Digestive System Part IV: Small & Large Intestines
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
---|---|---|---|---|---|
Small intestine | organ in which most chemical digestion and most absorption occur; extends from pyloric region of stomach to cecum of large intestine; longest organ of digestive tract; subdivisions are duodenum, jejunum, ileum
π
|
||||
Duodenum | subdivision of small intestine; extends from pyloric sphincter to constitute about the first 10 inches of small intestine; receives enzymes from pancreas via pancreatic duct, receives bile from liver & gallbladder via common bile duct
π
|
||||
Jejunum | middle portion of small intestine; makes up superior left coils of small intestine
π
|
||||
Ileum | terminal (distal) and longest portion of small intestine; makes up inferior right coils of small intestine; joined to cecum of large intestine at ileocecal valve
π
|
||||
Ileocecal valve | located at junction of ileum of small intesting and cecum of large intestine; controls movement of food residue from small intestine to large intestine
π
|
||||
Hepatopancreatic ampulla | bulb formed by pancreatic duct and bile duct where they enter wall of duodenum; opens into duodenal lumen via major duodenal papilla
π
|
||||
Circular folds/plicae circularis, villi, microvilli | structural features of small intestine that greatly increase its surface area and thus account for small intestineβs extensive absorptive capacity
π
|
||||
Circular folds/Plicae circulares | circular wrinkles in small intestine lining; increase surface area for absorption
π
|
||||
Villi | about 1mm high; finger-like projections of small intestine mucosa; give it velvety appearance/feel; covered w/ layer of simple columnar epithelium; core is made of lamina propria; each contains network of blood capillaries and lymphatic capillary/lacteal
π
|
||||
Microvilli | tiny, microscopic, bristle-like projections of upper surface of mucosal epithelial cells; significantly amplify surface area of epithelial cells, thus enhancing nutrient absorption
π
|
||||
Goblet cells | in lining epithelium of small intestine; secrete a coating of mucus onto internal surface of both small and large intestine
π
|
||||
Enteroendocrine cells of duodenum | cells in lining epithelium of small intestine; secrete hormones including cholecystokinin, which stimulates gallbladder to release stored bile
π
|
||||
Cholecystokinin | hormone secreted by enteroendocrine cells of duocenum; stimulates gallbladder to release stored bile
π
|
||||
Intestinal glands/intestinal crypts/crypts of Lieberkuhn | indentations of cells in mucosa between villi; epithelial cells in these indentations secrete intestinal juice and renew mucosal epithelium by undergoing rapid mitosis and moving continuously into the villi
π
|
||||
Aggregated lymphoid nodules/Peyerβs patches in ileum | lymphoid tissue in lamina propria and submucosa of small & large intestine; keeps large numbers of bacteria in the lumen of small and large intestines from getting out of hand.
π
|
||||
Intestinal flora | normal permanent bacterial residents of intestinal lumen of both small and large intestines; produce some essential vitamins including vitamin K and some B vitamins which the intestines absorb
π
|
||||
Large intestine | larger in diameter than small intestine, but shorter; extends from ileum of small intestine to anus; absorbs water, some electrolytes, some components of bile, some vitamins; eliminates indigestible food residue as feces
π
|
||||
Ileocecal valve | located at junction of ileum and cecum; regulates movement of food residue from small intestine into large intestine
π
|
||||
Cecum, appendix, colon, rectum, anal canal | subdivisions of large intestine
π
|
||||
Cecum | sac-like beginning of large intestine in the lower, right portion of abdominal cavity
π
|
||||
Appendix (vermiform appendix) | small, worm-shaped tubular structure attached to cecum; contains lymphoid tissue to combat bacteria, but an excessive accumulation of bacteria can cause inflammation
π
|
||||
Appendicitis | inflammation of appendix due to excessive accumulation of bacteria; prone to rupture, which could cause extremely large number of bacteria to be released into abdominal cavity, which can lead to peritonitis
π
|
||||
Colon | includes ascending, transverse, descending, and sigmoid portions
π
|
||||
Ascending colon | portion of colon; from cecum extends up right side of abdominal cavity and makes turn near liver called hepatic flexure
π
|
||||
Hepatic flexure | turn of ascending colon near the liver
π
|
||||
Transverse colon | portion of colon extending horizontally across abdominal cavity from hepatic flexure to a turn near the spleen called the splenic flexure
π
|
||||
Splenic flexure | turn of transverse colon near spleen
π
|
||||
Descending colon | portion of colon; extends down left side of abdominal cavity from splenic flexure and to sigmoid colon
π
|
||||
Sigmoid colon | portion of colon shaped somewhat like sideways βSβ that extends from descending colon to rectum in posterior pelvic cavity
π
|
||||
Rectum | subdivision of large intestine; extends straight down through the posterior pelvic cavity to anal canal
π
|
||||
Anal canal | subdivision of large intestine; extends the length of about 1.5β from end of rectum to anus; surrounded by external anal sphincter and internal anal sphincter
π
|
||||
External anal sphincter | anal sphincter consisting of skeletal muscle, so can be voluntarily controlled
π
|
||||
Internal anal sphincter | anal sphincter consisting of smooth muscle; cannot be voluntarily controlled
π
|
||||
Teniae coli | three longitudinal strips along colon; contain smooth muscle, so have muscle tone and cause the colon to pouch-up into pucker-like units called haustra (sing. Haustrum)
π
|
||||
Diverticula | abnormal protrusions/outward herniations of mucosa through colon wall caused by greater exertion of pressure due to lack of fiber in diet; can result in diverticulosis or diverticulitis if inflamed or infected
π
|
||||
Defecation | involves mass peristaltic movements that move feces into rectum and anal canal, and relaxation of anal sphincters
π
|
||||
Hemorrhoids | varicosities of veins in anal canal; result from straining to defecate or deliver a baby
π
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
mbtrimm
Popular Biology sets