Digestive System

Total Flash Cards » 45
Text Size: S | M | L
What are 4 functions of the digestive system? 1. ingestion- food/liquid enter digestive tract, 2. mechanical processing- chewing, churning, mixing, 3. digestion-chemical, enzymatic breakdown of food, 4. secretion-by glandular accessory organs
And the other 4 functions? 5. Absorption-organic molecules, electrolytes, vitamins, 6. compaction-dehydration of indigestible materials, waste; 7. excretion- waste products secreted into the digestive tract; 8. defecation-elimination of fecal material from the body
What is the histology (tissue) of the digestive tract? mucosa, submucosa, muscalaris externa, serosa
What is the mucosa made up of? Mucosal epithelium, lamina propia, and muscularis mucosa. Plica folds the mucosa so it can absorb more
What is the submucosa made of? areolar tissue surrounding musclaris mucosa, contains blood vessels, lymphatics, exocrine glands
What is 'Peristalis'? Process which moves bolus by wavelike contractions in the musclaris externa, circular and longitudinally oriented muscles,
What is segmentation Process whereby the circular muscles of muscalaris externa churn and mix the bolus to break it up
What makes the stomach growl? Peristalis begins two hours no matter what after you eat, except now the digestive tract is empty
What is the difference between the parietal and and visceral peritoneum? Parietal peritoneum is on the inner lining of the digestive tract's body wall, visceral peritoneum/serosa is located on the outer lining of the tract
Mesentaries? fused, double sheets of peritoneal membrane
Locations of the specific mesentaries? lesser omentum- lies between stomach and liver, greater omentum- "fatty apron" that hangs beneath the stomach, disgusting looking; Mesentary proper-suspends and wraps most of the small intestine; Mesocolon- suspends and wraps part of the large intestine
What are the functions of the mesentary? stabilize the organs and provide access routes for veins, arteries and nerves to the digestive tract
Intraperitoneal organs stomach, liver, jejunum, ileum, transverse colon, sigmoid colon, appendix
retroperitoneal organs (fused with posterior abdominal wall doudenum, pancreas, ascending colon, descending colon, kidneys, adrenal glands
Digestive functions of the oral cavity analysis of ingested products (tongue), mechanical processing (chewing), lubrication, digestion of carbohydrates
What are the three salivary glands and where are they located? 1) Parotid salivary glands-deep in the head 2)sublingual-under the tongue 3)submandibular-in the jaw area under sublingual
1st phase of swallowing Buccal phase- compression of bolus against hard palate, elevation of soft palate and retraction of tongue
2nd phase of swallowing pharyngeal phase- bolus contacts posterior pharyngeal wall, elevation of larynx, folding of epiglottis
3rd phase of swallowing esophageal phase- opening of upper esophagal sphincter, peristalsis, opening of lower espohagual sphincter
Functions of the stomach
1. bulk storage, 2. mechanical breakdown of digested foods 3. chemical digestion begins 4. beginning absorption of water, aspirin, alcohol
define rugae longitudinal folds in the mucosa that allow the expansion of the gastric lumen
What are the four types of cells located in the stomach? mucous, parietal cells break down acids, Chief cells=pepsinogen, Enteroendocrine cells=gastrin (hormone)
Define peptic ulcer a sore or hole in the lining of the stomach caused by bacteria
What are the sections of the small intestine doudenum (10in) Jejuneum (8ft) ileum (12ft)
functions of the doudenum the "mixing bowl', recieves chyme from the stomach and digestive enzymes (bile) from pancreas and liver
functions of jejunuem where bulk of chemical and nutrient absorption takes place
functions of ileum controls flow of material into the large intestine
small intestine secretions goblet cells-secrete mucous; enteroendocrine cells-secrete many hormones
divisions of the large intestine 1) Cecum 2) colon=ascending, transverse, descending, sigmoid 3) rectum=anal canal and anus
large intestine functions 1) reabsorption of water and electrolytes 2) compaction of intestinal contents into feces 3) absorption of vitamins 4) storage of fecal material before defecation
define epiploic appendages fat pouches that hang off the large intestine
define Haustra sacules between bands of circular muscles are accentuated taenia coli muscle contractions
movement through the large intestine 1) slow passage of material through with Haustral Churning 2) periodic mass movement via powerful muscle contractions 3) distension of rectal wall to stimulate conscious urge to defecate
define difference between Internal and External anal sphincter Internal- involuntary smooth muscle External- voluntary smooth muscle whose relaxation allows for defecation
define diverticulitis inflammation of abnormal pouches (diverticulum) that are not even normally found in the large intestine
Functions of the liver performs 200+ functions relating to 1) metabolic regulation 2) hematological regulation=blood reservoir and filter/remover of dead blood cells and 3) bile production
How is bile drained from the liver? drained through right and left hephatic ducts into the common hephatic duct
where does bile emanate after a fatty meal is eaten comes from gallbladder (where it's stored) by way of common bile duct which empties into the doudenum. helps facilitate breakdown of lipids
define hephatic portal system blood flowing from veins in digestive system drain into the liver by way of the hephatic portal vein, blood is then filtered by sinusoids
define cirrhosis of the liver destruction of hepatocytes, often due to alcohol
functions of the pancreas 1) exocrine secretion- secretion of pancreatic juice to aid in digestion 2) secretion of hormones to regulate blood sugar levels by way of Islets of Langerhans, hormones=insulin and glucagon
What are the 3 unpaired branches of abdominal aorta that supply blood to the digestive tract? 1) Celiac trunk 2) Superior mesenteric artery 3) Inferior mesenteric artery
What does the celiac trunk supply? stomach, liver, gallbladder, pancreas, spleen, and part of the doudenum
What does the Superior Mesenteric artery supply? most of the doudenum, jejunuem, ileum, cecum, appendix, ascending colon, and 1/2 of the transverse colon
What and where is the appendix? tube connected to the cecum of the large intestine-has no real purpose