Question

20Points: 41-45. Trace the blood through the heart detailing the flow as it enters the heart from the upper and lower parts of the body. Also, in your discussion include the two branches of the circulatory system 46-50. Discuss the electrical conduction through the heart. Discuss how the electrical impulses are generated and the pathway in which it is transmitted through the heart muscle to induce contraction.

Answer 1

41-45 1) Oxygen poor blood travels through the inferior or superior vena cava ror coronary sinus
2 Deoxygenated blood enters the right atrium
3) Blood passes through the tricuspid valve
4) Blood enters right ventricle
5) Blood moves through the pulmonary valve
6) Blood enters the pulmonary trunk and arteries where the blood is carried to the lungs
7) Blood loses carbon dioxide and gains oxygen in the pulmonary capillaries
8) The oxygenated blood enters the pulmonary veins
9) Blood enters the left atrium
10) Blood travels through the bicuspid/mitral valve
11) Blood enters the left ventricle
12) Blood moves throught the aortic valve
13) Blood travels through the aorta and systemic arteries
(14) Blood loses oxygen and gains carbon dioxide in the systemic capillaries.

The two branches of the circulatory system are the (i) systemic circulation which delivers blood to all body cells and carries wastes away; and (ii) pulmonary circulation which eliminates carbon dioxide ad oxygenates blood

46-50. Electrical conduction system of the heart:
(1) The sinuatrial node (SA) or pacemaker generates the impulses.
The SA is located in the wall of the right atrium near the opening of the superior vena cava. The specialized muscle fibers that make up this structure are unique in that they can continually and rhythmically send impulses without any stimulation from the nervous system
(2) The impulses pause at the atrioventricular node (AV) for 0.1 sec
(3) The AV bundle connects the atria to the ventricles
(4) The bundle branches conduct the impulses through the intraventricular septum
(5) The Purkinje fibers stimulate the contractile cells of both the ventricles. These fibers extend out to all areas of the two ventricles and since they are further enlarged, the speed of the impulse conduction is also additionally increased. Upon completion of impulse transmission through the Purkinje fibers, the ventricles will fully depolarize and then contract simultaneously.