Biological Rhythms Vocabulary

Flashcards on Biological Rhythms

Chronobiology

The study of biological clocks and their associated rhythms; also referred to as biochronometry.

Rhythm

A recurrent event characterized by its period, frequency, amplitude, and phase.

Period

The length of time required to complete one cycle of a rhythm.

Frequency

The number of completed cycles per unit of time.

Amplitude

The amount of change in the rhythm above or below the average value.

Phase

A point in a rhythm relative to some objective time point.

Circadian Rhythm

A biological rhythm with a period of about 24 hours.

Circatidal Rhythm

A biological rhythm with a period of about 12.4 hours, closely tied to changes in tides.

Circalunar Rhythm

A biological rhythm with a period of about 29.5 days, closely tied to phases of the moon.

Circannual Rhythm

A biological rhythm with a period of about 12 months.

Exogenous

Relating to a substance or process outside the organism (e.g., light).

Endogenous

Relating to a substance or process within the organism (e.g., genes).

Diurnal

Active during the day.

Nocturnal

Active at night.

Crepuscular

Active at dawn and dusk.

Zeitgeber

A potent environmental time cue or temporal synchronizer.

Free-running Rhythm

A biological rhythm that is not synchronized to its natural zeitgeber and expresses its own endogenous rhythm.

Entrainment

The synchronization of biological rhythms to a periodic environmental cue.

Photoperiod

Day length, or the amount of light per day.

Biological Rhythms and Health

linked with negative mental and physical outcomes