Cardiovascular System and Cardiac Cycle

Vocabulary flashcards covering the structure and function of the cardiovascular system, heart chambers, cardiac cycle, arteries, veins, and capillaries.

Components of the CVS

The three main components of the cardiovascular system: the heart, blood vessels, and blood.

Functions of the CVS

Carrying oxygen from the lungs to the rest of the body, preventing infection, transporting important substances such as hormones, and removing waste products from the cells.

Double Circulatory System

A circulatory system in which blood flows into the heart twice during one circuit of the body, following the route Body-Heart-Lungs-Heart-Body.

Cardiac Muscle

The muscle that makes up the heart, whose cells are interconnected to allow impulses to spread rapidly from cell to cell.

Myogenic

The characteristic of heart muscle that enables it to contract and relax on its own accord without fatigue.

Atrium

The top chamber on each side of the heart.

Ventricle

The bottom chamber on each side of the heart.

Heart Valve

A structure that separates an atrium and a ventricle to ensure blood flows in only one direction through the heart.

Cardiac Cycle

Each individual heartbeat, which is divided into three stages: atrial systole, ventricle systole, and diastole.

Atrial Systole

The stage of the cardiac cycle lasting $0.1\,\text{sec}$ in which muscles in the walls of both atria contract.

Ventricle Systole

The stage of the cardiac cycle lasting $0.3\,\text{sec}$ in which both ventricles contract.

Diastole

The stage of the cardiac cycle during which all chambers of the heart relax.

Sinoatrial Node (SAN)

Also known as SAN, a node responsible for controlling and coordinating the contraction of the heart muscle.

Arteries

Blood vessels that carry blood away from the heart, most of which carry oxygenated blood.

Pulmonary Artery

The exceptional artery that carries deoxygenated blood away from the heart to the lungs.

Structure of Arteries

Blood vessels characterized by thick muscular walls, elastic tissue, and a small lumen (internal space) to withstand high blood pressure.

Functions of Arteries

Transporting oxygenated blood, maintaining blood pressure, and carrying nutrients and hormones.

Veins

Blood vessels that carry blood towards the heart, most of which carry deoxygenated blood.

Pulmonary Veins

The exceptional veins that carry oxygenated blood from the lungs to the heart.

Structure of Veins

Blood vessels characterized by thinner walls, less muscle and elastic tissue, a larger lumen, and internal valves.

Vein Valves

Structures inside veins that stop lower-pressure blood from flowing backwards, especially in the legs where blood moves against gravity.

Functions of Veins

Returning blood to the heart and preventing the backflow of blood.

Capillaries

Tiny blood vessels that connect arteries and veins.

Capillary Bed

Networks formed by capillaries throughout body tissues.

Structure of Capillaries

Vessels with walls one cell thick and an extremely narrow lumen where red blood cells often pass through in single file.

Functions of Capillaries

Serving as sites of exchange between blood and tissues where blood pressure lowers, allowing oxygen to move into cells, nutrients to move into tissues, and carbon dioxide and waste to enter the blood.