structure of heart
What are the network blood vessels that comprise the heart? bonus: name their functions as well
arteries: carry blood away from the heart
veins: return blood to the heart
Capillaries: thin walled vessels that are located in between small arteries and veins
What types of cells influence cardiac output?
Nodal cells: establish rate of contraction through SA and AV nodes
Conducting cells: distribute stimuli to myocardium
Systemic circuit: carries blood to and from the rest of the body
Pulmonary Circuit: carries blood to and from the lungs
What are pacemaker cells?
They are nodal cells that reach threshold and fire first. It is an SA node or cardiac pacemaker.
What are the muscular chambers of the heart with their function?
right atrium: receives blood from systematic circuit
right ventricle: pumps blood into the pulmonary circuit
Left atrium: receives blood from pulmonary circuit
left ventricle pumps blood into systematic circuit
Describe the path of an impulse?
1. SA node activity and atrial activation begins.
2. Stimulus spreads across atrial surface and reaches the AV nodes
3. There is a delay at the AV nodes and the atrial contraction begins
4. The impulse travels along the intraventricular septum to the purkinja fibers.
5. The fibers distribute and relay the impulse throughout the ventricular myocardium. Atrial contraction is completed and ventricular contraction starts.
What are the three layers of the heart wall?
epicardium: visceral layer of pericardium covering the outer surface of the heart
myocardium: muscular wall of the heart containing cardiac muscles, blood vessels, and nerves
endocardium: covers inside of chambers and heart valves
What is the difference between systole and diastole?
Systole- ejects blood from chambers
diastole- pump blood into the chambers
What is the pericardium?
pericardium surrounds the heart and lines the pericardial cavity
What are the steps for the cardiac cycle?
1. atriole systole begins
2. atriole systole ends and atrial diastole begins
3. ventricular systole- first phase
4. ventricular systole- second phase
5. ventricular diastole- early
6. ventricular diastole-late