Physiology : Electrocardiography Questions 1. Explain how beta blockers would al
ID: 38018 • Letter: P
Question
Physiology : Electrocardiography Questions
1. Explain how beta blockers would alleviate symptoms of dizziness associated with Wolff-Parkinson- White
2. Why does a heart will continue to beat, even if there were no action potentials coming from the brain or spinal nerves?
3. What will happen to the rate of contraction of the ventricle in a human heart, if there is no signal coming from the sinoatrial node and why?
4. Why would tachycardia cause dizziness?
Please someone help me: these are due soon, thank you
Explanation / Answer
In patients with Wolff-Parkinson- White dizziness is a common symptom because the brain and all other cells are not receiving the adequate amount of oxygen because of decreased stroke volume (amount of blood per beat) since the ventricles do not have time to fill completely before they contract. Heart has a specialized network for conduction of electrical impulses. sinoatrial node generates the action potential for normal beating of heart but not brain or spinal cord. Signals from brain can only control (make it faster or slower) heart beats. Hence heart will continue to beat, even if there were no action potentials coming from the brain or spinal nerves. The electrical signals coming from sinoatrial node caused atria to contract and pump blood into your ventricles thereby transporting signal to a group of cells at the bottom of the right atrium called the atrioventricular node, or AV node. Then the signal travels down to bundle of conduction cells called the bundle of His, which divides the signal into two branches: one branch to the left ventricle and another to the right ventricle. This results in contraction of the ventricles. When there is no signal coming from the sinoatrial node it results in heart block then AV node would become the heart