is biologically possible, but ovulation and menstruation are often irregular for years after menarche.
Spermarche
A boy’s first ejaculation of sperm. Erections can occur as early as infancy, but ejaculation signals sperm production. Spermarche may occur during sleep (in a “wet dream”) or via direct stimulation.
Pituitary
A gland in the brain that responds to a signal from the hypothalamus by producing many hormones, including those that regulate growth and that control other glands, among them the adrenal and sex glands.
Adrenal glands
Two glands, located above the kidneys, that respond to the pituitary, producing hormones.
HPA (hypothalamus–pituitary–adrenal) axis
A sequence of hormone production originating in the hypothalamus and moving to the pituitary and then to the adrenal glands.
Gonads
The paired sex glands (ovaries in females, testicles in males). The gonads produce hormones and mature gametes.
HPG (hypothalamus–pituitary–gonad) axis
A sequence of hormone production originating in the hypothalamus and moving to the pituitary and then to the gonads.
circadian rhythm
A day–night cycle of biological activity that occurs approximately every 24 hours
What body parts of a teenage boy or girl are the last to reach full growth?
For girls, breasts; for boys, final public hair growth
How do hormones affect the physical and psychological aspects of puberty?
All the biological changes of puberty are the result of massive increases in androgens (especially testosterone) in boys and estrogens in girls. Hormones also affect sleep patterns and emotions, although some of that is sociocultural more than biological.
Why do adolescents experience sudden, intense emotions?
Both hormonal fluctuations and the new experiences of body changes affect emotions. The levels of hormones fluctuate dramatically, especially in girls, and that trigger sudden emotional rushes.
How does the circadian rhythm affect adolescents?
The circadian rhythm shifts toward eveningness, which makes morning alertness particularly hard. That affects school achievement, especially when high schools start early in the morning.
What are the consequences of sleep deprivation?
Less alertness and more depression. The most troubling may be dozing off while in class or while driving.
What are the ethnic and cultural differences in the timing of puberty?
When children are well nourished, those with ancestors from Africa tend to be start puberty earlier, and those with ancestors from Asia later, than those with ancestors from Europe. However, ethnic differences are less significant than differences in body fat.
How does diet affect age of puberty?
A certain weight (about 100 pounds) seems to be a prerequisite for puberty to begin.
How does stress affect when a girl is able to become pregnant?
Stress correlates with earlier puberty and ovulation.
Growth spurt
The relatively sudden and rapid physical growth that occurs during puberty. Each body part increases in size on a schedule: Weight usually precedes height, and growth of the limbs precedes growth of the torso.
Body image
A person’s idea of how their body looks.
Anorexia nervosa
An eating disorder characterized by self-starvation. Affected individuals voluntarily undereat and often overexercise, depriving their vital organs of nutrition. Anorexia can be fatal.
Bulimia nervosa
An eating disorder characterized by binge eating and subsequent purging, usually by induced vomiting and/or use of laxatives.
Binge eating disorder
Frequent episodes of uncontrollable overeating to the point that the stomach hurts. Usually the person feels shame and guilt but is unable to stop.
Primary sex characteristics
The parts of the body that are directly involved in reproduction, including the vagina, uterus, ovaries, testicles, and penis.
Secondary sex characteristics
Physical traits that are not directly involved in reproduction but that indicate sexual maturity, such as a man’s beard and a woman’s breasts.
Child sexual abuse
Any erotic activity that arouses an adult and excites, shames, or confuses a child, whether or not the victim protests and whether or not genital contact is involved.