Week6- Heart

4 6

10

60 100

5 6

90 95

100

no

40 60

20 40

no

starts with the closure of AV valves., ends with the closure of semilunar valves.

Atrial systole is part of the diastole., During isovolumetric contraction the aortic valve is closed., In the ventricular ejection phase the left ventricular and the aortic pressure change in parallel.

It can be closed during diastole., It can be closed during systole., It can be open during diastole.

The first heart sound is caused by the AV valves closure., In the ventricular ejection phase the left ventricular and the aortic pressure change in parallel., During isovolumetric contraction the aortic valve is closed.

At increased heart rate the time of diastole decreases more than the time of systole., The stroke volume is the blood volume which is ejected by the left ventricle in 1 cardiac cycle.

Are closed during the isovolumetric relaxation., Open at the end of isovolumetric contraction.

While the aortic valve is open the left ventriccular pressure and the aortic pressure change simultaneously., The second heart sound is caused by the closure of the semiunar valves., During isovolumetric contraction the aortic valve is closed., During atrial systole the mitral valve is open and the aortic valve is closed.

Aortic valve closure is followed by the isovolumetric relaxation., The atrial systole occurs during diastole., Aortic valve closes at around 100 mmHg pressure.

It s gated by the hyperpolarization of the cells., It can be activate by cycli nucleotides., It is responsible for the pacemaker potential.

sympathetic stimulation, epinephrine, atropine

Fast VD Na+ channel, L-type Ca++ channel, Delayed rectifier K+ channel

It is responsible for the pacemaker potential., This is a non-selective monovalent cation channel., It is gated by cyclic nucleotides., The SA node contains the most If.

The slow depolarization is initiated by the HCN channels.

The maximal negative potential is increased in pacemaker cells., N. vagus stimulation., Activation of Ach-regulated K+ channels., Reduction in the slope of prepotential.

Delayed rectifier K+ channel., Channle that provides the inward Na+ current (If), induced by hyperpolarization., T-type Ca++ channel., L-type Ca++ channel.

It can be closed during atrial systole., It can be open during systole., It can be closed during systole.

The mitral valve opens if the atrial pressure is higher than the ventricualr one., All the valves are closed during the isovolumetric contraction,

Fast VD Na+ channel., L-type Ca++ channel., Delayed rectifier K+ channel.

this is a non-selective, cation channel, it is responsible for the pacemaker cell

epinephrine, atropine, sypathetic stimulation

The DHPR is a voltage sensor., The Ca++ transport via the RyR is a passive transport.

AP on sarcolemma., AP on T tubule., Ca++ binding to troponin C.

the myofilaments do not change their length., cross bridges are formed bw myosin and actin.

0.27

0.53

80