The mass transport system is all linked to the heart in mammals. The electrical stimulation of the heart is generated by the sinoatrial node SAN. It does not need stimulation from a nerve in order to contract. We refer to the heart as being myogenic.
Collagen prevents the electrical activity generated by the SAN passing directly from the atria to the ventricles. This is because collagen is non-conducting and so the electrical impulses have to pass via the atrioventricular node in order to progress any further down the heart. Carrying on with the formation of the heart; coronary arteries can be found on the surface of the heart muscle. They provide the heart muscle with oxygen for respiration. The ventricles contract from the bottom upwards to ensure all the blood is squeezed from the ventricles.
Ventricles have thicker walls than atria because they must pump blood further. The atria only push blood into the ventricles, whereas the ventricles have to pump the blood either to the lungs or all the way around the body. The thicker muscle can contract with greater force, and so pump blood at higher pressure.
Purchase access. Rent article Rent this article from DeepDyve. Access to free article PDF downloads. Save your search. Customize your interests. Create a personal account or sign in to:. Privacy Policy. Make a comment. One to one online tuition can be a great way to brush up on your Biology knowledge.
Answered by Hasan I. Answered by Runzhi C. Answered by Shoam B. Answered by.
0コメント