Cardiac Overview Flashcards
Name the path of blood through the pulmonary circuit starting at the superior and inferior vena cava
- superior/inferior vena cava
- right atrium
- tricuspid valve (right AV valve)
- right ventricle
- pulmonary valve
- pulmonary artery
-pulmonary capillaries (on alveoli)
-pulmonary vein - left atrium
- mitral valve (bicuspid)
- left ventricle
- aortic valve
- aorta
What are the two types of Myocardial cells?
- Contractile (Cardiomyocytes)
- Nodal and Conducting
Nodal and Conducting Cells characteristics
- self excitable (ability to generate action potentials)
- minimal actin and myosin
What is the threshold for a nodal cell to conduct an action potential?
-40mV
Charge of the cell during 1)Depolarization and 2)Repolarization
Depolarization - cell is more positive than RMP
Repolarization - returns back to RMP
Main differences between action potentials in a neuron vs a nodal cell
- Neuron AP is generated and conducted much faster
- In depolarization of a neuron - Na+ rushes in
In depolarization of a myocardial nodal cell - Na rushes in but then right when repolarization starts, Ca rushes in to hold contraction for a bit
What is considered to be the pacemaker of the heart?
SA Node (Sinoatrial node)
- in right atrium
- fastest to excite = generation of APs
What is the conducting system path for action propagation through the heart?
1) SA Node –> Atrial Muscle –> AV Node –> Bundle of His –> Left and Right bundle branches –> Purkinje fibres –> Ventricular Muscle
What is occurring in the heart during each phase of the PQRST cycle?
P - Atrial Depolarization
QRS - Ventricular depolarization
T - Ventricular repolarization
