Midterm 2: Liver, Gallbladder, Pancreas, Spleen Flashcards
pear shaped organ adjacent to inferior-posterior surface of the liver
Gallbladder
What is the lumen of the gallbladder lined with?
Simple columnar epithelium
main function of the gallbladder
store bile that is produced by the liver
What is the flow of bile from the liver to the gallbladder?
hepatic ducts → common hepatic duct → juncture of cystic duct and common bile duct (or just ‘bile duct’) → cystic duct → gallbladder
Flow of bile from the liver to the duodenum of the small intestine
hepatic ducts → common hepatic duct → bile duct → hepatopancreatic ampulla → duodenal lumen
What kind of secretions does the pancreas have?
Both exocrine and endocrine
Describe the exocrine secretions of the pancreas
Secreted directly into the ducts.
Secreted in their inactive form (prohormones = zymogens)
Enzymes secreted are proteases, pancreatic lipase and amylase, and nucleases (RNA/DNA digestion), and HCO3- secretions
Where is the spleen located?
upper right quadrant of abdominal cavity
Where does the spleen get its arterial blood?
splenic artery, one of the three main branches of the celiac trunk
Where does the spleen drain its blood?
hepatic portal system
Spleen function
Filters worn out RBC and breaks down heme from the hemoglobin to produce bilirubin. Sends it to the liver through the hepatic portal system vasculature then gets excreted by the body through feces or urine
What are the endocrine secreting cells in the islets of Langerhans od the pancreas? What do they secrete?
Alpha cells: glucagon
Beta cells: insulin
Delta cells: somatosatin
Gamma/PP cells: pancreatic polypeptide
Describe the alpha cells in the pancreas.
- Endocrine
- Synthesize glucagon which then passes through portal circulation to the liver where its binds to receptors on the hepatocytes that line the sinusoids of the liver lobule; the hepatocytes then convert glycogen to glucose; glucose then is released into circulation that ultimately results in increased blood sugar levels.
Describe the beta cells in the pancreas
Endocrine
Synthesize insulin which has an opposing effect on blood sugar levels compared to glucagon; these cells are, by far, the most numerous within the Islets.
Describe the delta cells in the pancreas
Somatostatin production which inhibits both synthesis of glucagon and insulin within their respective cells of the Islets.
Describe the gamma/pp cells in the pancreas
Inhibits exocrine function via pancreatic polypeptide (PP); rarest of the cell types within the Islets.
Where is the liver located?
upper right quadrant of abdominal cavity with portion of left lobe crossing mid-line into the upper left quadrant
Lobes of the liver
4 lobes. Right Left Caudate Quadrate
How is the liver suspended in the abdominal cavity?
By 2 peritoneal ligaments.
The falciform ligament attaches the liver to the anterior wall of abdominal cavity and attaches a small portion to diaphragm.
The coronary and triangular ligaments attach liver to the diaphragm
What is the the round ligament on the liver?
located at inferior edge of falciform ligament and is remnant of umbilical vein.
What enters at the hilum/ portages hepatis on the liver?
Portal vein, hepatic artery, hepatic ducts
Flow of venous, arterial, and bile flow in the liver
venous and arterial blood enter the liver while bile flow in the hepatic duct runs countercurrent
Describe the lobules of the liver
- Hexagonal-shaped functional unit of the liver with the portal triad located at the corners of the hexagon; the portal triad contains:
1) vein (a distal branch of the portal vein)
2) artery (a distal branch of the right and left hepatic artery)
3) bile duct (a small branch which, when combined with other similar ducts, will eventually form the hepatic ducts)
What are the sinusoids of the liver? What are they lined with? Describe
- Vascular channels (discontinuous capillaries) contains venous blood from portal circulation and arterial blood from the hepatic artery,
- Lined mostly with hepatocytes, but also contain phagocytic Kuppfer cells. The sinusoid nearest the periphery of the lobule is the most oxygenated while the center of the lobule contains blood that is more deoxygenated. At the center of the lobule, a central vein collects venous blood and eventually returns it to the inferior vena cava via the hepatic vv.
