Coordination and response: The nervous system Flashcards
label a diagram of the
eye
what do sensory neurones do
carry information from the sense organs too the CNS
what do motor neurones do
carry instructions from the CNS to the effector organs (muscles/glands)
what do neurones carry
electrical impulses
what are the junctions between neurones called
synapses
what does a nerve contain
neurone such as sensory nerves, motor nerves and mixed nerves
do reflex actions involve conscious though
no
what do reflex actions involve
stimulus –> receptor –> sensory neurone –> relay neurone in CNS –> motor neurone –> effector –> response
what do sense organs detect
changes inside and outside your body
what does the pupil reflex control
the amount of light coming into your eye
what does your CNS contain
spinal cord and the brain
what does the central nervous system give you
rapid responses to changes in your environment (stimuli)
what type of nervous system runs all over your body
peripheral nervous system (made up of spinal nerves and cranial nerves)
what is an individual nerve cell called
neurone
what happens at a synapse (the tiny gaps in between neurones)
the electrical nerve impulse that is being carried cannot cross the synapse so chemical transmitters are released, they diffuse across the gap and when they reach the next neurone, they bind to receptors on the membrane and a new impulse starts up
label a motor and sensory neurone
printed out
how does your brain understand a reflex action that has just taken place
impulses travel to your conscious brain which make you aware of what has happened in the reflex reaction, such as taking your hand quickly away from a hot object
what is an example of a spinal reflex
knee-jerk reflex
what is an example of a cranial reflex
pupil reflex
what are the main sense organs
- eye (vision)
- ear (hearing and balance)
- tongue (taste)
- nose (smell)
- skin (touch, pressure, temperature and pain)
- muscles (stretch receptors)
all receptors are what of energy
transducers
what is it called when your lens changes shape to focus your eye
accommodation
what happens to the lens when you look at distant objects to your eye
the ciliary muscles relax and the suspensory ligaments pull tight, the lens goes thin as the light needs to be bent to focus on the retina
what happens to the lens when you look at close objects to your eye
the ciliary muscles contract and the suspensor ligaments go slack, the lens widens and goes more spherical as the light needs to bend much more to be focused on the retina
what controls the amount of light that enters your eyes
iris and pupil reflex
what does the pupil do in dim light
enlarges (dilates) to let as much light as possible into the light
what does the pupil do in bright light
gets smaller (constricts) to protect the retina from damage
sequence of events in the eye reflex is as follows
stimulus (light intensity) –> retina (receptor) –> sensory neurones in optic nerve –> unconscious part of brain –> motor neurones in nerve to iris –> iris muscles (effector) –> response (change in size of pupil)
what happens to the iris in bright light
circular muscles contract and iris gets bigger
what happens to the iris in dim light
radial muscles contract and iris gets smaller
what in our brain controls our conscious thought
cerebrum
what in our brain is involved in coordination and balance
cerebellum
what in our brain controls basic bodily functions
medulla
what in our brain are involved in the chemical control of our body
hypothalamus and pituitary gland
in our eye what contains receptor cells that are sensitive to light
retina
in our eye what is the tough white outer layer
sclera
in our eye what muscle changes the size of the pupil
iris
in our eye is curved and os the transparent area at the front of the eye
cornea
in our eye what focuses the image on the retina
choroid
in our eye what sensory neurones carry impulses from the retina to the brain
optic nerve
in our eye what is the hole that allows light into the eye
pupil
in our eye what changes the shape of the lens
ciliary muscles
in our eye what attaches the ciliary muscles to the lens
suspensory ligaments
