Cardiovascular System - Part Component 2+5

Vocabulary flashcards covering the components, blood vessels, heart anatomy, circulations, electrical conduction system, and cardiac cycle.

Plasma

The liquid component of blood, accounting for $55\%$ of total blood volume.

Erythrocytes

Red blood cells that make up part of the solid portion ($45\%$) of blood.

Leucocytes

White blood cells that contribute to host defence and make up part of the solid portion ($45\%$) of blood.

Thrombocytes

Blood platelets responsible for clotting, making up part of the solid portion ($45\%$) of blood.

Tunica Adventitia

The outer fibrous sheath layer common to all blood vessels.

Tunica Media

The middle layer of a blood vessel, composed of smooth muscle and elastic fibre.

Tunica Intima

The smooth innermost lining of endothelium in a blood vessel.

Arteries

Blood vessels that transport blood away from the heart.

Capillaries

Microscopic blood vessels with walls formed by a single layer of cells that permit the interchange of gases, nutrients, and waste products.

Veins

Blood vessels that carry blood back to the heart, featuring one-way valves to prevent back-flow.

Mediastinum

The central thoracic compartment where the heart is situated (behind the sternum, in front of the spine, between the lungs, and to the left of the midline).

Pericardium

The outer layer or sac of the heart wall.

Myocardium

The middle muscular layer of the heart wall responsible for pumping action.

Endocardium

The smooth inner endothelial layer lining the chambers of the heart.

Pulmonary Circulation

The circulatory circuit that deals specifically with the passage of blood through the lungs.

Systemic Circulation

The circulatory division responsible for transporting blood throughout the entire body.

Coronary Circulation

The specialized circulatory pathway supplying oxygenated blood directly to the heart muscle.

Heart Valves

Structures separating the heart chambers and vessels, consisting of the Tricuspid Valve, Pulmonary Valve, Mitral Valve, and Aortic Valve.

Sino-Atrial (SA) Node

The main natural pacemaker of the heart, located in the right atrium, that generates electrical impulses and transmits them to the AV node.

Atrio-ventricular (AV) Node

A node in the right atrial wall that delays the impulse from the SA node to allow the atria to fully contract before relaying it to the Bundle of His.

Bundle of His

A pathway of cardiac conduction fibres that splits into left and right bundle branches to distribute electrical impulses to the left and right ventricles.

Atrial Systole

The phase of the cardiac cycle during which the atria contract, lasting $0.1\,\text{sec}$.

Ventricular Systole

The phase of the cardiac cycle during which the ventricles contract, lasting $0.3\,\text{sec}$.

Cardiac Diastole

The relaxation phase of the cardiac cycle, lasting $0.4\,\text{sec}$.