Cardiovascular Physiology 1

Flashcards covering Cardiovascular Physiology, focusing on anatomy and electrical activity of the heart.

Cardiovascular System

The heart, blood vessels, and blood that work together to transport molecules throughout the body.

Heart

A muscular organ enclosed in the pericardium, located in the chest (thorax).

Pericardium

Fibrous sac surrounding the heart.

Epicardium

Fibrous membrane closely affixed to the heart.

Myocardium

The walls of the heart, composed primarily of cardiac muscle cells.

Endothelial Cells/Endothelium

Thin layer of cells lining the inner surface of the cardiac chambers and blood vessels.

Atrioventricular (AV) Valves

Valves located between the atrium and ventricle in each half of the heart, allowing blood to flow from atrium to ventricle but not vice versa.

Tricuspid Valve

The right AV valve with three fibrous flaps or cusps.

Bicuspid Valve

The left AV valve with two flaps, also known as the mitral valve.

Papillary Muscles

Muscular projections of the ventricular walls that connect to the AV valves via chordae tendinae to prevent valve prolapse.

Chordae Tendinae

Fibrous strands that connect the AV valves to the papillary muscles, preventing the valves from being pushed up into the atrium.

Pulmonary and Aortic Valves (Semilunar Valves)

Valves located at the openings of the right ventricle into the pulmonary trunk and the left ventricle into the aorta.

Stenotic Valve

A narrowed valve that offers high resistance to flow, requiring high pressure to cause flow across the valve.

Myocardium

The cardiac muscle cells arranged in layers that are tightly bound together and completely encircle the blood-filled chambers.

Intercalated Disks

Structures that join adjacent cardiac cells end to end, containing desmosomes and gap junctions.

Desmosomes

Hold the cells together and to which the myofibrils are attached within the intercalated disks.

Gap Junctions

Allow action potentials to spread from one cardiac cell to another.

Conducting System

Network of specialized cardiac cells that initiate the heartbeat and help spread the impulse rapidly throughout the heart.

Atrial Natriuretic Peptide

Hormones secreted by certain cells in the atria.

Sympathetic and Parasympathetic Nerve Fibers

Nerve fibers that supply the heart.

Coronary Arteries

The arteries supplying the myocardium.

Coronary Sinus

A large vein into which most of the coronary veins drain, emptying into the right atrium.

Sinoatrial (SA) Node

A small group of conducting-system cells in the right atrium near the entrance of the superior vena cava, which act as the normal pacemaker for the heart.

Atrioventricular (AV) Node

A portion of the conducting system located at the base of the right atrium, which delays the spread of action potentials to allow atrial contraction to complete before ventricular excitation occurs.

Bundle of His (Atrioventricular Bundle)

Conducting-system fibers in the interventricular septum.

Purkinje Fibers

Large conducting cells that rapidly distribute the impulse throughout much of the ventricles.