Chapter 9- Digestive System

Question 1

Intracellular Digestion

Answer 1

Involves oxidation of glucose and fatty acid to make energy

Question 2

Where does extra cellular digestion occur?

Answer 2

In the lumen of the elementary canal. (Runs from the mouth to the anus)

Question 3

Mechanical versus chemical digestion

Answer 3

Mechanical digestion is the physical breakdown of large food particles into smaller food particles. Chemical digestion is an enzymatic cleavage of chemical bonds such as the peptide bonds of proteins or the glycosidic bonds of starches.

Question 4

What is the path of food through the digestive system

Answer 4

Oral cavity > Pharynx > Esophagus > Stomach > Small intestine > Large intestine > Rectum

Question 5

What are the accessory organs of the digestive system

Answer 5

Salivary glands, pancreas, liver, gallbladder.

Question 6

What is the enteric nervous system?

Answer 6

In the wall of the elementary canal and controls peristalsis.

Question 7

Which branch of the nervous system controls peristalsis

Answer 7

Both the sympathetic and parasympathetic nervous system‘s.

The parasympathetic nervous system upregulates the digestive system. The sympathetic nervous system downregulates the digestive system.

Question 8

Which hormone promotes hunger? Which hormone promotes the satiety?

Answer 8

Ghrelin, Glucagon

Leptin, Cholecystokinin

Question 9

What hormone promotes thirst?

Answer 9

ADH (vasopressin) and aldosterone

Question 10

Mouth

Answer 10

Start of mechanical digestion through mastication.

Salivary amylase and lipase start a chemical digestion of food.

Question 11

What enzymes chemically break down food in the mouth?

Answer 11

Salivary amylase and lipase

Question 12

What is food called once it is broken down within the mouth?

Answer 12

Bolus

Question 13

Pharynx

Answer 13

Connects the mouth and posterior nasal cavity to the esophagus

Question 14

What sphincter separates the lower esophagus and the stomach?

Answer 14

The lower esophageal (cardiac) sphincter

Question 15

What propels food down the esophagus

Answer 15

Peristalsis (contraction)

Question 16

What are the four parts of the stomach?

Answer 16

Fundus-Top
Body-Long curved side
Antrum- thinner transition into small intestine
Pylorus- bottom portion that connects to small intestine

Question 17

Cells that line the stomach 

Answer 17

Mucous cells
Chief cells
Parietal cells
G cells

Question 18

Mucous cells

Answer 18

produces bicarbonate rich mucus to protect the stomach

Question 19

Chief cells

Answer 19

Secretes pepsinogen, a protease activated by the acidic environment of the stomach

Question 20

Parietal cells

Answer 20

Secretes hydrochloric acid and intrinsic factor for vitamin B12 absorption

Question 21

G cells

Answer 21

Secrete gastrin a peptide hormone that increases HCl secretion and gastric motility

Question 22

What is food particles called after mechanical and chemical digestion in the stomach?

Answer 22

Chyme

Question 23

Food passes from the stomach into the duodenum of the small intestine through which sphincter?

Answer 23

Pyloric sphincter

Question 24

What are the three parts of the small intestine?

Answer 24

The duodenum- site of chemical digestion
The jejunum-nutrient absorption
The ileum-nutrient absorption

Question 25

The presence of chyme in the duodenum causes the release of which enzymes?

Answer 25

Brush border enzymes such as disaccharides (Maltase isomaltase lactase and sucrase) and peptidases (dipeptidase) Responsible for breakdown of dimers and trimers of biomolecules into absorbable monomers.

Question 26

Where a brush border enzymes present?

Answer 26

On the luminal surface of the cells lining the duodenum

Question 27

Role of disaccharidaces in digestion

Answer 27

Disaccharidase digest disaccharides in the duodenum. Examples include maltase which digests maltose, lactase which digests lactose and sucrase that digests sucrose. Lack of a particular disaccharidase causes an inability to break down the corresponding disaccharide. Undigestive disaccharides have an osmotic effect and pull water into the stool causing diarrhea.

Question 28

What is bile

Answer 28

A complex fluid composed of bile salts, pigments, and cholesterol. Aids in digestion and absorption of fats and fat-soluble vitamins in the small intestine. Made up of pigments, bile salts, pigments such as bilirubin (from the breakdown of hemoglobin) and cholesterol which can be stored in the gallbladder or secreted in the duodenum directly.

Question 29

Bile salts

Answer 29

Derived from cholesterol. Important role in the mechanical digestion of fats and facilitate the chemical digestion of lipids. Emulsifies fats and cholesterol into micelles. 

Question 30

Pancreatic juice

Answer 30

Complex mixture of several enzymes in a bicarbonate rich alkaline solution. Help neutralize acidic chyme and provides an ideal working environment for a digestive enzymes. 

Question 31

Enteropeptidase

Answer 31

Activates trypsinogen and procarboxypeptidase initiating an activation cascade

Question 32

Secretin

Answer 32

Stimulates the release of pancreatic juices into the digestive tract slows motility

Question 33

Cholecystokinin

Answer 33

Stimulates

Question 34

Aminar cells

Answer 34

Located in the pancreas, produces pancreatic juices that contain by carbonate, pancreatic amylase, pancreatic peptidases such as trypsinogen, chymotrypsinogen, carboxypeptidases and pancreatic lipase

Question 35

What is the role of the liver in digestion?

Answer 35

Processes nutrients through glycogenesis and glycogenolysis, storage and mobilization of fats and gluconeogenesis ``` Produces urea. Detoxifies chemicals. Activates or in a activates medication. Produces bile. Synthesizes albumin and clotting factors. ```

Question 36

Gallbladder

Answer 36

Stores and concentrates bile

Question 37

The villi in the small intestine contain what two structures that interacts with the lymphatic system?

Answer 37

A capillary bed and a lack teal or a vessel of the lymphatic system

Question 38

What compounds enter the capillary bed within the valet of the small intestine?

Answer 38

Water soluble compounds such as monosaccharides, amino acids, water soluble vitamins, small fatty acids, and water

Question 39

What types of molecules enter the lack teals in the valley of the small intestine?

Answer 39

Fat soluble soluble such as fats cholesterol and fat soluble vitamins.

Question 40

Large intestine

Answer 40

Absorbs water and salts, forming semisolid feces

Question 41

Cecum

Answer 41

Out pocketing that accepts fluid from the small intestine through the ileocecal valve. Site of attachment of the appendix.

Question 42

Parts of the colon

Answer 42

Ascending, transverse, descending, and sigmoid

Question 43

What valve accepts fluid from the small intestine?

Answer 43

Ileocecal valve

Question 44

Rectum

Answer 44

Stores feces to be excreted through the anus

Question 45

Gut bacteria produces which vitamins?

Answer 45

Vitamin K and vitamin B7 a.k.a. biotin