Answer: Micro villi
Explanation:
The cellular structures that increases the superficial surface area of the cell is known as micro villi. It is an extension of cell membrane.
This structure helps in the increasing the surface area for the maximizing the absorption of food materials.
It also helps in providing a large area in a very compacted space. It is found at many places in the human body such as in small intestine.
I think atoms are made up of three parts
Answer:
<h2>
potassium</h2>
Explanation:
The heartbeats of the heart are controlled by the sinoatrial node also known as the pacemaker of the heart. The impulse is generated in the conducting cells of the pacemaker as a result of the movement of sodium, potassium and calcium ions.
The sodium channels allow the movement of sodium into the cell which depolarizes the membrane from -60mv to -40 mv. At this point, the calcium gated channels open which allow the entry of the calcium in the cell which depolarizes the cell up to +5mv.
At this point, the potassium channels open which allows the potassium ions to move out of the cell. This repolarizes the cell and hence the cycle again begins. Reducing the permeability of the potassium ions help generate the autorhythmicity due to repolarization and thus is the correct answer.
