Chapter 23 A&P II

Infants have ____ deciduos teeth, whereas adults have ______ permanent teeth

20; 32

Bacteria constitute about __________% of the dry weight of the feces.

30

________ break(s) down ___________

Peptidases; proteins

______ is the physiological process that moves a nutrient from the outside to the inside of the body.

absorption

a hepatic (portal) triad consists of

bile ductule, branch of the hepatic artery and branch of hepatic portal vein

of the following components of bile, only ______ has/have a digestive function

bile salts

The buccal phase of swallowing is under _____ control and the pharyngo-esophageal phase is ______

central nervous sytem (CNS); controlled by autonomic reflexes

Pepsinogen is produced by ____________ and is activated by ___________.

chief cells; hydrochloric acid (HCL) secreted by parietal cells

Lecithin prepares fats for hydrolysis by forming

emulsification droplets

The ____ regulates digestive tract motility, secretion, and blood flow, and its neurons are found in the ______

enteric nervous system; submucosa and muscularis externa

which of these is not a component of the pancreatic juice?

enterokinase

The enterogastric reflex serves to

inhibit gastric motility when there is chyme in the small intestine

The _______ of the small intestine is/are similar to the ________ of the stomach.

intestinal crypts; gastric pits

The serous membrane that suspend the stomach and intestines from the abdominal wall are called

mesenteries

_________ transport lipids to the surface of the intestinal absorptive cells, which process them into _________

micelles, chylomicrons

The migrating motor complex

milks the chyme toward the colon

the surface of the tongue is covered with ____ stratified squamous epithelium, and has bumps called ____, site of taste buds.

nonkeratinized; lingual papillae

These are normally found in saliva except

protease

These nutrients are all absorbed without being digested except

proteins

the small intestine has a very large absorptive surface associated with all these structures except

rugae

Defecation is stimulated by

stretching of the rectum

The ______ glad is an extrinsic salivary gland, whereas the ____ gland is an intrinsic salivary gland

submadibular; lingual

The organ that stores excess glucose and releases it later into the blood is

the liver

Most fat is digested by pancreatic lipase.

true

The digestive system processes food, extracts nutrients, and eliminates the residue

true

The liver is the body's largest gland.

true

both chemical and mechanical digestion start in the mouth and continue in the stomach

true

Bacterial flora carry out all of the following except

digest most of the proteins we get in the diet

From superficial to deep, these are the structures found in a typical tooth.

enamel, dentin, pulp

Absorption of many nutrients starts in the stomach.

false

Gastric juice consists entirely of water and hydrochloric acid.

false

odor, sight, and taste stimulate salivatory nuclei in the cerebral cortex

false

the brush borders of intestinal absorptive cells contain numerous goblet cells

false

the enteric nervous system regulates much of the digestive activity but its action depends on the central nervous system

false

the large intestine absorbs water, fats, and salts.

false

the large intestine is longer than the small intestine.

false

the small intestine begins with the duodenum, which is its longest segment.

false

The three most abundant classes of nutrients are

fats, proteins, and carbohydrates

_____ which is secreted by ______ cells, is necessary for vitamin B12 absorption.

intrinsic factor, parietal

Each of the following lists some of the tissue layers of the digestive tract. Which one has them in correct order from lumen to external surface?

lamina propria, muscularis muscosae, submucosa, muscularis externa, serosa

The ________ synthesizes bile acids by metabolizing _________.

liver, cholesterol

The swallowing center is located in

medulla oblongata

Carbohydrate digestion begins in the _______ whereas protein digestion begins in the _______.

mouth; stomach

Chemical digestion breaks down _____ into ______

nucleic acids; nucleotides

Hydrochloric acid (HCL) is secreted by ___ cells

parietal

Which of the following enzymes functions at the lowest pH?

pepsin

Proteins are digested by different enzymes acting in the following sequence

pepsin, trypsin, carboxypeptidase, dipeptidase

________ is a horomone, whereas _________ is an enzyme

secretin, pepsin

Amino acids and monosaccharides are absorbed in the __________, and fatty acids are absorbed in the __________.

small intestine, small intestine too

Why are several digestive enzymes secreted as zymogens?

so they act only in the stomach lumen and do not digest intracellular proteins

These are all accessory organs of the digestive system except

spleen

the muscle tone of the _________ along the colon contracts it lengthwise, causing its walls to bulge and form pouches called ________.

taeniae coli; haustra

________ is associated with food stretching the stomach and activating myenteric and vagovagal reflexes which in turn stimulate gastric secretions.

the gastric phase

Acid reflux into the esophagus ("heartburn") is normally prevented by

the lower esophageal sphincter (LES)

The small intestine is suspended from the abdominal wall by

the mesentery

the sodium glucose transport protein (SGLP)

transports glucose and sodium from the intestinal lumen into the epithelial cells

Which of these nutrients is absorbed by the lacteals of the small intestine?

triglyceride

Both pancreatic juice and bile are secreted into the duodenum.

true

Chylomicrons are secreted from the basal surface of the absorptive cells and taken into the lacteal in the villus

true

Enamel is found in the crown of a tooth, whereas dentin is part of both crown and root.

true

Which of these is the site of contact digestion?

brush border of small intestine

Pancreatic enzymes are secreted in response to the hormone

cholecystokinin (CCK)