IV. LONG ANSWER TYPE QUESTIONS
A. Answer these questions.
1. Trace the various steps of digestion that food undergoes from the time it is placed in the mouth to the time it gets absorbed by the cells.
2 List the organs of human digestive system and describe the part each of them play in the digestion
3. Explain the features of oesophagus and how peristalsis moves food along the oesophagus.
4. What is the role of the following in the digestion of b. Trypsin c. Maltase e. Pepsin of food. food? a. Rennin d. Ptyalin f. Lipase
Answers
Explanation:
The digestive processes are ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation. Some chemical digestion occurs in the mouth. Some absorption can occur in the mouth and stomach, for example, alcohol and aspirin.
Explanation:
Answer of Question 1.
when we chew food by buccal cavity it goes down to the food pipe oseophagus and this goes in the intestine. small intestine absorbs all energy and vitamins and all important things then it goes to the large intestine and it absorbs energy and goes to the rectum. rectum stores it time to time passes it to the anus and waste out from our body.
Answer of Question 2.
The digestive system is mainly responsible for providing the body with energy and nutrients present in the food that we consume. This body system is composed of main organs that form the digestive tract and accessory organs that release important secretions to the main organs which help in the digestive process.
The main organs of the digestive system are mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus.
Mouth. The mouth is the organ that functions for the ingestion of food. Mechanical digestion (mastication) also happens in the mouth as well as initial chemical digestion of fats and carbohydrates.
Esophagus. The food (bolus) that is initially digested in the mouth is propelled by the esophagus to the stomach through the peristaltic movement of its smooth muscles.
Stomach. The stomach releases digestive acids and enzymes (protease) that aid in the continuation of the mechanical digestion of food and initiation of chemical digestion of proteins. This organ also performs vigorous peristaltic movement that churns bolus into chyme and prepares it for final chemical digestion in the small intestine.
Small intestine. This organ contains digestive enzymes (pancreatic enzymes and brush border enzymes) that complete the digestion of food into simple substances. Nutrients, water, and electrolytes are also mainly absorbed by the small intestine.
Large intestine. The remaining nutrients and water from the undigested food are absorbed by the large intestine. This also compacts the undigested food in preparation for elimination.
Rectum. This section of the large intestine stores the food waste (feces) prior to defecation.
Anus. The anus is the opening of the terminal section of the digestive tract through which the feces leaves the body.
Answer of Question 3.
Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract. It starts in the esophagus where strong wave-like motions of the smooth muscle move balls of swallowed food to the stomach. There, the food is churned into a liquid mixture called chyme that moves into the small intestine where peristalsis continues.
Stretching out a piece of intestine will make it easier to see the wave-like motion. The motion mixes and shifts the chyme back and forth. This lets the bloodstream absorb nutrients through the walls of the small intestine.
In the large intestine peristalsis helps water from undigested food be absorbed into the blood stream. Then, the remaining waste products are excreted through the rectum and anus.
Answer of Question 4.
(a) rennin - digest protein in infants.
(b)trypsin - digest protein ( proteases and peptones)
(c)Maltese - converts Maltese into glucose.
(d)ptyalin - it produced by pancreas. it is also called pancreatic. a mylase which digest carbohydrate.
(e)pepsin of food - digestion of proteins.
(f)lipase food - digestion of fats.