FINAL: Lower GI Tract Flashcards
What is the difference between exocrine and endocrine
exocrine glands secrete substances into a ductal system to an epithelial surface, endocrine glands secrete products directly into the bloodstream
What is the exocrine function of the pancreas
Pancreatic enzymes (acinar cells)
- involved in the GI tract, attached directly to the pancreatic duct
What is the endocrine function of the panreas
Hormones (islets of Langerhans)
- do not attach to pancreatic duct, release insulin/glucagon directly into the capillaries
What are the pancreatic hormones that function to balance glucose levels in our body
Insulin and glucagon
How does insulin balance glucose levels in the body
- it is released in response to high blood glucose levels
- stimulates cells to take up glucose for use
- stimulates liver to store additional glucose as glycogen
Fed stage - think glucose is IN
What is glycogen
The storage form of sugar in between meals
How does glucagon function to balance glucose levels in our body
- it is released in response to low blood glucose
- stimulates release of stored glucose
Think glucose is GONE
What is diabetes
A disease defined by high levels of blood glucose
What is type 1 diabetes
Total lack of insulin production
- usually an autoimmune attack on the pancreas
What is type 2 diabetes
Insulin resistance ( problem with cell signaling and cell receptors)
- pancreas still releases insulin
What is the function of the large intestine
Reabsorption of water and salts, resulting in feces
About 1.5 meters long
What are the four regions of the large intestine
Ascending (includes cecum and appendix)
Transverse
Descending
Sigmoid
What are the structures that help with muscle contractions to move feces
Tenia coli: longitudinal bands (muscularis)
Haustra: sacs/pockets
Epiploic appendages: lobules of fat
What is the appendix
Vermiform (worm-shaped) tube, role in immune system of the gut
what is the cecum
The wider section of the ascending colon
What happens in the large intestine?
- digestive tract receives about 9 liters of water a day - only about .2 liters are lost in feces
- process relies on osmosis
- more solute (ions and proteins) in tissue and blood rather than in lumen
- water diffuses from lumen into tissues and blood
- many diseases disrupt this function
What are gut microbiome and their function
- the microorganisms found in our gut
- they change throughout life
- can be impacted by genetics and the environment
- major function is secretion of metabolically important molecules
What is the function of the rectum
Holds feces until defecation
What is the function of the anal canal and how does it work
Feces gets passed through the anal canal during defecation
Anal canal is controlled by two sphincters
- internal -> involuntary
- external -> voluntary
Mucosa layer is stratified and produces extra mucus during defecation
