Digestive System

Question 1

What begins mechanical digestion in the mouth?

Answer 1

The voluntary act of chewing (mastication)

This process involves the skeletal muscles of the mouth and pharynx.

Question 2

What is peristalsis?

Answer 2

An involuntary propulsive process that moves food in one direction

Contraction of muscles that push down food further

Question 3

What is segmentation?

Answer 3

A process occurring in the intestines where non-adjacent portions contract and relax to move chyme

This process helps mix and propel partly digested food.

Question 4

What is the primary function of saliva?

Answer 4

To lubricate food and begin chemical breakdown

Saliva contains enzymes that initiate the digestion of carbohydrates and fats.

Question 5

What are the three pairs of major salivary glands?

Answer 5

1. Parotid glands
2. Submandibular glands
3. Sublingual glands

These glands secrete saliva into the oral cavity.

Question 6

What is the function of the esophagus?

Answer 6

To serve as a passageway for food from the pharynx to the stomach

The esophagus is approximately 25 cm long and has four layers.

Question 7

What is the primary role of the stomach?

Answer 7

Storage and mechanical breakdown of food

The stomach can stretch to accommodate a large volume of food.

Question 8

What is chyme?

Answer 8

A creamy paste formed from food mixed with gastric juices

This process occurs in the stomach during digestion.

Question 9

What regulates the passage of chyme into the small intestine?

Answer 9

The pyloric sphincter

This valve controls the flow of chyme from the stomach.

Question 10

What enzyme is activated by the acidic environment in the stomach?

Answer 10

Pepsin

Pepsin is the active form of pepsinogen, which is secreted by the chief cells.

Question 11

What do chief cells secrete?

Answer 11

Pepsinogen and gastric lipase

Question 12

What is the function of gastric lipase?

Answer 12

Continues the digestion of fats

Question 13

What do mucous cells secrete to protect the stomach?

Answer 13

Bicarbonate-containing mucus

Question 14

What is the function of the gastroesophageal sphincter?

Answer 14

Prevents the reflux of acidic contents

Question 15

What regulates the release of chyme into the small intestine?

Answer 15

Pyloric sphincter (valve)

Question 16

What are gastric folds called?

Answer 16

Rugae

Question 17

What is the primary digestive function of the liver?

Answer 17

Production of bile that helps breakdown fat

Question 18

Where is bile stored and concentrated?

Answer 18

Gallbladder

Question 19

What hormone signals the gallbladder to contract?

Answer 19

Cholecystokinin (CCK)

Question 20

What structure allows bile to spill into the duodenum?

Answer 20

Duodenal papilla

Bile can also flow directly from the liver to the duodenum.

Question 21

What process occurs when blood sugar is too high?

Answer 21

Glycogenesis
Glucose converted to glycogen

Question 22

What process occurs when blood sugar is too low?

Answer 22

Glycogenolysis
Glycogen turned into glucose

Question 23

In prolonged fasting, how does the liver produce glucose?

Answer 23

Gluconeogenesis

Question 24

What toxic waste product does the liver convert to urea?

Answer 24

Ammonia

Question 25

Which hormones does the pancreas secrete as an endocrine gland?

Answer 25

* Insulin * Glucagon * Somatostatin

Question 26

What stimulates the acinar cells of the pancreas to release enzyme-rich juices?

Answer 26

Cholecystokinin (CCK)

Question 27

What is the role of secretin in digestion?

Answer 27

Stimulates duct cells to release bicarbonate-rich solution

Question 28

What is the primary site of nutrient absorption in the small intestine?

Answer 28

Jejunum and ileum

Question 29

What structure increases the surface area for absorption in the small intestine?

Answer 29

Microvilli

Question 30

What is the primary mechanism for lipid and water absorption in the small intestine?

Answer 30

Simple diffusion

Question 31

True or False: The pancreas has both endocrine and exocrine functions.

Answer 31

True

Question 32

What do Brunner's glands secrete?

Answer 32

Bicarbonate-containing fluid

Question 33

What is the role of bicarbonate in the small intestine?

Answer 33

Neutralizes acidic chyme

Question 34

Fill in the blank: The small intestine is subdivided into the _______, jejunum, and ileum.

Answer 34

duodenum

Question 35

Which region of the small intestine is primarily responsible for absorption?

Answer 35

Jejunum

Question 36

What nutrients does the ileum primarily absorb?

Answer 36

Vitamin B12, bile salts, and unabsorbed nutrients

Question 37

What is the role of the ileocecal valve?

Answer 37

Controls movement of chyme into the large intestine

Question 38

What does the large intestine primarily absorb?

Answer 38

Water and certain vitamins Electrolytes

Question 39

Fill in the blank: The large intestine is larger in _______ than the small intestine but shorter in length.

Answer 39

diameter

Question 40

What is the first portion of the large intestine called?

Answer 40

Cecum

Question 41

What is the function of resident bacteria in the large intestine?

Answer 41

Digest materials and produce vitamins

Question 42

What vitamins do resident gut flora help synthesize?

Answer 42

Vitamin K, biotin, thiamin, riboflavin

Question 43

What lubricates the walls of the large intestine?

Answer 43

Mucus

Question 44

What is the term for the blind-ended tube attached to the cecum?

Answer 44

Appendix

Question 45

How is the colon subdivided?

Answer 45

Ascending, transverse, descending, and sigmoid colon

Question 46

What is the final part of the large intestine that opens to the anus?

Answer 46

Rectum

Question 47

What is the function of the rectal ampulla?

Answer 47

Storage area for feces before elimination

Question 48

What is the enteric nervous system (ENS)?

Answer 48

A network of neurons in the gastrointestinal tract controlling digestive function

Question 49

What effect does the parasympathetic nervous system have on digestive activities?

Answer 49

Stimulates digestive activities

Question 50

What effect does the sympathetic nervous system have on digestive activities?

Answer 50

Inhibits digestive activities

Question 51

Fill in the blank: The rectum ends with an involuntary internal sphincter and a _______ external sphincter.

Answer 51

[voluntary]

Question 52

What happens to the internal and external sphincters during defecation?

Answer 52

Internal sphincter relaxes, external sphincter contracts

Question 53

What is the primary function of the rectum?

Answer 53

Storage and elimination of waste

Question 54

What is the process of taking food into the body called?

Answer 54

Ingestion ## Footnote It is the first stage of digestion.

Question 55

Which hormones are involved in the digestive process?

Answer 55

Gastrin, Secretin, Cholecystokinin (CCK), and bile ## Footnote These hormones regulate various aspects of digestion.

Question 56

What is defecation?

Answer 56

The final stage of digestion where waste products are expelled ## Footnote Involves the anus.

Question 57

What does gastrin do?

Answer 57

Stimulates secretion of gastric juice ## Footnote Gastric juice is a mixture of hydrochloric acid and pepsinogen.

Question 58

What triggers the release of cholecystokinin (CCK)?

Answer 58

Detection of fats and proteins in the duodenum ## Footnote CCK stimulates the gallbladder to release bile.

Question 59

What is the role of secretin in digestion?

Answer 59

Stimulates the pancreas to release bicarbonate-rich pancreatic juice ## Footnote Helps neutralize acidic gastric juice.

Question 60

What is bile essential for?

Answer 60

Fat digestion and absorption ## Footnote Also carries waste products into the feces.

Question 61

What hormones regulate blood sugar levels?

Answer 61

Insulin and glucagon ## Footnote Insulin allows glucose uptake; glucagon stimulates conversion of glycogen into glucose.