Chapter 24: The Digestive System

Question 1

The __________ is long tube that is open at both ends
for the transit of food during processing
 Named portions of the tube include the
esophagus, stomach, small intestine, large
intestine, and rectum

Answer 1

Gastrointestinal (GI) Tract

Question 2

_________ are not part of the GI tract,
but they do contribute to food processing
 Accessory structures include the teeth,
tongue, salivary glands, liver, gall bladder,
and pancreas

Answer 2

Accessory structures

Question 3

 Submucosal plexus
 Myenteric plexus

Answer 3

Enteric Nervous System

Question 4

Autonomic Nervous System

Answer 4

Parasympathetic
 Sympathetic

Question 5

___________ regulate GI secretion and
motility in response to stimuli within the GI tract

Answer 5

GI reflex pathways

Question 6

The _________ is the largest serous membrane
in the body

Answer 6

peritoneum

Question 7

The ______ is formed by the cheeks, hard and soft
palates, and tongue

Answer 7

mouth

Question 8

_____________ lie outside the mouth and empty
their contents into ducts which deliver saliva into the
oral cavity

Answer 8

Salivary glands

Question 9

3 pairs:

Answer 9

Parotid
 Submandibular
 Sublingual

Question 10

 The ______, together with associated muscle,
forms the floor of the oral cavity
 Composed of skeletal muscle covered with mucous
membrane
 Participates in chewing, swallowing, and speech
 The upper and lateral surfaces of the tongue are
covered with papillae, some of which contain taste
buds

Answer 10

TONGUE

Question 11

The _____ project into the mouth and are adapted
for mechanical digestion

Answer 11

teeth

Question 12

 Chewing mixes food with saliva and forms a
bolus which can be easily swallowed

Answer 12

Mechanical digestion

Question 13

Salivary amylase converts polysaccharides to
disaccharides

Answer 13

Chemical digestion

Question 14

The ______ is a funnel shaped tube that extends
from the internal nares to the esophagus posteriorly
and to the larynx anteriorly
 The pharynx is composed of skeletal muscle and
lined with mucous membrane

Answer 14

PHARYNX

Question 15

The __________ is a collapsible, muscular tube that
lies posterior to the trachea and connects the
pharynx to the stomach

Answer 15

esophagus

Question 16

The __________ is a J-shaped enlargement of the GI
tract

Answer 16

stomach

Question 17

Mixes saliva, food, and gastric juice to form
chyme
 Serves as a reservoir for food before release
into the small intestine
 Secretes gastric juice, which contains HCl,
pepsin, intrinsic factor, and gastric lipase
 Secretes gastrin into the blood

Answer 17

Functions of the Stomach

Question 18

 Lies posterior to the stomach
 Produces enzymes that digest
carbohydrates, proteins, fats, and nucleic
acids
 Produces sodium bicarbonate which buffers
stomach acid
 Empties its contents into the duodenum

Answer 18

PANCREAS

Question 19

The _______ makes bile, which is important in the
emulsification of fats
 The gallbladder stores bile until it is needed

Answer 19

liver

Question 20

The liver is composed of hepatocytes, bile
canaliculi, and hepatic sinusoids

Answer 20

Histology of the Liver

Question 21

 Carbohydrate, lipid, and protein metabolism
 Processing of drugs and hormones
 Bilirubin excretion
 Bile salt synthesis
 Storage
 Phagocytosis
 Vitamin D activation

Answer 21

Functions of the Liver and Gallbladder

Question 22

The majority of digestion and absorption occur in the

Answer 22

SMALL INTESTINE (SI)

Question 23

 Segmentations mix chime with digestive juices and
bring food into contact with mucosa for absorption;
peristalsis propels chime through small intestine
 Completes digestion of carbohydrates, proteins,
lipids; begins and completes digestion of nucleic
acids
 Absorbs about 90% of nutrients and water that pass
through digestive system

Answer 23

Functions of the Small Intestine

Question 24

 Circular folds increase the surface area for
digestion and absorption in the small intestine

Answer 24

Circular Folds in the SI

Question 25

___________ provides a vehicle for absorption of substances from chyme as they come in contact with the villi

Answer 25

Intestinal juice

Question 26

_____________ enzymes, found on the surfaces of the microvilli of absorptive cells, break down food products

Answer 26

 Brush border

Question 27

Localized contractions

Answer 27

Segmentation

Question 28

Propulsive contractions

Answer 28

Peristalsis

Question 29

Digestion of:  Carbohydrates  Proteins  Lipids  Nucleic Acids

Answer 29

Chemical Digestion in the SI

Question 30

Haustral churning, peristalsis, and mass peristalisis drive contents of colon into rectum  Bacteria in colon convert proteins into amino acids, break down amino acids, and produce some B vitamins  Absorption of some water, ions, and vitamins  Formation of feces  Defecation

Answer 30

Functions of the Colon

Question 31

Distension reaches a certain point and the walls of the haustra contract to squeeze contents onward

Answer 31

Haustral churning

Question 32

A strong peristaltic wave that begins in the transverse colon and quickly drives the contents of the colon into the rectum

Answer 32

Mass peristalsis

Question 33

The last stages of digestion occur through bacterial action  Substances are further broken down by bacteria  Some vitamins are synthesized by bacterial action

Answer 33

Chemical Digestion in the Colon

Question 34

 The colon absorbs water, electrolytes, and some vitamins

Answer 34

Absorption

Question 35

Consist of water, inorganic salts, sloughed-off epithelial cells, bacteria, products of bacterial decomposition, and undigested portions of food

Answer 35

Feces

Question 36

Rectal wall distends and stretch receptors send sensory nerve impulses to the sacral spinal cord  Motor impulses travel back to the descending colon, sigmoid colon, rectum, and anus  Longitudinal rectal muscles contract and the internal anal sphincter opens

Answer 36

Defecation Reflex

Question 37

Stimulates gastric secretion and motility

Answer 37

Cephalic phase

Question 38

Neural and hormonal mechanisms

Answer 38

Gastric phase

Question 39

Neural and hormonal mechanisms

Answer 39

Intestinal phase

Question 40

Decreased secretory mechanisms and motility  Loss of strength and tone of digestive muscular tissue  Changes in neurosecretory feedback  Diminished response to pain and internal sensations

Answer 40

Aging and the Digestive System

Question 41

 Tooth decay  Periodontal diseases  Ulcers  Diverticula  Tumors  Hepatitis  Anorexia nervosa

Answer 41

Digestive System Disorders