CONCEPT REVIEW (DIGESTION)

Question 1

The GI tract is a continuous multilayered tube extending from the _________ to the _____________.

Answer 1

mouth

anus

Question 2

GI tract organs include the mouth, _____________, esophagus, stomach, small intestine, and large intestine

Answer 2

pharynx

Question 3

The accessory digestive organs include the teeth, tongue, salivary glands, ___________, gallbladder, and pancreas.

Answer 3

liver

Question 4

Digestion includes six basic processes: what are they?

Answer 4

Digestion includes six basic processes:

ingestion,

secretion,

mixing and propulsion,

mechanical and chemical digestion,

absorption,

and defecation.

Question 5

The peritoneum is the _________ serous membrane of the body. The parietal peritoneum lines the abdominopelvic cavity wall, and ___________ peritoneum covers some of the cavity organs. The peritoneal cavity is a thin space containing serous fluid that is located between the parietal peritoneum and visceral peritoneum.

Answer 5

largest

visceral

Question 6

The GI tract is regulated by an intrinsic set of nerves known as the __________________and by an extrinsic set of nerves that is part of the autonomic nervous system (ANS).

Answer 6

enteric nervous system (ENS)

Question 7

The ENS consists of neurons arranged into two plexuses: the _____________ of the muscularis controls GI tract motility, and the _______________ of the submucosa controls GI tract secretions.

Answer 7

myenteric plexus

submucosal plexus

Question 8

Although the ENS can function independently, it is subject to regulation by the ANS. Parasympathetic stimulation ____________ GI tract secretion and motility by increasing the activity of ENS neurons. Sympathetic stimulation ___________ GI tract secretion and motility by inhibiting ENS neurons.

Answer 8

increases

decreases

Question 9

There are two dentitions: the_______ deciduous (primary) teeth and ______ permanent (secondary) teeth. The permanent teeth include incisors, cuspids, premolars, and molars.

Answer 9

20

32

Question 10

Through mastication, food is mixed with saliva and shaped into a soft, flexible mass called a
_______. Salivary amylase begins the digestion of starches into disaccharides. Lingual lipase breaks down triglycerides into fatty acids and diglycerides.

Answer 10

bolus

Question 11

Swallowing consists of voluntary oral, ______________, and involuntary esophageal stages.

Answer 11

involuntary pharyngeal

Question 12

TRUE OR FALSE

The pharynx is a funnel-­shaped tube that extends from the internal nares to the esophagus posteriorly and to the larynx anteriorly. The pharynx has both respiratory and digestive functions.

Answer 12

TRUE

Question 13

What term is used to describe the movement of a bolus from the mouth to the stomach?

Answer 13

Deglutition moves a bolus from the mouth to the stomach

Question 14

The stomach ____________ breaks down the bolus and mixes it with gastric secretions.

Answer 14

mechanically

Question 15

The 4 Regions of the stomach?

Answer 15

cardia, fundus, body, and pyloric part.

Question 16

The stomach mucosa contains __________that open into gastric pits. Gastric glands secrete ­gastric juice composed of mucus, ___________, pepsinogen, gastric lipase, and _________.

Answer 16

gastric glands

hydrochloric acid

intrinsic factor

Question 17

The stomach muscularis has _________ alternately arranged layers of smooth muscle.

Answer 17

three

Question 18

Mechanical digestion in the stomach consists of mixing waves that mix food with __________ and macerate it to a soupy ___________.

Answer 18

gastric juice

chyme

Question 19

Chemical digestion consists mostly of the conversion of proteins into peptides by __________. Chief cells secrete pepsinogen, activated to pepsin by acidic pH, which begins ____________.

Answer 19

pepsin

protein digestion

Question 20

Gastric lipase allows digestion of___________ into fatty acids and monoglycerides.

Answer 20

triglycerides

Question 21

What is absorbed in the stomach?

Answer 21

Absorption by the stomach is limited to water, certain ions, drugs, and alcohol.

Question 22

The liver is composed of a right lobe and left lobe that is continuous with the quadrate and caudate lobes. The lobes of the liver contain ____________radiating out from a central vein and many sinusoids containing phagocytic reticuloendothelial cells.

Answer 22

hepatocytes

Question 23

What do hepatocytes do?

Answer 23

Hepatocytes secrete bile into bile canaliculi

Question 24

The liver receives oxygenated blood from the hepatic artery; nutrient­ rich venous blood from the GI tract enters from the hepatic portal vein. The liver processes and ____________ blood before it enters the venous circulation.

Answer 24

detoxifies

Question 25

In the small intestine, bile breaks down large lipid globules into small lipid globules in a process called _________________. Between meals, bile enters the gallbladder for storage.

Answer 25

emulsification

Question 26

Where is bile stored?

Answer 26

The gallbladder is a sac located on the posterior surface of the liver that stores and concentrates bile.

Question 27

The small intestine is divided into three parts, what are they?

Answer 27

The small intestine is divided into the duodenum, the jejunum, and the ileum that joins the large intestine at the ilocecal sphincter.

Question 28

Explain the digestion of carbohydrates

Answer 28

Digestion of carbohydrates begins by salivary amylase from the mouth and pancreatic amylase in pancreatic juice. The resulting glucose subunits are digested by brush border enzymes into monosaccharides.

Question 29

Explain the digestion of protein

Answer 29

Digestion of proteins begins by pepsin from the stomach and continues in the small intestine by the action of trypsin, chymotrypsin, and carboxypeptidase in pancreatic juice. Protein digestion is completed by brush border peptidases.

Question 30

Explain the digestion of lipids

Answer 30

Some digestion of lipids occurs in the stomach by lingual lipase and gastric lipase. Once in the small intestine, larger lipid globules are emulsified into smaller lipid globules by the bile salts in bile. Pancreatic lipase attacks the smaller lipid globules, completing the digestion of triglycerides into fatty acids and a monoglyceride.

Question 31

The colon is divided into 4 parts. What are they?

Answer 31

The colon is divided into ascending, transverse, descending, and sigmoid portions

Question 32

_________ inhabiting the lumen break down remaining carbohydrates, proteins, and bilirubin; and produce vitamin K and some B vitamins.

Answer 32

Bacteria

Question 33

When mass peristalsis pushes feces into the ________, distension of the rectal wall initiates the defecation reflex.

Answer 33

rectum

Question 34

What are the three phases of digestive activities?

Answer 34

Digestive activities occur in three overlapping phases: cephalic phase, gastric phase, and intestinal phase.

Question 35

What happens in the Cephalic phase?

Answer 35

During the cephalic phase of digestion, salivary glands secrete saliva and gastric glands secrete gastric juice in order to prepare the mouth and stomach for food that is about to be eaten.

Question 36

What happens in the Gastric phase?

Answer 36

The presence of food in the stomach causes the gastric phase, involving peristalsis and gastric juice secretion from gastric glands. The hormone gastrin stimulates gastric juice secretion.

Question 37

What happens in the Intestinal phase?

Answer 37

During the intestinal phase of digestion, food is digested in the small intestine. In addition, reflex activity slows gastric motility in order to slow the exit of chyme from the stomach, which prevents the small intestine from being overloaded with more chyme than it can handle. Secretin and cholecystokinin stimulate the secretion of pancreatic juice into the small intestine.

Question 38

What is meant by metabolism?

Answer 38

Metabolism refers to all of the chemical reactions of the body

Question 39

_______________, the complete oxidation of glucose to CO2 and H2O, involves glycolysis,the Krebs cycle, and the electron transport chain.

Answer 39

Cellular respiration,

Question 40

Glycolysis breaks down glucose into ____ molecules of pyruvic acid. Each molecule of pyruvic acid that enters the Krebs cycle is first converted to ____________.

Answer 40

two acetyl coenzyme A