Cardiovascular System: The Heart and Blood Vessels

Flashcards covering the anatomy of the heart, blood vessels, and related concepts from a lecture.

Mediastinum

Anatomical region extending from the sternum to the vertebral column, the first rib and between the lungs.

Pericardium

Membrane surrounding and protecting the heart.

Fibrous Pericardium

Tough, inelastic, dense irregular connective tissue that prevents overstretching, provides protection, and anchorage.

Serous Pericardium

Thinner, more delicate membrane with a double layer (parietal and visceral) that reduces friction with pericardial fluid.

Epicardium

External layer of the heart wall; visceral layer of serous pericardium; smooth, slippery texture to outermost surface.

Myocardium

95% of the heart wall; consists of cardiac muscle.

Endocardium

Inner layer of the heart wall; smooth lining for chambers of heart, valves and continuous with lining of large blood vessels

Atria

Receiving chambers of the heart.

Ventricles

Pumping chambers of the heart.

Sulci

Grooves on the surface of the heart containing coronary blood vessels.

Fossa Ovalis

Remnant of foramen ovale in the interatrial septum.

Tricuspid Valve (Right Atrioventricular Valve)

Valve through which blood passes from the right atrium into the right ventricle.

Trabeculae Carneae

Ridges formed by raised bundles of cardiac muscle fiber in the right ventricle.

Pulmonary Valve (Pulmonary Semilunar Valve)

Valve through which blood leaves the right ventricle into the pulmonary trunk.

Bicuspid/Mitral/Left Atrioventricular Valve

Valve through which blood passes from the left atrium into the left ventricle.

Aortic Valve (Aortic Semilunar Valve)

Valve through which blood passes from the left ventricle into the ascending aorta.

Ductus Arteriosus

Shunts blood from pulmonary trunk to aorta during fetal life.

Ligamentum Arteriosum

Remnant of ductus arteriosus after birth.

Atrioventricular Valves

Valves located between the atria and ventricles; tricuspid and bicuspid valves.

Semilunar Valves

Valves that open when pressure in ventricle exceeds pressure in arteries; aortic and pulmonary valves.

Systemic Circuit

Left side of heart; receives blood from lungs and ejects blood into aorta.

Pulmonary Circuit

Right side of heart; receives blood from systemic circulation and ejects blood into pulmonary trunk.

Coronary Circulation

Network of blood vessels in the myocardium.

Anastomoses

Provide alternate routes or collateral circuits for blood to reach the heart muscle.

Coronary Veins

Collects blood from coronary capillaries; empties into right atrium.

anastomosis

union or joining of two blood vessels (nerves or lymphatics)

collateral

alternative route of circulation to an area provided by a collateral circulation

ischemia

insufficient blood supply to an organ or a tissue, usually due to a blocked artery

infarction

localized necrosis resulting from an obstruction of the blood

Autorhythmic Fibers

Specialized cardiac muscle fibers that repeatedly generate action potentials that trigger heart contractions.

Conduction System

Begins in sinoatrial (SA) node; propagates through atria; reaches atrioventricular (AV) node; enters atrioventricular (AV) bundle (Bundle of His); enters right and left bundle branches; Purkinje fibers conduct action potential to remainder of ventricular myocardium.

Electrocardiogram (ECG or EKG)

Composite record of action potentials produced by all the heart muscle fibers.

Cardiac Cycle

All events associated with one heartbeat; systole and diastole of atria and ventricles.

Auscultation

Use of a stethoscope to listen to the sound of heartbeat, primarily from blood turbulence caused by closing of heart valves.

Cardiac Output (CO)

Volume of blood ejected from left (or right) ventricle into aorta (or pulmonary trunk) each minute; CO = stroke volume (SV) x heart rate (HR).

Cardiac Reserve

Difference between maximum CO and CO at rest.

Preload

Degree of stretch on the heart before it contracts; greater preload increases the force of contraction; preload proportional to end-diastolic volume (EDV).

Frank-Starling Law of the Heart

The more the heart fills with blood during diastole, the greater the force of contraction during systole.

Contractility

Strength of contraction at any given preload; positive inotropic agents increase contractility, negative inotropic agents decrease contractility.

Afterload

Pressure that must be overcomed before a semilunar valve can open; increase in afterload causes stroke volume to decrease.

Vascular System

Taking blood to the tissues and back

Vascular shunt

Directly connects an arteriole to a venule

True capillaries

Exchange vessels

anastomosis

union or joining of two blood vessels (nerves or lymphatics)

collateral

alternative route of circulation to an area provided by a collateral circulation

Arteriosclerosis

abnormal thickening and abnormal hardening of the vessel walls in the arterial system

Atherosclerosis

endothelial cells are injured; inflammation occurs, macrophages release free radicals and enzymes that further damage the vessel wall

Fatty Streak

First lesion to appear as a result of atherogenesis, consisting primarily of foam cells in the subendothelial space

Varicose Veins

Damage to one or more valves in a vein causing Venous distention and pooling of blood

Aneurysm

Localized dilation or outpouching of a blood vessel or cardiac chamber

Systolic Pressure

Pressure at the peak of ventricular contraction

Diastolic Pressure

Pressure when ventricles relax

Hypotension

Low systolic

Hypertension

High systolic