How does the insulin and glucagon secreted by the pancreas function in glucose metabolism?
Answer 1: Insulin and glucagon work together to keep glucose levels in the blood within the normal range. When there is an elevated blood glucose level, this stimulates beta cells in the pancreas to secrete insulin. The insulin facilitates the uptake of glucose by body cells, and the liver will uptake the glucose and store it as glycogen. These actions return blood glucose levels back to normal. When there is decreased blood glucose, this stimulates the alpha cells in the pancreas to produce glucagon. The glucagon travels to the liver and facilitates the conversion of glycogen to glucose. This glucose is released in the bloodstream to return levels back to normal.
Cardiovascular System
The cardiovascular system is composed of the heart, blood vessels (arteries, veins, and capillaries), and blood. The heart is the pump that contracts to move the blood. The blood vessels transport blood throughout the body. The blood is the fluid that contains cells, nutrients, and gases.
Blood flows through the body in two distinct pathways: the pulmonary pathway and the systemic pathway. The blood flowing in the pulmonary pathway is deoxygenated and it delivers this blood to the lungs to be oxygenated again. The blood flowing in the systemic pathway leaves the lungs full of oxygen and flows through the heart to be delivered to the body tissues.
The following activity demonstrates the correct order for the pulmonary and systemic circulation as you trace a drop of blood flow through the body:
Pulmonary Circulation Systemic Circulation 1. Venules 1. Pulmonary veins 2. Veins 2. Left atrium 3. Vena cava 3. Left ventricle 4. Right atrium 4. Aorta 5. Right ventricle 5. Arteries 6. Pulmonary arteries 6. Arterioles 7. Lung 7. Capillaries
Respiratory System
The respiratory system functions to supply the body with oxygen. People inhale oxygen and exhale carbon dioxide. This facilitates the delivery of oxygenated blood to all of the body cells.
