I. Blood Circulation A. Physical Requirements 1. Pumps Left ventricle
Right ventricle
2. Vasculature: arteries, arterioles, capillaries, venules, veins 3. Blood Volume 4. Unidirectional Flow B. Outline of the Human System 1. 4 chambered heart a. Atria
b. Ventricles
2. Systemic circuit
3. Pulmonary circuit C. Flow = Pressure / Resistance 1. General a. Flow Definition b. Pressure: direct relationship to flow 1. Applies to arteries (a) an*logy
c. Resistance: indirect relationship to flow 1. Applies to arterioles
2. an*logy
d. Calculating flow throughout the body Flow through the systemic and pulmonary systems 1. Systemic circulation: pressures
2. Pulmonary circulation: pressures
D. Flow: Velocity and Cross-Sectional Area E. Poiseuille's Law F. Flow and Pressure: Vascular Elasticity vs. Vascular distensibility II. The Heart A. Functional Gross anatomy 1. Layers Epicardium
Myocardium
Endocardium
2. Valves a. Atrioventricular (mitral)
b. Semilunar
3. Papillary muscles and chordae tendinae: 4. Venous return a. Vena cavae: deoxygenated
b. Pulmonary veins: oxygenated 5. Arterial outflow a. Aorta
b. Pulmonary trunk C. Cardiac Cycle 1. General definitions a. Systole
b. Diastole 2. Definitions in terms of the cardiac cycle a. Systole
b. Diastole 3. Components of the cardiac cycle, pressure and volume changes a. Diastisis
b. Atrial systole and ventricular diastole
c. Atrial diastole and ventricular systole Types of Cardiac tissue Type 1: Spreads the signal and contracts
Type 2: Starts the signal, spreads the signal but does not contract
Type 3: Endocrine: dumps ANP: Atrial natriuretic protein B. Type I tissue: spreads the signal and contracts 1. Spreads the signal via gap junctions a. Ephatic synapses
b. Signal moves almost simultaneously
c. Cells respond as 1 2. Contracts in response to the signal a. Myofilaments are arranged into sarcomere
b. Signal sets into motion calcium release and cross bridge cycling
c. Implications 1. Time delay
2. Increase calcium availability, increased cycling, increased strength D. Type I Ventricular Myocardium 1. Review absolute refractory period in neuron
2. Absolute refractory period in vent myocardium
3. Significance: avoid tetany Diagram of key events in the cardiac cycle E. The pacemaker system and Electrocardiography 1. Electrical conducting system of the heart: autortyhmic cells a. SA node: sets the pace for the heart
b. AV node
c. Bundle of HIS
d. Lt and rt bundle branches
e. Purkinje fibers
f. Ventricular muscle 2. EKG tracing: Lead II a. P wave
b. QRS complex
c. PR segment
d. T wave
e. PR interval F. Neurochemical control of heart rate 1. Normal range a. Bradycardia
b. Tachycardia 2. Medullary centers: part of ANS which is regulating the rate at which the SA node fires a. Cardioinhibitory center
b. Cardioacceleratory center 3. Baroreceptor reflexes a. General: baroreceptors
b. Carotid sinus reflex: Decrease pressure, increase heart rate and cardiac output
increase pressure, decrease heart rate and cardiac output
c. Bainbridge reflex: increase venous return and increased pressure in the vena cavae, heart rate increases
d. Effect of the respiratory cycle on heart rate
Inspiration: decreased thoracic pressure, decrease venous return, decrease CO, decrease pressure at carotid sinus, reflexively HR increases Early expiration
Late expiration