Divisions of the nervous system
§ The brain consists of the brain stem (controls basic functions like sleeping and breathing), the cerebellum (controls movement and balance) and the cerebral hemispheres (controls higher order functions like hearing, vision, memory and perception and thought).
§ The spinal cord controls reflex actions and automatic behaviours.
§ The peripheral nervous system divides into the Somatic and Autonomic nervous systems
§ The somatic nervous system controls how we feel pain, temperature, pressure etc aswell as controlling voluntary and involuntary movements.
§ The autonomic nervous systemcontrols respiration, heart rate, digestion and emotions like fear and stress.
§ The parasympathetic nervous system controls body activity such as arousal, and initial stages of sexual activity.
§ The sympathetic nervous system controls raises arousal, mobilises body in times of activity e.g. fight or flight.
Neuronal and synaptic transmission
§ Neurons are nerve cells which exist throughout the body – nervous system.
§ They communicate from neuron to neuron and to and from muscles and organs.
§ Three types – sensory (receives information from senses), relay (connects other neurons together) and motor (carry messages away from the CNS to organs and muscles).
Neurons connect to one another across a synapse, in which impulses are passed or received by other neurons or cells. Synaptic transmission allows electrical messages from one neuron to transfer an adjacent neuron.
Neurotransmitters are a chemical substance which either increase (excitatory synapse) or decrease (inhibitory synapse) the transfer of electrical impulse.
Because neurotransmitters are chemicals, they affect behaviour and mental processes. One type of neurotransmitter is serotonin – low levels can produce aggressive behaviour while an increase can cause restlessness or hallucinations.
Localisation of function
Localisation of function
§ Different areas of the brain are associated with particular physical and psychological functions.
Lateralisation of function
§ The dominance of one hemisphereof the brain for particular physical and psychological functions.
§ Left brain functions include logic, language, science and maths.
§ Right brain functions include intuition, creativity, art and music.
The human brain is made up of three concentric layers - the central core (regulates our primitive and involuntary behaviours), the limbic system (controls emotions) and the cerebrum (regulates higher mental processes).
Different functions are located in different areas of the cerebrum;
§ The frontal lobe is processes body movement and reasoning.
§ The occipital lobe processes vision.
§ The temporal lobe processes auditory information…