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Biology - Response to stimuli, How is the nervous system divided?, What…

- - - - Receptor
        
        Sensory nueron
        
        CNS
        (it's where the information gets processed)
        
        Motor nueron
        
        Effector
        (usually a muscle or gland)
        
        Response
        (e.g muscle contracts)
        
        1 more item...
        
        What are the 2 parts to the CNS?
        
        Brain
        
        Spinal cord
        (it's what connects the brain to the rest of thre body - where the relay nuerone is)
        
        Receptors
        
        What is a Receptor?
        
        They detect a change in stimuli . Receptors only respond to a specific stimuli (eg. There is a receptor for changes in heat, a receptor for pain ect)
        
        How does do receptors work?
        How do they convert the outside world into perception?
        
        A receptor changes energy from one form to another (e.g light to electrical nerve impulses that the brain understands. That nervous impulse its called a generator potential :red_flag:
- - - - Sympathetic nervous system - Gets the body ready for action, speeds up an activity, fighr or flight response
        (eg. Increasing the heartbeat)
      - Parasympathetic nervous system - slows down an activity, calms the body down, concerned with conserving energy
        (eg. slowing down a heartbeat)
- - - - Rods
        
        What is visual acuity?
        
        Kinda like resolution - the ability to distinguish between 2 ponts
        
        What colours are rods able to identify?
        
        only black and white
        
        why?
        
        Because they are unable to distinguish beteen different wavelengths
        
        Do rods have high or low visual acuity?
        
        Low
        
        why?
        
        cos many rod cells are connected to a single bipolar cell This is called retinal convergence, So there are fewer separate impulses that your brain recieves, compared to cone cells
        
        Are they very senstitive to light (can see dim lights) or are they not sensitive to light?
        
        you use rods to see at night. They are very sensitive to light
        
        why?
        
        In order for a genrator potential to be created, theres a pigment called rhodopsin that needs to be broken down. Low intensity light is enough to break it down
      - Cones
        
        How are rods and cones distributed?
        
        Many more rods than cones
        
        many rods are grouped together whereas cones look isolated
        
        why?
        
        Many rods are grouped together cos they all connect to a single nueron.
        Only 1 cone cell is connected to a nuerone
        
        Why can we percieve colour with cones?
        
        There are 3 different types of cone cells that detect 3 different ranges of wavelength. Therefore, we can see in colour
        
        Are cones more or less sensitive to light compared to rods?
        
        They are less sensitive to light (they are best used to see bright light)
        
        why?
        
        Remember, a single cone cell is connected to a nuerone, so it takes more light to trigger a threshold for an action potential
        
        Do cone cells provide high or low visual acuity?
        
        High
        
        Why?
      - Whats the fovea?
        
        What's the blind spot?
- - - - What is the SAN?
        
        It's a distinct group of cells in the right atrium that initiates the heartbeat
    - - why?
        
        This gives time for the ventricles to fill up with blood, without the AVS, the verticles woudn't be full enough and we wouldn't have enough oxygen dekivered to our muscles
    - - What is the difference between the purkyne fibres and the bundle of his?
        
        The purkyne fibres make up the bundle of his.
        (eg. the muscle cells make up my arm)
  - - - How does exercise increase your heart rate?
        
        The increased level of CO2 decreases the pH of the blood (making it more acidic)
        
        this is detected by the chemoreceptors on the
        walls of the cartoid artery and the aorta
        
        What is the cartoid artery?
        
        they are the arteries that serve the brain. Chemoreceptors are on those arteries
        
        What is the aorta?
        
        The blood vessel that takes blood out of the heart and to the muscles
        
        What are chemoreceptors?
        
        They are receptors that detect changes in blood pH
        
        The detection of a lower blood pH increases the frequency of impulses to the medula oblongata
        
        What is the medulla oblongata?
        
        The medulla oblongata is a reigon in the brain that controlls the heart rate
        (The brain controls the heart rate, so it has to go to the medulla oblongata first)
        
        How does it control heart rate?
        
        The medulla oblongata is linked to the SAN
        but one center in linked via the sympathetic nervous system and another center is linked via the parasympathetic nervous system
        
        This send electrical impulses down the sympathetic nervous system to the SAN
        
        This increases the rate of electrical waves produced by the SAN, increasing heart rate
        
        This increases blood flow causes more CO2 to be removed faster (blood is flowing faster and being removed by the lung faster) (im breathing faster)
        
        This results blood pH increasing back to normal. a higher freq. of impules sent to the medulla oblongata which send impulses via the parasympathetic nervous system
        
        (so the heart beat is back to normal)
        
        This increases the amount of carbon dioxide produced by the tissues
        
        I do some exercise
    - - What happens if my blood pressure is increased?
        
        Pressure receptors on the walls of the cartoid arteries and the aorta sends a higher frequency of nerve impulses to the center that decreases heart rate in the medula oblongata.
        
        this sends impulses down via the parasympatetic nervous system, decreasing my heart rate
      - What happens if my blood pressure decreases?
        
        Pressure receptors on the cartoid arteries and the aorta sends a higher frequency of impulses to the center responsible for increasing heart rate in the medulla oblongata.
        
        This send impulses along sympathetic nervous system, increasing heart rate (which hopefully increases blood pressure