How nerve agents affect the nervous system

Nerve agents cause their toxic effects by blocking an enzyme that acts as the body’s ‘off switch’ for glands and muscles, causing them to be constantly stimulated

1

The nervous system

Electrical impulses fire all the time to activate muscle by triggering the release of a chemical called ACh

Nerve cell

Electrical

impulse

ACh

released

2

Muscle function

ACh is then broken down by an enzyme that stops muscle from becoming overstimulated

Enzyme

Pre-synaptic

cells

ACh

Impulse

created in

muscle

ACh

broken

down

3

The effects of nerve agents

The enzyme is blocked by the nerve agent and levels of ACh increase. Muscles become overstimulated and the victim rapidly loses control of vital functions

Nerve agent

molecules

ACh

Muscle

becomes

over-

stimulated

1

The nervous system

Electrical impulses fire all the time to activate muscle by triggering the release of a chemical called ACh

2

Muscle function

ACh is then broken down by an enzyme that stops muscle from becoming overstimulated

Enzyme

Pre-synaptic

cells

ACh

Electrical

impulse

Impulse

created in

muscle

ACh is

broken

down

Nerve cell

3

The effects of nerve agents

The enzyme is blocked by the nerve agent and levels of ACh increase. Muscles become overstimulated and the victim rapidly loses control of vital functions

ACh

released

Nerve agent

molecules

ACh

Muscle

becomes

over-

stimulated