nervous system

The nervous system

Recap

• What causes eczema? Irritance (creams, soaps,scents), food allergies, 

• What might treat it? Emollient - barrier/moisturiser,(topical) steroid cream, steroid tablets, UV therapy 

• How might it affect someone's mental health? Chronic (long term), poorly

Nervous system is split into 2 - central(brain and spinal cord) and peripheral(rest of body)

Peripheral is split into autonomic (subconscious and uncontrollable) and somatic (controllable)

Autonomic nervous system - sympathetic (arousal- heart speeding up) and parasympathetic division (rest - slowing body down)

Somatic nervous system - sensory(input) and motor(output)

CNS

PNS

• This part of the nervous system can sustain more damage 

• This part of the nervous system is autonomic

• Made of the brain, brainstem and spinal corn

• This part is parasympathetic and sympathetic 

• This part of the nervous system is responsible for receiving sensory information

• Is responsible for processing sensory information 

• This part is somatic 

• Made of sensory, relay and motor neurons 

Neural pathway

Input - receptor (pns)- sensory neuron (pns)- Brain (cns)- spinal cord (cns)- relay neuron (cns)- motor neuron (pns)- effect

If it is a reflex action it misses out the brain and spinal cord

Reflexes : 

• Knee jerk

• Pupil reacting to light

• Pain avoidance 

Nervous system

Both

Endocrine system

• Uses electrical and chemical messages

• fast

• Works autonomously

• Processes outside stimuli to produce a response 

• Uses chemical messages

• slower

When an electrical impulse reaches the axon terminal it cannot jump across, it reaches vesicles holding neurotransmitters. The vesicles travels to the end of the axon and move across the synapse 

Action potential

• The neuron i usually negative due to a high concentration of Na-

• In order to send an electrical impulse the polarity (whether it's + or -) must change 

• When the dendrites receives a neurotransmitter the parts of the cell takes in an influx of K+ ions which makes its positive

• They immediately leave the first area which goes back to being negative but the positive K+ ions travel down the cell

Parkinson's Disease

Symptoms:

• Loss of nerve cells 

Causes:

• environmental factors:

- head injury

- area of residence

- occupation 

- exposure to metals

- solvents and PCB’s

- pesticide exposure 

• Gender - males

• Genetic links 

Stage 1 - Tremors on one side of the body, changes…