biopsychology - y1

key assumption of biopsychologists

behaviour and activities are caused by activity in nervous and endocrine system

motor neuron

carries messages from cns to effectors (glands and muscles), short dendrites and long axons

relay neuron/ interneuron

transfers messages from sensory neurons to other interconnecting neurons or motor neurons, short dendrites and short or long axons

sensory neuron

carries messages from pns to cns, long dendrites and short axons

cns (central nervous system)

brain and spinal chord

pns (peripheral nervous system)

transmits messages via neurons to and from cns, divided into auntonomic and somatic nervous system

ganglia

cluster of neuron cell bodies located outside cns, involved in processing and transmitting nerve signals

autonomic nervous system

governs vital unconscious functions e.g. breathing

somatic nervous system

governs muscle movement, receives info from sensory receptors

endocrine system

works alongside cns and consists of glands which secrete hormones into the bloodstream

soma/ cell body

contains nucleus with genetic info

dendrites

carries nerve impulses from neighbouring neurons to the cell body

axon

carries impulses away from soma down lenght of neuron

myelin sheath

fatty layer insulating and protecting the axon, speeds up electrical transmission of impulse

nodes of ranvier

segments myelin sheath, speeds up signal transmission by forcing it to ‘jump’

terminal buttons

end of axon, communicates with next neuron across synapse

when is a neuron fired

when an action potential is caused by the change in polarity of the neuron for a split second sending an electrical impulse down the axon

summation

net effect of sum of excitatory (+ve) and inhibitory (-ve) neurotransmitters, if more +ve then cell more likely to fire but if more -ve then cell lesslikely to fire

synaptic trasmission

electrical signal arrives at synaptic terminal of pre synaptic neuron, vesicles with neurotransmitters arrive at the presynaptic membrane and fuse with it releasing the chemicals into the synaptic cleft for it to diffuse across, n.transmitters fuse with pst synaptic receptor on dendrites of next neuron, chemical message converted back to electrical impulse

reflex arc e.g. knee jerk

stimulus is detected by sense organs in pns and sends message via sensory neuron to cns, message then sent to motor neuron via relay neuron, message then sent to effector

sympathetic state

fight or flight mode, more energy produced to deal with emergency, sympathetic ns neurons linked to all parts of body to allow rapid response

parasympathetic state

rest and digest, energy conserved, relaxes us once threat has disappeared

fight or flight response

amygdala detects threat and sends message to hypothalamus, a signal is then sent to the pituitary gland to stimulate the adrenal cortex to release adrenaline, autonomic nerves allow the body to enter a sympathetic state

physiological changes associated with fof response

inhibited digestion, increased hr, bp, breathing rate, respiration, glucose synthesis