The Biological Perspective of Psychology

• Nervous system


  An extensive network of specialized cells that carry information to and from all parts of the body
• Neuroscience


  Deals with the structure and function of neurons, nerves, and nervous tissue, and their relationship to behavior and learning
• Neuron


  The basic cell that makes up the nervous system and receives and sends messages within that system
• Parts of a neuron

  • Dendrites: branch-like structures that receive messages from other neurons
  • Soma: the cell body of the neuron, responsible for maintaining the life of the cell
  • Axon: long, tube-like structure that carries the neural message to other cells
• Glial cells


  Grey fatty cells that provide support for the neurons to grow on and around, deliver nutrients to neurons, produce myelin to coat axons, and clean up waste products and dead neurons
• Myelin


  Fatty substances produced by certain glial cells that coat the axons of neurons to insulate, protect, and speed up the neural impulse
• Generating the message: neural impulse

  1. Ions: charged particles

  2. Resting potential: the state of the neuron when not firing a neural impulse

  3. Action potential: the release of the neural impulse consisting of a reversal of the electrical charge within the axon

  4. All-or-none: a neuron either fires completely or does not fire at all

  5. Return to resting potential
• Axon terminals


  Rounded areas at the end of the branches at the end of the axon, responsible for communicating with other nerve cells
• Synaptic vesicles


  Sack-like structures found inside the axon terminal containing neurotransmitters
• Neurotransmitter


  Chemical found in the synaptic vesicles which, when released, has an effect on the next cell
• Synapse/synaptic gap


  Microscopic fluid-filled space between the rounded areas on the end of the axon terminals of one cell and the dendrites or surface of the next cell
• Receptor sites


  Holes in the surface of the dendrites or certain cells of the muscles and glands, which are shaped to fit only certain neurotransmitters
• Excitatory neurotransmitter


  Neurotransmitter that causes the receiving cell to fire
• Inhibitory neurotransmitter


  Neurotransmitter that causes the receiving cell to stop firing
• Reuptake


  Process by which neurotransmitters are taken back into the synaptic vesicles
• Central nervous system (CNS)


  Part of the nervous system consisting of the brain and spinal cord
• Spinal cord


  A long bundle of neurons that carries messages to and from the body to the brain that is responsible for very fast, lifesaving reflexes
• Sensory neuron


  A neuron that carries information from the senses to the central nervous system
• Motor neuron


  A neuron that carries messages from the central nervous system to the muscles of the body
• Interneuron


  A neuron found in the center of the spinal cord that receives information from the sensory neurons and sends commands to the muscles through the motor neurons
• Afferent neuron


  Another term for a sensory neuron
• Efferent neuron


  Another term for a motor neuron
• Interneurons also make up the bulk of the neurons in the brain
• Peripheral nervous system (PNS)


  All nerves and neurons that are not contained in the brain and spinal cord but that run through the body itself
• Divisions of the PNS

  • Somatic nervous system
  • Autonomic nervous system
• Somatic nervous system


  Division of the PNS consisting of nerves that carry information from the senses to the CNS and from the CNS to the voluntary muscles of the body
• Pathways of the somatic nervous system

  • Sensory pathway
  • Motor pathway
• Sensory pathway


  Nerves coming from the sensory organs to the CNS consisting of sensory neurons
• Motor pathway


  Nerves coming from the CNS to the voluntary muscles, consisting of motor neurons
• Autonomic nervous system (ANS)


  Division of the PNS consisting of nerves that control all of the involuntary muscles, organs, and glands
• Divisions of the ANS

  • Sympathetic division (fight-or-flight system)
  • Parasympathetic division
• Sympathetic division

  Part of the ANS that is responsible for reacting to stressful events and bodily arousal
• Parasympathetic division


  Part of the ANS that restores the body to normal functioning after arousal and is responsible for the day-to-day functioning of the organs and glands
• Endocrine glands


  Glands that secrete chemicals called hormones directly into the bloodstream
• Hormones


  Chemicals released into the bloodstream by endocrine glands
• Ibn Sina in his book 'Al-Qanun' had written on issues such as anatomy, central nervous system, hemispheric specialisation of the brain, and spinal cord
• Pituitary gland


  Gland located in the brain that secretes human growth hormone and influences all other hormone-secreting glands (also known as the master gland)
• Pineal gland


  Endocrine gland located near the base of the cerebrum that secretes melatonin
• Thyroid gland

  Endocrine gland found in the neck that regulates metabolism
• Pancreas


  Endocrine gland that controls the levels of sugar in the blood