GIT L3: Lower GIT Flashcards
What are 6 steps in the peristaltic contractions of the stomach (gastric emptying and mixing)?
- Contraction from fundus to antrum
- Strong contraction at the end pulls the 2 sides of the stomach and increases the pressure at the end of the pyloric valve
- Some of the food spills out “emptying”
- Pyloric valves closes
- No liquid can pass anymore
- Returning wave makes the “mixing”
What is the function of the duodenum section of the small intestine?
Juices important for absorption are released
Since the stomach only produces peptin (which absorbs protein) this part is important to absorb other nutrients
What are 2 parts of the pancreas?
- Endocrine part
- insulin and glucose
- Exocrine part
- Duct cells - secrete aqueous alkaline solution
- to balance the acidity back to neutral as the small intestine does not have the strength to sustain in such an acidic pH
- Lubrication for transport
- Acinar cells- secrete digestive enzymes important for digestion of food
- Duct cells - secrete aqueous alkaline solution
What are the 2 cells in the exocrine part of the pancreas?
- Duct cells - secrete aqueous alkaline solution
- to balance the acidity back to neutral as the small intestine does not have the strength to sustain in such an acidic pH
- Lubrication for transport
- Acinar cells- secrete digestive enzymes important for digestion of food
What do the duct cells secrete?
aqueous NaHCO3 – solution
What do acinar cells secrete?
digestive enzymes
What is the control of pancreatic aqueous NaHCO3- secretion?
What is the control of pancreatic digestive enzyme secretion?
What are 2 hormones that are produced when food will activate receptors of the wall of the duodenum?
- Secretin
- CCK
What is the importance of regulation within the GIT?
2 different inputs activate certain cell types and will produce different outcomes (that are both very important for the contra-balance of acidity and the production of enzymes needed for digestion of food)
What are pancreatic enzymes?
Zymogen granules of secretory cells contain digestive enzymes:
What are 4 digestive pancreatic enzymes?
- Proteolytic enzymes: break certain proteins apart
- Trypsinogen (inactive)
- Chemo-trypsinogen
- Pro-carboxypeptidase
- Alpha-amylase: similar to salivary amylase, breaks down carbohydrates
- Lipase: breaks down complex lipids (triglycerides)
- Nucleases: break down nucleic acids
What are proteolytic enzymes?
break certain proteins apart
- Trypsinogen (inactive)
- Chemo-trypsinogen
- Pro-carboxypeptidase
What is alpha-amylase enzymes?
- similar to salivary amylase
- breaks down carbohydrates
What is lipase?
breaks down complex lipids (triglycerides)
What are nucleases?
break down nucleic acids
What are 3 external features of the liver and gallbladder?
- Metabolic Functions
- Bile Production
- Blood circulation and filtration
What is the functional organisation of the liver?
- Blood comes in from liver
- Gets filtered
- Produced into bile
- Collected from liver and stored into gall bladde
Bile is released connected to the pancreas
What is one function of the liver in terms of the GIT?
produce & secrete bile (600-1200ml/day)
What is bile?
An alkaline solution containing bile salts, bile pigments, cholesterol, neutral fats, phospholipids, and electrolytes
Where is bile stored?
Gallbladder