paper 2: biopsychology🥼🧬

• Central Nervous System (CNS)

  Made up of brain and spinal cord
• Brain


  • The outer layer is developed and contains the cerebral cortex (gray matter) which distinguishes our higher mental functions from animals
• Brain


  • Divided into two hemispheres
• Peripheral Nervous System (PNS)


  Transmits messages to and from the CNS
• Autonomic Nervous System (ANS)


  Controls automatic functions such as heartbeat and response to stress
• Somatic Nervous System (SNS)


  Controls voluntary functions such as muscle movement
• Sympathetic nerves


  Part of the autonomic nervous system, deals with fight or flight response
• Parasympathetic nerves


  Part of the autonomic nervous system, deals with resting and digesting
• Endocrine system


  Works along with the nervous system to control bodily functions
• Hormones


  Chemical substances secreted into the bloodstream that regulate the activity of cells and organs
• Hormones react slowly compared to the nervous system
• Pituitary gland


  The main endocrine gland that controls the release of hormones from all other endocrine glands
• Thyroxine


  A hormone produced by the thyroid gland that affects cells in the body and can make the heart beat faster
• Endocrine system regulates the body's growth, sexual development and other functions
• Fight or flight response when faced with stress


  1. ANS changes from parasympathetic to sympathetic state

  2. Pituitary gland releases ACTH

  3. Adrenal gland releases adrenaline

  4. Physiological changes in the body (increased heart rate, breathing)

  5. PNS returns to parasympathetic state when threat diminishes
• Parasympathetic nervous system


  Opposes the sympathetic nervous system, acts as a 'brake' to reduce the effects of the fight or flight response
• Sympathetic nervous system


  Prepares the body to fight or run away (increases heart rate, breathing rate)
• Sensory neuron


  • Found in receptors, carries nerve impulses to spinal cord and brain
  • Some stop at spinal cord allowing for quick reflex actions
• Relay neuron


  • Found between sensory input and motor output, allow communication between sensory and motor neurons
• Motor neuron


  • When stimulated, release neurotransmitters that bind to receptors on muscles to trigger a response
• Cell body (soma)


  Contains the nucleus and genetic material
• Dendrites


  Branch-like structures that carry nerve impulses towards the cell body
• Axon


  Carries impulses away from the cell body, covered in a fatty myelin sheath that speeds up transmission
• Nodes of Ranvier


  Gaps in the myelin sheath that speed up transmission by forcing the impulse to 'jump' across
• Terminal buttons


  At the end of the axon, communicate with the next neuron across the synapse
• Electrical transmission in neurons

  1. Neuron in resting state has negatively charged inside

  2. Activation causes inside to become positively charged for a split second (action potential)

  3. Action potential travels down the axon
• Synapse


  Gap between neurons where chemical transmission occurs
• Neurotransmitters


  Chemicals that diffuse across the synapse and bind to receptors on the next neuron
• Excitation


  Increases the likelihood the next neuron will pass on the electrical message
• Inhibition


  Decreases the likelihood the next neuron will pass on the electrical message
• Neurotransmitters


  • Serotonin (inhibition)
  • Adrenaline (excitation)
• In the 19th century, the localisation of brain function was discovered, contradicting the holistic theory that all parts of the brain are involved in all processing
• Lateralisation


  The dominance of one hemisphere of the brain for particular physical and psychological functions
• Left hemisphere


  • Controls the muscles on the right side of the body
• Right hemisphere


  • Controls the muscles on the left side of the body
• Motor cortex


  • Located at the back of the frontal lobe, controls voluntary movements on the opposite side of the body
• Somatosensory cortex


  • Receives information from the skin (touch, heat, pressure), the amount of area devoted to a body part indicates its sensitivity
• Visual cortex


  • Located in the occipital lobe, each eye sends information from the right visual field to the left visual cortex and vice versa
• Auditory cortex


  • Located in the temporal lobes, processes auditory information
• Language centres


  • Broca's area (converts thought into speech)
  • Wernicke's area (understands speech and produces speech)