A&P II: Chapter 25 review

What are the three phases of gastric activity?

1. cephalic phase 2. gastric phase 3. intestinal phase

The submucosa is labeled letter ______ in the figure.

A

What hormone is secreted by the small intestine in response to the presence of fats in the small intestine?

Cholecystokinin

T or F: The role of the liver in digestion is to produce digestive enzymes.

F - The liver produces bile for fat emulsion. The pancreas produces the digestive enzymes.

T or F: The stomach is innervated by parasympathetic, but not sympathetic, fibers.

False - both branches of the autonomic system innervate the stomach; the PSNS stimulates the digestive system and the SNS inhibits it

Briefly explain why this statement is false, or reword it to make it true: Fat is not digested until it reaches the duodenum.

Fat digestion begins in the stomach.

Briefly explain why this statement is false, or reword it to make it true: Hepatocytes secrete bile into the hepatic sinusoids.

Hepatocytes secrete bile into the bile canaliculi.

Briefly explain why this statement is false, or reword it to make it true: Hepcidin increases iron availability by promoting its intestinal absorption.

Hepcidin inhibits iron absorption and prevents iron overload.

Briefly explain why this statement is false, or reword it to make it true: A tooth is composed mostly of enamel.

Most of the tooth is dentin.

Briefly explain why this statement is false, or reword it to make it true: Most of the water in the digestive tract is reabsorbed in the large intestine.

Most of the water is absorbed by the small intestine.

What protect the stomach lining from the acidic contents?

Mucous coat, Epithelial cell replacement, Tight junctions

sigmo-

S-shaped (ex: sigmoid)

Briefly explain why this statement is false, or reword it to make it true: Secretin is a hormone that stimulates the stomach to secrete digestive enzymes.

Secretin stimulates the liver and pancreas to secrete bicarbonate and inhibits gastric secretion.

Briefly explain why this statement is false, or reword it to make it true: The ileal papilla regulates the passage of chyme from the stomach into the duodenum.

The ileal papilla regulates the passage of residue from the ileum of the small intestine into the cecum of the large intestine.

Briefly explain why this statement is false, or reword it to make it true: Lipids enter the circulation when the intestinal lacteals take up the micelles from by the small intestine.

The lacteals take up chylomicrons, not micelles.

Briefly explain why this statement is false, or reword it to make it true: The only monosaccharide absorbed by the small intestine is glucose.

The small intestine absorbs not only glucose by also fructose and galactose.

Briefly explain why this statement is false, or reword it to make it true: Tight junctions of the small intestine prevent anything from leaking between the epithelial cells.

Water, glucose, and other nutrients pass between cells, through the tight junctions.

Which are functions of saliva? (select all that apply) a. Dissolves molecules so they can be tasted b. Chemically digests proteins c. Cleanses mouth and teeth d. Inhibits the chemical digestion of starch e. Aids in swallowing

a. Dissolves molecules so they can be tasted, c. Cleanses mouth and teeth, e. Aids in swallowing

Which are functions of mesenteries? (select all that apply) a. Provide passage for nerves b. Secrete hormones c. Provide passage for blood vessels d. Hold abdominal viscera in place

a. Provide passage for nerves, c. Provide passage for blood vessels, d. Hold abdominal viscera in place

Which of the following cells secrete digestive enzymes? a. chief cells b. mucous neck cells c. parietal cells d. goblet cells e. enteroendocrine cells

a. chief cells

The lacteals absorb __________. a. chylomicrons b. micelles c. emulsification droplets d. amino acids e. monosaccharides

a. chylomicrons

Which of the following is a periodontal tissue? a. the gingiva b. the enamel c. the cement d. the pulp e. the dentin

a. the gingiva

What phase of gastric regulation includes inhibition by the enterogastric reflex? a. the intestinal phase b. the gastric phase c. the buccal phase d. the cephalic phase e. the pharyngoesophageal phase

a. the intestinal phase

How long is the gallbaldder?

about 10 cm

the uptake of nutrient molecules into the epithelial cells of the digestive tract and then into the blood or lymph

absorption

The enzyme that digests dietary starch is salivary or pancreatic __________.

amylase

The acidity of the stomach halts the action of __________ by promotes the action of __________, both of which are salivary enzymes.

amylase; lipase

Which of the following enzymes acts in the stomach? a. chymotrypsin b. lingual lipase c. carboxypeptidase d. enteropeptidase e. dextrinase

b. lingual lipase

Which of the following are found in intestinal juice? a. Bicarbonate b. Mucus c. Water d. Secretin e. Chymotrypsin

b. mucus, c. water

Lysozyme, immunoglobulin A, mucus, electrolytes and water are all found in which of the following? a. gastric juice b. saliva c. pancreatic juice d. bile

b. saliva

Which are functions of the oral cavity? (select all that apply) a. Excretion of wastes b. Speech c. Respiration d. Absorption of nutrients e. Ingestion

b. speech, c. respiration, e. ingestion

Fats entering the duodenum are coated with lecithin and __________ to keep them emulsified and enhance the efficiency of their digestion.

bile acids

freno-

bridle (ex: frenulum)

Which substances are absorbed from the stomach? a. Alcohol, fat b. Proteins and sugar c. Aspirin, lipid-soluble drugs

c. Aspirin, lipid-soluble drugs

Which describes the fundus of the stomach? a. It is the region adjacent to the distal portion of the lesser curvature. b. It is the large main region. c. It is the domed superior region. d. It is the narrow terminal region.

c. It is the domed superior region.

Which are found in saliva? Select all that apply. a. Fibrin b. Gastrin c. Mucus d. Pepsin e. Lipase f. Lysozyme g. Water h. Amylase

c. Mucus, e. Lipase, f. Lysozyme, g. Water, h. Amylase

Which is true of chemical digestion in the stomach? a. There is no digestion occurring in the stomach. b. Partial digestion of only protein occurs in the stomach. c. Partial digestion of both protein and fat can occur in the stomach.

c. Partial digestion of both protein and fat can occur in the stomach.

All of the following contribute to the absorptive surface area of the small intestine except __________. a. its length b. the brush border c. haustra d. circular folds e. villi

c. haustra

Which of the following is not an enzyme? a. chymotrypsin b. enteropeptidase c. secretin d. pepsin e. nucleosidase

c. secretin

antro-

cavity (ex: antrum)

The stomach receives sympathetic innervation from the ______.

celiac ganglion

What is the semi-liquid mixture of partially digested food within the stomach known as?

chyme

absorbing water and consolidating the indigestible residue into feces

compaction

Which of the following enzymes does not digest any nutrients? a. chymotrypsin b. lingual lipase c. carboxypeptidase d. enteropeptidase e. dextrinase

d. enteropeptidase

the elimination of feces

defecation

another name for the act of swallowing

deglutition

the mechanical and chemical breakdown of food into a form usable by the body

digestion

The brush border enzyme that finished the job of protein digestion, splitting the last 2 amino acids apart, is called __________.

dipeptidase

jejuno-

dry (ex: jejunum)

What are the segments of the small intestine in the order through which food passes?

duodenum ➝ jejunum ➝ ileum

Secretin is __________. a. a zymogen b. a nutrient c. an emulsifier d. a neurotransmitter e. a hormone

e. a hormone

The submucosal and myenteric plexuses collectively constitute the __________ nervous system.

enteric

The segment of the digestive tract indicated in the figure is the __________.

esophagus

The pharynx connects the oral cavity to the __________ and the nasal cavity to the __________.

esophagus; larynx

T or F: The only purpose of intestinal motility is to move residue along the digestive tract.

false - motility also mixes chyme with secretions and brings chyme into contact with intestinal lining

The region of the stomach indicated by the green arrow in the figure is the __________ region.

fundus

The sac on the underside of the liver that serves to store and concentrate bile is called the __________.

gallbladder

Anatomically, the __________ of the stomach most closely resemble the __________ of the small intestine.

gastric pits; intestinal crypts

Food in the stomach causes G cells to secrete __________, which in turn stimulates the secretion of HCl and pepsinogen.

gastrin

the study of the digestive tract and the diagnosis and treatment of its disorders

gastroenterology

porto-

gateway (ex: portal)

pyloro

gateway (ex: pyloric)

The mucus-secreting cells in the epithelium of the intestine are called __________ cells.

goblet

Blood from the superior mesenteric vein joins the splenic vein then flows into the ______.

hepatic portal system

the selective intake of food

ingestion

entero

intestine

Within the absorptive cells of the small intestine, ferritin binds the nutrient __________.

iron

chylo-

juice (ex: chylomicron)

Enzymes that digest lipids are called __________.

lipases

-elle

little (ex: micelle)

hepato-

liver (ex: hepatocyte)

Act through autonomic nerve fibers that carry sensory signals from the digestive tract to the brainstem and motor commands back to the digestive tract

long (vagovagal) reflexes

What are the gastric rugae?

longitudinal folds in the stomach lining

another name for the act of chewing

mastication

The sheet of connective tissue that hold the abdominal viscera in place are called __________.

mesenteries

Cusps are a feature of the __________ surfaces of the molars and premolars.

occlusal

The stomach receives what type of stimulation via the vagus nerve?

parasympathetic

The __________ salivary gland is named for its proximity to the ear.

parotid

The inactive form of pepsin is __________.

pepsinogen

the predominant type of involuntary muscle contraction occurring in the stomach

peristalsis

A(n) ______ is any enzyme that digests proteins.

protease

What hormone is secreted by the small intestine in response to the presence of acidic chyme?

secretin

What liver function contributes to the process of digestion?

secretion of bile

stretching or chemical stimulation of the digestive tract acts through the myenteric plexus to stimulate contractions in nearby regions of the muscularis externa (ex: peristaltic contractions of swallowing)

short (myenteric) reflexes

Stellate macrophages occur in blood-filled spaces of the liver called __________.

sinusoids

gastro

stomach

logy

study of

The layer of the digestive tract wall indicated in the figure is the ______.

submucosa

The small intestine receives nearly all of its blood supply from the ______.

superior mesenteric artery

What is the initial segment of the small intestine?

the duodenum

What muscles produce the up-and-down crushing action of the teeth during mastication?

the masseter and the temporalis

What part (a cavity) of the digestive system functions in ingestion, speech, and respiration?

the oral cavity

What is the lumpy yellow organ in the picture?

the pancreas

Which segment of the alimentary canal is indicated by the letter A in the figure?

the pharynx

What is the significance of the epithelial tight junctions and the mucous coat lining the stomach?

they protect the stomach lining from acid damage

Nervous stimulation of gastrointestinal activity is mediated mainly through the parasympathetic fibers of the __________ nerves.

vagus

The forceful ejection of stomach and intestinal contents from the mouth is called ______.

vomiting

What does the emetic center of the medulla oblongata stimulate?

vomiting

emet-

vomiting (ex: emetic)

An enzyme that is secreted in its inactive form is known as a ______.

zymogen