The first heart sound is

True or False The first heart sound results from a closure of semilunar valves.

The first heart sound results from the closure of semilunar valves.

Indicate whether the following statements are true of false : (a) Both auricles of amphibian heart open into the same ventricle. (b) Prawn's heart carries only oxygenated blood. (c ) Purkinje fibres are nerve fibres supplying the ventricular muscles. (d) The first heart sound results from a closure of semilunar valves. (e ) The vagus nerve reduces the heart rate. (f) The A-V node normally initiates the cardiac impulse. (g) Semilunar valves open during the ventricular diastole.

which one is the first heart sound ?

The first heart sound lubb' is associated with

The first heart sound lubb' is associated with

The "lubb" sound (first heart sound) is caused by

The "lubb" sound (first heart sound) is caused by

The "lubb" sound (first heart sound) is caused by

Read the following statement and choose the correct option. A. The first heart sound (lub) is associated with the closure of both semilunar valves. The duration between the adjacent second heart sound and first heart sound is 0.3 seconds C. The cardiac output is the stroke volume multiplied by the number of heartbeats per minute.