This set of Clinical Science Questions and Answers for Freshers focuses on “Anatomy and Physiology of G.I.T. – 2”.
1. The cells of the small intestine have a special structure that helps in the absorption of food. This structure is ________
d) attachment sites
Explanation: The inner lining of the intestines are lined with villi which help increase the surface area of absorption. These villi have blood and lymph supply and have microvilli which further increase the surface area for absorption.
2. Fats effectively begin digesting due to __________
a) Salivary emulsification
b) Esophageal emulsification
c) Acidic emulsification
d) Bile emulsification
Explanation: Fat molecules are usually a clumped mass and it is difficult to act upon them to digest them. Due to their large size, their surface area is too small. Bile salts cause emulsification which breaks down the fats into smaller globules which allows the various digestive enzymes to work on them and finally digest them.
3. Fats are absorbed by ________ in the form of a ________
a) micelles, lacteal
b) lacteal, enterocytes
c) enterocytes, micelles
d) miclles, enterocytes
Explanation: The fats in their digested state consist of free fatty acids, monoglycerides, cholesterol and lysolipids. They cannot be absorbed directly by the enterocytes of the villi. Thus, the digested fats are encapsulated into small balls of bile which allow them to enter the villi and get absorbed by the enterocytes. These enterocytes have microvilli to allow better absorption. On entering the enterocytes, monoglycerides, cholesterol and lysolipids react with 2 units of Fatty acids to form these enter the lacteals, a part of the lymphatic system. From here, they can enter blood as needed.
4. Enzyme secreted by the small intestine to digest protein is ____________
Explanation: Peptidase is the last enzyme that is secreted for the digestion of the proteins. Trypsin and chymotrypsin are secreted by the pancreas in their inactive forms called zymogens. When trypsinogen and chymptypsinogen are secreted by the pancreas and they enter the duedenum, they get converted into trypsin and chymotrypsin due to the activation action of enterokinase.
5. The enzyme that breaks ________ into 2 glucose molecules is ________
a) maltose, lactase
b) lactose, lactase
c) maltose, maltase
d) lactose, maltase
Explanation: Maltose is a diasaccharide which is made of two molecules of glucose. Maltase is secreted by the small intestine and it breaks down maltose into two glucose. Lactase breaks lactose into glucose and galactose while sucrase breaks sucrose into glucose and fructose.
6. An enzyme that is secreted by infants but not by adults
Explanation: Renin is the enzyme that helps in the digestion of milk in the infants. As the children grow up, the production of this enzyme goes down and so it is not found in adults. Renin is found in all mammalian infants which feed on their mother’s milk.
7. Amylase works in pH as _________
a) 1.3 – 2.5
b) 2.5 – 5.7
c) 5.7 – 6.8
d) 6.8 – 7.2
Explanation: Amylase is a slightly basic enzyme and so it needs a basic medium to work. When the food is ingested, the mouth has a basic medium due to the presence of saliva. Thus, the salivary amylase starts digesting the food. When the food enters the stomach, the acidic medium stops the work of the salivary amylase. When the food moves to the duodenum, the pancreatic amylase starts working.
8. pH in the small intestine is __________
Explanation: The digestive enzymes mostly work in the basic or mildly basic mediums. When the food reaches the stomach, the high pH content of the stomach destroys the microbes and any other harmful material in the food. Then the food moves down to the small intestine where the bile salts help neutralize the acidity of the food and then make them slightly basic to allow the intestinal enzymes to work on them.
9. The _______ connects the small intestine and liver.
a) pulmonary vein
b) renal vein
c) hepatic portal
d) cardiac vein
Explanation: The hepatic portal connects the small intestine and the liver. After food has been digested by the intestines, the extracted nutrients and toxins move to the liver to allow the liver to purify the blood. The liver breaks down the toxic substances into less harmful substances and allows the blood to carry it away to the kidney where it gets filtered out.
Sanfoundry Global Education & Learning Series – Clinical Science.
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