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152 Cards in this Set
- Front
- Back
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Definition: taking food and water into the mouth
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ingestion
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Definition: chewing, mixing, and churning food
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mechanical digestion
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Definition: digestive enzymes breakdown food
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chemical digestion
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Definition: a muscular tube that winds through the body and is responsible for the digestion and absorption of food (oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, anus)
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digestive/GI tract
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Definition: organs that aid in the breakdown of foodstuffs (teeth tongue, gallbladder, salivary glands, liver, and pancreas)
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accessory digestive organs
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What are the three major functions of the tunics of the GI tract?
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-secretion of mucus
-absorption of end products of digestion -protection against infectious disease |
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What do the mucus secretions of tunics do?
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-protect digestive organs from digesting themselves
-ease food along the tract |
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The stomach and small intestine mucosa contain what two things?
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-enzyme secreting cells
-hormone-secreting cells |
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What are the 4 tunics of the digestive tract?
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mucosa
submucosa muscularis serosa/adventitia |
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Definition: innermost layer that lines the lumen of the alimentary canal
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mucosa
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The mucosa layer consists of what three things?
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mucous epithelium
lamina propria muscularis mucosae |
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Definition: connective layer tissue containing the submucosal plexus, blood vessels, and small glands
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submucosa
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Definition: consists of an inner layer of circular smooth muscle and an outer layer of longitudinal smooth muscle
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muscularis
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The ______ is between the two muscle layers.
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myenteric plexus
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Definition: forms the outermost layer of the digestive tract
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serosa/adventitia
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Definition: consists of the nervous plexuses within the wall of the digestive tract
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enteric nervous system
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What are the two major plexuses of the enteric NS?
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submucosal nerve plexus
myenteric nerve plexus |
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Definition: regulates glands and smooth muscle in the mucosa
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submucosal nerve plexus
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Definition: major nerve supple that control GI tract mobility
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myenteric nerve plexus
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Definition: an enteric neuron that detects changes in the chemical composition of the digestive tract
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sensory neuron
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Definition: an enteric neuron that stimulates or inhibits smooth muscle contraction and glandular secretion
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motor neurons
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Definition: an enteric neuron that connects sensory to motor neurons
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interneurons
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Nervous regulation involves local reflexes in the ____ and ____ reflexes.
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ENS
CNS |
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Definition: a serous membrane that lines the abdominopelvic cavity and organs
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peritoneum
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Definition: peritoneum that extends from the body wall to many of the abdominopelvic organs
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mesenteries
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Definition: the space between the lips or cheeks and the alveolar processes, which contain the teeth
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vestibule
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Definition: lies medial to the alveolar processes
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oral cavity proper
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The withstand abrasions, the mouth is lined with _______.
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stratified squamous epithelium
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Definition: part of the roof of the mouth that assists the tongue in chewing
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hard palate
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Definition: part of the roof of the mouth that is a mobile fold mostly of skeletal muscle; contains the uvula and closes off the nasopharynx during swallowing
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soft palate
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What are the 3 functions of the tongue?
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- gripping and repositioning food during chewing
-mixing food with saliva and forming the bolus -initiation of swallowing and speech |
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Definition: secures the tongue to the floor of the mouth
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frenulum
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Definition: 20 teeth that erupt between 6-24 mos of age; replaced by 32 permanent teeth between 5-11 years of age
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deciduous teeth
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What are the 4 types of teeth?
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incisors
canines premolars molars |
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Definition: exposed part of the tooth above the gingiva; dentin covered by enamel
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crown
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Definition: acellular material composed of calcium salts and hydroxyapatite crystals
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enamel
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Definition: portion of the tooth embedded in the jawbone; composed of dentin
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root
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Within the dentin of the root is the ______, which is filled with ____, _____, and ______.
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pulp cavity
pulp blood vessels nerves |
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Definition: hold the teeth in the alveoli
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periodontal ligaments
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Definition: produce and secrete saliva
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salivary glands
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What are the functions of saliva?
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-cleanses the mouth
-moistens and dissolves food chemicals -aids in bolus formation -contains enzymes that break down starch |
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What are the three pairs of salivary glands?
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parotid
submandibular sublingual |
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What are the two cells of the salivary glands and what do they produce?
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serous: enzymes, ions, and mucin
mucous: produce mucous |
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Definition: 97-99.5% water and slightly acidic solution
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saliva
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What does saliva contain?
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-electrolytes
-digestive enzyme: salivary amylase -proteins: mucin, lysozyme, defensins, and IgA -metabolic wastes: urea and uric acid |
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Salivation is controlled primarily by what?
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parasympathetic system of the ANS
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Salivation is triggered by what two things?
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-ingested food which stimulates chemoreceptors and pressoreceptors
-the thought of food |
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Salivation is inhibited by what?
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strong sympathetic stimulation
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Definition: sphincters in the esophagus that regulate movement
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upper and lower esophageal sphincters
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Definition: a bolus of food is moved be the tongue from the oral cavity to the pharynx
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voluntary phase of swallowing
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Definition: a reflex caused by the stimulation of stretch receptors in the pharynx; the soft palate closes the nasopharynx; the epiglottis, vestibular folds, and vocal folds close the opening into the larynx; the pharyngeal muscles move the bolus into the esophagus
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pharyngeal phase
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Definition: a reflex initiated by the stimulation of stretch receptors in the esophagus; a wave of contraction moves the food into the stomach
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esophageal phase
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Definition: contraction to move food through the GI tract
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peristalsis
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Definition: temporary "storage tank" where chemical breakdown of proteins begins and food is converted from a bolus to chyme
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stomach
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Definition: opening from the stomach to the esophagus
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gastroesophageal opening
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Definition: opening from stomach to duodenum
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pyloric orifice
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What are the major regions of the stomach?
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cardiac part
fundus body pyloric part (contains pyloric sphincter) |
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The lateral sides of the stomach consists of what?
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the greater and lesser curvatures
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The wall of the stomach consists of what 4 things?
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external serosa
muscle layer (longitudinal, circular, and oblique) submucosa simple columnar epithelium |
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Definition: produce an alkaline mucous with bicarbonate, which coats and protect the stomach lining
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surface mucous cells
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Definition: folds of the mucosa and submucosa of the stomach
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rugae
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The ____ and ____ produce juice in the stomach.
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gastric pits
gastric glands |
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Definition: gastic secretory cells that secretes acid mucus
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mucous neck
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Definition: gastic secretory cells that secretes HCl and intrinsic factor
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parietal cells
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Definition: gastric secretory cells that produce pepsinogen
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chief cells
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Pesinogen is activated to _____ by ________ and _______.
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pepsin
HCl in the stomach pepsin (positive feedback) |
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Definition: gastric secretory cells that produce regulatory hormones (gastrin, histamine, endorphins, serotonin, CCK, and somatostatin into the lamina propria)
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endocrine cells
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Definition: ingested food mixed with gastric juice
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chyme
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____ protects the lining of the stomach. _____ digests proteins. ___ promotes pepsin activity and kills microorganisms. ______ is necessary for vitamin B12 absorption. _____ and ____ regulate stomach secretions.
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mucus
pepsin HCl intrinsic factor gastrin histamine |
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A _____ moves H+ out of parietal cells in exchange for K+.
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proton pump
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Definition: initiated by sight, smell, taste, or thought of food; nerve impulses from the medulla stimulate HCl, pepsinogen, gastrin, and histamine secretion
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cephalic phase of stomach secretion
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Definition: initiated by distention of the stomach, which stimulates gastrin secretion ad activates CNS and local reflexes that promote secretion
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gastric phase of stomach secretion
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Definition: acidic chyme enters the duodenum and stimulates neuronal reflexes and the secretion of hormones (secretin and CCK) that inhibit gastric secretions
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gastrointestinal phase of stomach secretion
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_____ mix the stomach contents with stomach secretions to form ____. ________ move the chyme into the duodenum.
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waves
chyme peristaltic waves |
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Definition: vomiting
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reverse peristalsis
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Definition: the body's major digestive organ where digestion is completed and absorption occurs; runs from the pyloric sphincter to the ileocecal valve
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small intestine
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What are the three subdivisions of the small intestine?
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duodenum
jejunum ileum |
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Where do the bile and pancreatic ducts empty?
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duodenum
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Definition: deep folds of the mucosa and submucosa in the small intestine
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circular folds
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Definition: fingerlike extensions of the mucosa in the small intestine
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villi
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Definition: tiny projection of absorptive mucosal cells' plasma membranes in the small intestine; forms the brush border
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microvilli
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The epithelium of the mucosa in the small intestine is _______.
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columnar epithelium
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Definition: pits between the villi in the mucosa of the small intestine
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intestinal glands
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Definition: cells found in the mucosa of the small intestine that produce digestive enzymes
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absorptive cells
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Definition: cells found in the mucosa of the small intestine that produce a protective mucus
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goblet cells
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Definition: cells found in the mucosa of the small intestine that protect the intestinal epithelium from bacteria
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granular cells (Paneth cells)
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Definition: cells found in the mucosa of the small intestine that produce regulatory hormones
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endocrine cells
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Definition: aggregated lymphoid follicles found in the submucosa of the small intestine
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Peyer's patches
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The _____ protects the small intestine against digestive enzymes and gastric acids. Digestive enzymes (_______ and _______) are bound to the ______.
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mucus
disaccharidases peptidases intestinal wall |
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What 3 things stimulate intestinal secretion?
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chemical or tactile stimulation
vagal stimulation secretin |
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_____ contraction mix intestinal contents. _______ contractions move materials distally.
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segmental
peristaltic |
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What 3 things stimulate contractions in the small intestine?
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distension of the intestinal wall
local reflexes PNS |
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What stimulates the contraction of the ileocecal sphincter?
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distension of the cecum
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What are the 4 lobes of the liver?
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right
left caudate quadate |
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_______ liver lobules are the structural and functional units of the liver.
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hexagonal-shaped
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Definition: composed of hepatocyte (liver cell)plates radiating outward from a central vein
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lobules
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_________ are found at each of thesix corners of each liver lobule
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portal triads
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Definition: conduct bile toward the duodenum
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hepatic duct
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Definition: supplies oxygen-rich blood to theliver
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hepatic artery
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Definition: carries venous blood with nutrientsfrom digestive viscera
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hepatic portal vein
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The portal triad consists of what 3 things?
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hepatic duct
hepatic artery hepatic portal vein |
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The_____ are composed of columns of hepatocytes separated by the _______. _______ are enlarged spaces filled with blood and lined with endothelium and hepaticphagocytic cells.
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hepatic cords
bile canaliculi sinusoids |
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Definition: hepatic macrophages found in liversinusoids
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Kupffer cells
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What are the 4 functions of the liver?
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-produces bile
-stores and processes nutrients, produces new molecules, and detoxifies -hepatic phagocytic cells phagocytize red blood cells, bacteria, and other debris -produces blood components |
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What is the functions of bile?
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contains bile salts that emulsify fat
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Branchesof the hepatic artery and the hepatic portal vein in the portal triads emptyinto ____, which empty into _____, which join to form the ____, whichleave the liver.
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hepatic sinusoids
central veins hepatic veins |
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_____ collect bile from hepatocytes and jointhe _____ inthe portal triads. These converge to form the right and left hepatic ducts,which exit the liver. Theleft and right hepatic ducts join to form the _____. The ____ fromthe gallbladder joins the common hepatic duct to form the ____. This and pancreatic duct join at the ____, which opens into the duodenum at the_____.
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bile canaliculi
small hepatic ducts common hepatic duct cystic duct common bile duct hepatopancreatic ampulla major duodenal papilla |
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Definition: a small sac on the inferior surfaceof the liver; stores and concentrates bile
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gallbladder
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Definition: a yellow-green, alkaline solutioncontaining bile salts, bile pigments, cholesterol, neutral fats, phospholipids,and electrolytes
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bile
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Bile salts are ____ derivatives that: ______, facilitate fat and cholesterolabsorption, and helps make ______.
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cholesterol
emulsify fat cholesterol soluble |
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_____ recycles bile saltstherefore they are never voided in the feces.
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enterohepatic circulation
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The chief bile pigment is______, a waste product of _____. It is metabolized bybacteria in the small intestines and _____ is produced, which gives feces its darkcolor.
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bilirubin
heme urobilogen |
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Acidic,fatty chyme causes the duodenum to release _____ and _____ into the bloodstream.
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Cholecystokinin (CCK)
secretin |
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Cholecystokinin causes: the gallbladder to contract and______, relaxation of the ______ of thebile duct and hepatopancreatic ampulla. Secretin _____ (water and bicarbonate ions). As a result, bile enters theduodenum.
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release bile
sphincters increases bile secretion |
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_____ causes weak contractions of the gallbladder.
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vagal stimulation
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Definition: secretes pancreatic juice whichbreaks down all categories of foodstuff
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pancreas
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Definition: clusters of secretory cells thatcontain zymogen granules with digestive enzymes; connect to a duct system thateventually forms the pancreatic duct
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acini
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The pancreatic duct joins the _____. The accessory pancreaticduct empties into the duodenum at the _____.
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hepatopancreatic ampulla
minor duodenal papilla |
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Thepancreas also has an endocrinefunction. Theislets of Langerhans release of ____ and ____.
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insulin
glucagon |
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Theaqueouscomponent ofpancreatic juice is produced by the ____ and contains_____. Its a water solution of enzymes andelectrolytes (primarily HCO3–). It ______ acidic chyme and provides ______ forpancreatic enzymes.
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small pancreatic ducts
bicarbonate ions neutralizes optimal environment |
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Theenzymaticcomponent ofpancreatic juice is produced by the ____ and contains enzymes that digestcarbohydrates, lipids, and proteins. Enzymes are released in _____ andactivated in the ______.
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acini
inactive form duodenum |
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_______ stimulates the release of the aqueous component, which neutralizes acidic chyme. ______ stimulates the secretion of the enzymatic component and relaxation of thesphincters of the pancreatic duct and hepatopancreatic ampulla. ____ increases and ____ decreases secretion ofenzymes.
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secretin
cholecystokinin parasympathetic stimulation sympathetic stimulation |
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The large intestine extendsfrom the _____ to the ____. It absorbs ____ and eliminate the waste via _____. It issubdivided into the ____, _____, ____, _____, and _____.
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ileocecal valve
anus water feces cecum appendix colon rectum anal canal |
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The _____ forms a blind sac at the junctionof the small and large intestines. The ____ is a blindtube off the cecum.
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cecum
vermiform appendix |
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The colon has distinctregions: _____, _____, _____, and _______. The sigmoid colon joins the _____. The _____, the last segment ofthe large intestine, opens to the exterior at the anus. The anal canal contains two______ to allow the movement of feces.
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ascending colon
transverse colon descending colon sigmoid colon rectum anal canal sphincters |
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Definition: three bands of longitudinal smooth muscle in its muscularis
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teniae coli
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What are 3 unique features of the large intestine?
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-teniae coli
-huastra -epiploic appendages |
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Definition: pocketlike sacs caused by the tone of the teniae coli
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haustra
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Definition: fat-filled pouches of visceralperitoneum
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epiploic appendages
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Themucosal lining of the large intestine is ____ withmucus-producing _____.
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simple columnar epithelium
crypts |
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The bacteria in the large intestine do what 5 things?
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–Colonize the colon
–Ferment indigestible carbohydrates –Release irritating acids and gases(flatus) –Synthesize B complex vitamins andvitamin K –Constitute about 30% of the dryweight of the feces |
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_____ mix the contents and moves them slowlytoward the anus. Massmovements are strong peristaltic contractions that occur three or four times aday.
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Haustra
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Definition: elimination of feces
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defecation
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Distension of rectal walls causedby feces: stimulates contraction of the_____ and relaxes the _____. ______ moves feces throughthe sphincter. Voluntary activity regulatesmovement through the ______.
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rectal walls
internal anal sphincter reflex activity external anal sphincter |
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Definition: thebreakdown of organic molecules into their component parts
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digestion
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Definition: thebreaking of covalent chemical bonds in organic molecules by digestive enzymes
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chemical digestion
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Definition: uptakeof digestive tract contents
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absorption
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Definition: thedistribution of nutrients throughout the body
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transport
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Carbohydrate digestion begins in the ____ with _____ digesting starches. _____ finishes theprocess in the _____. Simplesugars are also broken down here.
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mouth
salivary amylase pancreatic amylase small intestine |
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Protein digestion: protein is broken down into amino acids. It begins in the _____ with _____. _____ and ______ are alsoimportant protein digesting enzymes.
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amino acids
stomach pepsin trypsin chymotrypsin |
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In lipid digestion,the ______ is the sole source oflipid digestion by _____. Lipids enter ______ and are transported tosystemic circulation via _____.
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small intestine
lipases lacteals lymph |
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Nucleic acids are broken down by _____ inthe _____.
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pancreatic nucleases
small intestine |
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In carbohydrate digestion, ____ are broken down into ____ by a number of different enzyme. These are then taken up by ____ via ____ that is powered by a Na+ gradient or by facilitateddiffusion. They are carried to the ____, where thenon-glucose sugars are converted to glucose. Glucose is transported to the cellsthat require energy.
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polysaccharides
monosaccharides intestinal epithelial cells symport liver |
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Glucose enters the cells through ____. ____ influences the rate of glucose transport.
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facilitated diffusion |
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Definition: the transformation of large lipid droplets into smaller droplets and isaccomplished by bile salts
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emulsification
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_____ digests lipid molecules to form ____ and a _____. ______ form around lipid digestion products and move to epithelial cells of the _____, where the products pass into the cells via _____. Withinthe epithelial cells, free fatty acids are combined with ____ to form ____.
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lipase
fatty acids monoglyceride micelles small intestine simple diffusion monoglycerides triglycerides |
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______ coat triglycerides, phospholipids, and cholesterol to form ______. These enter _____ within intestinal villi and are carried through the lymphatic system to the bloodstream. Triglycerides are stored in _____, converted into other molecules, or used as energy.
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proteins
chylomicrons lacteals adipose tissue |
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LDLare taken into cells by _____, which is controlled by anegative-feedback mechanism.
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receptor-mediated endocytosis
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____ transports cholesterol to cells, and ____ transports it from cells to the liver.
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LDL
HDL |
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____ in the stomach breaks proteins into smaller polypeptide chains. ____ from the pancreas produce smallpeptide chains. _____,bound to the microvilli of the small intestine, break down peptides. Tripeptides, dipeptides, and amino acids areabsorbed by ____ that is powered by a Na gradient. Aminoacids are transported to the ___, where the amino acids can be modified orreleased into the bloodstream. Aminoacids are actively transported into cells under the stimulation of _____ and _____. Amino acids are used as building blocksor for ____.
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pepsin
proteolytic enzymes peptidases symport liver growth hormone insulin energy |
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About __ liters of water enters thedigestive tract each day. It can move in either direction acrossthe wall of the small intestine, depending on the _______ across theepithelium. Epithelial cells actively transport__, ___, __, and ___ fromthe intestine. _____ move passivelythrough the wall of the duodenum and jejunum but are actively transported fromthe _____.
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9
osmotic gradients Na K Ca+2 Mg+2 chloride ions ileum |
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Themucous layer, the connective tissue, the muscles, and the secretions all tendto _____ as a person ages. Thesechanges make an older person more open to _____ and _______.
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decrease
infections toxic agents |
