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