Which of the following statement best describes the function of sinoatrial node?
Correct answer: D. It sends out electrical impulses to atrial muscles causing both atria to contract.
- A. It sends out electrical impulses to ventrictes to contract.
- B. It is present at upper end of the left atrium
- C. It consists of small number of diffusely oriented cardiac fibers
- D. It sends out electrical impulses to atrial muscles causing both atria to contract.
Explanation
Explanation:SA node or the pacemaker is located in the right atrium and it sends out impulses causing both Atria to contract. This option is incorrect because the SA node is responsible for initiating and coordinating the contraction of the Atria, not the ventricles. This option is incorrect because the SA node is located in the right atrium, near the entrance of the superior vena cava. This option is also incorrect because the SA node consists of a group of specialized cardiac muscle cells, not fibers.
This question appeared on the UHS MDCAT 2009 paper, which you can sit online with every answer explained.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Cardiac Cycle and Heartbeat
The cardiac cycle describes atrial systole, ventricular systole and diastole, including pressure changes, blood movement and the opening or closing of heart valves. It also covers the conduction pathway from the sinoatrial node through the atrioventricular node, bundle of His and Purkinje fibres, and relates these events to heartbeat sounds.
Practise Circulation
695 free Circulation MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Cardiac Cycle and Heartbeat questions
Heartbeat is normally regulated by:
The 'lub' sound in a heartbeat is produced during which phase of cardiac cycle?
What is the average adult Pulse rate?
Which one of the following statements best describes the function of sinoatrial node?
In ECG, QRS wave represents:
The interval of pacemaker signals from S.A.N to A.V.N is: