162 MHR • Unit 2 Homeostasis
SECTION REVIEW
- How is sensory information important to you?
- List three parts of your body that relay sensory
information to the brain. - Draw a diagram of the eye. Use a coloured
marker to highlight those parts of the eye that are
part of the nervous system. Use a differently coloured
marker to highlight the part of the eye that is mostly
muscle. Use a third coloured marker to highlight the
parts of the eye that are vascular (tissue supplied
by blood). - Describe the path of light through each part of
the eye, from the outermost structure to the retina. - Explain why there is a blind spot in one portion
of the retina. - Identify those parts of the eye that are
responsible for allowing light in. - Identify those parts of the eye that are
responsible for keeping light out. - Draw a feedback loop showing how the eye
responds to low levels of light. - Distinguish between rod cells and cone cells
and identify the advantage of each. - List three disorders of the visual system.
- How would you explain to a young child the
nature of the damage that can be done to the eye
by staring directly at the Sun in the sky? - Describe how your eye focusses on details of
close images, such as the words on this page. Make
a sketch that shows how the lens of the eye changes
shape as you focus on near and distant objects. - Identify how the skin collects information about
the outside world. - Try the following experiment to find out which
parts of your hand are most sensitive to touch. Push
two pins through a small card, about 2 mm apart.
Draw an outline of your hand. Have a lab partner
lightlytouch the tip of the pins to different parts of
your hands and fingers. Without looking, say whether
you feel one or two pins for each test. Mark each test
on the drawing, indicating whether you felt one or
two pins. When finished, analyze the drawing to
determine which parts of your hands and fingers
are most sensitive to touch. - If you wear eyeglasses or contact lenses,
investigate the type and strength of the corrective
lenses you are using. Find out if the prescription for
each eye is the same or different. If possible (and if
your teacher judges it appropriate to do so), compare
the corrective lenses you use to those used by your
classmates. What type of corrective lenses are most
common in your class? Discuss and debate the pros
and cons of wearing eyeglasses versus contact
lenses. - When you are outside on a sunny day, you feel
heat, not light. How can you decide if a sowbug
responds to light stimulus, but not heat stimulus? - A severe impact to the head can cause
blindness. Understanding the mechanisms of sight
involve study of brain activity as well as study of the
eye. How can research into the neurology of vision
be used to develop safe helmets? - Some activities put people at risk for injury. For
one activity (such as hockey) identify how risk of
injury can be reduced. - What can you do to prevent damage to your
hearing from extremely loud or persistent noises in
your environment? Is the school presently doing
enough to protect student hearing? What types of
policies could be adopted to help protect students
from hearing loss while attending noisy school
functions, such as school dances?
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