chapter 24 review

Which of these conditions causes inhibition of gastric secretion?

-hypotonic or hypertonic solution in the duodenum -distention of the duodenal wall -pH less than 2 in the duodenum -fats in the duodenum

duodenal glands

-produce protective mucus

goblet cells

-produce protective mucus

Given these structures: 1. cecum 2. descending colon 3. rectum 4. sigmoid colon 5. transverse colon Choose the arrangement that lists the structures in the order food passes through them from the small intestine to the anus.

1. cecum 5. transverse colon 2. descending colon 4. sigmoid colon 3. rectum

Arrange these parts of the small intestine in order from largest number of villi and circular folds to smallest number of villi and circular folds. 1. duodenum 2. ileum 3. jejunum

1. duodenum 3. jejunum 2. ileum

Given these sphincters: 1. external anal sphincter 2. ileocecal sphincter 3. lower esophageal (cardiac) sphincter 4. pyloric sphincter Arrange them in the order in which food passes through them.

3. lower esophageal (cardiac) sphincter 4. pyloric sphincter 2. ileocecal sphincter 1. external anal sphincter

Arrange these events in the order in which they occur during fat digestion, absorption, and transport: 1. chylomicrons enter lacteals 2. triglycerides, phospholipids and cholesterol coated with protein 3. fatty acids and glycerol packaged into micelles 4. bile salts emulsify fats 5. lipase digests fat

4,5,3,2,1 4. bile salts emulsify fats 5. lipase digests fat 3. fatty acids and glycerol packaged into micelles 2. triglycerides, phospholipids and cholesterol coated with protein 1. chylomicrons enter lacteals

The optimum pH for trypsin and chymotrypsin is about

7-9

Which of these phases of stomach secretion is correctly matched?

Gastrointestinal phase: stomach secretions are inhibited.

Parietal cells in the lining of the stomach secrete

HCl and intrinsic factor.

A major transport lipoprotein that has 92% lipid and 8% protein is a(n)

VLDL (very low-density lipoprotein).

Which cells in the small intestine have digestive enzymes attached to their surfaces?

absorptive cells

Starch is broken down to its disaccharide, maltose, by the enzyme

amylase

If you suck on a plain piece of bread, it will begin to taste sweet after a few moments. Saliva contains the digestive enzyme ________________, which breaks down starch into ________________.

amylase, maltose

Most of the enzymes produced in the large intestine and the formation of Vitamin K occurs in

bacteria.

The lipids that can be absorbed across the epithelial wall of the small intestine are hydrophobic and would have a difficult time in the watery lumen to come in contact with the epithelial membrane. These lipids are able to move easily in the watery lumen because of interaction with

bile salts

Lipids are emulsified by ____________ and digested by ______________.

bile salts; lipase

Disscharides like sucrose, lactose, and maltose are digested primarily in the

brush border of the small intestine

The hydrogen ions that form hydrochloric acid of the stomach come from

carbonic acid.

Duodenal gland secretion is stimulated by

chemical (acid) or tactile stimulation.

Which one of the following cells in the gastric glands produce pepsinogen?

chief or zymogenic cells

Secretion of the enzymatic component of pancreatic juice is stimulated by the hormone

cholecystokinin

Which of these hormones causes contraction of the gall bladder?

cholecystokinin

Once absorbed into the epithelial cell of the small intestine, free fatty acids and glycerol are recombined and a protein coat is added to form a

chylomicron

The "pyloric pump" describes

chyme moving from the stomach into the small intestine.

The aqueous component of pancreatic secretions

contains bicarbonate ions.

Saliva

contains lysozyme, which has a weak antibacterial action.

Glucose and galactose in the small intestine are taken into the epithelial cell by __________ and passed into the interstitial fluid by ___________.

cotransport; facilitated diffusion

Stimulation by the sympathetic nervous system will cause which one of the following effects in the inferior esophagus, stomach, small intestine and large intestine?

decreases peristalsis by inhibition of smooth muscle

Which two regions of a tooth contain living cells?

dentin and cementum

The acini of the pancreas produce

digestive enzymes.

Gastrin secretion is stimulated by

duodenal pH greater than 3.

The most nutrient absorption takes place in the

duodenum and jejunum.

The liver, gallbladder, and pancreas are connected to ducts that enter the

duodenum.

One of the major functions of bile salts is to

emulsify fat to fatty droplets.

The esophageal phase of swallowing is caused by the

enteric reflex.

Which of these inhibits secretion and motility of the stomach?

enterogastric reflex

Trypsinogen when activated by ___________ will break down proteins in the ___________.

enterokinase; small intestine

Which one of the following is most easily absorbed in the oral cavity?

fatty acids

All of these occur in the large intestine EXCEPT:

fatty acids are absorbed.

In the regulation of stomach secretions, distension of the stomach activates local reflexes and a parasympathetic reflex. This is called the _____________ phase.

gastric

The greatest amount of stomach secretion takes place during the

gastric phase.

Surface area of the stomach is increased by

gastric pits.

Parasympathetic stimulation causes endocrine cells in the stomach to release the hormone

gastrin

Which of these hormones stimulates stomach secretions?

gastrin

The mucosal lining of the large intestine contains predominantly

goblet cells.

Which cells in the small intestine may help protect the intestinal epithelium from bacteria?

granular cells

In the liver, blood from the __________ and the hepatic artery flow into the hepatic sinusoids and become mixed.

hepatic portal vein

A lipoprotein has the following components: 5% tryglyceride, 20% cholesterol, 30% phospholipid, and 45% protein. This molecule would be best described as a

high-density lipoprotein.

Name the functions of the digestive system

ingestion, digestion, secretion, absorption, propulsion

Stimulation of the internal anal sphincters by the sympathetic nervous system or stimulation of the external anal sphincter by the somatic motor nervous system would

inhibit the defecation reflex.

Which one of the following functions best describes the effects of the hormone cholecystokinin?

inhibits gastric secretions, stimulates pancreatic secretions (high in enzymes), stimulates contraction of the gall bladder and relaxation of the sphincter of Oddi

Stimulation by the parasympathetic nervous system will cause the __________ anal sphincter to _____________.

internal; relax

The parietal cells in the gastric glands of the pyloric region produce _____________ that bonds with Vitamin _______ to make it more readily absorbed in the ileum.

intrinsic factor; B12

The pharyngeal phase of swallowing is ___________ , which is controlled by __________ muscle.

involuntary; skeletal

Bacteria and other foreign material absorbed by the small intestine are destroyed by ___________ cells found lining the hepatic sinusoids.

kupffer

Besides capillaries, villi also contain lymphatic vessels called

lacteals

Once chylomicrons leave the simple columnar epithelium of the small intestine, they diffuse into

lacteals

The lymphatic capillaries in the villi of the small intestine are called

lacteals

All of these are enzymes that digest protein EXCEPT

lipase

Micelles are

lipids surrounded by bile salts.

Cholesterol that is required to produce steroids and bile salts is carried in

low-density lipoproteins (LDL).

Saliva decreases gingivitis and caries because it contains immunoglobulin A and

lysozymes

Dentin

makes up most of the structure of the teeth.

These contractions occur 3 to 4 times a day and involve large parts of the transverse and descending colon. These contractions are called

mass movements.

Chewing or mastication reflex originates in the _______________ and the ability to initiate or stop chewing originates in the _______________.

medulla oblongata; cerebrum.

The stomach produces acids, which denature protein, and pepsin that digests protein. The cell membranes of the epithelial cells lining the stomach contain protein. The protein in the epithelial cells are not denatured or digested because

mucus coats the epithelium.

Brunner's glands produce __________ and are found in the _____________.

mucus; duodenum

The majority of lipase is produced by the

pancreas

Histamine stimulates the ________________ cells to release ______________.

parietal; HCl

The largest pair of salivary glands, which produce mostly watery saliva, are the

parotid glands.

The muscular contractions, which move material through the digestive tract, are called

peristalsis

absorptive cells

produce digestive enzymes

endocrine cells

produce regulatory hormones

The major food digested by gastric secretions is

protein

The low pH of the stomach activates enzymes that digest _____________ while inactivating enzymes that digest ______________.

proteins; starch

The center of the tooth, which is filled with blood vessels, nerves, and connective tissue, is called the

pulp

Cells in duodenum monitor chyme coming from the stomach that has a pH of 1. You would expect the duodenal cells to

release secretin, which inhibits gastric secretions.

Which structures produces enzymes that digest carbohydrates?

salivary glands, pancreas, lining of the small intestine

Bile secretion is stimulated by the hormone ______________ in response to ______________.

secretin; low pH of the chyme

Contractions that mix material in the small intestine are called

segmental contractions.

The __________ secretes peptidases and disaccharidases, whereas the __________ secretes trypsin, chymotrypsin, amylase, lipase, and nucleases.

small intestine, pancreas

Most of the protein digesting enzymes are produced by the

stomach and pancreas.

The term gastrointestinal (GI) tract refers to the

stomach, small intestine and large intestine.

The salivary gland that produces primarily mucus is the _____________ salivary gland.

sublingual

The nervous system or systems that can control peristalsis in the inferior esophagus, stomach, small intestine and large intestine is (are) the

sympathetic and parasympathetic nervous systems.

The major duodenal papilla is

the opening of the hepatopancreatic ampulla in the duodenum.

Successive contraction of constrictor muscles occurs and the epiglottis covers the opening in the larynx. This describes

the pharyngeal phase of swallowing.

During deglutition (swallowing),

the swallowing center in the medulla oblongata is activated.

Branches of which autonomic nerve carry the parasympathetic motor neurons to the enteric plexi?

vagus

Which of the following cranial nerves carries sensation from the digestive tract to the CNS?

vagus

Which one of the following is absorbed in the GI tract without being digested?

vitamins