Card Set Information
Anatomy Physiology Clinical
Pancreas revision for medical students
List the major arteries of the pancreas.
- Most arise from celiac trunk.
-Anterior/posterior pancreaticoduodenal arteries branch from gastroduodenal.
- Inferior pancreaticoduodenal anastomoses with SMA.
- Dorsal pancreatic from proximal splenic
- Greater pancreatic from distal splenic
- Transverse pancreatic from dorsal/greater supply inferior aspect of body/tail
At what vertebral level does the pancreas sit?
Blood tests for pancreatic function?
- Serum amylase
- Serum lipase
- FBC, U+Es, blood glucose, ABG, plasma calcium
Briefly describe the process of alcohol-induced pancreatic fibrosis.
1. Alcoholic byproducts cause pancreatic acinar cell damage.
2. This causes inappropriate trypsinogen activation.
3. Cytokine release
4. Stellate cell activation causes release of collagen and fibronectin
What enzymes are synthesised in the pancreas?
: trypsinogen and chymotrypsinogen (zymogens)
- Pancreatic lipase
Which surfaces of the pancreas are covered in peritoneum?
Anterior surface of the pancreas; the pancreas is a retroperitoneal organ.
In which types of cells are insulin and glucagon secreted from?
- Insulin is secreted from beta cells.
- Glucagon is secreted from alpha cells
- Both alpha and beta cells are located within Islets of Langerhans.
List the stages of insulin production.
N-terminus is removed to form
2. C chain of Proinsulin is removed to form
List mediators of Beta cell activation.
- blood glucose
- amino acids
- fatty acids
What physical property is required for optimal production of insulin within the islets?
- Cell-to-cell contact.
- 6 connexins form a connexon. Connexons of one cell dock to the connexon of an adjacent cell, mediated by E-cadherin.
- Result is clusters of 20-30 beta-cells producing insulin
List the 4 main types of glucose receptor and describe each.
: expressed in erythrocytes and BBbarrier.
: bidirectional transporter, expressed in liver, renal tubule, pancreatic beta-cells, s.intestine. Transports glucose, galactose and fructose into portal system from intestinal mucosa.
: Expressed in neurons
: Major transporter in muscle and adipose tissue.
How does a lack of insulin lead to ketone formation?
1. Lack of glucose entering muscle cells causes body to utilise fats as energy substrate.
2. Adipose releases triglycerides.
3. Broken down into FFAs.
4. FFAs enter liver cells.
5. FFAs are converted into fatty acyl carnitine.
6. FACarnitine is coverted into Acetyl CoA in mitochondria.
7. A.CoA > Aceloacetate > Acetone / Beta-Hydroxybutyrate
NB - Acelocetate and B-Hydroxybutyrate cause H
dissociation and result in metabolic acidosis
Why should potassium levels be checked before giving insulin to a T1DM patient?
Insulin activates the NA/K ATPa
se, causing a flux of potassium into cells.
NB - Serum potassium should be > 3.3mEq/L before initiating insulin therapy.
Briefly describe the types of insulin available for diabetic patients.
Used for premeal injection in multiple-dose regimens. These analogues act and disappear more rapidly than human insulin.
Intermediate and long-acting insulin
Action of human insulin can be prolonged with addition of zinc or protamine. Can be premixed with soluble insulin.
What are the normal blood glucose ranges, before and after meals?