the sinus venosus of frog is located on
Answers
In Amphibians, such as the frog, the pacemaker is the sinus venosus, an enlarged region between the vena cava and the right atrium
HOPE THIS WILL HELP YOU ✌✌
Answer:
Explanation:
The heart of the frog has three chambers, one ventricle and two atria. Blood leaves the heart from the ventricle through a single truncus arteriosus which is short and soon branches into two aortic arches which loop left and right and dorsal to the heart to rejoin as a single aorta in the mid dorsal region of the body cavity. Each aortic arch has a branch leading to the lungs and skin where oxygenation occurs. Carotid arteries also branch off the aortic arches and supply the head region. Veins bring blood to the left and right atria. Both atria then empty into the single ventricle. Blood from the ventricle thus enters either the pulmonary or body circulation.
Because there is only a single ventricle there is some mixing of oxygenated and deoxygenated blood. Ventricular folds prevent a complete mixing of the arterial and venous blood.
Excitation of the frog heart heart is myogenic, that is, contraction of the heart originates within the muscle itself. In Amphibians, such as the frog, the pacemaker is the sinus venosus, an enlarged region between the vena cava and the right atrium. This the cells of the pacemaker are termed “leaky”, meaning that calcium ions leak into the cells. Leaking of positive ions causes a slow depolarization to threshold, thus initiating an action potential that quickly spreads throughout the musculature