Cholinergic system and cholinesterase inhibitors

Key Concepts Cholinesterase inhibitors are a class of compounds that includes chemical warfare nerve agents and certain insecticides. Fatalities occur mainly due to effects on respiration due depression of respiratory drive, paralysis of muscles of respiration, bronchoconstriction, and airway obstruction from profuse respiratory tract secretions. Treatment includes the use of atropine, 2-PAM, diazepam, and aggressive supportive care. About This and Other Case Studies in Environmental Medicine This educational case study document is one in a series of self-instructional courses designed to increase the primary care provider's knowledge of hazardous substances in the environment and to promote the adoption of medical practices that aid in the evaluation and care of potentially exposed patients.

The human nervous system consists of two main parts, the central nervous system CNS and the peripheral nervous system PNS.

The CNS contains the brain and spinal cord. The PNS includes the motor neurons that are responsible for mediating voluntary movement. The PNS also includes the autonomic nervous system which encompasses the sympathetic nervous system, the parasympathetic nervous system, and the enteric nervous system.

The sympathetic and parasympathetic nervous systems are tasked with the regulation of all involuntary activities. The enteric nervous system is unique in that it represents a semi-independent part of the nervous system whose function is to control processes specific to the gastrointestinal system.

The nervous systems of the body are composed of two primary types of cell: Two important concepts relate to the functioning of the nervous system. These terms are efferent and afferent.

Efferent connections in the nervous system refer to those that send signals from the CNS to the effector cells of the body such as muscles and glands. Efferent nerves are, therefore, also referred to as motor neurons.

Afferent connections refer to those that send signals from sense organs to the CNS. For this reason these nerves are commonly referred to as sensory neurons. Another important cellular structure in nervous systems are the ganglia. The term ganglion refers to a bundle mass of nerve cell bodies.

In the context of the nervous system, ganglia are composed of soma cell bodies and dendritic structures. The dendritic trees of most ganglia are interconnected to other dendritic trees resulting in the formation of a plexus.

In the human nervous system there are two main groups of ganglia. The dorsal root ganglia, which is also referred to as the spinal ganglia, contains the cell bodies of the sensory nerves.

The autonomic ganglia contain the cell bodies of the nerves of the autonomic nervous system. Nerves that project from the CNS to autonomic ganglia are referred to as preganglionic nerves or fibers.

Chapter 13 - Synapses

Conversely, nerves projecting from ganglia to effector organs are referred to as postganglionic nerves or fibers.

Generally the term ganglion relates to the peripheral nervous system. However, the term basal ganglia also basal nuclei is used commonly to describe the neuroanatomical region of the brain that connects the hypothalamus, cerebral cortex, and the brainstem.

Neurons Neurons are the highly specialized cells of all nervous systems e. These cells accomplish this role through specialized membrane-to-membrane junctions called synapses. Most neuron possess an axon which is a long protrusion from the body soma of the neuron to the synapse. Axons can extend to distant parts of the body and make thousands of synaptic contacts such as is the case with the CNS neurons of the spinal cord.

Axons frequently travel through the body in bundles called nerves. The synapses are termed pre-synaptic and post-synaptic.

The pre-synaptic synapse will release secretory granule contents in response to the propagation of an electrochemical signal action potential down its axon.

The released substance termed a neurotransmitter will then, most likely, bind to a specific receptor on the membrane of the post-synaptic synapse, thereby, propagating the initial action potential to the next neuron. The human nervous system is composed of hundreds of different types of neurons.Correspondingly, cholinesterase inhibitors have been developed both as therapeutics and as neurotoxic agents, in chemical warfare and as agricultural insecticides.

Exposure to anti-ChE results in cholinergic hyperexcitation and modified levels and composition of cholinesterases with multisystem acute effects that can be lethal or result in long. MATERIAL SAFETY DATA SHEET Ficam® W Insecticide Date of Issue: September 13th, 4.

List of Cholinesterase inhibitors:

FIRST AID MEASURES If poisoning occurs, immediately contact a doctor or Poisons Information Centre (telephone 13 11 26), and. Cholinesterase inhibitors (also called acetylcholinesterase inhibitors) are a group of medicines that block the normal breakdown of acetylcholine.

Acetylcholine is the main neurotransmitter found in the body and has functions in both the peripheral nervous system and the central nervous system. For. Therapy targeting the cholinergic system: Cholinesterase inhibitors have observed the failure of the ascending cholinergic system of the brain.

There are both marked reduction and neuronal dropout in synaptic densities in the projections from cholinergic neurones located in substantia innominata of.

The cholinergic toxidrome represents the acute phase of cholinesterase inhibitor poisoning. It results from the accumulation of excessive levels of acetylcholine in the synapses, glands, smooth muscles, and motor end plates where cholinergic receptors are found.

Cholinesterase Inhibitors: Including Insecticides and Chemical Warfare Nerve Agents Part 4: The Cholinergic Toxidrome Section Laboratory Assessment of the Cholinergic Toxidrome Direct Measurement of Cholinesterase Inhibitors and Their Metabolic Byproducts.