14. Cardiovascular System Anatomy and Physiology

Comprehensive vocabulary flashcards covering heart wall layers, chambers, valves, systemic and pulmonary blood flow pathways, vascular tunics, blood pressure principles, and the cardiac conduction system.

Mediastinum

The mid-sagittal cavity located in the middle of the lungs where the heart is situated.

Fibrous Pericardium

The thick, fibrous outer layer of the pericardium that surrounds the entire heart and anchors it directly to the diaphragm.

Serous Pericardium

The double-layered inner membrane of the pericardium consisting of the parietal and visceral pericardium surrounding the fluid-filled pericardial space.

Parietal Pericardium

The layer of the serous pericardium that forms the superficial wall of the pericardial space.

Visceral Pericardium

The deep layer of the serous pericardium (also called the epicardium) that forms the deep wall of the pericardial space and adheres directly to the myocardium.

Pericardial Fluid

Fluid contained within the pericardial space that cushions the heart from external trauma and lubricates mechanical cardiac components during movement.

Myocardium

The thickest of all heart layers, composed entirely of cardiac muscle tissue responsible for contracting and pumping blood.

Endocardium

The deepest layer of the heart wall, composed of an inner endothelial lining that covers muscular ridges called trabeculae.

Trabeculae

Irregular muscular shapes lining the inner surface of the endocardium that disrupt smooth flow to prevent unwanted suction and serve as origin points for chordae tendineae.

Interventricular Septum

The muscular partition that separates the right ventricle from the left ventricle.

Interatrial Septum

The internal muscular wall that separates the right atrium from the left atrium.

Tricuspid Valve

An atrioventricular valve containing three cusps that regulates blood flow between the right atrium and the right ventricle.

Bicuspid Valve (Mitral Valve)

The atrioventricular valve containing two cusps that regulates blood flow between the left atrium and the left ventricle.

Pulmonary Valve

A semilunar valve located on the ventral portion of the heart between the right ventricle and the pulmonary artery.

Aortic Valve

A semilunar valve located on the dorsal aspect of the heart between the left ventricle and the aorta.

Chordae Tendineae

Tendon-like cords extending from the endocardium trabeculae to the atrioventricular valve cusps to prevent them from inverting during ventricular contraction.

Vena Cava

The largest vein in the body, divided into cranial and caudal branches, that collects deoxygenated systemic blood and returns it to the right atrium.

Aorta

The largest artery in the body, consisting of ascending and descending segments, that receives high-pressure oxygenated blood from the left ventricle to distribute systemically.

Pulmonary Artery

The large vessel carrying deoxygenated blood away from the right ventricle into the lungs for gas exchange.

Pulmonary Vein

The vessel carrying freshly oxygenated blood from the lungs back to the left atrium of the heart.

Artery

A high-pressure blood vessel that carries blood away from the heart and towards peripheral body tissues.

Arteriole

A small branch of an artery leading into capillaries.

Capillary

The microscopic blood vessel that connects arterioles and venules, serving as the site of gas and nutrient exchange with tissues.

Venule

A small blood vessel that collects blood from capillaries and drains into veins.

Vein

A capacitance blood vessel that carries blood back towards the heart and away from tissues, typically equipped with one-way valves.

Endothelium

The simple squamous epithelial lining that directly coats the inner lumen of all blood vessels.

Tunica Intima

The innermost blood vessel layer, consisting of the vascular endothelium and elastic tissue.

Tunica Media

The middle layer of a blood vessel wall, composed predominantly of smooth muscle cells.

Tunica Externa

The outermost tunica of a blood vessel, containing mostly collagen fibers and some elastic fibers.

Vasa Vasorum

A network of small blood vessels supplying the walls of large blood vessels themselves.

Coronary Arteries

Vessels branching directly from the base of the aorta that wrap around the heart to supply oxygenated blood to the myocardium.

Coronary Veins

Vessels that collect deoxygenated blood from cardiac tissue and deliver it back into the vena cava.

Systole

The contraction phase of a cardiac chamber during which blood is expelled into the arterial system or subsequent chamber.

Diastole

The relaxation phase of the cardiac cycle during which heart chambers fill with returning blood.

Sinoatrial (SA) Node

The primary physiological pacemaker of the heart, located in the right atrium, where normal cardiac electrical impulses originate.

Atrioventricular (AV) Node

A specialized cardiac conduction cluster that delays and conducts impulses from the atria to the ventricles, triggering atrial contraction.

Bundle of His

The specialized cardiac tract that conveys electrical impulses from the AV node down through the interventricular septum toward the apex.

Purkinje Fibers

Conductive terminal fibers extending through the ventricular myocardium that trigger synchronized ventricular contraction from the apex upward.

Electrocardiogram (EKG)

A diagnostic recording of the heart's electrical activity over time during cardiac cycles.

P-Wave

The first deflection on an EKG tracing, representing electrical atrial depolarization.

QRS Complex

The major EKG wave formation representing rapid ventricular depolarization prior to ventricular contraction.

T-Wave

The EKG deflection following the QRS complex that represents ventricular repolarization.

Ventricular Premature Contraction (VPC)

An ectopic, early cardiac depolarization originating in the ventricles, visible as abnormal wide complexes on an EKG tracing.

Ventricular Fibrillation (V-fib)

A severe cardiac arrhythmia characterized by rapid, chaotic, and uncoordinated electrical activity of the ventricles, resulting in loss of cardiac output.

Sinus Arrhythmia

A normal physiological variation in heart rhythm where the heart rate decreases during expiration and increases during inspiration.