Ch.2: Body Systems and Heart Health

alveoli

Tiny air sacs in the lungs where gas exchange occurs.

autonomic nervous system (ANS)

System controlling involuntary body functions like heart rate and digestion.

bronchi

Large air passages that branch from the trachea into the lungs.

central nervous system (CNS)

Brain and spinal cord; main control center of the body.

cerebral vascular accident (CVA)

Stroke caused by interrupted blood flow to the brain.

chronic obstructive pulmonary disease (COPD)

Long-term lung disease causing airflow limitation.

diaphoresis

Excessive sweating.

diaphragm

Dome-shaped muscle that drives breathing.

dysautonomia

Dysfunction of the autonomic nervous system.

dyspnea

Difficulty or labored breathing.

electrolytes

Charged minerals essential for nerve, muscle, and fluid balance.

homeostasis

Body’s ability to maintain stable internal conditions.

hyperkalemia

Elevated potassium levels in the blood.

hypertension

High blood pressure.

infarct

Area of dead tissue caused by lack of blood supply.

metabolic syndrome

Cluster of conditions increasing risk for heart disease and diabetes.

metabolism

Chemical processes that convert food into energy.

nephrons

Functional units of the kidney that filter blood and form urine.

neurons

Nerve cells that transmit electrical signals.

neurotransmitters

Chemical messengers used by neurons to communicate.

obstructive sleep apnea

Disorder where airway blockage causes pauses in breathing during sleep.

parasympathetic nervous system (PSNS)

Branch of ANS that promotes rest, digestion, and recovery.

peripheral nervous system (PNS)

All nerves outside the brain and spinal cord.

pH (potential of hydrogen)

Measure of acidity or alkalinity.

renin

Kidney enzyme that helps regulate blood pressure.

sympathetic nervous system (SNS)

Branch of ANS that activates “fight or flight” responses.

thermoregulation

Control of body temperature.

trachea

Windpipe carrying air to the bronchi.

vagus nerve

Major nerve controlling heart rate, digestion, and parasympathetic activity.