1) All voluntary actions are controlled by Forebrain ( Cerebrum). 1) All reflex actions are controlled by Hind brain ( Cranial Reflex action and spinal cord ( Spinal reflex actions) 2) It may spontaneously initiate actions without any sensory stimulation. 2) It is caused by sensory stimulation e.g.
; blinking of the eyes. 3) It has slow response as cerebrum needs time to think before an action. 3) It has Fast response. 4) It makes decision about making action like controlling skeletal muscle. 4) It is not under control of will.
5) It has various responses to same stimulus. E.G; When you get hungry, you decide what to eat or if you want to eat or not. 5) It has same responses to same stimulus e.g. ; Knee Jerk. 6) raising hand when someone wants to ask question or waving at someone when saying bye bye are examples of voluntary actions.
6) Pumping of heart, blinking of eye, peristalsis movement, knee jerk are examples of reflex or involuntary actions 7) Response is based on Experience. 7) Response is quick to avoid any upcoming danger. 8) Impulse passes over to opposite side of the body. For e.
g. right side of the brain controls left side of the body and vice versa.(Steane, 2017) 8) Stimulus, Neurones, action all on same side of body. (Steane, 2017) Autonomicnervous system controls the internal environment of the body without consciousintervention and helps to control vital functions such as maintaining heartbeat,digestion, temperature, composition of blood and excretion. For e.g. when instress, heart rate, blood pressure, and blood sugar goes up, this is controlledby autonomic nervous system. The two types of autonomic nerves, sympathetic andparasympathetic, have opposite effects but balance each other most of the time.
Both nerves produce different responses in a specific organ. The sympatheticresponses prepare the body to cope at the time of stress and parasympatheticresponses assists to conserve or restore energy. (Aviva.co.uk, 2017) The autonomic nervous system controls the involuntary action orreflex action, however the voluntary action or somatic nerves works togetherwith autonomic nervous system. For e.g.
When the skin is exposed to cold air itbecomes blue, this is autonomic. At the same time impulses are sent to brainfor sensation of cold, this is somatic or voluntary action.ROLE OFAMPHETAMINES IN TRANSMISSION OF NERVE IMPULSES:Amphetamines stimulates the central nervous system, they arepsychostimulants. They speed up the transmission of nerve impulses byincreasing the presence of three chemicals in brain known as neurotransmitters.They are Dopamine, Serotonin and Norepinephrine or noradrenaline.Amphetamines brings subjective changes in consciousness and moodthat user might find pleasant (Euphoria) or increased alertness.Release of dopamine into brain gives a sense of reward and pleasurelike consuming a nice meal or when hugging your child.Increase in serotonin level will cause diminishing of painperception, aggressiveness, appetite, and sexual behavior.Norepinephrine causes body’s flight or fight response, increasingheart rate, release of glucose from energy stores etc.What normally happens is, dopamine is normally released in synapseas a result of pleasurable activities such as eating food and then is recycledby transporters back to the nerve cell and good feeling is over.Amphetamines causesincrease in dopamine levels by invading the nerve cell preceding the synapseand release extra dopamine in synapse and then prevent it from being recycledmaking the feeling lasting longer and intense