Why is the SA node called pacemaker of the heart ? Write its full from.

Why is the S-A node called pace-maker of the heart ?

Explain the following : (a) Why does the atrial systole normally precedes the ventricular systole ? (b) Why is S-A node called the pacemaker of the heart ? (c ) Why does the ventricle relax as a closed chamber in the early phase of its diastole ? (d) Why is there no mixing of deoxygenated and oxgenated blood in mammalian heart ? (e ) Why can you palpate the pulse on an artery in each heart beat ? (f) Why does the lymph contain much less proteins than the plasma ? (g) Why does the ventricle contract as a closed chamber in the early phase of its systole ? (h) Why is the closed circulatory system more efficient than the open one ? (i) Why does the left ventricle has a thicker wall than the right ventricle ?

Why is sinuatrial (SA) node also called the pacemaker of heart?

SA node acts as a pacemaker of the heart because of the fact that it

Assertion : The AV node is also called as the pacemaker of the heart. Reasoning : It is because of the fact that the AV node determines the rate of heartbeat.

Sino-atrial node is called the pacemaker of our heart. Why?

Indicate whether the following statements are true or false : (i) Fish heart contains only oxygenated blood. (ii) Closure of A-V valves produces the second heart sound. (iii) The vagus nerve retards the heart rate. (iv) The S-A node is the pacemaker of the heart. (v) Columnae carneae occur in the auricles. (vi) Purkinje fibres are nerve fibres present in the heart wall.

Assertion: SA node malfunctioning leads to disturbance of Heart rat Reason: SA node is the pacemaker of heart producing electric impulse for heart contraction

Assertion : Though AV node generates impulses, it is still not called as the pacemaker of heart. Reason : The rythmicity of impulse production is not highest in AV node in the neuromuscular conduction pathway.