Question

In which the following can generate action potentials without any external stimuli?
A. Sino-atrial node (SAN)
B. Atrioventricular node (AVN)
C. Purkinje fibers
D. All of the above

Answer 1

Hint: Regular coronary heart rhythm (sinus rhythm) relies upon on ordinary interest of the sinoatrial node, a heterogeneous series of fairly specialized myocytes within the proper atrium in a for all intents and functions in a huge way. Sino-atrial nodes (SAN) are called a pacemaker and for the most elements can genuinely generate movement potentials with none outside stimuli, which for the maximum component is pretty considerable.

Complete answer:
The Sinoatrial node is a set of cells positioned within the wall of the proper atrium of the coronary heart, or so that they thought. These cells can spontaneously without a doubt produce an electrical impulse, which travels via the heart through the electrical conduction device causing it to contract in a type of big manner. In a healthful coronary heart, the SA node continuously produces movement potential, putting the rhythm of the heart and so especially is called the coronary heart's quite natural pacemaker, so these cells can spontaneously especially produce an electrical impulse, that essentially travels through the coronary heart through the electrical conduction device inflicting it to settlement, which kind of is reasonably large. The rate of action potential production typically is encouraged via nerves that supply it, demonstrating that the price of motion pretty capability production is stimulated with the aid of nerves that supply it, which is reasonably sizable.

Hence, the correct answer is option A. Sino-atrial nodes can generate action potentials without any external stimuli.

Note: The surely sinoatrial node mostly is a banana-fashioned shape that varies in size, generally between 10-30 millimeters lengthy, 5–7 mm huge, and 1–2 mm deep, pretty opposite to famous perception.