Topic 4 Key Terms Glossary Flashcards

Flashcards for Topic 4 Key Terms Glossary

acute responses

The body’s immediate, short-term responses that last only for the duration of the activity and for a short time afterwards (recovery)

arteries

Large, thick-walled blood vessels that carry blood away from the heart

arterioles

Small blood vessels that branch off from arteries and extend to capillaries

arteriovenous oxygen difference (a-VO2 diff.)

The difference between the concentration of oxygen in the arterial blood and the concentration of oxygen in the blood in the veins; measured in mL/100 mL of blood.

atria

The two upper chambers of the heart that receive blood from the veins and pump it into the lower chambers (ventricles).

blood consists of

Plasma, red and white blood cells, and platelets.

blood vessels

A transport network of arteries, capillaries, and veins that carries nutrients and waste around the body.

capillaries

Tiny blood vessels in the cardiovascular system between the ends of the arterioles and the venules; they are the site for the exchange of gases between the cells and the cardiovascular system.

cardiac cycle

The movement of blood through the heart in one heartbeat; it consists of alternate systole and diastole of the atria and the ventricles.

cardiac output (Q)

The amount of blood ejected from the left ventricle of the heart per minute; Q = SV × HR, and is measured in litres per minute (L/min).

cardiovascular system

The heart and blood vessels circulate blood throughout the body, delivering water, oxygen and nutrients to cells, and removing waste products such as carbon dioxide

coronary arteries

The arteries that supply oxygen and nutrients to the cardiac muscle (heart).

deoxygenated blood

Oxygen-poor (carbon dioxide-rich) blood

diastole

A relaxation of the heart muscle.

one heartbeat

One contraction and relaxation of the heart muscle.

homeostasis

A constant internal environment for optimal functioning of the body and its systems.

hyperthermia

A rise in the body’s core temperature above 37.5–38.3 °C

hypothermia

A reduced core body temperature below 35 °C

oxygenated blood

Oxygen-rich blood

precapillary sphincters

One-way valves that control blood flow within capillaries.

pulmonary circulation

The arteries and veins that feed blood from the heart to and from the lungs where blood is oxygenated.

steady state

The state in which oxygen supply equals oxygen demand and energy is being supplied aerobically

stroke volume (SV)

The amount of blood ejected from the left ventricle with each heartbeat (contraction) of the heart; measured in millilitres per beat (mL/beat).

systemic circulation

The arteries and veins that feed blood from the heart to the whole body and back to the heart again for reoxygenation.

systole

A contraction of the heart muscle, specifically the ventricles.

systolic blood pressure

The blood pressure recorded as blood is ejected during the contraction phase of the heart cycle; the higher of the two blood-pressure values.

thermoregulation

The maintenance of core body temperature within a narrow range.

vasoconstriction

A process whereby blood vessels narrow or constrict, causing a decrease in blood flow.

vasodilation

A process whereby blood vessels increase their diameter, causing an increase in blood flow.

veins

Blood vessels that carry deoxygenated blood and waste products from the body’s cells back to the heart.

venous pooling

A collection of blood in the leg veins when high-intensity activity stops too suddenly.

ventricles

The two lower chambers of the heart that receive blood from the atria and pump it to the lungs (right ventricle) and to the body (left ventricle).