Cardiovascular System Flashcards

Flashcards for Cardiovascular System Lecture Review

Pericardium

Double-walled sac that encloses the heart, made up of the parietal pericardium and the epicardium (visceral pericardium).

Epicardium (visceral pericardium)

Serous membrane covering heart; the external heart surface and contains coronary blood vessels.

Myocardium

Composes most of the heart mass; thickest layer. Layer of cardiac muscle cells (cardiomyocytes). Provides structural support, attachment for cardiac muscle, and electrical insulation.

Endocardium

Smooth inner lining of heart and blood vessels. The simple squamous epithelium layer is over thin areolar tissue WITHOUT adipose tissue. Covers the valve surfaces and is continuous with the endothelium of blood vessels.

Atria

Superior chambers of the heart that receive blood returning from the lungs or body.

Ventricles

Inferior chambers of the heart that pump blood into arteries, sending blood to the lungs or body.

Superior and Inferior Vena Cava (SVC and IVC)

Empties venous, oxygen-depleted blood into the right atrium:

Pulmonary Trunk Arteries (PTA)

Sends de-oxygenated blood away from the right ventricle to the lungs.

Pulmonary Veins (PV)

Brings oxygenated blood from lungs to the left atrium.

Aorta (A)

Sends oxygenated blood from the left ventricle to the rest of the body.

Tricuspid Valve

Right AV valve; regulates blood flow between the right atrium and right ventricle.

Mitral (bicuspid) Valve

Left AV valve; lets oxygen-rich blood from your lungs pass from the left atrium into the left ventricle.

Pulmonary Valve

Semilunar (SL) valve; controls blood flow from the right ventricle into the pulmonary arteries.

Aortic Valve

Semilunar (SL) valve; lets oxygen-rich blood pass from the left ventricle into the aorta, then to the body.

Pulmonary Circuit

Vessel route that supplies blood to the pulmonary alveoli for gas exchange and then returns it to the heart; all blood vessels between the right ventricle and the left atrium of the heart. It is shorter and low pressure.

Systemic Circuit

All blood vessels that move blood from the left ventricle to all organs of the body and back to the right atrium of the heart. It has a longer pathway and higher pressure.

Coronary Circulation

Supplies blood to the tissue and structures of the heart. Coronary arteries are located within the epicardium and deliver blood when the heart is relaxed.

Sinoatrial (SA) node cells

Autorhythmic (pacemaker) cells in the heart.

Contractile cells

Cardiomyocytes that receive AP from pacemaker cells via gap junctions.

Sinus rhythm

Normal heartbeat triggered by the SA node.

Electrocardiogram (ECG, EKG)

Composite of all AP generated by nodal and contractile cells at a given time.

Systole

Contraction of the heart muscle.

Diastole

Relaxation of the heart muscle.

P wave

Movement of depolarization wave from SA node through atria; SA node fires, atria depolarize and contract.

QRS complex

Ventricular depolarization.

T wave

Ventricular repolarization and relaxation.

Cardiac Cycle

One complete contraction and relaxation of all four chambers of the heart. Blood flow through heart during one complete heartbeat: atrial systole and diastole followed by ventricular systole and diastole.

End Diastolic Volume (EDV)

The volume of blood in each ventricle at the end of ventricular diastole.

Isovolumetric Contraction

Phase where ventricles contract, but do not eject blood. Pressures in aorta and pulmonary trunk are still greater than those in the ventricles

End Systolic Volume (ESV)

Any blood remaining in ventricle chambers

Ejection Fraction (EF)

Measurement of effective pumping in the heart.

Blood Pressure (BP)

Atrial BP; measured from its highest point during cardiac systole to its lowest during diastole. Measured in mmHg.

Cardiac Output (CO)

The amount of blood ejected by each ventricle in 1 minute.

Stroke Volume (SV)

Amount of blood ejected from the heart in a single heart beat.

Preload

Degree the cardiac muscle cells stretch (tension) before contraction (Frank starling law of heart).

Afterload

Pressure the ventricle must overcome to eject blood.

Contractility

Contractile strength achieved at given muscle length.

Factors affecting Stroke Volume (SV)

Preload, afterload, and contractility.

Factors increasing Heart Rate (HR)

Sympathetic nervous system stimulation, hormones like epinephrine, and decreased blood pressure.

Factors decreasing Heart Rate (HR)

Parasympathetic nervous system stimulation (vagal tone), increased blood pressure, and certain drugs.

Formula for Cardiac Output (CO)

CO = HR
R imes SV

How is Blood Pressure (BP) Calculated?

BP = CO
R imes Total Peripheral Resistance (TPR)

What affects Preload?

Venous return and filling time.

What affects Afterload?

Arterial blood pressure and vascular resistance.

What affects Contractility?

Calcium availability, sympathetic stimulation, and certain medications.

Tricuspid Valve

Right AV valve; regulates blood flow between the right atrium and right ventricle.

Mitral (bicuspid) Valve

Left AV valve; lets oxygen-rich blood from your lungs pass from the left atrium into the left ventricle.

Pulmonary Valve

Semilunar (SL) valve; controls blood flow from the right ventricle into the pulmonary arteries.

Aortic Valve

Semilunar (SL) valve; lets oxygen-rich blood pass from the left ventricle into the aorta, then to the body.

Superior and Inferior Vena Cava (SVC and IVC)

Empties venous, oxygen-depleted blood into the right atrium:

Pulmonary Trunk Arteries (PTA)

Sends de-oxygenated blood away from the right ventricle to the lungs.

Pulmonary Veins (PV)

Brings oxygenated blood from lungs to the left atrium.

Aorta (A)

Sends oxygenated blood from the left ventricle to the rest of the body.

Path of blood flow

Right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary artery → lungs → pulmonary veins → left