L2 Introduction to GI Physiology Flashcards
What are the mesenteries?
The mesenteries suspend the organs, supports them and keeps them from tangling. The mesenteries are a fold of the peritoneum which attaches the stomach, small intestine, pancreas, spleen, and other organs to the posterior wall of the abdomen. Also carries blood vessels, nerves and lymphatics. The fat pads cushion and protect organs.
What is the peritoneum?
A membranous tissue that lines the abdominal cavity parietal peritoneum) and the viscera (visceral peritoneum).
What is the GI blood supply?
The main blood supply to the GI tract comes from:
- SMA - superior mesenteric artery
- IMA - inferior mesenteric artery
- Coeliac artery - This branches to the hepatic artery
What is the general structure of the GI tube?
The four main levels of the digestive tube:
- Mucosa
- Submucosa
- Muscularis externa
- Serosa
This is the same structure from the mouth to the anus.
What are the types of junctions between cells?
- Occulding junction: Tight junction seals between epithelia cells
- Cell-cell anchoring junctions - adherent which connect actin fibres in one cell to those of the next
- Channel forming junctions - desmosomes connect intermediate filaments in one cell to those in the next cell
- Cell-matrix anchoring junctions: gap junctions allows the passage of small water soluble molecules from one cell to the next
What is the extrinsic nervous system?
The extrinsic nervous system is the nervous system that is external to the bowel and it consists of autonomic, sensory and motor nerves. In this step we focus on the autonomic nervous system.
What is the centric nervous system in the gut?
The myenteric and submucosal Plexi. They communicate within and between the Plexiglas. The processes extend to the target cells. This is modulated by input from the ANS.
These act on smooth muscle cells, secretory cells, endocrine cells ad blood vessels.
What are interstital cells of Cajal?
They act as the pacemaker of the GI Smooth Muscle. These cells make connections with each other and smooth muscle cells.
In what condition is there the flattening of the villi?
Coeliac disease due to a gluten intolerance
