Long Answer Question 2
3) Calcium in the diet of a teenager is actively absorbed in the small intestine and transferred into the intestinal capillaries. Describe the route this calcium would follow to end up in the upper arm. Describe in detail the role of calcium at the neuromuscular junction as well as its role in the mechanism of muscle contraction and relaxation of the triceps. Considering the function of calcium in bone growth, explain in detail how the humerus would grow in length.
Calcium in the diet of a teenager is absorbed in the small intestine and transferred to the intestinal capillaries. It diffuses into the bloodstream through the gastric vein into the hepatic vein and then through the common iliac vein into the superior/inferior vena cava that brings the blood into the right atrium of the heart. The sinoatrial node which is located in the right atrial wall, would send an electrical impulse through the heart, causing it to contract. This would then trigger the AV node (which is located between the septum between two atria) to contract as well. When the AV node contracts it sends an impulse through the AV bundle and into the purkinje fibers (which in return causes the entire heart to contract). After going through the right atrium, when the heart contracts it opens up the tricuspid valve, therefore pushing the calcium into the right ventricle. When the heart contracts again (SA node contracts again through AV bundle and purkinje fibers) it causes the pulmonary semilunar valve to open and enters the pulmonary trunk and pulmonary arteries which then brings the blood into the lungs. Then it goes through a systemic loop (the tissue capillaries of the lungs) , which takes the now oxygenated blood and returns to the heart via the pulmonary veins from the lungs. Then from the pulmonary veins the blood enters the left atrium (SA node will contract, causing AV node to contract, sending impulse through the AV bundle, ending at the purkinje fibers) and...
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