Digestive system and Metabolism
What is the correct general equation for cellular respiration?
C6H12O6 + 6 O2→ 6 CO2 + 6 H2O + ATP energy
Amylase is secreted by _______.
both the salivary glands and the pancreas
Which of the following answers correctly lists the phases of the swallowing process before the bolus enters the stomach?
buccal, pharyngeal esophageal
The movement of nutrients from the digestive tract lumen across the epithelium is called
absorption
Functions of the stomach include all of the following except
absorption of triglycerides.
A balanced diet is important to provide the body with all the necessary nutrients to ensure physiological functioning. What is the name of the process where new organic molecules are synthesized?
anabolism
The nasogastric tube will be inserted through the nose, travel through the pharynx and will ultimately end in the stomach. After passing through the pharynx, what long muscular passageway will the NG tube pass through to get to the stomach?
esophagus
G cells of the stomach secrete
gastrin
Which of the following processes takes place in the cytosol of a eukaryotic cell?
glycolysis
Select the correct sequence of steps as energy is extracted from glucose during cellular respiration.
glycolysis → acetyl CoA → citric acid cycle → electron transport chain
Parietal cells secrete
hydrochloric acid
The purpose of the fecal transplant is to get healthy bacteria inside the digestive tract so they can colonize the large intestine. After the fecal transplant is deposited into the stomach, it must pass through the small intestine before reaching its target. What is the name of the last part of the small intestine before it connects to the large intestine?
ileum
Brush border enzymes are found in the
microvilli
In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain?
mitochondrion
The lamina propria and mucous epithelium are components of the
mucosa
What is the layer labeled "4"?
muscularis externa
Sandwiched between the layer of circular and longitudinal muscle in the muscularis externa is the
myenteric plexus
Chief cells secrete
pepsinogen
Each tooth is held in the alveolar socket by the
periodontal ligament
Waves of muscular contractions that propel the contents of the digestive tract are called
peristalsis
The enzyme amylase digests
polysaccharides
What is the function of the structure labeled "7"? (Lymphoid nodule)
protection from bacteria
Enzymes are _______.
proteins that function as catalysts
What is the name of the structure that connects the stomach to the duodenum of the small intestine?
pyloric sphincter
An enzyme secreted by the gastric mucosa of a newborn that coagulates milk proteins is
rennin
Which of the following descriptions best matches the term submucosal plexus?
sensory neural network
A colonoscopy is a common diagnostic tool to check for colorectal cancer. Sometimes an investigation of the distal segment of the colon is all that is needed. What is the name of this distal segment of the colon?
sigmoid
What type of epithelium covers the structure labeled "6"? (villi)
simple columnar
The majority of nutrient absorption occurs in the
small intestine
The stomach secretes the hormone ghrelin which functions to
stimulate hunger.
Chemical protein digestion begins in the
stomach
Large blood vessels and lymphatics are found in the
submucosa
What is the layer labeled "3"?
submucosa
The substance that the enzyme acts on is called its _______.
substrate
Muscles known as the pharyngeal constrictors function in
swallowing
Which accessory organ of the digestive system does not produce any enzymes or digestive secretions?
teeth
Which of these is NOT a function of the stomach?
to secrete enzymes that break down carbohydrates
An enzyme that digests proteins into peptides is
trypsin
What chemical is found in the fluid that flows through the pancreatic duct?
trypsinogen
Which of these duodenal hormones and actions are mismatched?
vasoactive intestinal peptide; inhibit intestinal blood flow
Which of the following is not found in the large intestines?
villi
Which energy-rich molecule produced by cellular respiration directly powers cell work?
ATP
Which of these statements about water balance in the digestive system is true?
About 150-200 ml/day are lost in the feces. About 7000 ml/day enter by secretion. About 2000 ml/day enter by mouth. (All of these statements are true.)
Which statement describes the citric acid cycle?
This process produces some ATP and carbon dioxide in the mitochondrion.
Which statement describes glycolysis?
This process splits glucose in half and produces 2 ATPs for each glucose.
Which of the following statements describe the absorptive state?
-Blood sugar is high. -Triglyceride levels are high in the blood stream.
Match the gastric phase on the left (1-3) with the correct description on the right (4-6): 1. intestinal phase 4. prepares stomach for arrival of food 2. gastric phase 5. stomach empties and decreases secretions 3. cephalic phase 6. stomach secretes juice and mixes food into chyme
1 and 5; 2 and 6; 3 and 4
Which structure controls the contraction of the muscularis externa?
10 myenteric plexus
Place the following structures in order as food passes into them. 1. cecum 2. duodenum 3. ileum 4. jejunum 5. stomach
5, 2, 4, 3, 1.
The epithelium lining the stomach, small intestine, and most of the large intestine is simple columnar; the epithelium in the oral cavity, esophagus, and pharynx is stratified squamous. Are these two statements true or false?
Both statements are true.
Which statement describes the electron transport chain?
This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration
Blockage of the common hepatic duct would interfere with digestion of
Fats
Proper digestion requires the coordinated effort of many hormones with various effects. How do gastrin, cholecystokinin (CCK), and secretin influence digestion?
Gastrin: - released during cephalic, gastric, and intestinal phases - released in response to the presence of partially digested peptides - secreted by the stomach and duodenum - has a stimulatory effect on parietal cells and chief cells Cholecystokinin: - released only during the intestinal phase independent of pH level Secretin: - released during the intestinal phase when the pH drops below 4.5
Which of the following molecules is broken down in cellular respiration, providing fuel for the cell?
Glucose
What statement does NOT pertain to the cephalic phase of gastric secretion?
It controls the rate at which chyme enters the small intestine.
During the postabsorptive state, the liver catabolizes lipids and amino acids to produce acetyl-CoA. Which of the following can build up in the blood when levels of acetyl-CoA in the liver increases?
Ketone bodies
In which area do you see most of the cell's ATP generated by aerobic respiration?
Mitochondria
Which of the following is the direction in which most bile would flow between the indicated points?
Most bile would flow from C to A for storage and from A to B for secretion.
A balanced diet contains all the ingredients needed to maintain homeostasis. Many important compounds in the body contain nitrogen atoms (N compounds), including amino acids, the bases of RNA and DNA, creatine, and porphyrins. Despite the importance of nitrogen, the body neither stores nitrogen nor maintains reserves of N compounds. The body can synthesize the carbon chains of the N compounds but must obtain nitrogen atoms either by recycling N compounds or by absorbing nitrogen from the diet. Pregnant or lactating women like Justine actively synthesize N compounds. When an individual absorbs more nitrogen than he or she excretes, he or she is said to be in what state?
Positive nitrogen balance
Which of the following describes the local response in the stomach during the gastric phase of gastric regulation? Select the best answer.
Released histamines stimulate parietal cells to secrete acid.
Which of the following hypotheses would address the question of why salivary amylase and lingual lipase do not work in the stomach?
Salivary amylase and lingual lipase do not work below a pH of 4.5
A stratified squamous epithelial lining can be found in all of the following except in the
Stomach
Sensory nerve cells, parasympathetic ganglia, and sympathetic postganglionic fibers can be found in the
Submucosal plexus
During digestion of triglycerides, fatty acids enter the intestinal mucosa by diffusion; then, they are resynthesized into triglycerides. Which of the following statements correctly describes what happens next?
The triglycerides are coated with proteins and then secreted into the interstitial fluid, where they diffuse into intestinal lacteals.
What do the gastroenteric reflex and the gastroileal reflex have in common?
They both respond to signals associated with the distension of the stomach wall.
What is the name of the structure labeled "6"?
Villi
Adequate nutrition is necessary to prevent deficiency disorders and ensure physiological functioning. Justine's diet is lacking vitamin A, a fat-soluble vitamin. What are the other fat-soluble vitamins?
Vitamins D, E, an K
Stimulation of gastric stretch receptors causes all of the following except
a decrease in myenteric plexus stimulation.
A drug that blocks the action of carbonic anhydrase in parietal cells would result in
a higher pH during gastric digestion.
Which of the following descriptions best matches the term cholecystokinin (CCK)?
causes gallbladder to contract
The pouchlike structure that joins the ileum at the ileocecal valve is the
cecum
Triglycerides, steroids, phospholipids and fat-soluble vitamins that are coated with proteins are called
chylomicrons.
A feature of the digestive tract wall that increases surface area available for absorption is the
circular folds.
Contraction of the muscle layer labeled "9" (circular layer of smooth muscle) causes the digestive tract to
constrict.
Which of the following descriptions best matches the term myenteric plexus?
coordinates activity of muscularis externa
The absorption of some sugars in the small intestine involves
cotransport
A disease that attacks and disables the myenteric plexus would
decrease intestinal motility.
Which of the following functions occurs in the part of the digestive system indicated by the arrow (Large intestines, Descending colon)?
dehydration and compaction of indigestible materials
Maltose is a _______.
disaccharide
Bile salts aid in the digestion of fats by ________ large fat droplets.
emulsifying
Which hormone drives the most pathways in the absorptive state?
insulin
The layer of loose connective tissue that directly supports the digestive epithelium is the
lamina propria
Which group of nutrients is being absorbed by this process? (lacteal)
lipids
Products of fat digestion are transported initially by
lymphatic vessels.
The technical term for chewing is
mastication
Digestion refers to the
mechanical and chemical breakdown of food
The ________ are double sheets of peritoneal membrane that suspend the visceral organs and carry nerves, lymphatics, and blood vessels.
mesenteries
Vitamins are organic molecules that are cofactors in many metabolic pathways. One of the important functions of the bacteria in the large intestine is to generate three vitamins: biotin and B12, which are both water soluble, and a third fat-soluble vitamin that is especially important in blood clotting. What is the fat-soluble vitamin produced by the bacteria in the colon?
vitamin k
What is the function of the green-colored structure indicated by the arrow (lacteal)?
Transport of lipids
