Exam 4 - Digestive System 3 Flashcards
Forceful ejection of stomach and intestinal contents (chime) from mouth
vomiting/retching
Where is vomiting/retching integrated?
Medulla
Retching
- LOWER ESOPHAGEAL SPHINCTER relaxes while the stomach and duodenum contract spasmodically
- chime enters the esophagus but returns to stomach (DOES NOT PASS THE UPPER ESOPHAGEAL SPHINCTER)
Vomiting
when abdominal contraction FORCES UPPER ESOPHAGEAL SPHINCTER TO OPEN
Potential problems of vomiting
Chronic vomiting - may cause dangerous fluid, electrolyte, and acid-base imbalances
Aspiration - food into lungs
Sheet of mesentery that suspends the liver from diaphragm and anterior abdominal wall (separates left and right)
Falciform ligament
Remnant of the umbilical vein
round ligament (ligamentum teres)
Where does the gallbladder adhere to the liver?
adheres to ventral surface between right and quadrate lobe
G and Q go together
Porta hepatis
where vessels, ducts, nerves exit/enter liver
Functions of the liver
- bile production
- storage
- nutrient interconversion
- synthesis
- detoxification
- phagocytosis
Liver: Bile production
- Bile salts emulsify fats and are reabsorbed in the ileum
- Neutralizes and dilutes stomach acid
What do bile salts contain?
- minerals
- bile pigments (bilirubin)
- bile acids/salts (steroids)
- lecithin
Secretin
(from the duodenum) stimulates bile secretions, increasing water and bicarbonate ion content of the bile
Liver: storage
- glycogen, fat, vitamins, copper, and iron
- hepatic portal blood comes to liver from small intestine
Liver: nutrient interconversion
- amino acids to energy producing compounds
- hydroxylation of vitamin D; vitamin D then travels to kidney where it is hydroxylated again into its active form
Liver: synthesis
albumins, fibrinogen, globulins, heparin, clotting factors
Liver: detoxification
hepatocytes convert ammonia to urea (infection/decontaminant activity)
Liver: phagocytosis
KUPFFER CELLS phagocytize worn-out and dying red and white blood cells, some bacteria
Interior of liver is filled w/ tiny cylinders called
hepatic lobules
Hepatic sinusoids
lined w/ hepatic phagocytic (Kupffer) cells which REMOVE BACTERIA AND DEBRIS FROM BLOOD
What makes up the common hepatic duct from liver?
right and left hepatic ducts
What makes up the common bile duct?
common hepatic duct along w/ the CYSTIC DUCT FROM GALLBLADDER
What makes up the duodenum?
common bile duct and pancreatic duct from pancreas
Function of bladder
stores and concentrates bile
- bile backs up into gallbladder from a filled bile duct
- between meals, bile is concentrated 5-20X
What is the gallbladder stimulated by?
Cholecystokinin (from intestine) and vagal stimulation
Enterohepatic circulation
about 80% of bile acids are reabsorbed in ileum and get reused 2 or more times during digestion of average meal
- 20% THAT IS NOT REABSORBED IS BODY’S ONLY WAY OF ELIMINATING EXCESS CHOLESTEROL
Where is the pancreas located?
it is a retroperitoneal gland; posterior to stomach
Endocrine and exocrine pancreas
- secretes insulin and glucagon into the blood
- secretes 1500 mL of pancreatic juice (water, enzymes, zymogens, and sodium bicarbonate) into duodenum
Pancreatic acinar cells
secrete ENZYMES and ZYMOGENS (protease enzyme precursors) while ducts secrete BICARB to buffer HCL from stomach
Enzymes that acini secrete
Lipase (fats)
Amylase (starch)
Ribonuclease
Deoxyribonuclease
Zymogens
Chymotrypsinogen
Procarboxypeptidase
Trypsinogen
Trypsinogen is converted by to..
trypsin by enterokinase (on surface of epithelial cells)
What does trypsin convert?
Other 2 zymogens into chymotrypsin and carboxypeptidase
Where is bicarbonate produced?
in the pancreas
Cholecystokinin
released from duodenum in response to arrival of acid and fat
Secretin
released from duodenum in response to acidic chyme
