<span>The order of impulse conduction in the heart, from beginning to end, is </span><span>SA node, AV node, bundle of His, bundle branches, and Purkinje fibers.
SA node, or the sinus node, is the heart's natural pacemaker. AV node, or the atrioventricular node, spreads electrical impulses from the atria to the ventricles. The bundle of His, as well as bundle branches, are a part of the electrical conduction system of the heart. Purkinje fibers send nerve impulses through the heart.
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Answer:
b number is the answer is it ok
B<span>acteria Reproduces </span>by binary fission. In this process the bacterium, which is a single cell, divides into two identical daughter cells. Binary fission begins when the DNA of the bacterium divides into two (replicates)
<span>This condition is called Edema. It is when something swells up, which happens when too much fluid is trapped in the soft tissues. Blood vessels emit the fluid which fills up in the soft tissue. It can happen because of burns, allergic reactions, and even pregnancy. (Sometimes women's feet swell.)</span>
If the inner lining of the air sacs neither thin nor highly vascularized, then it can be inferred that AIR SACS ARE CANNOT BE THE SITES OF GASEOUS EXCHANGE BETWEEN AIR AND BLOOD. Air sacs are generally lined with mucus and surrounded with blood capillaries.
In case of birds, air sacs play an important role in respiratory system.
