nervous system
eyes
lense
compound
humans and most mammels
uses a lense and photo sensitive cells to see
mostly in insects and invertibrates
predators and prey
use lost of simple eyes to make a good wide view good for prey
predators have forward facing eyes that are usually good at spotting moving objects
prey usually have less depth perception but a much larger FOV
hearing
outer ear gathers sound
middle ear transmits vibrations
inner ear recepts sound and turns them into electrical systems
three bones in the ear malleus(hammer), incus(anvil), stapes(stirrup)
birds only have 1 bone (columella) and no outer ear
taste
taste buds are all on the surface coverd by a mucus membrain
most animals can only taste whether or not a substance is eatable or not
nerve cells
neurons are the basic unit of anervous system
a large cell with lots of dendrites that receive signals, this then carries across the axon and is transmites along to the next neuron.
motor neurons transmit signals to muscles so they can move
synapses are conectors betwean nerves thaat use a chemichal to make electric signals betwean synapses.
fight or flight
uses adrenaline or noradrenalin
the base reaction to run or fight in a stressfull situation
sensory neurons pick up senses like touch to taste
sent mesages electrochemicly so chemicals make charges that carry signals
ions in the nervous system
sodium na+
potasium k+
calcium ca2+
chlorine cl-
used for transmition from neuron to muscle
rods and cones make up photo receptors that change the light into electrical signals. cones deal with colour so if they are damaged you can be colour blind.
neurological deseases
degenarative myelopathy afects the spinal chord and can cause paralaysis and usualy ocurs in olded dogs. there is no treatmant.
listeriosis is caused by a bacterial infection and causes blood poisoning and misscarrage also partial paralasys eventualy fatal if not treated
seisures are caused by abnormal electrical activity and causes convulsions.
action potential
neurons comunicate electrochemicaly through nerve impulses
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