Lecture 1 B6 Flashcards
What valve is on the left between atria and ventricles?
Bicuspid
What valve is on the right between atria and ventricles?
Tricuspid
What is the name of the valve that is between right ventricle and the lungs?
Pulmonary valve
What is the name of the valve that is between left ventricle and the aorta?
Aortic valve
Period of contraction, force generation and blood expulsion
Systole
Period of relaxation, filling with blood, readying for next systole
Diastole
Left atrial fibrillation (improper excitation and contraction) would most greatly affect filling of which other heart compartment?
Left ventricle (first in front of disfunction) Right ventricle (first behind disfunction)
Explain some about electrophysiology of the heart.
Highly modified myocytes No contraction, only action potentials Connected to myocytes via gap junctions Modulated by ANS Dysregulation of this leads to arhythmia and altered pump function
What are the steps in conduction?
Sinoatrial node- 1st to depolarize
Atrioventricular node- AP from atria to ventricles
Bundle of His (AV Bundle)
Bundle Branches- feeds each ventricle
Purkinje system- speeds conduction to Ventricular myocytes
What is the importance for the AV nodal delay?
Ensures that the Atria have ejected their blood into the ventricles first before the ventricles contract.
Ectopic
abnormal
Heart rate is modulated by
Altering SA node firing rate
Altering conduction through the AV node
What 3 changes can lead to a postiive chronotrope (affecting heart rate)?
B1 receptors
Increase funny current
Increase Ca current
What 4 changes can lead to a negative chronotrope (affecting heart rate)?
M2 Receptors
Decrease funny current
Decrease Ca current
Increase K current
What 3 changes can lead to a positive dromotrope (conduction velocity)?
B1 receptors
Increase Ca current during upstroke
Shortens ERP
