Cardiac
Cardiovascular Anatomy & Physiology
I. Structures and Functions Heart Muscle * Has 3 layers (epicardium, myocardium, and endocardium) and a surrounding sac called the pericardium * Location: In the mediastinum, above the diaphragm, and is surrounded on both sides by lung * Shape: Resembling triangle, with base parallel to the right edge of the sternum
Heart Chambers * The right side of the heart is a low pressure system and the left side is a high pressure system and each side has an atrium and ventricle. * Here is the Right Atrium (RA,) Right Ventricle (RV,) Left Atrium (LA,) Left Ventricle (LV,) and the Medial Wall separating the RV and LV.
Valves
* The heart contains the two atrioventricular valves (AV) and two semilunar valves as well as the Chordae Tendineae and the Papillary Muscles * AV valves are Tricuspid Valve and Mitral Valve * Semilunar valves are Pulmonic Valve and Aortic Valve * Chordae Tendineae and Papillary Muscles work together to prevent valve leaflets from turning inside out.
* Normally, the cavity between the pericardial layers contains 10-30mL of serous fluid * A pericardial effusion occurs if additional blood or fluid collects in this space. If the amount of fluid continues to increased and cardiac chamber filling is impeded, cardiac tamponade results * VAGUS – major PNS innervation of the heart * CALCIUM – is the main cation affecting electrical stimulation of the heart * THRESHHOLD – is the stimulus that changes the resting membrane * COLD – is the condition that slows down blood flow
II. Conduction System
Cellular Electrophysiology of the Heart * The fast, more organized tracts include the SA Node, AV junction (AV node and the Bundle of His,) and Purkinje fiber. * SA and AV Nodes * SA Node is the major pacemaker of the heart. It keeps intrinsic heart rate at 60100 bpm * The AV node receives impulse from atria and slows
I. Structures and Functions Heart Muscle * Has 3 layers (epicardium, myocardium, and endocardium) and a surrounding sac called the pericardium * Location: In the mediastinum, above the diaphragm, and is surrounded on both sides by lung * Shape: Resembling triangle, with base parallel to the right edge of the sternum
Heart Chambers * The right side of the heart is a low pressure system and the left side is a high pressure system and each side has an atrium and ventricle. * Here is the Right Atrium (RA,) Right Ventricle (RV,) Left Atrium (LA,) Left Ventricle (LV,) and the Medial Wall separating the RV and LV.
Valves
* The heart contains the two atrioventricular valves (AV) and two semilunar valves as well as the Chordae Tendineae and the Papillary Muscles * AV valves are Tricuspid Valve and Mitral Valve * Semilunar valves are Pulmonic Valve and Aortic Valve * Chordae Tendineae and Papillary Muscles work together to prevent valve leaflets from turning inside out.
* Normally, the cavity between the pericardial layers contains 10-30mL of serous fluid * A pericardial effusion occurs if additional blood or fluid collects in this space. If the amount of fluid continues to increased and cardiac chamber filling is impeded, cardiac tamponade results * VAGUS – major PNS innervation of the heart * CALCIUM – is the main cation affecting electrical stimulation of the heart * THRESHHOLD – is the stimulus that changes the resting membrane * COLD – is the condition that slows down blood flow
II. Conduction System
Cellular Electrophysiology of the Heart * The fast, more organized tracts include the SA Node, AV junction (AV node and the Bundle of His,) and Purkinje fiber. * SA and AV Nodes * SA Node is the major pacemaker of the heart. It keeps intrinsic heart rate at 60100 bpm * The AV node receives impulse from atria and slows