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The Brain (p&a r 5.1.5 g, h, i, j, k) - Coggle Diagram

- - - - Object touching the eye
      - Bright light
      - Loud sounds
      - Sudden movement near the eye
    - - Sensory neurone —> pons (brain stem) —> relay neurone —> motor neurone —> facial muscles
- - - - Relay neurones which allow complex connections
      - Most are non-myelinated
      - Grey in colour
    - - Contains many non myelinated relay neurones making up the grey matter
      - Also contain myelinated neurones making up outer regions of white matter
      - Myelinated neurones can carry impulses up & down spinal chord at high speed over long distances
      - Peripheral nerves enter & leave spinal chord carrying action & potential to & away from body
  - - - composed of sensory & motor neurones
      - usually bundled together in connective tissue sheath to form nerves
    - - Sensory fibres entering their CNS are dendron of the sensory neurone
      - are myelinated.
      - Their cell body is in the Dorsal root easing to the spinal chord
      - Then have short axon connecting to other neurones in CNS
    - - Somatic nervous system
        
        Somatic nervous system is concerned with conscious or voluntary control
        
        e.g. sending signals to skeletal muscles
      - Autonomic nervous system
        
        Autonomic nervous system is concerned with controlling effectors that are involuntary or not under conscious control
        
        E.g. cardiac muscle, smooth muscle of gut & blood vessels
        
        Neurones tend to be non-myelinated - speed not essential
        
        Autonomic means self-governing
        
        2 neurones are involved pre & post ganglionic neurone - a ganglion is a small swelling
        
        splits further into sympathetic & parasympathetic nervous systems (see above)
      - Conducts action potentials from the CNS to effectors
      - Motor neurone in pic has myelinated axon - normally have myelinated axon
      - Cell body within CNS
- - - - Temperature receptors
      - Osmoreceptors (intimate ADH release with Posterior Lobe of Pituitary gland)
    - - Pituitary gland consists of 2 lobes
      - ADH is made in hypothalamus & passes down neurosecretory cells to posterior lobe of Pituitary gland to be released
  - - - Stress
      - Growth
      - Reproduction
      - lactation, etc…
  - - - Suggests it’s a motor area as can understand but not speak
  - - - Suggests association area that is messing things up due to damage
- - - - These are the 1st regions to sensory info. Different areas deal with different senses
        
        E.g. primary visual area deals with vision, primary auditory area deals with hearing
    - - Receive info from 2 or more primary sensory areas & integrate the info.
      - Our cerebrum can now make sense of what our eyes, ears etc tell us bout the environment
      - Huge amount of cerebrum is made of association areas
      - The pre-frontal association area (pre-frontal cortex) is concerned with planning actions & movements:
        
        Focussing attention
        
        Predicting consequences of actions
        
        Anticipating events in environment
        
        Planning for future
        
        Coordinating & adjusting complex behaviours
        
        personality
      - There is another area called the Limbic association area which is concerned with emotions & memory
    - - Send impulses to effectors (muscles & glands)
- - - - Allows more light into the eyes
        Retina more sensitive to light
    - - Higher rate & pressure
      - Faster deliveries of glucose & O2 to muscles
      - CO2 removed from muscles at higher rate
    - - Diverts bloods away from skin & gut to your muscles
        Arterioles in liver & muscles dilate
    - - Supplies energy for muscle contraction
    - - Converts glucose to stable fro mod energy such as ATP
    - - Makes hair stand up, sign of aggression & can make some mammals look bigger
    - - Increases gaseous exchange so more O2 enters blood & supplies aerobic respiration
    - - Natural painkillers realised so if you are wounded you can still continue your activity
  - - - E.g. sight, sound, smell, pain —> primary sensory areas
  - - - Adrenaline (epinephrine) will be released from the Adrenal Medulla. Adrenaline will cause the following events to continue for a prolonged period
      - Relax smooth muscle in bronchioles
      - Increase stroke volume of heart
      - Increase heart rate
      - Vasoconstriction (general) to increase blood pressure
      - stimulates conversion of glycogen to glucose
      - Dilates pupils
      - Increase mental awareness
      - Inhibits gut action
      - Body hairs stand erect
    - - Binds to receptors on CSM
      - G protein stimulated which activates the enzyme adenyl cyclase
      - Adenyl cyclase converts ATP to cAMP (cyclic AMP = 2nd messenger)
      - cAMP activates various enzymes inside the cell to change its behaviour