Digestive System

Question 1

Explain the function of the mouth

Answer 1

Teeth bite and chew food into a soft pulp that is easy to swallow
Saliva moistens food and makes it slippery
Amylase, an enzyme, breaks down start chanting and complex carbs into sugars

Question 2

Explain the esophagus

Answer 2

A muscular tube that moves the food down with peristalsis (wives of muscular contractions)

Question 3

Explain the different sphincters

Answer 3

Cardiac sphincter - between esophagus and stomach. Stops stomach acid from flowing back up into the esophagus (reflux) damage or weakness to this valve causes heartburn
Pyloric sphincter - between stomach and small intestine.

Question 4

Explain the stomach

Answer 4

J-shaped. Has muscles that aid in mechanical digestion.
Gastric fluid that releases after meals (hrochloric acid, Pepsi opens and mucus)
Mucous to protect stomach lining from acid
HCl kills harmful substances and converts pepsinogen to Pepsin, which begins to breakdown proteins

Question 5

What happens when the mucous layer of the stomach breaks down?

Answer 5

Acids in the stomach erode a holes causing an ulcer.

Question 6

Explain the small intestine

Answer 6

Has 3 parts: duodenum, jejunum and ileum

• fingerlike projections called villi, which increase its SA
• when acidic chyme enters, a hormone called secretin is released and taken to great pancreas where it signals the release of bicarbonate ions (to neutralize chyme) and enzymes for digestion.

Question 7

Explain some enzymes released from the pancreas.

Answer 7

Enterokinase turns trypsinogen into trypsin which breaks proteins into polypeptides
Erepsins break polypeptides into amino acids
Amylase digests carbs
Disaccharides complete digestion of carbs
Lipase break down fats into fatty acids and glycerol

Question 8

What else does the pancreas release?

Answer 8

Insulin, which releases glucose from glycogen

Glucagon, which stores glucose as glycogen

Question 9

Explain the gall bladder

Answer 9

Bag-like, tucked under the liver.
Stores the bile that is made in the liver
As food from a. Meal enters the small intestine, bile flows from the gall bladder along the bile duct into the intestine.

Question 10

Explain bile

Answer 10

Bile breaks down fats. When stomach is empty, bile is stored in gall bladder. When fats are present in small intestine, CCK is released and causes the gall bladder to release bile

Question 11

Explain the funtions of the liver

Answer 11

Detoxification of blood
Synthesis of blood proteins
Destruction of old erythrocytes and conversion of hemoglobin into bile
Production of bile
Storage of glucose as glycogen

Question 12

Explain what happens when there is a problem with the liver

Answer 12

Jaundice, yellowing of the skin. Caused by obstruction of bile duct (gall stones) or cirrhosis of the liver, which commonly occurs in alcoholic.

Question 13

Explain the large intestine

Answer 13

Home to bacteria that live on unabsorbed nutrients. Bacteria in here, like E. coli, produce vitamins b12 and K. Water is absorbed. Waste is transported to the rectum, expansion of this chamber increases urge to defecate. Cellulose provides bulk.

Question 14

What is an enzyme?

Answer 14

Substances that act as catalysts for digestion.

Question 15

Why must protein digesting enzymes be stored in inactive form?

Answer 15

To prevent them from digesting other proteins in the body

Question 16

Why doesn’t trypsin remain active in the duodenum?

Answer 16

Pepsin only works In acidic environments. Turns off once in the duddenum.

Question 17

Why doesn’t starch digestion happen in the stomach?

Answer 17

Amylase doesn’t work in the stomach.

Question 18

How are nutrients absorbed?

Answer 18

Absorbed into the villi of the small intestine, then to the capillaries and blood stream. Circulated around the body and delivered to cells.

Question 19

Explain pancreatitis and how it is clogged plus common contributors.

Answer 19

Inflammation if the pancreas. Basic cause is the enzymes within it being activated too early and digesting it. Alcohol, obstruction of bile duct (gall stones), some medications.

Question 20

What are gall stones.

Answer 20

When your bile duct is clogged. Causes solid chunks in bile duct or urinary system.