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137 Cards in this Set
- Front
- Back
What is the name of the tube that extends from the mouth to the anus, and includes the mouth, pharynx, esophagus, stomach, small intestine, large intestine and anal canal? |
alimentary canal |
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Name the four layers of the wall of the alimentary canal. |
mucosa, submucosa, muscular layer, and serosa |
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Which layer of the wall of the alimentary canal is epithelium, connective tissue, and smooth muscle? What are its functions? |
mucosa; protection against acidic ebolus, moving the ebolus along, secretion of mucus, and absorption |
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What layer of the wall of the alimentary canal is composed of loose connective tissue, blood vessels, lymphatic vessels, and nerves? What are its functions? |
submucosa; nourishes surrounding tissues and transports absorbed minerals |
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What is the layer of the wall of the alimentary canal that is composed of smooth muscle fibers in circular and longitudinal groups? What are its functions? Is it voluntary or involuntary? |
muscular layer; movements of the tube and its contents; involuntary |
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Which layer of the wall of the alimentary canal is composed of epithelium and connective tissue? What are its functions |
serosa; protection and releasing fluid for lubrication to prevent friction with other organs |
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What two fibers make up the muscular layer of the wall of the alimentary canal? What do each of the fibers do? |
circular fibers and longitudinal fibers; circular fibers contract to decrease the diameter of the tube and longitudinal fibers contract to shorten it |
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What is the term for the passageway of the digestive tube? |
lumen |
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What is the name of the fingerlike protrusions in the mucosa layer of the alimentary canal? What is the purpose of these protrusions? |
villi (singular: villus); increase surface area for absorption
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What is inside each villus of the alimentary canal? |
blood vessels and lacteal |
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What is the lacteal in a villus of the alimentary canal? |
a lymphatic capillary which absorbs lipids |
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What type of cells line a villus? |
simple columnar epithilium |
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Are microvilli cilia? |
NO |
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What is the purpose of microvilli? |
To make even more surface area for absorption |
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What are the mucus-secreting cells that are abundant throughout the mucosa? |
goblet cells |
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What are the two types of movement in the digestive system? What does each one do? |
mixing motion and propultion; mixing motion is when smooth muscles in the small segments of the tube contract rhythmically, mixing food with gastric/pancreatic juices (depending on where the motion is done) and propulsion is the utilization of peristalsis to push food through the alimentary canal |
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What is the wavelike motion in the alimentary canal in which a ring of contraction occurs in the wall of the tube and continues progressively along its length? |
peristalsis |
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What is the mixing motion in the small intestine that aids in mixing by alternatively contracting and and relaxing the smooth muscle in sections of the organ? |
segmentation |
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What type of movement(s) does the esophagus have? |
propulsion |
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What type of movement(s) does the stomach have? |
propulsion and mixing |
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What type of movement(s) does the small intestine have? |
mixing and propulsion |
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What type of movement(s) does the colon have? |
propultion |
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What is the process of breaking up particles into smaller pieces and mixing them with saliva? |
mastication |
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What 3 things does the tongue do? |
taste, moves food, and helps in swallowing |
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What are the three regions of the pharynx and where is each located? |
nasopharynx (behind the nasal cavity), oropharynx (behind the oral cavity), and laryngopharynx (behind the voice box) |
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What part of the digestive system receives food and begins digestion? |
mouth |
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What is the thick muscular organ that occupies the floor of the mouth and nearly fills the oral cavity when it is closed? |
tongue |
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What is the name of the membranous fold that connects the midline of the tongue to the floor of the mouth? |
lingual frenulum |
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What composes the body of the tongue? |
skeletal muscle fibers that run in several directions |
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What are the rough projections on the surface of the tongue that provide friction that helps handle food and contain the taste buds? |
papillae |
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What is the posterior region of the tongue called? |
root |
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What are the rounded masses of lymphatic tissue that cover the root of the tongue? |
lingual tonsils |
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What are the masses of lymphatic tissue on the posterior wall of the pharynx? |
pharyngeal tonsils |
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What are the hardest structures in the body? |
teeth |
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What are the chisel-shaped teeth which have sharp edges that bite off large pieces of food? |
incisors |
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What are the cone-shaped teeth that grasp and tear food? |
canines (cuspid) |
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What are the teeth with flattened surfaces that grind food particles? |
premolars (bicuspids) and molars |
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What are the two parts of a tooth? |
crown and root |
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What is the hardest substance in the human body? |
enamel |
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What is the outer layer of teeth? |
enamel |
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What is the bulk of a tooth beneath the enamel that is similar to bone in that it is living and is able to regenerate? |
dentin |
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What is the central cavity of a tooth that contains blood vessels, nerves, and connective tissue? |
pulp cavity |
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What allows passageway for the blood vessels and nerves to reach the central cavity? |
root canal |
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What is the inflammation of the gums called? What can it lead to? |
gingivitis; the destruction of the periodontal ligaments and eventually tooth loss |
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What is the thin layer of bonelike material that encloses the root? |
cementum |
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What surrounds the cementum, is composed of collogen, and attaches the tooth to the jaw? |
periodontal ligaments |
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What is the name of the gums? |
gingiva |
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What causes tooth decay? |
acid from bacteria or what we consume demineralizes the enamel |
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What secretes saliva? |
salivary glands
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What fluid moistens food, helps bind them, and begins the chemical digestion of carbohydrates? |
saliva |
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Where does digestion begin? Where does absorption begin? |
in the mouth; in the stomach |
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What are the two types of secreting cells in the salivary glands? |
serous and mucous |
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What is the digestive enzyme that splits starch and glycogen molecules into disaccharides, staring the chemical digestion of carbohydrates? Which cells produce this: serous cells or mucous cells? |
salivary amylase; serous |
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What is the thick liquid that bonds to food particles and acts as a lubricant during swallowing? Which cells produce this: serous cells or mucus cells? |
mucus; mucus cells |
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What are the three major salivary glands? |
parotid, submandibular, and sublingual |
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What are the largest of the salivary glands? Where are they? What do they secrete? What are they primarily composed of: serous or mucus cells? |
parotid glands; anterior to and somewhat inferior to each ear; saliva; serous |
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Which salivary glands are in the floor of the mouth on the inside surface of the lower jaw? What secretory cells are they composed of? |
submandibular; equally serous and mucus cells |
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What salivary glans are the smallest and are on the floor of the mouth inferior to the tongue? What secretory cells are they composed of? |
sublingual; primarily mucus |
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What connects the nasal and oral cavities with the larynx and esophagus? |
pharynx |
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What provides a passageway for air during breathing? |
nasopharynx |
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What portion of the pharynx is for food moving downwards from the mouth and for air moving to and from the nasal cavity? |
oropharynx |
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What part of the pharynx extends from the upper border of the epiglottis downward to the lower border of the larynx and is a passageway to the esophagus? |
laryngopharynx |
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What muscles pull the walls of the pharynx inwards during swallowing? |
pharyngeal constrictor muscles |
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What is the name for the mass of food the tongue forms into a ball during swallowing? |
bolus |
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What is the front part of the roof of the mouth called? |
hard pallete |
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What is the name for the back part of the roof of the mouth that goes up during swallowing to close the opening to the nasal cavity? |
soft pallete |
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What is the name for the flaplike structure attached to the larynx that closes off the top of the trachea during swallowing to prevent food from entering? |
epiglottis |
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What is the the ring of muscle fibers just superior to the point where the esophagus joins the stomach that remain contracted to help prevent regurgitation into the esophagus? |
lower esophageal sphincter |
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What are the 4 regions of the stomach? |
cardia, fundus, body, and pyloris |
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What are the folds of the stomach called? |
gastric folds |
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What is the circular layer of fibers at the end of the pyloric canal that controls gastric emptying? |
pyloric sphincter |
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What are the small openings that dot the mucous membrane of the inner lining of the stomach? |
gastric pits |
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What are the three types of secretory cells that compose a gastric gland? |
mucous cell, parietal cell, and chief cell |
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Which secretory cell of a gastric gland secrete mucus? Where are they found? |
mucous cells; in the necks of the glands near the opening of the gastric pits |
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Which secretory cell of a gastric gland secretes digestive enzymes? |
chief cell |
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Which secretory cell of a gastric gland releases a solution containing hydrochloric acid? |
parietal cells |
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What do the products of the mucus cells, chief cells, and parietal cells form? |
gastric juice |
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What secretory cell of the gastric gland secretes pepsinogen? |
chief cell |
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What is the inactive for of pepsin? How is it broken down into pepsin? |
pepsinogen; by coming in contact with the hydrochloric acid from parietal cells and breaking down quickly |
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What is the protein splitting enzyme that breaks nearly all protein into shorter polypeptides? |
pepsin |
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Does pepsin break protein into amino acids? |
NO |
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What aids in vitamin B12 absorption in the small intestine? What secretory cell of the gastric glands secretes this? What disease could develop if this is not secreted? |
intrinsic factors; parietal cells; pernicious anemia |
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What provides a viscous, alkaline protective layer on the stomach's inner surface? |
mucus |
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Name the five major components of gastric juice. |
pepsinogen, pepsin, hydrochloric acid, mucus, and intrinsic factors |
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What is the name of the nerve fiber that stimulates the release of gastric juice from the gastric glands? |
parasympathetic preganglionic nerve fiber in vagus nerve |
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What two things are released after the impulses from the parasymphathetic preganglionic nerve fiber in vagus nerve? |
gastric juices and gastrin |
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What is the peptide hormone that increases the secretory activity of gastric glands? |
gastrin |
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What are the three phases of gastric secretion? |
cephalic phase, gastric phase, and intestinal phase |
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During which phase of gastric secretions is gastric juice secreted in response to the sight, taste, smell or thought of food? |
cephalic phase |
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During which phase of gastric secretion is gastrin released in response to food mechanically and chemically stimulating the stomach, which, in turn, results in the secretion of gastric juice? |
gastric phase |
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During which phase of gastric secretion occurs as food enters small intestine and stimulates intestinal cells to release intestinal gastrin, which in turn promotes the secretion of gastric juice? |
intestinal phase |
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What is the semifluid paste of food particles and gastric juice produced by the mixing movements of the stomach wall? |
chyme |
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Why does the pyloric sphincter release food into the duodenum in small portions? |
because the duodenum must have time to neutralize the acidic chyme |
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What take the longest to digest? |
meat and fats |
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What is the name for the tube that extends down the length of the pancrease and transports pancreatic juice to the small intestine? |
pancreatic duct |
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What is the pear-shaped sac in a depression on the interior surface of the liver? What is its purpose? |
gallbladder; store and release bile |
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How does bile help in the digestion of fat? |
by emulsifying it (mechanically breaking it down) |
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What is the name for the ducts that connect the gallbladder to the liver? |
hepatic ducts |
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What is the peptide hormone that stimulates the pancrease to secrete bicarbonate ions when chyme enters the duodenum? What do these bicarbonate ions do? |
secretin; neutralize acidic chyme |
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What are the liver's functioning units? |
hepatic lobules |
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What are the vascular channels that separate platelike groups of hepatic cells from each other? |
hepatic sinusoids |
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What vein carries blood from the digestive tract and newly absorbed nutrients into the sinusoids? |
hepatic portal vein |
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What artery brings oxygenated blood to the sinusoids to mix with the blood from the hepatic vein to flow through and nourish the hepatic cells? |
hepatic artery |
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What are the macrophages fixed to the inner lining of the hepatic sinusoids that remove most of the bacteria from the blood through phagocytosis? |
Kupffer cells |
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Kupferr cells break dead red blood cells down to ____, which is further broken down into ______ and ______, which breaks down into ________ and finally ________. |
hemoglobin; heme and globin; biliverdin; bilirubin |
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After Kupferr cells break red blood cells all the way down to bilirubin, what structures do they enter? What do they enter after that? |
bile ductules; bile duct |
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What are the 7 major functions of the liver? |
carbohydrate metabolism, lipid metabolism, protein metabolism, storage, blood filtering, detoxification, and secretion |
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Specifically, what does carbohydrate metabolism mean? |
polymerizing glucose to glycogen, breaking down glycogen to glucose, and converting noncarbohydrates to glucose |
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Specifically, what does lipid metabolism mean? |
oxidizing fatty acids; synthesizing lipoproteins, phospholipids, and cholesterol; and converting portions of carbohydrate and protein molecules into fats |
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Specifically, what does protein metabolism mean? |
deaminating amino acids, forming urea, synthesizing plasma proteins, and converting certain amino acids into other amino acids |
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Specifically, what does storage in the liver entail? |
storing glycogen, vitamins A, D, and B, iron, and blood |
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Specifically, what does the blood filtering in the liver entail? |
removing damaged red blood cells and foreign substances by phagocytosis |
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Specifically, what does detoxification in the liver entail? |
removing toxins from the blood |
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Specifically, what does secretion in the liver entail? |
producing and secreting bile |
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What are the primary functions of the small intestine? |
digestion and absorption |
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Give the five steps of fat absorption in the small intestine. |
Fatty acids enter epithelial cell, fatty acids are used to synthesize fats in endoplasmic reticulum, fats collect in clusters encased in protein to form chylormicrons, chylormicrons leave epithelial cell and enter lacteal, lymph in lacteal transports chylormicrons away from intestine |
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What movement occurs when the wall of the small intestine becomes overdistended or irritated and sweeps the contents into the large intestine very quickly? |
peristaltic rush |
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What is the condition that results from a peristaltic rush and is characterized by frequent defecation and watery stools? What would happen if this condition is prolonged? |
diarrhea; imbalances in water and electrolyte concentrations |
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What is formed by the last few centimeters of the large intestine? |
anal canal |
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What is the name of the six to eight longitudinal folds of the mucous membrane of the anal canal? |
anal columns |
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How much of a digestive function does the large intestine have? |
little to no function |
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What is the S-shaped portion of the large intestine? |
sigmoid colon |
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What is the name of the opening at the end of the anal canal? |
anus |
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What lies next to the sacrum and generally follows its curvature, leading to the anal canal? |
rectum |
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What are the names of the two muscles that guard the anus? Which one is composed of smooth muscle under involuntary control? Which one is composed of |
internal anal sphincter muscle and external anal sphincter muscle; internal anal sphincter muscle; external anal sphincter muscle |
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What two things is the large intestine limited to absorbing? |
water and electrolytes |
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What produces intestinal gas? |
Bacteria actions in the large intestine |
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How are the peristaltic waves of the large intestine different from that of the small intestine? |
they happen only two or three times a day, producing mass movement which push the intestinal contents towards the rectum |
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What are composed of materials not digested or absorbed, along with water, electrolytes, mucus, and bacteria? |
feces |
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What percentage of water is feces? |
75% |
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From what does the color of feces derive? |
bile pigments altered by bacterial action |
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Where does the pungent odor of feces come from? |
a variety of compounds that the bacteria produce |
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What are two disorders of the large intestine? |
diverticulosis and colorectal cancer |
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What disorder of the large intestine is caused by parts of the intestinal wall weakening and the inner mucous membrane protruding through? |
diverticulosis |
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What is the condition in which chyme accumulates in the outpouching of the mucous membrane and becomes infected? |
diverticulitis |
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What increases the risk of developing diverticulosis? |
lack of dietary fiber |
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What is the fourth most prevalent cancer in the U.S. and the second common cause of cancer death? |
colorectal cancer |