co-ordination and control 2.80, 2.82, 2.87, 2.88, 2.89, 2.90, 2.91, 2.92, 2.94, 2.86, 2.83, 2.84, 2.85, 2.81, 2.93, 2.78B, 2.72B, 2.95B Flashcards
what does coordinated mean?
means that the body is able to make things happen in different parts of the body at the right time.
which two organ systems help the body be coordinated?
the nervous system
endocrine (hormone) system
what three things do a coordinated response require?
stimulus
receptor
effector
what’s a stimulus?
change in the animal’s surroundings
e.g. a ball is thrown towards you
what’s a receptor?
the organ that detects the change
e.g your eye
what’s an effector?
muscles are the effectors
e.g contract as you catch the ball
how is a link made between the stimulus and response?
nervous or endocrine system
what happens when our receptors detect the stimulus?
they change its energy into nerve impulses.
e.g eye, turns light into nerve impulse
ear, turns sound into nerve impulse
and so on
what is the CNS?
central nervous system
consists of the brain, spinal cord.
CNS coordinates all the nervous responses like moving or reflexes
what’s the peripheral nervous system?
peripheral nervous system contains all of the other nerves which send impulses to the effectors.
what are the three types of neurones?
sensory, relay and motor
what order are the impulses sent via the neurones?
impulses from receptor pass along
sensory neurons
until they reach the brain and spinal cord (central nervous system)
impulses are passed to
relay neurons
in the central nervous system.
impulses then passed along motor neurons
REMEMBERTO MENTION SYNAPSES
structure of motor neuron:
nucleus
end of cell body
contains all genetic information of cell
structure of motor neuron:
dendrite
tree like projections that connect to different neurones
one neurone can connect to many other neurones
structure of motor neuron:
cell body
main section of cell, containing nucleus
structure of motor neuron:
axon
long section, electrical impulses travel long distances through the axon
structure of motor neuron:
myelin sheath
insulates the axon and speeds up the transmission of impulses
what are reflexes?
reflexes are automated
do not involve brain
very fast actions, involving the three neurones: sensory, relay, motor
movement of the impulse from receptor to effector is reflex arc
what is the reflex arc?
movement of the impulse from receptor to effector
what’s the steps involved in the reflex arc?
receptors detect the stimulus
send an impulse along sensory neurone
sensory neurone passes the impulse to spinal cord to a relay neurone
relay neurone passes impulse to motor neurone
motor neurons causes the effect to contract and avoid stimulus
what’s the gap between neurones called?
synapse
how do the synapses work?
electrical impulse travels along axon
triggering the nerve ending of a neurone to release chemical messagers called neurone transmitters
chemicals diffuse across gap and bind with receptor molecules of the membrane of next neurons
receptor molecules on second neuron hind to specific chemicals stimulating the second neurone to transmit the electrical impulse
what type of organ is the eye?
sensory organ, which detects light and sends impulses to the brain which converts info into image
structure of eye:
cornea
a curved transparent disc at front of eye, convex (already bends some of the light)
does the focusing
