The Enteric Nervous System PDF

The enteric nervous system 22 November 2024 11:12 The enteric nervous system is a division of the autonomic nervous system, which innervates the GIT (and pancreas and biliary system), and is responsible for many important functions. This innervation is **intrinsic**, meaning it can function indep...

The enteric nervous system 22 November 2024 11:12 The enteric nervous system is a division of the autonomic nervous system, which innervates the GIT (and pancreas and biliary system), and is responsible for many important functions. This innervation is **intrinsic**, meaning it can function independently, however it does communicate with the brain and CNS for particular functions. It is made up of a network of sensory, motor and inter-neurones which communicate with receptors and effectors via 2 main plexuses of ganglion cells and their fibre bundles - - -------------------------------------------------------------- ----------------------------------------------------------------------------------- A diagram of a structure Description automatically generated  -------------------------------------------------------------- ----------------------------------------------------------------------------------- ### **Components of enteric nervous system** **Sensory (afferent) neurones**: - - - **Interneurones** - **Secretomotor (efferent) neurones** - - **Enteric reflexes** -------------------- These reflexes are called **short reflexes**, as the nervous component of these reflexes is contained within the gut, they do not need the CNS. ### **Motility reflex** This reflex allows **peristalsis** - the rhythmic movement of food along the GIT. The **myenteric plexus** co-ordinates this reflex. 1. 2. 3. 4. 5. A diagram of relaxation and relaxation Description automatically generated ### **Secretory reflex** This reflex allows release of chemicals into the stomach and small intestine lumen to aid in food digestion. It is co-ordinated by the **submucosal plexus**. 1. 2. 3. ### **Blood flow reflex** We don't know as much about this. Involves both plexuses. 1. 2. 3. ### **Integration with the CNS** The ENS can send information to the brain, and the brain can send information back. Actions involving these can therefore be considered **long reflexes**. - - - - - **Enteric nervous system disorders** ------------------------------------ Enteric nervous system function decreases with age, as a result of death of neurones over time. There are ENS specific disorders, as well as other disorders that also affect the ENS. ### **ENS-specific** - - - ### **General neurological disorders.** **Parkinson's disease** - - - **Peripheral neuropathies** - **Myasthenia gravis** - ### **Disorders of gut-brain axis:** **IBS (irritable bowel syndrome)** - - - ### **Drugs which target ENS** - - - - -