Question

1. practice: understanding various organ systems

self assessment

1. practice: understanding various organ systems

respond to the following based on your reading.
question 1
describe what is meant by a \feedback loop\ and how the body responds to changes to maintain homeostasis in blood sugar.

check my answer

question 2
describe the four major steps of digestion, and discuss the organs involved in each.

Explanation:

A feedback loop is a process where the output of a system influences its own input. In blood - sugar homeostasis, when blood sugar rises, the pancreas secretes insulin which prompts cells to take up glucose, lowering blood sugar. When blood sugar drops, the pancreas releases glucagon which causes the liver to release stored glucose, raising blood sugar. The four major steps of digestion are ingestion (taking in food through the mouth), propulsion (movement of food through the digestive tract via peristalsis, involving the esophagus, stomach, and intestines), mechanical and chemical digestion (mechanical - chewing in the mouth, churning in the stomach; chemical - enzymes in saliva, stomach acid, pancreatic enzymes etc., involving mouth, stomach, pancreas, small intestine), and absorption (nutrients absorbed into the bloodstream through the lining of the small intestine).

Answer:

Question 1: A feedback loop is a circular process where the output of a system affects its input. In blood - sugar homeostasis, when blood sugar levels increase, the pancreas secretes insulin, which signals cells to take in glucose, thus lowering blood - sugar levels. When blood - sugar levels decrease, the pancreas releases glucagon, which prompts the liver to release stored glucose, raising blood - sugar levels.
Question 2: The four major steps of digestion are:

1. Ingestion: Taking food into the mouth. The organ involved is the mouth.
2. Propulsion: Movement of food through the digestive tract by peristalsis. Organs involved include the esophagus, stomach, and intestines.
3. Mechanical and chemical digestion: Mechanical digestion involves chewing in the mouth and churning in the stomach. Chemical digestion is the breakdown of food by enzymes such as in saliva, stomach acid, and pancreatic enzymes. Organs involved are the mouth, stomach, pancreas, and small intestine.
4. Absorption: Nutrients are absorbed into the bloodstream through the lining of the small intestine. The main organ is the small intestine.