the nervous system Flashcards
what are the three types of neurons
- sensory neurons
- motor neurons
- inter neurons
what is the function of the sensory neuron
transmits impulse from sensory organs to the CNS
what is the function of motor neurons
sends impulses from the CNS to specific muscles/ organs
what is the function of interneurons
transmit impulses between sensory and motor neurons within brain or spinal cord
the CNS is surrounded by a shock absorbing fluid called _______ ______ (CSF)
cerebrospinal fluid
what is the advantage of keeping the circulating blood separate from the brain and spinal cord tissues
it gives the brain and spinal cord some protection from changes to blood composition, toxins and pathogens
step one in responding to a stimulus
receptors detect a stimulus
step two in responding to a stimulus
the impulse is sent along the sensory neuron to the spinal cord
step three in responding to a stimulus
the CNS integrates the information and, if necessary sends it to the brain for processing
step 4 in responding to a stimulus
impulse is sent from the CNS along the motor neurons to the effector
step 5 in responding to a stimulus
the effector generates the response
the sympathetic nervous system-
prepares the body for flight flight fright and sex
the parasympathetic nervous system-
prepares the body for rest and calms it down
parts of the body that detect stimuli and change as a result of the stimuli
receptors
the type of receptor that detects the presence of chemicals
chemoreceptors
the type of receptor that detects changes in temperature
thermoreceptors
the type of receptor that detects mechanical changes in the environment
mechanoreceptors
the type of receptor that detects the presence of light
photoreceptors
the fold of skin that covers the eye to clean and protect it
eyelid
the transparent covering on the eye that protects it and help to converge light rays that enter the eye
cornea
the white part of the eye that is made of collagen that provides protections dan support
sclera
the layer of light sensitive cells at the back of the eye that detect rays that are focused by the cornea and lens
retina
the layer of blood vessels with a black pigment that nourishes the eye and absorbes light
choroid
the ring of muscles that is coloured. it controls the amount of light entering the eye
iris
the hole in the middle of the iris that allows light to enter the eye
pupil
the hole in the middle of the iris that allows light to enter the eye
pupil
the structure in the eye that is transparent and can change shape that focuses light onto retina and focus objects
lens
the structure in the eye that is attached to the underside of the lens and produces aqueous humour and helps focus by altering shape of lens
ciliary body
the structure in the eye that is located behind the lens that give the eyeball its shape
vitereous
the structure in the eye that is found behind the cornea and provides nutrients to the cornea and lens
aqueous humour
the structure in the eye that is found in the lateral side of the eye and helps orientate the pupil away from the centre of the body
lateral rectus muscles
the structure in the eye that is found on the medial side of the eye which orientates the pupil towards the centre of the body
medial rectus muscle
the spot located in the macula which has a high density of cone cells. gives sharp central vision and is where light is focused into
fovea
the blind spot where there are no photoreceptors where the optic nerve leaves the eye
optic disk
the bundle of fibres that relay information from the retina and fovea to the brain
optic nerve
the photoreceptor of the retina that is sensitive to light and can function in dim light/darkness
rods
the photoreceptor of the retina that work best in higher light intensity and allow some species to see in colour
cones
