Exam 3 Study Guide: Sleep, Dreaming, Circadian Rhythms, Homeostasis, Hormones, and Emotions

These flashcards cover essential vocabulary and concepts from the lecture notes related to sleep, circadian rhythms, hunger, hormones, and emotions.

Circadian Rhythm

A consistent cycle of body activity and behavior that occurs over about 24 hours.

Diurnal Animals

Animals that sleep at night.

Nocturnal Animals

Animals that sleep during the day.

Crepuscular Animals

Animals that are active at twilight, sleeping in the middle of day and night.

Zeitgebers

External stimuli like sunlight that influence circadian rhythms.

Free-running Clock

A circadian rhythm shown by animals when not provided zeitgebers.

Circannual Cycles

Yearly cycles affecting migration, hibernation, and sexual reproduction.

Unihemispheric Sleep

A type of sleep where only half the brain sleeps while the other remains conscious.

Chronobiology

The study of how the time of day affects the biology, physiology, and behavior of living organisms.

Suprachiasmatic Nucleus (SCN)

A structure in the hypothalamus crucial for establishing and maintaining circadian rhythms.

Melanopsin

A photopigment in the retina that is sensitive to blue light.

Pineal Gland

A gland that secretes melatonin and plays a role in circadian rhythms.

Polysomnography

An instrument used in sleep labs to measure physiological responses during sleep.

Electroencephalogram (EEG)

A method to measure the electrical activity of the brain.

Beta Waves

High frequency, low amplitude brain waves (12 – 38 Hz) associated with alert wakefulness.

Alpha Waves

Brain waves (8 – 12 Hz) associated with a relaxed, awake state.

Theta Waves

Low frequency, high amplitude brain waves (3 – 8 Hz) associated with light sleep.

Delta Waves

Very low frequency, high amplitude brain waves (0.2 – 3 Hz) associated with deep sleep.

REM Sleep

Rapid Eye Movement sleep associated with dreaming and high frequency brain activity.

REM Rebound

An increase in REM sleep after a period of sleep deprivation.

Glymphatic System

A system that removes waste from the brain during sleep.

Insomnia

Inability to sleep, often associated with stress and health problems.

Sleep Apnea

Difficulty breathing during sleep, causing interrupted sleep.

Narcolepsy

A disorder characterized by excessive daytime sleepiness and sudden sleep episodes.

Hormones

Messenger molecules in the body that send signals to organs and tissues.

Homeostasis

The maintenance of a stable internal environment in the body.

Endocrinology

The study of the endocrine system and the effects of hormones.

Hypothalamus

A brain region that regulates homeostasis and hormones.

Set Points

Optimal levels for the body’s internal states upheld by feedback loops.

Leptin

A hormone released from fat cells that suppresses appetite.

Ghrelin

A hormone that promotes hunger and increases dopamine activity related to food.

Sexual Dimorphism

Differences in physical characteristics between male and female members of the same species.

Oxytocin

A hormone that plays a role in bonding and is released during childbirth.

Vasopressin

A hormone that may play a role in long-term mate bonding.

Stressors

Events that push the body out of homeostasis causing a stress reaction.

Acute Stress

Short-term stress that occurs in response to an immediate threat.

Chronic Stress

Long-term stress that persists over an extended period of time.

Eustress

Positive stress that can be beneficial for health.

Distress

Negative stress that can harm mental and physical health.