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Science 7th grade
Nervous system modified review sheet
Question | Answer |
---|---|
Homeostasis- | maintaining a constant internal balance; responding to stimuli |
Stimuli- | An external or internal change that brings about a reaction |
Neurons- | Nerve cells that are made up of axons, dendrites and cell body |
Axons- | Carry impulses AWAY from the cell body |
Dendrites- | Carry impulses TO the cell body |
Sensory Neurons- | Send Impulses(information) to the Brain and Spinal cord |
interneurons- | found in brain and spinal cord and send impulses from sensory neurons to motor Neurons |
Motor Neurons- | relay information to muscles or glands in the body |
Impulse transfer | Impulse moves from axon of one neuron to dendrites of another; Moves across synapse |
Synapse- | space between axon and dendrites |
neurotransmitters | chemicals that are released that carry impulse across synapse |
central nervous System (CNS) | made up of brain and spinal cord |
Peripheral Nervous System (PNS) | made up of all nerves outside of the CNS; all nerves in your head and coming off of spinal cord |
Cerebrum | largest part; where thinking occurs; memory is stored and movements are controlled |
Cortex | outer portion; have ridges and grooves that increase surface area so more complex thoughts can occur |
Cerebellum | Under the cerebrum; coordinates voluntary muscle movements,maintain balance and muscle tone. i.e. helps ride a bike |
Brain stem | base of brain; connects to brain to spinal cord |
medulla | controls involuntary actions like hearbeat, breathing, blood pressure, coughing, sneezing swallowing and vomiting |
Spinal cord | in adult is as wide as adult thumb |
spinal cord | carries impulses from teh body to the brain and from the brain to the body |
reflexs | involuntary automatic response to a stimulus - controlled in your spinal cord - brain acts after reflex to help you figure out what to do to make pain stop |
Drugs | directly affect the nervous system |
Drugs | destroy brain and liver cells |
Drugs | can be a depressant and slow down responses of CNS as well as thinking processes |
Drugs | can be a stimulant that speeds up heart rate, cause sleeplessness and can cause kidney to make more urine |
Nearsighted | focus in front of retina |
farsighted | focus behind retina |
Cornea | transparent membrane that protects the eye - allows light to enter |
Pupil | opening the fron of the eye that allows light to enter |
Retina | light sensitive area in the back of the eye |
rods | detect dim light; used in night vision |
cones | detect colors |
rods and cones | impulses from these photoreceptors travel to brain along the optic nerve |
Iris | the part of the eye gives its color |
lens | piece of curved material behind the pupil that allows the light to pass through but changes its direction - focuses entering light on the retina |
Curved lens | looking at objects close to the eye - lens is more curved |
flatter lens | looking at objects far away - lens is flatter |
hearing-now sound moves | 1) sound begins when object starts to vibrate because air particles push on each other and transfer energy |
hearing- now sound moves 2 | 2) waves move from outer ear to middle ear(causes tiny bones in eardrum to vibrate) to cochlea of the inner ear fluid |
Job of neurons in cochlea | convert waves to electrical impulses and sends them to the part of the brain that interprets sound |
Taste buds | contain receptors for taste; located in teh papillae |
4 types of taste buds | sweet sour salty bitter |
Olfactory cells | receptors for smell that are located in the upper part of your nasal cavity. brain combines information from your taste buds and nose to give a sense of smell |