Heart Flashcards
The ____ is highly complex, consisting of the heart and a closed system of blood vessels.
cardiovascular system
The _____ is a hollow, muscular, four-chambered (left and right atria, and left and right ventricles) organ located in the middle of the thoracic cavity between the lungs in the space called the .
heart, mediastenum
The anterior chest area that overties the heart and great vessels is called the
precordium
The right side of the heart pumps blood to the lungs for gas exchange (______) by removing CO2 from blood and replenishing oxygen supply.
pulmonary circulation
It occurs between alveoli and the blood of lungs; the left side of the heart pumps blood to all other parts of the body (_____).
systemic circulation
The large veins and arteries leading directly to and away from the heart referred to
great vessels.
called chordae tendineae, anchor the AV valve flaps to papillary muscles within the ventricles.
Collagen fibers
The right and left sides of the heart are separated by a partition called the
septum
The ___ receive blood returning to the heart and pump blood into the ventricles. The ____pump blood out of the heart.
thin-walled atria, thicker-walled ventricles
is a tough, inextensible, loose-fitting, fibroserous sac that attaches to the great vessels and surrounds the heart.
pericardium
serous membrane lining, the _____, secretes a small amount of pericardial fluid that allows for smooth, friction-free movement of the heart.
parietal pericardium
This same type of serous membrane covers the outer surface of the heart and is known as the .
epicardium
is the thickest layer of the heart, made up of contractile cardiac muscle cells.
myocardium
is a thin layer of endothelial tissue that forms the innermost layer of the heart and is continuous with the endothelial lining of blood vessels
The endocardium
have a unique inherent ability. They can spontaneously generate an electrical impulse and conduct it through the heart.
Cardiac muscle cells
The generation and conduction of electrical impulses by specialized sections of the myocardium regulate the events associated with the filling and emptying of the cardiac chambers. The process is called the
cardiac cycle
is located on the posterior wall of the right atrium near the junction of the superior and inferior vena cava. The ____, with inherent rhythmicity, generates impulses (at a rate of 60–100 per minute) that are conducted over both atria, causing them to contract simultaneously and send blood into the ventricles.
The sinoatrial (SA) node (or sinus node)
The current, initiated by the SA node, is conducted across the atria to the ____ located in the lower interatrial septum. The __ node slightly delays incoming electrical impulses from the atria and then relays the impulse to the AV bundle (bundle of His) in the upper interventricular septum.
atrioventricular (AV) node
The electrical impulse then travels down the right and left bundle branches and the ____ in the myocardium of both ventricles, causing them to contract almost simultaneously.
Purkinje Fibers
Although the SA node functions as the “_____,” this activity shifts to other areas of the conduction system, such as the Bundle of His (with an inherent discharge of 40–60 per minute), if the SA node cannot function.
pacemaker of the heart
The cardiac cycle has two phases: diastole (relaxation of the ventricles, known as ___) and systole (contraction of the ventricles, known as ____)
filling, emptying
This valve closure also prevents blood from flowing backward (a process known as ___) into the atria during ventricular contraction.
regurgitation
S1 sound is louder than an S2 . This occurs when the mitral valve is wide open and closes quickly. UHyperkinetic states in which blood velocity increases such as fever, anemia, and hyperthyroidism UMitral stenosis in which the leaflets are still mobile but increased ventricular pressure is needed to close the valve
Accentuated S1
Sometimes the S1 sound is softer than the S2 sound. This occurs when the mitral valve is not fully open at the time of ventricular contraction and valve closing. Examples include: UDelayed conduction from the atria to the ventricles as in first-degree heart block, which allows the mitral valve to drift closed before ventricular contraction closes it UMitral insufficiency in which extreme calcification of the valve limits mobility UDelayed or diminished ventricular contraction arising from forceful atrial contraction into a noncompliant ventricle, as in severe pulmonary or systemic hypertension
Diminished S1
This occurs when the left and right ventricles contract at different times (asynchronous ventricular contraction). Examples include: UConduction delaying the cardiac impulse to one of the ventricles, as in bundle branch block UVentricular ectopy in which the impulse starts in one ventricle, contracting it first, and then spreading to the second ventricle
Split S1
This occurs when the mitral valve is in different positions when contraction occurs. Examples include: URhythms in which the atria and ventricles are beating independently of each other UTotally irregular rhythm such as atrial fibrillation
Varying S1
S2 is louder than S1 . This occurs in conditions in which the aortic or pulmonic valve has a higher closing pressure. Examples include: UIncreased pressure in the aorta from exercise, excitement, or systemic hypertension (a booming S2 is heard with systemic hypertension) UIncreased pressure in the pulmonary vasculature, which may occur with mitral stenosis or congestive heart failure UCalcification of the semilunar valve, in which the valve is still mobile, as in pulmonic or aortic stenosis
accentuated S2
S2 is softer than S1 . This occurs in conditions in which the aortic or pulmonic valves have decreased mobility. Examples include: UDecreased systemic blood pressure, which weakens the valves, as in shock UAortic or pulmonic stenosis, in which the valves are thickened and calcified, with decreased mobility
A diminished S2
can be heard over the second or third left intercostal space. It is usually heard best during inspiration and disappears during expiration. Over the aortic area and apex, the pulmonic component of S2 is usually too faint to be heard and S2 is a single sound resulting from aortic valve closure. In some clients, S2 may not become single on expiration unless the client sits up. Splitting that does not disappear during expiration is suggestive of heart disease.
Normal (Physiologic) Split S2
This is an increase in the usual splitting that persists throughout the entire respiratory cycle and widens on expiration. It occurs when there is delayed electrical activation of the right ventricle. An example: URight bundle branch block, which delays pulmonic valve closing
Wide Split S2
This is a wide splitting that does not vary with respiration. It occurs when there is delayed closure of one of the valves. An example: UAtrial septal defect and right ventricular failure, which delay pulmonic valve closing
Fixed Split S2
S2 that appears on expiration and disappears on inspiration— also known as paradoxical split. It occurs when closure of the aortic valve is abnormally delayed, causing A2 to follow P2 in expiration. Normal inspiratory delay of P2 makes the split disappear during inspiration. An example: Left bundle branch block
Reversed Split S2
S3 is often termed ____, and S4 is called ___
ventricular gallop, atrial gallop
is the amount of blood pumped by the ventricles during a given period of time (usually 1 minute)
Cardiac output (CO)
is the amount of blood pumped from the heart with each contraction (stroke volume from the left ventricle is usually 70 mL)
Stroke volume
An inspiratory increase in venous pressure, called ____, may occur in clients with severe constrictive pericarditis.
Kussmaul’s sign
S3 and S4 pathologic sounds together create a quadruple rhythm, which is called a
summation gallop
