lower digestive tract Flashcards
body’s major digestive organ, extends from pyloric sphincter to large intestine
Small intestine
5% of the length – about 10 inches (first part)
Enzymes produces by pancreas ducted into duodenum via pancreatic ducts
duodenum
Jejunum
40% of the length – about 8 feet
60% of the length, meets large intestine at the Ileocecal valve about 12 feet
Ileum
modifications of the mucosal layer – each contains an arteriole, venule, and lymph vessel
Villi
tiny projections of plasma membrane of mucosa cells
Microvilli
deep folds of mucosa and submucosa layers
Circular folds
approx. 5 feet long, extends from Iliocecal valve to anus
Function is to dry out indigestible food by absorbing water and eliminate waste as feces
large intestine
blind sac, first part of large intestine; appendix attached here
cecum
travels up right side of abdominal cavity; ileum attached here via ileocecal valve
ascending colon
subdivisions of the large intestine
cecum
colon
rectum
travels across abdominal cavity; bends at liver (hepatic flexure) and spleen (splenic flexure)
transverse colon
travels down left side of abdominal cavity and enters pelvis; spleen to iliac crest
descending colon
after entrance to pelvis becomes S-shaped
Sigmoid colon, rectum, and anal canal are in pelvis and end at the anus
sigmoid colon
transverse folds/valves slow down feces(to reabsorb water) & hold it until defecation; 2 sphincters – internal = smooth muscle, external = skeletal muscle
rectum
large, continuous sheet of serous membrane; covers digestive organs
Peritoneum
lines the walls of the entire abdominal cavity
parietal layer
visceral layer
forms the serous outer coat of the organs
fan-shaped projection of the parietal peritoneum
Allows free movement of each coil of the small intestine; helps prevent strangulation of the intestine
Mesentery
a continuation of the serosa of the greater curvature of the stomach; first part of the duodenum to the transverse colon
Deposits of fat; help insulate, cushion, and protect abdominal organs
Greater omentum
liver to lesser curvature of stomach & first part of duodenum
Lesser omentum
largest gland in the body
liver
Four lobes and suspended from diaphragm by mesentery cord =
Falciform ligament
anatomical units of the liver, tiny hexagonal or pentagonal cylinders
Hepatic lobules
produced in lobules - yellow-green watery solution containing bile salts (emulsify fats), pigments, cholesterol, phospholipids, and electrolytes
travels through canaliculi to join bile ducts
bile
liver right lobe
5/6
right lobe proper
caudate lobe
quadrate lobe
liver left lobe
no subdivisions
each lobe has a branch of hepatic vein in center
detoxification
bile secretion
metabolism
storage (minerals& vitamins)
protein synthesis
functions of the liver
exocrine and endocrine glands
exo> endo
pancreas
digestive enzymes
pancreatic juices
digestion of carbohydrates
pancreatic amylase
digestion of fats->triglycerides-> glycorol+ fatty acids
lipase
digestion of proteins
->amino acids
Trypsin and Chymotrypsin
nucleases
break down DNA and RNA
sodium bicarbonate
neutralize pH
disorders of liver and pancreas
Hepatitis-inflammation of liver
Cirrhosis
Pancreatitis- inflammation of pancreas
Pancreatic cancer
