Process by which the products of digestion pass through the lumen of the gastrointestinal tract into the blood or lymph.
Chemical or mechanical process of breaking down foodstuffs to substances that can be absorbed.
Food is contained in the gastrointestinal tract from the time of ingestion until it is completely digested and the waste prepared for elimination.
As food passes through the digestive tract, it becomes less complex and the nutrients are more readily available to the body.
Some of the microbes that often invade other organs of the body are rarely found in the stomach. The reason for this is the presence of HCl.
Kupffer cells are found in the liver and are responsible for removing bacteria and worn-out cells.
The pharyngeal-esophageal phase of swallowing is involuntary and is controlled by the swallowing center in the thalamus and lower pons.
The cell type of the wall of the large intestine, excluding anal cells, is very different from that of the small intestine.
Pepsinogen is the precursor to the gastric enzyme for protein digestion and is secreted by the parietal cells.
The myenteric nerve plexus provides the major nerve supply to the GI tract wall and controls GI motility.
The intrinsic ability of visceral smooth muscle to exhibit the stress-relaxation response is termed plasticity.
The major stimulus for production of intestinal fluid is distention or irritation of the intestinal mucosa by hypertonic or acidic chyme.
Ionic iron is actively transported into the mucosal cells, where it binds to the protein ferritin, a phenomenon called the mucosal iron barrier.
The layer of muscle in the intestine directly in contact with the serosa is the circular layer.
The mucosa is found only in the jejunum because this is the only part of the small intestine in need of mucus.
in the walls of the tract organs
The mechanical and chemical receptors that control digestive activity are located ________.
collect absorbed nutrients for metabolic processing or storage
The function of the hepatic portal circulation is to ________.
When we ingest large molecules such as lipids, carbohydrates, and proteins, they must undergo catabolic reactions whereby enzymes split these molecules. This series of reactions is called ________.
The sheets of peritoneal membrane that hold the digestive tract in place are called ________.
mucosa, submucosa, muscularis externa, and serosa
From the esophagus to the anal canal, the walls of every organ of the alimentary canal are made up of the same four basic layers. Arrange them in order from the lumen.
passageway between the oral cavity and the pharynx
The structure known as the fauces is the ________.
The capillaries that nourish the epithelium and absorb digested nutrients lie in the ________.
The plicae circulares and intestinal villi are found in which of the four layers of the alimentary tube wall?
The structures that produce new cells for the mucosa of the small intestine are the ________.
plicae circulares and intestinal villi
The absorptive effectiveness of the small intestine is enhanced by increasing the surface area of the mucosal lining. Which of the following accomplish this task?
There are 20 primary teeth, and by 24 months of age most children have all 20.
Select the statement that is true concerning primary teeth.
There are 32 permanent teeth, and the wisdom teeth are the last to emerge.
Which of the following is true concerning the number and type of permanent teeth?
serous cells and mucous cells
The salivary glands are composed of which two types of secretory cells?
electrolytes, digestive enzyme, mucin, lysozyme, wastes, and IgA
The solutes contained in saliva include ________.
initiates protein digestion and denatures proteins
In addition to storage and mechanical breakdown of food, the stomach ________.
Gastrin, histamine, endorphins, serotonin, cholecystokinin, and somatostatin are hormones that are released directly into the lamina propria. Which of the following cell types synthesize and secrete these products?
before food enters the stomach and is triggered by aroma, sight, or thought
There are three phases of gastric secretion. The cephalic phase occurs ________.
waves of muscular contractions that propel contents from one point to another
Peristaltic waves are ________.
B) protein and peptide fragments
Gastrin is a digestive hormone that is responsible for the stimulation of acid secretions in the stomach. These secretions are stimulated by the presence of ________.
You have just eaten a meal high in complex carbohydrates. Which of the following enzymes will help to digest the meal?
The ducts that deliver bile and pancreatic juice from the liver and pancreas, respectively, unite to form the ________.
Short-chain triglycerides found in foods such as butterfat molecules in milk are split by a specific enzyme in preparation for absorption. Which of the following enzymes is responsible?
Chemical digestion reduces large complex molecules to simpler compounds by the process of ________.
The ________ contains lobules with sinusoids (lined with macrophages) that lead to a central venous structure.
If an incision has to be made in the small intestine to remove an obstruction, the first layer of tissue to be cut is the ________.
Digestion of which of the following would be affected the most if the liver were severely damaged?
________ is locally regulated in the blood by the active form of vitamin D, which acts as a cofactor.
________ is/are not important as a stimulus in the gastric phase of gastric secretion.
produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion
The function of the goblet cells is to ________.
2 to 3 liters of gastric juice per day
Under normal conditions, the gastric mucosa pours out as much as ________.
fungiform and circumvallate
Which of the following are types of papillae on the tongue that contain taste buds?
A fluid secreted into the small intestine during digestion that contains cholesterol, emulsification agents, and phospholipids is ________.
The layer of the digestive tube that contains blood vessels, lymphatic nodes, and a rich supply of elastic fibers is the ________.
is longer than the small intestine
Which of the following is not characteristic of the large intestine? It ________.
the pharyngeal-esophageal phase, an involuntary process
The propulsion of food down the gastrointestinal tract includes ________.
Gastric secretion can be stimulated before food has entered the mouth.
Select the correct statement about the regulation of gastric secretion.
Chyme entering the duodenum can decrease gastric motility via the enterogastric reflex.
Select the correct statement about digestive processes.
cholecystokinin (CCK), an intestinal hormone responsible for gallbladder contraction
Chemical digestion in the small intestine involves ________.
If intact proteins are transported across the villus epithelium, an immune response may be generated.
Select the correct statement about absorption.
Iron and calcium are absorbed mostly by the duodenum.
Select the correct statement about electrolyte absorption.
You have just eaten french fries, buttered toast, ice cream, and whole milk. Which of the following glands would be active in helping you to digest this food?
Bile would be released from the gallbladder to emulsify the fat in the duodenum.
The ingestion of a meal high in fat content would cause which of the following to occur?
A baby is admitted to the hospital with a history of projectile vomiting after each feeding. On examination, it is found that the sphincter controlling food passage from the stomach to the duodenum is thickened and does not open readily. Because of the babyʹs loss of gastric juice, his blood probably indicates ________.
There are some 20 known pathogens found in the large intestine; our Ig ________ antibody-mediated response restricts them from going beyond the mucosa and causing problems.
a branch of the hepatic artery, a branch of the hepatic portal vein, and a bile duct.
The portal triad contains ________.
________ cells are found in the sinusoids of the liver and they remove debris from the blood as it flows past.
Premolars have a broad crown with rounded cusps but have only one root. Molars also have broad
crowns with rounded cusps but are larger than premolars. Molars have at least two roots.
Compare and contrast the structure and function of a premolar and a molar.
Chylomicrons are tiny fatty droplets composed of triglycerides, small amounts of phospholipids,
cholesterol, free fatty acids, and some protein.
What are chylomicrons?
The acidic gastric juices get regurgitated into the esophagus. This may happen when someone has
eaten or drunk too much, or it can be caused by extreme obesity or the discomfort of pregnancy. It is
sometimes due to obstructions or structural faults in the esophagus as well.
What is heartburn and what causes it?
Mechanical food processes are very important in the mouth (mastication) and stomach (contractions
causing mixing of food into chyme). The esophagus and pharynx are primarily food conduits. Protein
digestion begins in the stomach. Fat digestion begins in the small intestine.
Name two regions of the digestive tract where mechanical food breakdown processes are very important. Name two organs that are primarily food conduits. Name the organ where protein digestion is begun. Name the organ where fat digestion begins.
Watery stools are called diarrhea. Constipation is a condition in which too much water has been
absorbed and the stool becomes hard and difficult to pass. Any condition, such as irritation of the colon by bacteria that rushes food residue through the large intestine before that organ has had sufficient time to absorb the remaining water, is known as diarrhea. Constipation may ensue from the lack of fiber in the diet, improper bowel habits, laxative abuse, or anything that decreases motility.
Define constipation and diarrhea. Note possible causes of each.