9 Sensory Systems 1

1. Which sensory receptor is responsible for touch, pressure, hearing, and equilibrium? Thermoreceptors Photoreceptors Chemoreceptors Pain receptors (or nociceptors) Mechanoreceptors E. Mechanoreceptors

1. Which sensory receptor is responsible for touch, pressure, hearing, and equilibrium? Answer: e. Mechanoreceptors Explanation: Mechanoreceptors are responsible for the sensations we describe as touch, pressure, hearing, and equilibrium. In addition, the body has mechanoreceptors that detect changes in blood pressure and others that indicate the body’s position.

2. Which sensory receptors experience sensory adaptation? Pain receptors and taste receptors Light touch receptors and olfactory receptors Thermoreceptors and photoreceptors All of the above B. Light touch receptors and olfactory receptors

2. Which sensory receptors experience sensory adaptation? Answer: b. Light touch receptors and olfactory receptors Explanation: Sensory adaptation occurs when the sensory receptor stops responding even though the stimulus is still present. Pain receptors and photoreceptors do not adapt.

3. Under which conditions does the pupil become larger (dilates)? In dim light When you are frightened When you are very interested in something All of the above D. All of the above

3. Under which conditions does the pupil become larger (dilates)? Answer: d. All of the above Explanation: The pupil becomes larger (dilates) in dim light and smaller (constricts) in bright light. Pupil size is also affected by emotions. The pupils dilate when you are frightened or when you are very interested in something. They constrict when you are bored.

4. The aqueous humor in the anterior chamber of the eye is produced by ____. the retina the ciliary body the fovea the choroid B. the ciliary body

4. The aqueous humor in the anterior chamber of the eye is produced by ____. Answer: b. the ciliary body Explanation: Aqueous humor is a clear fluid that nourishes the lens and cornea and flushes away their wastes. It is produced continuously by the ciliary body and circulates through the anterior chamber before draining into blood vessels that surround the eye.

5. The ____ is a smooth muscle that controls the shape of the lens, while the ____ is a smooth muscle that controls the size of the pupil. iris; vitreous humor sclera; cornea ciliary body; iris retina; choroid body C. ciliary body; iris

5. The ____ is a smooth muscle that controls the shape of the lens, while the ____ is a smooth muscle that controls the size of the pupil. Answer: c. ciliary body; iris Explanation: The ciliary body controls the shape of the lens when focusing, a process called accommodation. The iris controls the amount of light that enters the eye by changing the size of the pupil.

6. Which photoreceptors are extremely sensitive to low levels of light? Rods Cones Bipolar cells Ganglion cells A. Rods

6. Which photoreceptors are extremely sensitive to low levels of light? Answer: a. Rods Explanation: There are only two types of photorecpetors in the human eye—rods and cones. Rods are sensitive to very low levels of light and permit vision in dimly lit environments. Cones require bright light for activation but permit us to see in color.

7. What is an irregular curvature of the cornea called? Astigmatism Convergence Farsightedness Nearsightedness A. Astigmatism

7. What is an irregular curvature of the cornea called? Answer: a. Astigmatism Explanation: Astigmatism results in a distorted visual image because of irregularities in the curvature of the cornea.

8. Contact lenses and glasses change the ____ of light rays to focus them directly onto the ____. bending; retina reflection; lens shape; sclera brightness; choroid body A. bending; retina

8. Contact lenses and glasses change the ____ of light rays to focus them directly onto the ____. Answer: a. bending; retina Explanation: The cornea and lens bend light rays so that they are focused directly onto the retina (not in front or in back of it). If needed, contact lenses and glasses will help the cornea and lens accomplish this task.

9. The ____ functions to equalize pressure on either side of the tympanic membrane. pinna oval window cochlea auditory tube D. auditory tube

9. The ____ functions to equalize pressure on either side of the tympanic membrane. Answer: d. auditory tube Explanation: The auditory tube connects the middle ear to the throat. Swallowing or yawning opens the tube and allows the pressure in the middle ear to equalize with the pressure outside of the ear.

10. Which organ is the first to respond to sound waves traveling in the air? The spiral organ Tympanic membrane (eardrum) Malleus Semicircular canals B. Tympanic membrane (eardrum)

10. Which organ is the first to respond to sound waves traveling in the air? Answer: b. Tympanic membrane (eardrum) Explanation: Sound first enters the ear by the external auditory canal, which leads to the eardrum or tympanic membrane, which perceives the vibrations.

11. Hearing and balance both are sensed by ____. chemoreceptors photoreceptors mechanoreceptors thermoreceptors C. mechanoreceptors

11. Hearing and balance both are sensed by ____. Answer: c. mechanoreceptors Explanation: Hearing and equilibrium are both detected by hair cells, which are mechanoreceptors.

12. Receptors that monitor the degree of muscle tension and provide input for balance and muscle coordination are called ____. Meissner’s corpuscles Merkel disks Muscle spindles Golgi tendon organs D. Golgi tendon organs

12. Receptors that monitor the degree of muscle tension and provide input for balance and muscle coordination are called ____. Answer: d. Golgi tendon organs Explanation: Muscle spindles monitor the length of a muscle and Golgi tendon organs detect the tension in a muscle. Input from both of these sensors is used by the brain to help regulate balance and coordination.

13. The taste of umami indicates ____. a high level of vitamin C a high level of protein a high level of energy a high level of salts and electrolytes B. a high level of protein

13. The taste of umami indicates ____. Answer: b. a high level of protein Explanation: There are five primary tastes. Sweet indicates a high level of calories. Salty indicates a high level of salt and electrolytes. A sour taste often suggests a high level of vitamin C. The taste of umami indicates the food has a high protein level. A bitter taste often means the food is spoiled or poisonous.