Cardiovascular System Flashcards

Flashcards reviewing key concepts of the cardiovascular system, based on lecture notes.

What is the function of the pericardium?

It protects the heart and allows its contraction with minimal friction.

What separates the right atrium from the right ventricle?

The tricuspid valve.

What separates the left atrium from the left ventricle?

The bicuspid (or mitral) valve.

What is the function of the papillary muscle and chordae tendineae?

They prevent eversion of the A-V valves into the atria during ventricular contraction.

What determines the opening or closure of cardiac valves?

Pressure difference across them.

What are the two main reasons backflow from the atria into the veins isn't usually a problem?

Normal atrial pressures are not much higher than venous pressures, and the sites of entry of large veins into the atria are partially compressed during atrial contraction.

What cell type lines the inner surface of the myocardium?

Endothelial cells (endocardium).

How much thicker is the left ventricular wall compared to the right?

Approximately 3 times thicker.

What is the functional capillary pressure?

17 mmHg

List components of the high pressure system in CVS.

Systemic arterial system (aorta, arteries, arterioles), Right and Left ventricles during systole, Arterial side of capillaries.

List components of the low pressure system in CVS.

Systemic veins, Pulmonary vessels, Right and left atria, Right and Left ventricles during diastole.

What are the two types of cardiac muscle fibers?

Contractile (99%) and Autorhythmic (1%).

What circulation starts from left ventricle to right atrium

Systemic Circulation (greater).

What circulation starts from right ventricle to the left atrium?

Pulmonary circulation (lesser).

What are the two components of the heart as a pump?

Compression pump and Suction Pump

What is the role of gap junctions in cardiac muscle?

Provide low resistance passages between cells.

What is the role of intercalated discs in cardiac muscle?

Provide mechanical cohesion between cells.

List 4 characteristics of cardiac muscle.

Automatic and Rhythmic (i.e., autorhythmic), Excitable, Conductive, Contractile.

What is the cardiac electric generator?

SA node.

What happens if the SA node fails?

The AV node is a potential pacemaker.

Which channels create the slow response fibers?

Slow Ca channels

List Autorhythmicity Factors.

Parasympathetic stimulation , Sympathetic stimulation, Fever, Hypothermia, Mild alkalosis , Mild acidosis , Mild hypoxia , Severe hypoxia

SAN , AVN 3-Conductivity

SAN , AVN 3-Conductivity is the ability of cardiac muscle to transmit action potential from one cell to the next.

What triggers contraction in cardiac muscle?

Increased intracellular Ca⁺⁺.

What are Positive inotropic factors?

Sympathetic stimulation, Catecholamines, digitalis, Mild heat, ↑Ca⁺⁺ in ECF

What are Negative inotropic factors?

Parasympathetic stimulation decrease atrial contractility, Ether chloroform and bacterial toxins, ischemia, Mild cold, ↑K⁺ in ECF

What is the function of capillaries?

Exchange vessels between blood and tissue.

What is the function of veins & pulmonary vessels?

Capacitance vessels, can accommodate large volume of blood under low pressure = volume reservoir.

What is the Windkessel function?

Aorta, pulmonary artery, & large arteries: windkessel function, elastic, distend due to ejection of blood and recoil during diastole.

What is a primary function of the arterioles?

Regulate rate of blood flow to the tissues. Maintenance of Arterial Blood Pressure by adjusting the peripheral resistance.