Cardiovascular System

Cardiology

Study of the heart and blood vessel system.

Vessels

Carry blood away (arteries) or toward (veins) heart.

Heart

Cone-shaped, hollow muscular structure for blood circulation.

Nutrients

Substances like glucose transported by the heart.

Hormones

Chemical messengers like cortisol transported by blood.

Gases

Oxygen and carbon dioxide exchanged in blood circulation.

Epicardium

Outer serous covering of the heart wall.

Myocardium

Thick muscular layer of the heart responsible for contraction.

Endocardium

Inner endothelial lining of the heart chambers.

Base of Heart

Rounded cranial end directed dorsad.

Apex of Heart

Pointy caudal end directed ventrad.

Pericardium

Serous membrane creating a closed cavity around the heart.

Visceral Pericardium

Epicardium; lines the surface of the heart.

Parietal Pericardium

Outer layer of pericardium reinforced by fibrous layer.

Cardiac Muscle

Muscle type constituting the myocardium.

Chambers of Heart

Four distinct sections including two atria.

Thoracic Radiograph

Imaging technique showing heart's radio-opacity compared to lungs.

Atrium

Chamber receiving blood via large veins.

Ventricles

Chambers pumping blood through arteries.

Atrioventricular Valve

Valves between atria and ventricles.

Bicuspid Valve

Left A-V valve with two flaps.

Mitral Valve

Another name for the bicuspid valve.

Tricuspid Valve

Right A-V valve with three flaps.

Chordae Tendineae

Fibrous cords tethering valve cusps.

Papillary Muscles

Muscles preventing A-V valve inversion.

Aortic Valve

Valve between left ventricle and aorta.

Pulmonary Valve

Valve between right ventricle and pulmonary trunk.

Systemic Circulation

Oxygenated blood movement to body.

Pulmonary Circulation

Blood circulation through the lungs.

Cranial Vena Cava

Vein draining blood from upper body.

Caudal Vena Cava

Vein draining blood from lower body.

Foramen Ovale

Fetal opening between right and left atria.

Ductus Arteriosus

Fetal connection between pulmonary artery and aorta.

Systolic Pressure

Pressure during ventricular contraction (120 mmHg).

Diastolic Pressure

Pressure during heart relaxation (80 mmHg).

Mean Blood Pressure

Average of systolic and diastolic pressures.

Cardiac Cycle

One complete contraction and relaxation cycle.

Cardiac Output

Blood pumped per ventricle per minute.

Stroke Volume

Blood pumped per ventricle per stroke.

End Diastole Volume

Blood volume in ventricle before contraction.

End Systole Volume

Blood volume in ventricle after contraction.

Preload

Ventricular stretch before contraction.

Afterload

Pressure heart must overcome to eject blood.

Contractility

Strength of heart's contraction.

Sinoatrial Node

Heart's natural pacemaker initiating impulses.

AV Node

Coordinates electrical impulses for ventricular filling.

Purkinje Fibers

Cells rapidly propagating action potentials.

Normal Sinus Rhythm

Healthy heart rhythm.

Tunica Externa

Outer layer of blood vessel.

Tunica Media

Middle layer containing smooth muscle.

Tunica Interna

Inner lining of blood vessel.

Arterial Blood Pressure

Function of cardiac output and vascular resistance.

Capillaries

Sites of gas exchange in tissues.

Tight Junctions

Connect endothelial cells, forming barriers.

Blood Pressure

Primary force pushing fluid out of capillaries.

Osmotic Pressure

Force keeping fluid in capillaries.

Neural Reflexes

Involuntary responses regulating blood pressure.

Humoral Agents

Substances in blood affecting vascular function.

Paracrine Agents

Local signaling molecules affecting nearby cells.