Lecture on Chronobiology and Bone Health

A set of vocabulary flashcards from the lecture covering key concepts in chronobiology and bone health.

Chronobiology

The study of time scales and cycles in biology.

Circadian Rhythm

An internal clock that functions on roughly a 24-hour cycle, regulating various biological processes.

Ultradian Rhythm

Biological rhythms that function in less than a 24-hour cycle.

Infradian Rhythm

Biological rhythms that function in more than a 24-hour cycle.

Suprachiasmatic Nucleus

The master clock in the hypothalamus that regulates circadian rhythms.

Ghrelin

A hormone that increases hunger levels, showing ultradian rhythm patterns.

Cortisol

A hormone with circadian and ultradian rhythm patterns, linked to stress and metabolism.

Metabolic Syndrome

A cluster of conditions that increase the risk of heart disease, stroke, and diabetes.

Bone Mineral Density (BMD)

The amount of mineral in bone; a key indicator of bone health.

DEXA Scan

A dual-energy X-ray absorptiometry scan used to measure bone mineral density.

Calcitonin

A hormone that helps to lower blood calcium levels.

Parathyroid Hormone (PTH)

A hormone that raises blood calcium levels when they are too low.

Osteoporosis

A condition characterized by weak and brittle bones, resulting in an increased risk of fractures.

Hydroxyapatite

An insoluble deposit of calcium and phosphate that forms the mineral structure of bones.

Vitamin D

A nutrient essential for calcium absorption and bone health.

Light Signals

Environmental cues that inform the suprachiasmatic nucleus and help regulate circadian rhythms.

Jet Lag

A temporary condition that results from the disruption of circadian rhythms, often caused by travel.

Cognitive Performance

The mental ability to perform tasks, often affected by timing of daily activities.

Diurnal Variation

Daily fluctuations in physical attributes, such as height or metabolic activity.

T-score

A measure used in bone density tests to determine risk of osteoporosis.