Card Set Information
Where does the alimentary canal begin?
What bone does the tongue attach to?
What is the space between the lips and gums called?
What event do the teeth help with?
What parts if digestion begin in the oral cavity?
Chemical and mechanical digestion
What covers the tongue and may contain taste buds?
How does the tongue help with mastication?
Manipulates food, initiates swallowing, and permits enjoyment
Identify locations of the parotid, sublingual, and submandibular glands
What composes the alimentary canal?
Mouth, pharynx, esophagus, stomach, small and large intestines
What composes the mucosa?
Epithelium, lamina propia, and muscularis mucosae
What is the epithelium composed of?
What is the lamina propia composed of?
Areolar connective tissue
What is the muscularis mucosae composed of?
What are the main functions of the mucosa?
Secretion of enzymes, mucus, hormones, etc.; absorption if digested foodstuffs; and protection against bacterial invasion
What is the submucosa composed if?
Moderately dense connective tissue containing blood and lymph vessels, lymphoid follicles, and nerve fibers
What is the function of the submicosa?
Protection and nutrition
What is the muscularis composed of?
2 layers of smooth muscle. The inner layer runs circular and the outer longitudinal
What does the muscularis do?
Regulates motility of the GI tract
What composes the serosa?
Epithelium and connective tissue
What is the outermost layer of the alimentary canal?
What is the innermost layer of the alimentary canal?
What is the second innermost layer of the alimentary canal?
What is the 2nd outermost layer of the alimentary canal?
What does the serosa become outside the abdominopelvic cavity?
What is another name for the esophagus?
Does the esophagus have any digestive or absorptive function?
What type of muscle exists at the superior and inferior ends of the esophagus?
Skeletal muscle at the superior end and smooth muscle at the inferior end
What controls food passage into the stomach?
What is the role of the fivefold adventiva?
It anchors organs to surrounding tissues
Is the gastroesophageal sphincter a true sphincter?
What is the site of temporary storage along with chemical and mechanical breakdown of food?
How many layers of muscle are in the stomach?
3 (oblique, circular, and longitudinal)
What is the area of the stomach that surrounds the office that food enters the stomach?
What is the region of the stomach superolateral to the cardiac region?
What is the midportion of the stomach?
What is the funnel shaped region of the stomach continuous with the small intestines?
What is the concave medial surface of the stomach called?
What is the convex lateral surface of the stomach called?
What extends from the lesser curvature?
Lesser omentum (from liver to curvature)
What extends from the greater curvature?
Greater omentum (which reflects down like an apron over the abdominal contents and attaches to the transverse colon)
What are the folds in the stomach lining?
What does the oblique layer of muscle allow?
What do the gastric glands secrete?
HCl and hydrolytic enzymes
What is the primary enzyme secreted by the stomach?
Where are proteins first broken down and what is responsible?
The stomach and pepsinogen
Where does most digestive activity occur in the stomach?
How does chyme enter the intestines?
Via the pyloric sphincter (a true sphincter)
What cells are located in gastric glands?
Chief and parietal cells
What do chief cells secrete?
What do parietal cells secrete?
HCl and intrinsic factor
What type of epithelium is in the stomach?
What are the 3 subdivisions of the small intestines?
Duodenum, jejunum, and ileum
Location of nearly all nutrient absorption
What are the hydrolytic enzymes bound to the microvilli of columnar epithelial cells?
Brush border enzyme
The orifice controlled by the sphincter of Oddi
The sphincter that allows pancreatic enzymes and bile to enter the duodenum
Sphincter of Oddi
What are the areas between villi of the intestines?
Minute projections if the surface plasma membrane of lining cells.
Finger Ike projections of the mucosa
Deep, permanent folds of the mucosa and submucosa they force chyme to spiral throughout the intestines
Circular folds (plicae circulares)
Scattered mucus producing glands in duodenum
Where does any undigested residue enter the large intestines?
The ileoceal sphincter
Aggregated lymphoid follicles on small intestines (especially the ileum)
Where is the higher concentration of goblet cells?
What are the subdivisions of the large intestines?
Cecum, vermiform appendix, colon, rectum, and anal canal
What is the vermiform appendix attached to?
What are the divisions of the colon?
Ascending colon, right colic flexure, transverse colon, left colic flexure, descending colon, and sigmoid colon.
What is the end of the anal canal?
How many sphincters does the anus have?
2, external (voluntary) and internal (involuntary)
What is the longitudinal muscle layer of the muscularis reduced to in the large intestines
What causes the formation of the haustra in the large intestines?
The shortened teniae coli
What are the pocketlike sacs of the large intestines called?
What is the largest gland in the body?
What digestive role does the liver play?
What is the function of bile?
Emulsifies fats to allow for more efficient lipase activity
Where is bile held when digestive activity is not occurring in the digestive tract?
Through what does bile enter the duodenum?
Exits the liver through the common hepatic duct and enters the duodenum through the bile duct
How does bile get from the liver to the gallbladder?
What organ of the digestive system has endocrine and exocrine functions?
What hormones does the pancreas produce?
Insulin and glucagon
What type of enzymes does the pancreas produce?
What function does the alkalinity of the pancreatic juice have?
It neutralizes the acidic chyme from the stomach entering the duodenum
What is the movement that moves food along the digestive system?
Identify the arteries and veins aiding the digestive system
What fan shaped double layer of peritoneum suspends the small intestines?
What is swallowing formally called?
What is movement of material along the alimentary canal?
What is the purpose of physical digestion?
Reduce bulk, increase surface area, and allows for chemical digestion
What is the purpose of chemical digestion
Hydrolyze large complex molecules into subunits
What is the transport of digestive end products into the blood or lymph?
What type of epithelium is the esophagus?
Non-keratinized stratified squamous epithelium
What does the longitudinal smooth muscle of the muscularis externa aid in?
What does the circular smooth muscle of the muscularis externa aid in?
Segmentation (mixing action)
What does saliva contain?
Segmentation (mixing action)
What part of saliva have protective roles?
Lysozyme and IgA antibodies
What nerves control the mouth?
facial and glossopharyngeal
What area of the brain responds to taste and physical contact on the tongue?
Salivary center in brainstem
What area of the brain responds to smell and anticipation?
Higher brain centers (cephalic control)
What role does the uvula have?
Hinges upwards during swallowing to prevent food from entering the nasal cavity.
What muscles contract to push food into the esophagus?
What is reflexive relaxation?
The upper and lower ends of the esophagus remain tonically contracted unless a bolus approaches
What controls the esophageal and pharyngeals contractions of swallowing?
Where are esophageal glands located?
What do the esophageal glands do?
Secrete mucus for lubricaation and protection
What allows food into the stomach?
Gastroesophageal region (cardiac sphincter)
What is a hital hernia?
Protrusion of stomach into the thorax through weakeness in the diaphram
What problems does a hiatal hernia propose?
Increased chance of acid to enter the esophagus and impared swallowing
What layer of the alimentary canal is thicker in the stomach?
Submucosa (more mucus secreting cells)
Where are extensive gastric pits located?
Body of the stomach
What are the roles of gastric pits?
Increased surface mucosa for secretion and absorption
What does H+ do in digestion?
Activates pespinogen to the active form pepsin
How ar respiration and digestion related?
H+ are derrived from the same chemical reaction of CO
O producing carbonic acid which substitutes HCO
What is the role of mucous surface cells?
Produce mucous lining
What is the role of mucoous neck cells?
Produce alkaline mucus to protect lining from acidity
What are the hormone producing cells of the GI tract called?
Which cells compose the enteroendocrine cell group?
G-Cells, ECL cells, and D-Cells
What hormones are produced by the enteroendocrine cells?
Gastrin, histamine, endorphines, seratonin, and somatostatin
What do ECL cells do?
What do G cells do?
What does gastrin do?
Stimulates ECL and parietal cells
What do D cells do?
What does somatostatin do?
Inhibits ECL and parietal cells
What are ways the stomach prevents itself from its acid?
Tight junctions of mucosal lining cells, alkaline mucous secreted, and constant exfoliation of lining cells.
What is absorbed in the stomach?
Water, electrolytes, monosaccharides, fat soluble molecules (like alcohol)
What causes peptic ulcers?
Not protected portions of the stomach lining
Where is the greatest porportion of ulcers?
In the duodenum
What is associated with ulcers?
Where does positive stimulus for the stomach come from?
Parsympathetic division via vagus nerve
When does the gastric phase begin?
With direct response to contact of food in the stomach via pressoreceptors
What is retropulsion?
When chyme surges backwards only to be pushed forward again into the pylorus
What happens in the gastric phase?
ACh and histamine are released, chyme surges forward, retropulsion, and release of gastrin into blood due to chyme in the pylorus
What causes increased churning and pressure in the stomach?
Presence of chyme in the pylorus
When does the intestinal phase start?
When chyme enters the duodenum
What happens in the intestinal phase?
G cells secrete gastrin (start signal), gastric inhibitory peptide (GIP) secreted (stop signal)
What inhibits gastrine secretion?
What does Gastric inhibitory peptide (GIP) do?
Inhibits stomach secretion and motility to give the duodenum more time to procede before more chyme comes in
What is the enterogastric reflux?
Decreased motility and forcefully closes the pyloric sphincter
Where is the site of most digestive enzyme release and the start of intensive digestion?
What timulates the release of CCK into the blood?
Presence of fatty chyme in the duodenum
What does CCK do?
Inhibits stomach, stimulates the release of enzymes by the pancreas, and stimulates contraction of the gall bladder to release bile
What does secretin do?
Decreases acid secretion by stimulating the pancrease to release bicarbonate
What controls passes out of the pancreas through the hepatopancreatic ampulla?
Sphincter of Oddi
What do the pancreatic duct and common bile duct become?
What makes up pancreatic juice?
Lipase, Tyyrpsin, chymotrypsin, carboxypeptidase, bicaronate, and amylase
What does lipase do?
Splits emulsified fats into glycerol and fatty acids
What do trypsin and chymotrypsin do?
Breaks polypeptides into dipeptides
What does carboxypeptidase do?
Splits dipeptides into amino acids
What does bicarbonate do?
Neutralizes acid to pH 8 (level needed for activity of protease activity)
What does amylase do?
Cleaves polysaccharides into shorter chains and disaccharides
What are some intestinal enzymes (Brush Border enzymes)?
Aminopeptidase, carboxypeptidase, sucrase, lactase, maltase, and enterokinase
What do aminopeptidase and carboxypeptidase do?
Split dipeptides into amino acids
What do sucrase, maltase, and lactase do?
Split disaccharides into monosaccharides
What does enterokinase do?
activates trypsinogen into trypsin (which activates chymotrypsin and carboxypeptidase)
What in the small intestines increases surface area?
Circular folds, villi, and microvilli
What is the source of secretory cells of the mucosa in the intestines?
What role does the muscularis mucosae have in the small intestines?
Contracts to move villi and increase exposure to contents
What is the function of the colon?
Absorption of remaining water and production of feces
When does the ilececal sphincter relax?
WHen peristalsis arrives from the ileum
What is haustral churning caused by?
What is mass peristalsis?
Large movements which occur at intervals
What is mass peristalsis initiated by?
What is the gastrocolic reflex?
Stimulation of the colon due to food entering the stomach
What vitamins are produced during mass peristalis?
Vitamin K and B
What is the defecation reflex?
Involuntary relaxation of the internal anal sphincter due to mass movement then voluntary relaxation of the external anal sphincter
How are monosaccharides and amino acids absorbed?
How are large molecules absorbed?
How ar fatty acids and fat-soluble molecules absorbed?
Aggregated into micelles and diffuse into phospholipid matrix of mucosal lining cells
What is the manufacturing function of the liver?
Manufature of blood proteins, urea, and bile
What does the liver store?
Glycogen, iron, and fatu soluble vitamins A,D,E, and K
Detoxification is carried out by what organ?
The liver metabolizes proteins through what processes?
Transamination and deamination
What processes does the liver control in reguards to glycogen?
Glycogenesis (glucose to glycogen), glycogenolysis (Glycogen to glucose), gluconeogenesis (non-carb source to glucose)
What are the absorptive phases of glycemic regulation?
Glycogenesis, protein manufacture, and lipogenesis
What are the stages of the post-absorptive phase of glycemic regulation?
Glycogenolysis, lipolysis, and gluconeogenesis
What are some hormones important to nutrient processing?
Insulin, glucagon, epinephrine, and cortisol