Nervious System

 

Dear sir/madams a the Great Western Ambulance Service,

                                                                                                        I am writing this letter to tell you about the central nervous system. Your brain monitors all unconscious proses such as breathing, heart rates and digestions and controls all voluntary movement within the body. The cerebellum controls all movement within the body and make sure that the skeletal structure stays straight and up right. The nerves out side the CNS (central various systems) ‘peripheral nervous system’ this sends a message back from the CNS to millions of sells within the body that has sense of smell, taste, touch and movement.

Motor Neurones are made up of 3 main areas

1.The cell body containing the nucleus and mitochondria.

2. The dendrites, which are highly branched extensions of the cytoplasm extending from the cell body within the grey matter of the spinal cord.

 3. The axon, this is the long body of the motor neurone that emerges from the spinal cord and its main function is the transmission of the nerve impulses along the myelin sheath.

·         Motor units are made up of the motor neurone and all of the muscle fibres that it is attached to.

·         The nerve impulse bounces along the myelin sheath, the thicker the myelin sheath is the faster the nerve impulse travels.

·         Eventually the impulse reaches the motor end plate within the muscle cells.

·         All or none- once the motor unit has been activated all of none of the muscles fibres will contract.

Varying the frequency of the stimulus, the higher the frequency (i.e the more messages being sent the stronger the contractions)

Varying the number of units recruited (i.e the more unit the stronger the contractions)

Your sincerely Sam Callaghan