control and communication 2.2 Flashcards
what is the human nervous system composed of
brain, spinal cord and associated nerves
what is the central nervous composed of
the brain and spinal cord
cerebrum
controls memory, personality, dreams and controls conscious thoughts
cerebellum
controls muscles movement, coordination and balance
medulla
controls heart rate, breathing and peristalsis
name the sense organs
sight, touch, smell, taste and hearing
sensory neurons
carries electrical impulses from receptors in the sense organs to the CNS
inter neurons
carries electrical impulses from the sensory neuron to the motor neuron
stays within the spinal cord
motor neuron
carries electrical impulses from the CNS to effectors
examples of effectors
muscles and glands
what is a reflex
an involuntary and almost instantaneous movement in response to a stimuli
why are reflex actions important
essential for survival and protect the body from harm
stages of the reflex arc
- stimulus picked up by receptors in the sense organ
- electrical impulses sent through sensory neuron to CNS
- chemical impulses cross the first synapse in CNS
- impulses pass through the inter neuron
- chemical impulses cross the second synapse and are picked up by motor neuron
- impulses are passed through the axon of the motor neuron and end in the muscles of the arm
- chemicals are released and the arm muscles contract bending the arm and. lifting the hand away from heat
what is a synapse
the space between two neurons
how do electrical impulses pass through the synapse
- an electrical impulse arrives at the axon of the first neuron
- the chemical transmitter is released and diffuses across the synapse
- the chemical transmitter binds to the receptor of the next neuron and triggers an electrical impulse to be sent
