Essentials of Anatomy and Physiology

Arterial Receptors—in large arteries; detect
changes in blood

1. Aortic arch—curves over top of heart. Aortic sinus
   contains pressoreceptors; aortic body contains
   chemoreceptors; sensory nerve is vagus (10th
   cranial).


2. Right and left carotid arteries in the neck; carotid
   sinus contains pressoreceptors; carotid body con-

tains chemoreceptors; sensory nerve is the glos-

sopharyngeal (9th cranial).

3. Pressoreceptors detect changes in blood pressure;
   chemoreceptors detect changes in pH or oxygen
   and CO 2 levels in the blood. This information is
   used by the vital centers in the medulla to change
   respiration or circulation to maintain normal blood
   oxygen and CO 2 and normal blood pressure.

The Senses 219

REVIEW QUESTIONS

1. State the two general functions of receptors.
   Explain the purpose of sensory neurons and sen-
   sory tracts. (p. 198)


2. Name the receptors for the cutaneous senses, and
   explain the importance of this information.
   (p. 199)


3. Name the receptors for muscle sense and the parts
   of the brain concerned with muscle sense.
   (p. 200)


4. State what the chemoreceptors for taste and smell
   detect. Name the cranial nerve(s) for each of these
   senses and the lobe of the cerebrum where each is
   felt. (pp. 200, 202)


5. Name the part of the eye with each of the follow-
   ing functions: (pp. 203–206)
   a. Change the shape of the lens
   b. Contains the rods and cones
   c. Forms the white of the eye
   d. Form the optic nerve
   e. Keep dust out of eye
   f. Changes the size of the pupil
   g. Produce tears
   h. Absorbs light within the eyeball to prevent glare


6. With respect to vision: (pp. 207, 209)
   a. Name the structures and substances that refract
   light rays (in order)
   b. State what cones detect and what rods detect.

What happens within these receptors when light

strikes them?

c. Name the cranial nerve for vision and the lobe

of the cerebrum that contains the visual area

7. With respect to the ear: (pp. 210–215)
   a. Name the parts of the ear that transmit the
   vibrations of sound waves (in order)
   b. State the location of the receptors for hearing
   c. State the location of the receptors that respond
   to gravity
   d. State the location of the receptors that respond
   to motion
   e. State the two functions of the 8th cranial nerve
   f. Name the lobe of the cerebrum concerned with
   hearing
   g. Name the two parts of the brain concerned with
   maintaining balance and equilibrium


8. Name the following: (p. 216)
   a. The locations of arterial chemoreceptors, and
   state what they detect
   b. The locations of arterial pressoreceptors, and
   state what they detect
   c. The cranial nerves involved in respiratory and
   cardiac reflexes, and state the part of the brain
   that regulates these vital functions


9. Explain each of the following: adaptation, after-
   image, projection, contrast. (pp. 198–199)

FOR FURTHER THOUGHT

1. Why are the inner ear labyrinths filled with fluid
   rather than air? One reason is directly concerned
   with hearing, the other with survival.
   2. Michael’s summer job in his town was collecting
   garbage. At first he thought the garbage and the
   truck smelled awful, but by the time he went home