Biopsychology

• What is the peripheral nervous system made up of?

  • thick bundles of axons, called nerves
  • two major subdivisions = somatic nervous system and the autonomic nervous system
• What is the somatic nervous system involved in?

  • activities traditionally thought of as conscious and voluntary
  • involved in the relay of sensory and motor information to and from the CNS.
  • consists of sensory and motor neurones.
• What does the nervous system control?

  • our internal organs and glands
  • considered to be involuntary
  • Made up of sympathetic and parasympathetic
• What is the role of the SNS?

  Responses to help us deal with emergencies
• Neurons from the SNS travel to virtually every organ and gland within the body, preparing the body for the rapid action necessary when the individual is under threat.
• What does the parasympathetic nervous system do?

  Relaxes them again once the emergency has passed.
• PNS is referred to as the rest and digest system.
• What are parasympathetic symptoms?

  • Kickstarts digestion
  • slows heartbeat
  • reduces blood pressure
• Describe the structure of neurones?

  • nucleus located in the soma
  • soma has branching extensions known as dendrites
  • neuron has small information processor.
  • dendrites act as input sites where signals are recieved from other neurons.
• What do terminal buttons do?

  Contain synaptic vesicles that house neurotransmitters.
• What is a synapse?

  • A synapse is a very small space between two neurons. It is an important site where communication between neurons happens.
• What is a synaptic cleft?


  Space between two neurones.
• What happens once neurotransmitters are released into the synapse?


  They travel across the small space and bind with corresponding receptors of the adjacent neuron.
• How is an action potential generated?

  • neurotransmitter binds to any receptor that it fits
  • binding triggers an action potential in the adjacent neuron, and an electrical impulse is transferred.
• What are receptors?

   protein molecules on the cell surface that vary in shape. A receptor will be a perfect match to a specific neurotransmitter.
• What do sensory neurons do?

  
  

  convert information from these sensory receptors into neural impulses. When these impulses reach the brain, they are translated into sensations of, for example, visual input, heat, pain etc.
• Where are sensory receptors found?

  • eyes
  • tongue
  • skin
• What do relay neurones do?

  Allow sensory and motor neurones to communicate with eachother.
• What is the role of motor neurones?

  When stimulated, motor neurones release neurotransmitters that bind to receptors on the muscle and trigger a response that leads to muscle movement.
• Where are motor neurones located?

  In the CNS
• What is an inhibitory neurotransmitter?

  Causes inhibition - results in neuron becoming more negatively charged and less likely to fire.
• What is the use of inhibitory neurotransmitters in mind?

  • calming the mind and body inducing sleep
  • filters out unnecessary excitatory signals.
• What type of neurotransmitters are excitatory?

  • noradrenaline
• How do excitatory neurotransmitters causes excitation?

  Cause excitation of the post synaptic neuron by increasing its positive charge and making it more likely to fire.
• What decides the likelihood of a cell firing?

  • nerve cell can receive both EPSPs and IPSPs at the same time.
  • likelihood of the cell firing is determined by adding up the excitatory and inhibitory synaptic input
  • the net sum of this calculation determines whether or not the cell fires.
• Is dopamine excitatory or inhibitory?

  • Can be both depending on which receptor it binds to.
• Role of dopamine:

  • associated with rewards as the brain releases it in response to pleasure
  • responsible for movement and co-ordination
• What is excess dopamine associated with?

  positive symptoms of schizophrenia.
• What type of neurotransmitter is seratonin?

  Inhibitory
• What is the use of seratonin?

  • regulates mood, appetite and sleep
• How do SSRI'S relieve the symptoms of depression?

  Increasing uptake levels of seratonin in the brain
• An inhibitory neurotransmitter binding with a postsynaptic receptor results in an inhibitory postsynaptic potential (IPSP), so is less likely to fire.
• What is the endocrine system made up of?

  A series of glands that produce chemical substances known as hormones.
• What are hormones?

  chemical messengers that must bind to a receptor in order to send their signal.
• How do hormones differ to a neurotransmitter?

  Hormones are secreted into the bloodstream and travel around the body.

  Hormones are slower to take affect

  Hormones are longer lasting
• How are hormones controlled?


  Interactions between the hypothalamus and the pituitary gland.
• What is the pituitary gland?

  'master gland' because its messenger hormones control all other glands in the endocrine system.

  Also secretes growth hormone, endorphins for pain relief.
• What does the thyroid gland do?

  • releases hormones that regulate growth, metabolism and appetite.
• What is hyperthyroidism or Grave's disease caused by?

  When the thyroid secretes too much of the hormone thyroxine.
• What are the adrenal glands involved in?

  Secrete hormones involved in the stress response such as adrenaline and noradrenaline.