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body coordination (nervous system (brain (cerebrum (right hemisphere…

- - - - collects information through receptors in sensory organs
      - coordinates movement of the body
      - receptors detect stimi (temperature, light, touch, smell, sound)
      - mechanoreceptors sensitive to touch stimuli e.g. stretching muscles (when bladder is full)
      - photoreceptors sensitive to light
      - chemoreceptors sensitive to chemicals e.g. sweetness/bitterness of food
      - skin very sensitive to protect body
      - hearing
        
        ear also helps you balance
        
        inner ear is fluid-filled semicircular canals
        
        if suddenly lean, fluid moves agains sensory hairs lining canal
        
        nerve impulse sent to brain, messages to muscle to help balance
      - sight
        
        1/6 of eye visible outside skull
      - smell and taste
        
        chemoreceptors for taste and smell work together
        
        10 000 taste buds on tongue
        
        chemicals bind to taste receptors, stimulate sensory nerves
        
        message to brain, sensation of taste
    - - controls involuntary actions e.g. heartbeat, digestion of food, sweating, changing pupil size
      - sympathetic: speeds up functions, body works more efficiently
      - prepares for emergencies --> more alert and ready to act
      - parasympathetic: slows everything down
      - in control when you are resting
      - prepares for intense activity by diverting blood away from areas that will not be used in action e.g. digestive system, skin
      - increases blood to muscles and lungs
      - stops peristalsis (muscular action that mixes food in intestines)
      - opens bronchioles to increase amount of entering air -- increases oxygen
      - increases heart rate --> increased blood flow to muscles
      - relaxes muscles in eyes, dilates pupils --> more light in eyes, improved distance vision
      - increases blood to heart
      - increased blood flow to digestive tract
      - digestion: stimulates salivary glands, increases rate of peristalsis
      - reduces diameter of bronchioles(reduced need for oxygen)
      - controls heartbeat
      - contracts muscles of eye, reduces diameter of pupil --> short vision
  - - - involuntary, very fast actions that protect your body from danger
      - receptors detect temp of skin
      - activates sensory neuron --> sends impulse to spinal cord
      - relay neuron within spinal cord passes message directly to motor neuron
      - sends impulses to muscles (effectors)
      - arm muscles contract (lift hand away)
      - only after is message sent to brain --> registers pain
      - nerve pathway called reflex arc
  - - - more than 80% of brain
      - over 10 billion neurons
      - folds increase surface area 3x
      - controls conscious thought and voluntary movement
      - receives sensory messages from body
      - right hemisphere
        
        controls left half of body
        
        creative, emotional e.g. music/art
      - left hemisphere
        
        controls right half of body
        
        language, logical thinking e.g. maths
    - - at base of cerebrum
      - coordination and balance
    - - controls vital functions (breathing, blood pressure, heart rate)
- - - - causes atria to contract
        
        stimulus reaches tissue between atria and ventricles (AV node) --> ventricles contract
  - - - increases rate at which heart beats
      - increases strength of contractions
      - causes heart to pump up to 5x normal blood per minute
    - - cellular respiration increases --> level of carbon dioxide in blood increases
      - change detected by receptors in carotid artery (neck) and aorta (heart)
      - message sent to brain, nerves stimulate heart to beat faster
      - as muscular activity increases, more blood is pumped back to right atrium
      - atrium wall stretches, stretch receptors send impulses to brain
      - heart beats faster
- - - - nutrients move by diffusion through cells of villi and capillaries
      - movement of particles of a substance from an area of high concentration to an area of low concentration
      - takes place in liquids and gases where particles can move around
      - after eating: high concentrations of glucose, amino acids, fatty acids, and glycerol in small intestine
      - low concentrations in bloodstream
      - molecules move by diffusion from the small intestine through cell membranes and into blood capillaries in the villi
      - flow of blood carries digested materials away -> always higher concentration in small intestine and lower concentration in blood
      - diffusion always continues
- - - - enzyme attaches to speed up process, then detaches unchanged
      - enzyme: chemical that speeds up rate of reaction up to 10 billion times without being used up in process
      - without enzymes, many reactions would be too slow to maintain life
      - over 700 types, each specific to one particular chemical reaction
      - each enzyme has particular shape that allows it to attach to specific molecule(s) 'substrate'
      - substrate: what will be changed by the chemical reaction