#21 Lower Digestive System Flashcards
functions of small intestine
Majority of chemical digestion occurs here
Digestive enzymes from pancreas
Bile from liver emulsifies (breaks down) fat so it can be chemically digested as well as protein and carbohydrates so we can absorb nutrients
Nutrient absorption
circular folds small intestine
plicae circulares (larger structure made up of Villi)
Act as speed bumps, can slow propulsion of food material
duodenum
begins at pyloric sphincter, extends to jejunem
Major duodenal papilla entrance of common bile duct
10-12 inches in length
Villi
2 Villi, domed structures, lined by simple columnar epithelia
Covered with simple columnar epithelium
Blood vessels and lacteals found internally
Goblet cells line epithelial with mucous
Intestinal crypt: at bottom of space between villi, filled with fluid secreted by cells within it that produce enzymes, ions. Helps with digestion and keeps material moist
microvilli
On apical surface of villar cells
Called the brush border
Contain brush border enzyme
Tethers enzymes to it
Increases surface area
Contain lacteals that allow the passage of fatty material that has been absorbed
functions of large intestine
Absorbs water and electrolytes
Forces feces toward rectum
rectal valves
Transverse folds
Separate feces from gas
internal anal sphincter
Smooth muscle
Involuntary
external anal sphincter
Skeletal muscle
Voluntary
anal sinuses
Produce mucus to lubricate anal canal to help with defecation
exocrine functions of the pancreas
acinar cells produce digestive enzymes and secrete them through pancreatic ducts
endocrine functions of pancreas
pancreatic islets produce the hormones insulin and glucagon
hepatocytes (part of hepatic lobule)
individual cells that form and make up lobule
sinusoids
part of hepatic lobule capillaries picks up proteins like albumin and globulin and carries them to central vein
bile canaliculi and ducts
part of hepatic lobule takes bile away from central vein and to bile ducts that go to hepatic duct and then to cystic duct
gallbladder function
Stores and concentrates bile
biliary tract function
carries bile to the duodenum (formed by right and left hepatic ducts )
peritoneal cavity
lined by serous membranes
intraperitoneal organs
stomach
Jejunum and ileum
Transverse and sigmoid colon
Appendix
Liver
Spleen
retroperitoneal organs
Most of the duodenum
Ascending and descending colon
Rectum
Pancreas
kidneys
mesenteries
Double layer folds of the peritoneum that suspend and support intraperitoneal organs
Include the:
greater omentum
Lesser omentum
Mesentery proper attaches small intestine to body wall
Mesocolon
hernias
Movement of small intestine out of normal place and into other parts of body
inguinal hernia
Intestines push through inguinal canal
More common in males
femoral hernia
intestines push through the femoral triangle
more common in females
hiatal hernia
stomach pushes through the esophageal hiatus
umbilical hernia
intestines push through the rectus abdominis
appendicitis
Fecal matter obstructs the appendix
it swells and bursts if untreated
intestinal obstruction
Any hindrance to movement of chyme or feces through the intestine
inflammatory bowel disease
Periodic inflammation of intestinal wall
Symptoms include cramping, diarrhea, weight loss, intestinal bleeding
colorectal cancer
Second most common cancer
Colonoscopy
liver cirrhosis
Liver cells are destroyed and replaced by connective tissue
Most commonly caused by alcoholism
Results in jaundice (yellowing of skin) and toxin buildup in blood
Treatment is a liver transplant
viral hepatitis
Inflammation of liver
Flu-like symptoms and jaundice
gallstones
Crystallization of cholesterol or calcium and bile salts
peritonitis
Inflammation of the peritoneum
