Download Nervous System Study Guide

Nervous System Study Guide
1. Identify the main function of the nervous system. –To control the body’s activities
by relaying messages
2. Identify the main divisions of the nervous system and list the body parts included
in each division.
a) central nervous system = brain and spinal cord
b) peripheral nervous system = nerves
3. Draw a neuron and label its main parts (dendrites, cell body, nucleus, axon, axon
tips).
4. List the function of each part of a neuron.
a) dendrites—carry a nerve impulse to the cell body
b) cell body—contains the nucleus
c) nucleus—control center of the cell
d) axon—carry a nerve impulse away from the cell body
e) axon tips—release the nerve impulse
5. Describe how two neurons are always joined. (_______ end to ________ end).
Neurons are always joined axon end to dendrite end.
6. Identify what a synapse is and how two joined neurons overcome a synapse.
A synapse is the gap between two neurons. The nerve impulse travels as an
electrical impulse through the neuron. However, the nerve impulse becomes a
chemical impulse as it travels across the synapse.
7. What is an “impulse”, and in what direction do impulses always travel across a
neuron?
The nerve impulse is simply the message that is being sent. A nerve impulse
always travels from dendrite end to axon end across a neuron.
8. Distinguish between a sensory, motor, and interneuron.
a) sensory neurons—nerve cells that carry a nerve impulse to the central
nervous system
b) motor neurons—nerve cells that carry a nerve impulse away from the
central nervous system and towards the muscle or gland that needs to
respond
c) interneurons—nerve cells found only in the brain and spinal cord
9. List the three main parts of the brain and identify what each part controls.
a) cerebrum—largest part of the brain; controls thinking, personality, the
senses, memory
b) cerebellum—part of the brain that controls balance and muscle
coordination
c) brain stem (medulla)—part of the brain that controls involuntary actions
such as breathing and heart rate
10. What is a reflex, and why does it occur quickly and automatically?
A reflex is caused by a nerve impulse that bypasses the brain. Bypassing the brain
allows the muscle or gland to respond quickly.
11. What role does the autonomic nervous system have? What role does the somatic
nervous system have?
autonomic nervous system—division of the peripheral nervous system that
controls involuntary actions
somatic nervous system—division of the peripheral nervous system that controls
voluntary actions
12. List the five sense organs and identify what “sense” they detect.
a) eye—sight
b) ear—hearing
c) tongue—taste
d) nose—smell
e) skin—touch
13. Draw the eye and label its parts.
14. List the parts of the eye and identify the function of each (sclera, choroids, retina,
cornea, iris, pupil, aqueous humor, lens, vitreous humor, optic nerve).
a) sclera—white of the eye; protective outer layer
b) choroid—middle layer of the eye that provides blood flow
c) retina—inner layer of the eye; image is reflecting onto the retina
d) cornea—transparent portion of the outer layer that allows light to enter
e) iris—colored portion of the eye; controls the size of the opening in the eye
f) pupil—opening in the eye that allows light in
g) aqueous humor—water-like substance in the eye
h) lens—focuses incoming light
i) vitreous humor—jelly-like substance in the eye that helps give the eye its
shape
j) optic nerve—carries nerve impulse to the brain where vision can be
interpreted
15. Identify the sensory neurons in the eye, where they are located, and what they
sense.
rods—located in the retina; help to see in dim light
cones—located in the retina; help to see colors
16. List the parts of the ear and identify the function of each part (external ear, ear
canal, ear drum, hammer, anvil, stirrup, cochlea, auditory nerve, semicircular
canals).
a) external ear—acts as a funnel to guide sound waves into the ear
b) ear canal—tube connecting external ear to middle ear
c) hammer—first of three small bones to pass the vibrations on towards the
inner ear
d) anvil—second of three small bones to pass the vibrations on towards the
inner ear
e) stirrup—third of three small bones to pass the vibrations on towards the
inner ear
f) cochlea—inner ear structure that aids in hearing
g) auditory nerve—nerve that carries vibrations to the brain to be interpreted
as sound
h) semicircular canals—inner ear structure that aid in balance
17. Distinguish between physical stimuli and chemical stimuli.
physical stimuli—hearing, seeing, touching
chemical stimuli—tasting and smelling
18. Distinguish between “taste” and “flavor”.
We recognize four basic “tastes”—sweet, sour, salty and bitter. However, we
recognize over 80 different odors that work together with taste and texture to
produce “flavor”.