IB Sports, exercise and health science A.1 Communication Key Definitions

The physiological adjustments the body makes over time in response to environmental changes such as heat, humidity, or altitude.

The ACL is a key ligament in the knee that stabilizes the joint by preventing excessive forward movement of the tibia relative to the femur.

Alveoli are tiny, balloon-like structures that are the primary site for the exchange of gases (O₂ and CO₂). They provide a large surface area for gas exchange due to their many folds.

The difference in oxygen content between arterial and venous blood, indicating how much oxygen is extracted by muscles during circulation.

A structure in the heart that delays electrical impulses to allow the atria to contract before the ventricles.

The pressure exerted by the weight of the atmosphere on a given surface. At sea level it is approximately 760 mmHg, and it falls as altitude rises.

Receptors that monitor changes in blood pressure.

The primary form of carbon dioxide transport in the blood, formed when CO₂ combines with water.

Blood pressure (BP) is the force exerted by blood on artery walls, measured in mmHg.

A type of fat tissue that generates heat through non-shivering thermogenesis by burning fat, especially in response to cold exposure.

A part of the heart’s conduction system that transmits impulses from the AV node to the ventricles.

The volume of blood the heart pumps per minute.

Cardiovascular drift is the gradual increase in heart rate (HR) observed during prolonged submaximal exercise, typically when the body is exposed to heat or thermoneutral conditions.

Receptors that detect changes in the chemical composition of the blood, including oxygen and carbon dioxide levels.

Transfer of heat through the movement of air or liquids

The corpus luteum is a temporary endocrine gland formed in the ovary after ovulation.

The dynamic process of losing body water. It is the action that produces a state of hypohydration.

The phase of the cardiac cycle when the heart relaxes and fills with blood.

Diastolic BP is the pressure during heart relaxation when the heart is filling with blood.

The passive movement of a gas from an area of higher partial pressure to an area of lower partial pressure. It is the mechanism by which oxygen and carbon dioxide move between the alveoli, blood, and tissues.

A specialized cell or structure that detects changes in the internal or external environment and sends signals to the control center.

A structure (e.g., muscle or gland) that responds to signals from the control center to restore homeostasis.

Electrolytes are minerals that carry an electrical charge, essential for fluid balance, nerve signaling, and muscle contraction.

A system of glands that release hormones into the bloodstream to regulate various body functions.