In a fish, electrical impulses that cause the heart to contract are initiated in theMultiple choice question.sinus venosus.SA node.conus arteriosus.ventricle.
Question
In a fish, electrical impulses that cause the heart to contract are initiated in the
- sinus venosus.
- SA node.
- conus arteriosus.
- ventricle.
Solution
The correct answer is sinus venosus.
Explanation
- In fish, the heart is structured differently than in mammals. The sinus venosus acts as a pacemaker where electrical impulses are generated, initiating the contraction of the heart.
- The SA node (sinoatrial node) is found in mammals and is not present in fish.
- The conus arteriosus is a part of the heart that helps in directing blood flow but does not initiate electrical impulses.
- The ventricle is a chamber of the heart that contracts but does not generate the impulses.
In summary, the sinus venosus serves as the primary pacemaker in the fish heart, making it responsible for initiating the electrical signals that lead to heart contractions.
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