general brain structure AO1s

• brain structure general

  Thalamus = receives info from senses, passes it on to appropriate cortex area, acts as a 'gate' of inf, has role in sleep and wakefulness

  Cerebellum = coordinates posture, balance and movement, receives and integrates info from spinal cord

  Corpus Collosum = dense collection of nerve cells, physically connect the two brain hemispheres = allows communication between them

  Limbic System = amygdala and other structures, role in regulating emotional responses and memory

  Hypothalamus = controlls motivational behaviour, role in stress response, maintains balance on bodily functions, homeostasis

  Frontal Lobe = front of brain, 40$ of cerebral cortex, controls high level cognitive functions eg thinking and problem solving, has motor cortex control

  Parietal Lobe = contains somatosensory cortex, processes sensory info from skin

  Occipital lobes - back of brain, contains visual cortex, deals with visual info

  Temporal Lobe = contains auditory cortex, deals with sound info, processes location volume and pitch of sounds, role in understanding language
• CNS and NTs general

  . Neurons = nerve cells which carry 'messages' as electrical or cehmical signals

  - dendrite = carry impluses from neighbouring neurons to cell body

  - axon = carries impulses down length of neuron

  - myelin sheath = fatty layer that covers and protects axon, speeds up electrical impulses

  - terminal button = where NT is released

  . Sensory Neuron = carries messages from sensory receptors to CNS

  . Motor = carries messages from CNS to effectors

  . Relay = connect sensory and motor neurons together

  . messages within a neuron are transmitted electrically, between neurons are transmitted chemically
• CNS and NTs - action potential

  at rest neuron is negatively charged inside, when sufficiently activated by a stimulus it becomes + charged for split second (depolarisation, this creates an electrical impulse (action potential)
• CNS and NTs - synaptic transmission

  . neurons are separated by a synaptic cleft

  1) process starts with an action potential - electrical impulse triggers release of NTs from vesicles in axon

  2) NTs diffuse as chemicals across the synapse

  3) fit into the matching receptor sites on the post synaptic neuron and signal gets converted back to electrical

  4) NTs remaining in synapse are reabsorbed into presynaptic neuron (reuptake) and process repeats