unit 3 AOS 1 psychology

• Dendrites: detects and receives information from other neurons. Receptors located on them to receive information from surrounding neurons.
• Soma: dendrites pass information to the neuron's soma (cell body). the soma integrates this information and then either the neuron fires an action potential or does not fire an action potential. the soma may collect and integrate information from thousands of other neurons
• Axon: a single tube-like extension that transmits neural information to other neurons, they can vary in size from the width of a single strand of hair to over 1m long.
• myelin sheath: A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.
• axon terminals: store and secretes neurotransmitters, which carry the neurons chemical message to other neurons.
• sensory neurons: carry information from sensory receptors, muscles, and internal organs to the CNS
• motor neurons: carry instructions from sensory receptors, muscles and internal organs to the CNS
• interneurons: create connections between sensory and motor neurons, and relay messages from one type of neuron to another type of neuron. only exists in the CNS.
• neurons: specialised nerve cells that receive, process, and transmit information to other cells within the body. messages in the nervous system are carried via neurons.
• peripheral nervous system: The peripheral nervous system is made up of all nerves located outside the CNS, include the cranial nerves that extend from the spinal cord and brain.
• somatic nervous system


  controls voluntary movements of skeletal muscles
• autonomic nervous system: the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.
• sympathetic nervous system: the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations
• parasympathetic nervous system: the division of the autonomic nervous system that calms the body, conserving its energy
• conscious response: Deliberate and voluntary actions that are intentionally initiated by the brain and performed by the body
• unconscious response: A reaction that does not involve awareness at the time of the response. Involuntary, unintentional, automatic and cannot control its occurrence
• spinal reflex: An unconscious, involuntary and automatically occurring response to certain stimuli without any involvement of the brain
• neurotransmitter: A chemical that relays signals across the synaptic gap between neurons
• synapse: The point of communication between two neurons or between a neuron and a target cell.
• excitatory effect: Stimulate or activate postsynaptic neurons, increasing likelihood of firing
• inhibitory effect: Block or suppress postsynaptic neuron activity, decreasing their likelihood of firing
• neuromodulator: A chemical molecule that has an effect on multiple postsynaptic neurons
• synaptic plasticity: The ability of synaptic connections to be changed over time in response to activity or experience
• synaptic change: The experience dependent, long-lasting changes to the strength of neuronal connections
• long-term potentiation (LTP): The long lasting strengthening of the synaptic connections between neurons after repeated high-intensity stimulation, resulting in enhanced synaptic transmission
• long-term depression (LDP): Long-lasting weakening of synaptic connections due to prolonged low-level stimulation of neural pathways which reduces synaptic efficacy
• sprouting: The growth of new dendritic spines and axon terminals, therefore allowing the formation of new synapses.
• rerouting: The reorganization by the formation of new connections between neurons to establish alternative pathways
• pruning: Where synapses that are not adequately activated are eliminated to increase the efficiency of neuronal transmissions
• stress: a state of physiological and psychological arousal produced by internal or external stressors that are perceived by the individual as challenging or exceeding their ability to cope
• stressors


  any stimuli that causes or produces stress
• internal stressor: originate from within the individual, including psychological and physiological processes in the body
• external stressors: originate from outside the individual, including environmental event, experiences and social influences
• acute


  stress/stressors that usually occur for a short period
• chronic: stress/stressor that usually continue for a prolonged period of time
• fight-flight-freeze response: a physiological response to acute stress that has evolved as an 'adaptive' response
• fight: dealing with the stressor directly by confronting and warding off the threat
• flight


  evading or escaping the stressor
• freeze


  immobilisation of the body to escape detection
• role of cortisol: - maintains body at elevated level of arousal

  - boosts energy levels

  - reduces digestive and reproductive functions

  - supresses immune system