Term
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Definition
• Four-chambered muscular organ
• Lies in mediastinum with apex on diaphragm, 2/3 of its bulk to left of midline of body and 1/3 to right |
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Term
| • Apical beat may be counted by |
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Definition
| placing stethoscope in 5th intercostal space on line with left midclavicular point |
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Term
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Definition
– Loose-fitting, inextensible sac (fibrous pericardium) around heart, lined with serous pericardium (parietal layer), which also covers outer surface of heart (visceral layer or epicardium)
– Small space between parietal and visceral layers of serous pericardium contains few drops of pericardial fluid |
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Term
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Definition
| protection against friction |
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Term
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Definition
| epicardium, myocardium (muscular wall), endocardium (lining) |
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Term
| • Intercalated discs found in myocardium allow |
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Definition
| direct contact between cells and muscle action potentials to spread from one fiber to another |
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Term
| • Cavities are formed by 2 atria and 2 ventricles |
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Definition
| ; atria separated by interatrial septum (contains fossa ovalis) and ventricles are separated by interventricular septum |
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Term
| ventricles have irregular folds called |
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Definition
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Term
| • Between atria and ventricles are |
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Definition
| atrioventricular (AV) orifices |
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Term
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Definition
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Term
| valves consist of 3 parts |
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Definition
| flaps, chordae tendinae, and papillary muscle |
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Term
| • Between ventricles and arterial circulation |
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Definition
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Term
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Definition
| pulmonary semilunar (right side), aortic semilunar (left side) |
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Term
| • Left ventricle receives blood via |
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Definition
| both major branches of left coronary artery and from one branch of right coronary artery |
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Term
| • Right ventricle receives blood |
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Definition
| via both major branches of right coronary artery and one branch of left coronary artery |
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Term
| • Each atrium receives blood |
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Definition
| from one branch of its respective coronary artery |
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Term
| • Only a few anastomoses(connection, joining together) |
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Definition
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Term
| • SA node (pacemaker of heart) |
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Definition
– Small mass of modified cardiac muscle at junction of superior vena cava and right atrium
– Inherent rhythmicity of SA node impulses set basic rate of heartbeat |
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Term
| – Ratio of sympathetic(Go up)/parasympathetic(slow down) impulses to node per minute and blood concentrations of epinephrine and thyroid hormone act on |
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Definition
| node to modify its activity and alter heart rate. Acedacholine is going to decrease heart rate. |
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Term
| • Atrioventricular node (AV node) |
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Definition
| small mass of modified cardiac muscle in septum between 2 atria |
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Term
| • AV bundle and bundle of His |
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Definition
| special cardiac muscle fibers originating in AV node and extending down interventricular septum |
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Term
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Definition
| extension of bundle of His fibers out into walls of ventricles |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
| • Fibers from plexuses terminate |
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Definition
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Term
| • Sympathetic impulses tend to |
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Definition
| accelerate and strengthen heartbeat; vagal impulses slow heartbeat |
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Term
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Definition
| • Record of the heart’s action currents (impulse conduction) |
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Term
| • Components of electrocardium |
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Definition
| – P wave , – QRS complex – T wave |
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Term
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Definition
| depolarization of atria(Contracting of the atria) |
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Term
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Definition
| depolarization of ventricles(contracting of ventricles)(Atria’s relax) |
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Term
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Definition
| repolarization of ventricles(the ventricles are relaxing) |
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Term
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Definition
Superior and Inferior Vena Cave
-Right Atrium
-Tricuspid valve
-Right Ventricle
-Semilunar valve
-Pulmonary Artery
-Lungs
-Pulmonary Vein
-left Atrium
-Bicuspid Valve
-Left Ventricle
-Semilunar valve
-Aorta
-Body back to beginning! |
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Term
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Definition
| systole and diastole of atria and ventricles |
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Term
| atria contract and as they relax |
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Definition
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Term
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Definition
| 0.8 seconds or from 70-80 times/minute |
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Term
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Definition
| - AV valves open and SL valves closed; ventricles relaxed; preceded by P wave |
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Term
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Definition
| rapid influx of blood into ventricles after opening of AV valves; characterized by gradual increase in ventricular pressure and volume reducing ventricular filling |
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Term
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Definition
| rapid ejection of blood from ventricles followed by reduced ejection (residual volume is blood remaining in ventricles following ejection phase - amount increases in heart failure); AV valves close resulting in first heart sound (lubb) |
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Term
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Definition
| ventricles relax; semilunar valves close resulting in 2nd heart sound (dupp) |
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Term
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Definition
| is total amount of blood ejected into arteries each minute |
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Term
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Definition
| – Volume of blood pumped by the ventricles per beat (stroke volume) |
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Term
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Definition
| Number of heart beats per minute, 5 liters pumped throughout the heart in one beat |
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Term
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Definition
| is ratio between maximum cardiac output a person can achieve and cardiac output at rest (avg. 4-5 times that of rest) |
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Term
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Definition
greater preload (stretch) on cardiac muscle fibers before contraction increases force of contraction (Frank-Starling law of the heart) 70% will be ejected with stroke volume (What fills the fintrical) (stroke volume-90%-90ml going out, 10 left.
Weak heart? Contarctility is only a 50% it affects blood pressure.) |
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Term
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Definition
| strength of contraction (Strength of contraction affects stroke volume.) |
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Term
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Definition
| sympathetic stimulation, glucagon, epinephrine, increased calcium in ECF |
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Term
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Definition
| - inhibition of sympathetic system, anoxia, acidosis, some anesthetics, increased potassium |
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Term
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Definition
| pressure that must be exerted by the ventricles to exceed the pressure in the arteries |
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Term
| • Autonomic nervous system control is result of |
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Definition
| opposing influences between parasympathetic (vagus) and sympathetic (accelerator nerve) stimulation (acetylcholine and norepinephrine) |
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Term
| • Centers within medulla oblongata act |
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Definition
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Term
| – Cardioinhibitory center |
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Definition
| parasympathetic impulses to slow heart rate |
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Term
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Definition
| – Cardioaccelerator center |
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Term
| – Cardioaccelerator center |
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Definition
| sympathetic stimuli that increases heart rate |
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Term
| • Cardiac pressoreflexes (baroreceptors) |
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Definition
| stretch receptors that send impulses to the cardioinhibitory and accelerator centers and influence ANS outflow |
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Term
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Definition
| stimulation (by high blood pressure) causes reflex slowing of heart |
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Term
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Definition
| stimulation (by high blood pressure) causes reflex slowing of the heart |
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Term
| – Decrease in aortic or carotid blood pressure |
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Definition
| initiates reflex acceleration of heart |
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Term
| • Chemoreceptors located near |
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Definition
| baroreceptors called carotid and aortic bodies |
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Term
| baroreceptors called carotid and aortic bodies |
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Definition
| detect changes in blood level of oxygen, carbon dioxide and hydrogen ions. |
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