8.4 Flashcards
How does smooth muscle stretch influence the likelihood of AP generation?
The more stretched smooth muscle is, the closer its resting potential moves to threshold, making it easier for contraction to occur
Does feeding inhibit or promote motilin release?
Inhibit
What does motilin control? What is that?
- Migrating motility complex
- Waves of peristaltic contractions that sweep along the small intestine during fasting,
How does the intensity of MMC contractions change during the three phases?
Becomes more intense, lasting shorter time per phase
What is the function of the salt and mucus solution that small intestine endocrine glands release?
- Protection
- Lubrication
Briefly describe carbohydrate digestion
- Polysaccharides broken down by salivary and pancreatic amylase
- Disaccharides broken down by corresponding enzyme (LMS)
- Glucose and galactose monomers actively enter the cell via SGLT symporter, fructose passively by GLUT-5
- Leave by facilitated diffusion through GLUT-2, enter capillary
Briefly describe protein digrestion
- Pepsin and pancreatic proteases digest proteins into AAs and peptides
- Enter cell via active transport
- Aminopeptidases and intracellular peptidases break down peptides further in cell
- Amino acids diffuse out of cell into bloodstream
Briefly describe lipid digestion
- Large globules emulsified by bile salts
- Pancreatic lipase hydrolyses into fatty acids and triglycerol
- Micelles carry these product to cells, where they are released and diffuse in
- Synthesised back into triglycerides
- Packed into lipoprotein chylomicrons
- Enter central lacteal, where they drain into the bloodstream
What type of enzymes does the pancreas release?
Pancreatic:
- Amlyase
- Protease
- Lipase
What are the pancreatic proteases?
- Trypsinogen
- Chymotrypsinogen
- Procarboxypeptidase
Where are cck and secretin released from?
Duodenum
What does CCK prompt the pancreas to release?
DIgestive enzymes
What does secretin prompt the pancreas to release?
Bicarbonate rich solution
Where are bile salts mostly recycled?
Terminal ileum
Which enterogastrone stimulates bile release?
Secretin
