The cardiovascular system (Lab midterm) Flashcards
two receiving chambers of the heart
right atrium- receives deoxygenated blood returning from the systemic circuit
left atrium- receives oxygenated blood from the pulmonary circuit
two main pumping chambers of the heart
right ventricle- pumps blood into pulmonary circuit
left ventricle- pumps blood into systemic circuit
outer anatomy of the heart
base, apex, apical impulse
upper portion of the heart that points towards the right shoulder(base of cone shape)
base
lowermost point of the heart (top of cone shape), points to the left hip
apex
pulse point of the heart at heart apex, palpated between the 5th and 6th left ribs just below the left nipple; may be difficult to palpate in women due to left breast, can auscultate with a stethoscope
apical impulse
three layers of the heart wall
1.pericardium
-fibrous & serous pericardium
2.myocardium
3.endocardium
two walled sac that surrounds the heart
pericardium
superficial layer of sac surrounding the heart; function is to protect the heart, anchors it to surrounding structures and prevents the heart from overfilling with blood
Fibrous pericardium
deeper layer of sac surrounding the heart; has 2 layers
Serous pericardium
outer layer; lines the internal surface of the fibrous pericardium
Parietal layer
deep layer; lies on the external surface of the heart
Visceral layer (epicardium)
middle layer of the heart wall that contracts; consists of circular or spiral bundles of contractile cardiac muscle cells, also contains the cardiac skeleton
Myocardium
innermost layer of the heart, continuous with the endothelial lining of blood vessels; lines the inside of the heart and covers cardiac skeleton of heart valves
Endocardium
two types of atrioventricular heart valves
tricuspid valve & mitral (bicuspid) valve
3 cusps; between the right atria and right ventricle, anchored to papillary muscles in the ventricle by chordae tendineae; prevents backflow of blood from right ventricle into right atrium
Tricuspid valve
2 cusps; between the left atria and left ventricle, anchored to papillary muscles in the ventricle by chordae tendineae
Mitral (bicuspid) valve
between right ventricle and pulmonary trunk; prevents backflow of blood into right ventricle
Pulmonary semilunar valve
between left ventricle and aorta; prevent backflow of blood into the left ventricle
Aortic semilunar valve
blood flow through right side of the heart (focus figure 18.1)
Superior vena cava- inferior vena cava-coronary sinus-right atrium- tricuspid valve-right ventricle-pulmonary SL valve- pulmonary trunk- to lungs- pulmonary capillaries
blood flow through left side of the heart (focus figure 18.1)
four pulmonary veins- left atrium- mitral valve- left ventricle- aortic valve- aorta
returns blood to the right atrium from body regions superior to the diaphragm
Superior vena cava
returns blood to the right atrium from body areas below the diaphragm
Inferior vena cava
carry deoxygenated blood away from the heart to the lungs
Pulmonary artery
carry oxygenated blood from the lungs back to the left atrium
Pulmonary vein
formed by cardiac veins; empties deoxygenated blood into the right atrium [made of the great cardiac vein, middle cardiac vein & small cardiac vein]
Coronary sinus
in the posterior interventricular sulcus; empties into the coronary sinus
Middle cardiac vein
receives oxygenated blood from the aorta, supplies oxygenated blood to interventricular septum, anterior ventricular walls, left atrium, and posterior wall of left ventricle; divides into the anterior interventricular artery and circumflex artery
Left coronary artery
receives oxygenated blood from the aorta, supplies oxygenated blood to right atrium and most of the right ventricle; divides into the right marginal artery and posterior interventricular artery
Right coronary artery
separates the left and right atria
Interatrial septum
separates the left and right ventricles
Interventricular septum
sequence of excitation in the cardiac conduction system
- SA node generates impulse
2.impulse pauses at AV node
3.AV bundle connects the atria to the ventricles
4.bundle branches conduct the impulse through the intraventricular septum
5.subendocardial conducting network depolarizes the contractile cells of both ventricles
ECG; represents atrial depolarization at SA node
P wave
ECG; represents ventricular depolarization
QRS complex
ECG; represents ventricular repolarization
T wave
a normal ECG tracing with appropriate P waves followed by a QRS complex and T waves
Normal sinus rhythm
abnormal ECG tracing with normal QRS and T waves but no P waves; SA node is not functioning
Junctional rhythm
P waves are present but not every P wave is followed by a QRS complex; AV node is not conducting some impulses from the SA node
Second-degree heart block
disorganized electrical activity, ECG looks chaotic; “shockable” rhythm means person needs to be defibrillated to try and get their heart back into normal sinus rhythm, seen in people having a heart attack
Ventricular fibrillation
