Digestive and Excretory System

Question 1

what is the first step of digestion?

Answer 1

ingestion

Question 2

what is the enzyme that starts the chemical breakdown of food

Answer 2

alpha-amylase

Question 3

what is the process of the chemical breakdown in the mouth and esophagus?

Answer 3

alpha amylase breaks down the carbs and the chewing of the food releases more carbs. a bolus forms and is swallowed, moving through the esophagus with the help of saliva. peristalsis, aka contractions of the smooth muscle, moves the food along. the food then passes through the lower part of the esophagus (smooth muscle)

Question 4

what are the major anatomical regions of the stomach

Answer 4

fundus, body and pylorus

1. fundus - collects extra gas produced from digestion and expands after a large meal for storage
2. body - primary site of digestion
3. pylorus - does not allow undigested food into small intestines

Question 5

the stomach glands contain endocrine glands - true or false

Answer 5

false - they contain exocrine glands

Question 6

what are the four major cell types in the stomach? and what does each do?

Answer 6

mucous, chief, parietal and G cells

1. mucous cells - composed of glycoprotein and electrolytes that lubricates the stomach
2. chief cells - secrete pepsinogen (inactive form of pepsin) which start protein digestion
3. parietal cells - secrete HCl
4. G cells - secrete gastrin which is a peptide hormone that stimulates the release of HCl

Question 7

what are the hormones that affect the secretion of the stomach juices

Answer 7

acetylcholine, gastrin and histamine

Question 8

what are the intestinal glands located between the villi

Answer 8

crypts of Lieberkuhn are exocrine glands that secrete a substance with a neutral pH and lysozyme, which regulates the bacteria in the intestine

Question 9

the pancreas is only a exocrine gland - true or false

Answer 9

false it is an endocrine gland as well that secretes insulin and glucagon (regulating metabolism)

Question 10

what are the major enzymes released by the pancreas

Answer 10

trypsin, chymotrypsin, pancreatic amylase, lipase, ribonuclease and deoxyribonuclease

Question 11

what does trypsin and chymotrypsin do

Answer 11

break down proteins into small polypeptides

Question 12

what does pancreatic amylase do

Answer 12

break down the polysaccharides into di and trisaccharides and break down carbs into oligosaccharides

Question 13

what is the pathway of bile

Answer 13

it is produced by the liver and stored in the gallbladder. from the gallbladder, the bile is released through the cystic duct and emptied into the common bile duct. the bile then gets emptied into the pancreatic duct

Question 14

what are the main functions of the large intestine

Answer 14

electrolyte and water absorption

Question 15

are the hormones involved in digestion endocrine or exocrine

Answer 15

endocrine

Question 16

as the density of lipoproteins increases, triglycerides decreases - true or false

Answer 16

true

Question 17

what is the point of hepatic portal vein

Answer 17

carries the blood from the digestive system to the liver so that it can be processed before it is taken to the rest of the body

Question 18

true or false - when the liver metabolizes fats or proteins, the acidity of blood decreases

Answer 18

false - it increases because when the liver metabolizes fat, it produces ketone bodies which are acidic

Question 19

how does the liver maintain blood glucose levels

Answer 19

through glucogenesis

Question 20

what are the four ways the liver acts as a storage

Answer 20

1. as a blood reservoir
2. stores a lot of glycogen as an energy reserve to regulate blood glucose levels
3. stores vitamins A, D and B
4. stores iron

Question 21

what are the two functions of Kupffer cells

Answer 21

1. phagocytize bacteria from the intestines

2. destroy irregular erythrocytes

Question 22

what are the three major functions of the kidney

Answer 22

1. excretes waste
2. regulating blood pressure
3. control plasma pH