CHAPTER 20 The Heart

20-1: The Heart The Pericardium Know chambers & where each pumps to Apex vs. base vs. mediastinum The Pericardium Pericardial sac vs. visceral pericardium vs. parietal pericardium Pericardial fluid

Superficial Anatomy of Heart Auricle, coronary sulcus The Heart Wall Epicardium vs. myocardium vs. endocardium Cardiac cells joined by intercalated discs Internal Anatomy See Cardiovascular Hotlist for structures to know, including functions

Blood Supply to the Heart Purpose of coronary circulation Coronary arteries vs. coronary veins (functions, not names) Read Spotlight Figure 20-10 (pg 682 – 683) on heart disease & heart attacks

20-2: Conducting System Cardiac Physiology The Conducting System Conducting system vs. contractile cells The Conducting System Initiate & distribute electric impulses SA node vs. AV node vs. AV bundle/bundle branches/Purkinje fibers Tachycardia vs. bradycardia

Electrocardiogram (ECG) Records heart’s electrical events P wave vs. QRS complex vs. T wave What is happening electrically & physically during each wave Arrhythmias Premature beats, fibrillation, asystole

Contractile Cells Bulk of atria & ventricular walls Action potential causes rapid depolarization, then plateau period, then repolarization Energy for cardiac contractions from mitochondria & glucose

20-3: Cardiac Cycle Phases of the Cardiac Cycle Cardiac cycle: systole & diastole Phases of the Cardiac Cycle Know Figure 20-16 (pg 692) Pressure & Volume Changes in Cardiac Cycle Use Cardiophysiology Worksheet to help learn this section Heart sounds—valves closing

20-4: Cardiac Output Understand EDV, ESV, SV, EF, CO & how to calculate (Cardiophysiology Worksheet) Factors affecting CO: Automatic innervation, hormones (affect HR) EDV, ESV (affect SV)

Factors Affecting HR Autonomic innervation—sympathetic NS (SNS) & parasympathetic NS (PNS) Cardioacceleratory vs. cardioinhibitory centers Blood pressure changes, increased venous return Hormones—epinephrine, norepinephrine, thyroid hormone

Factors Affecting SV EDV—filling time, preload ESV Greater EVD = greater SV Frank-Starling principle ESV Contractility—positive/negative inotropic affects (SNS causes positive; PNS causes negative) Afterload—increase causes decrease in SV