Cardiovascular System 1

Vocabulary flashcards covering the anatomical structures, circuits, valve functions, and tissue layers of the human cardiovascular system.

"Lub" sound

The normal heart sound caused by the closing of the Atrioventricular (AV) valves.

"Dub" sound

The normal heart sound caused by the closing of the Semilunar (SL) valves.

Heart murmur

An abnormal heart sound, often caused by issues like bicuspid valve regurgitation, which limits the amount of blood properly distributed to the body.

Mediastinum

The medial cavity of the thorax housing the heart, located superior to the diaphragm, anterior to the vertebral column, posterior to the sternum, and flanked by the lungs.

Apex of the heart

The inferiorly and leftward pointing tip of the cone-shaped heart.

Arteries

Vessels that carry blood away from the heart.

Veins

Vessels that carry blood towards the heart.

Coronary Circulation

The circulatory route that supplies the highly vascularized cardiac muscle with oxygen and nutrients and collects carbon dioxide waste.

Pulmonary Circuit

The blood pathway: Right Atrium → Tricuspid Valve → Right Ventricle → Pulmonary Semilunar Valve → Pulmonary Trunk/Arteries → Lungs → Pulmonary Veins → Left Atrium.

Systemic Circuit

The blood pathway: Left Atrium → Mitral/Bicuspid Valve → Left Ventricle → Aortic Semilunar Valve → Aorta → Body Tissues → Vena Cava → Right Atrium.

Left Ventricular Myocardium

The cardiac muscle layer of the left ventricle that is physically $3\times$ thicker than that of the right ventricle, designed to generate high pressure to pump oxygenated blood to the entire rest of the body.

Atrioventricular (AV) valves

Valves located between the atria and ventricles, consisting of the Tricuspid Valve on the right side and the Mitral/Bicuspid Valve on the left side.

Papillary muscles and chordae tendineae

Structures that act as tethers to anchor the AV valves to the ventricular walls, preventing the valves from inverting or blowing backward under high pressure.

Semilunar (SL) valves

Valves exiting the ventricles, including the Aortic Semilunar Valve (exits to tissues) and the Pulmonary Semilunar Valve (exits to lungs).

Pericardium

The membranous sac surrounding the heart consisting of an outer Parietal layer and an inner Visceral layer, separated by a cavity filled with lubricating fluid to prevent friction.

Epicardium

The outer layer of the heart wall (visceral pericardium) composed of simple squamous epithelium.

Myocardium

The middle layer of the heart wall made of cardiac muscle tissue, containing contractile cells and pacemaker cells.

Endocardium

The inner lining of the heart chambers made of thick, strong fibrous connective tissue.

Cardiac Skeleton

A structure that anchors and supports the myocardium, houses the valves, and provides an electrical delay so the atria can contract before the ventricles.

Intercalated discs and Gap Junctions

Specialized junctional structures in cardiac muscle that allow cells to act together as a single unit (functional syncytium).