46. Sensory Systems

Although we often assume that our sense organs are reporting a complete picture of the world to our brains, in fact the world is full of stimuli (very low frequency sound, cosmic rays, electrical fields, etc.) that our sense organs cannot detect. This situation is best characterized as a failure of our sense organs to do what to these stimuli?

You look all over for your glasses and then find them pushed back onto your forehead. This error could be attributed to __________.

A fish detects vibrations in the water around it by means of its lateral lines, rows of sensory receptors along each side of the body. Based on what you know about sensory receptors, the lateral line receptors are probably which of the following?

If we wait too long between meals, our blood glucose levels drop. Which receptors will respond to this decrease in blood glucose?

Which of the following classes of sensory receptors consists of neurons with naked dendrites?

The round window is found __________.

Organs in the inner ear of mammals are the cochlea, semicircular canals, and vestibule. Match them to their functions.

Sitting too close to the amplifiers at a concert may __________.

The brain determines the loudness of a sound from the __________.

If the basilar membranes in the ears were equal in width and flexibility along their length, how would this affect a person's sense of hearing?

A person born without otoliths in the ears would be __________.

Compound eyes are advantageous for small prey species to detect a potential predator because __________.

In the vertebrate eye, the __________ focuses light on the photoreceptors.

Which of the following correctly traces the path of light into your eyes?

What is the fluid in the anterior chamber of the eye?

Difficulty in distinguishing red from green is most likely due to a defect in which cells?

A human born with nonfunctional rhodopsin would __________.

Which of the following occurs when you move from a bright area into a darkened room?

Which of the following choices is the correct order of the neural pathways that light travels after hitting the retina?

Correct focusing of the image on the retina in humans is achieved by changing the __________.

The body uses the vitamin A precursors from some foods to make a substance called retinal, which __________.

When you move an object from 15 inches in front of your eyes to 10 inches in front of your eyes, the lenses __________.

The greatest concentration of cone receptors is found at the __________.

Some sensory processing occurs within the retina of the vertebrate eye. In one type of retinal processing, a horizontal cell that receives input from a stimulated rod or cone then inhibits surrounding photoreceptors and bipolar cells. This type of processing is called __________.

Incapacitating the muscles of a mammalian eye would result in an inability __________.

A baby is born with the normal number and distribution of rods but no cones. What would we expect the baby to be?

Which of the following statements is correct?

Taste and smell are two distinct senses in animals living in terrestrial environments. Animals living in aquatic environments, however, have no distinction between taste and smell. Which response might explain this difference?

Which of the following sensory receptors is incorrectly paired with its category? a. hair cell—mechanoreceptor b. snake pit organ—thermoreceptor c. taste receptor—chemoreceptor d. olfactory receptor—electromagnetic receptor

Complete this concept map summarizing sensory receptors.

Which of the following sensory receptors is incorrectly paired with its category? a. hair cell . . . mechanoreceptor b. taste receptor . . . chemoreceptor c. rod . . . electromagnetic receptor d. olfactory receptor . . . electromagnetic receptor

Which of the following are not known to be present in human skin? a. thermoreceptors b. electromagnetic receptors c. pressure receptors d. pain receptors

Which sensory distinction is not encoded by a difference in neuron identity? a. white and red b. red and green c. loud and faint d. salty and sweet

What do the receptor cells in the lateral line system along the sides of a shark and the cochlea of your ear have in common? a. They use hair cells to sense sound or pressure waves. b. They are organs of equilibrium. c. They use electromagnetic receptors to sense pressure waves in fluid. d. They use granules that signal a change in position and stimulate their receptor cells.

If you look away from this book and focus your eyes on a distant object, the eye muscles _________ and the lenses _________ to focus images on the retinas. a. relax . . . flatten b. relax . . . become more rounded c. contract . . . flatten d. contract . . . become more rounded

How does your brain determine the volume and pitch of sounds?

Eighty-year-old Mr. Johnson was becoming slightly deaf. To test his hearing, his doctor held a vibrating tuning fork tightly against the back of Mr. Johnson's skull. This sent vibrations through the bones of the skull, setting the fluid in the cochlea in motion. Mr. Johnson could hear the tuning fork this way, but not when it was held away from the skull a few inches from his ear. The problem was probably in the _________ . (Explain your answer.) a. auditory nerve leading to the brain b. hair cells in the cochlea c. bones of the middle ear d. fluid of the cochlea

When you first sit down to read in a coffee shop, the surroundings seem very loud. Yet after a few minutes reading you realize you hardly notice the noise at all. Why is that?

Hold your right eye closed. With your left eye, look at the + in the image below. Starting from about two feet away, slowly bring your head closer while looking at the +. What happens to the dot when you get close to the image? What property of the eye's structure does this exercise demonstrate?

Construct a graph in which membrane potential is on the y axis and time is on the x axis. Then draw the action potentials that occur when a bitter flavor is absent, followed by the action potentials that result when a person tastes a bitter flavor.

SCIENTIFIC THINKING We know that sea turtle hatchlings use Earth's magnetic field to navigate. Do they also use light cues from the moon to get from the sand to the ocean waves? Outline an experiment to answer this question.

Have you ever felt your ears ringing after listening to loud music? Can this permanently impair your hearing? Should manufacturers of music devices and producers of concerts be required to warn consumers? What effect might warnings have?