Monday, February 02, 2009

Regulation of Blood Pressure

Assalamualaikum...

After 1 week break b'coz of Chinese New Year, today my class continued with subtopic 1.2 from Biology Form 5. I planned to discuss the regulation of blood pressure, but my students made my blood pressure increased over than usual. They late again!!! Not 2, or 3 minutes, but 12 minutes! What a waste of time.

Argh...my mood ruined! But the class must go on. After advised them, give a short tazkeerah, I started my lesson.

Blood pressure is regulated by a negative feedback mechanism. Our brain can't control the contraction & relaxation of cardiac muscle b'coz the cardiac muscle is MYOGENIC. It can generates their own impulse to trigger the pumping of heart. But our brain can control the heart beat, increase the heart beat if the blood pressure is low or via versa. In medula oblongata of brain, a group of tissue called CARDIVASCULAR CENTRE play an important role in regulating blood pressure.

In controlling the blood pressure, there are two type of nerve that helps cardiovascular centre to increase or to slow down the heart beat.
Sympathetic nerve is to increase the heart beat and parasympathetic nerve is to slow down the heart beat.

Further information, download the related notes.

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