Bio 115 Sensory System

Question 1

Sensory reception

Answer 1

the detection of stimulus by sensory cell. Some sensory receptors respond to stimuli from within the body, such as blood pressure and body position. Other receptors detect stimuli from outside the body, such as heat, light, pressure, or chemicals. Most light receptors can detect a single quantum of light.

Question 2

Receptor potential

Answer 2

the change in membrane potential. Influence production of action potentials.

Question 3

Sensory transduction

Answer 3

the conversion of stimulus energy to a change in the membrane potential of a sensory receptor cell.

Question 4

Frequency coding

Answer 4

As the intensity of a stimulus increases, the frequency or rate of action potentials increases.

Question 5

Reception

Answer 5

The detection of a stimulus by sensory cells. Each sensory cell is either a specialized neuron or a non-neuronal cell that regulates a neuron

Question 6

Transduction

Answer 6

The conversion of stimulus energy to a change in the membrane potential of a sensory receptor cell

Question 7

Amplification

Answer 7

The strengthening of stimulus energy during transduction. Amplification that occurs in sensory receptor cells often requires signal transduction pathways that involve enzyme- catalyzed reactions.

Question 8

Transmission

Answer 8

Sensory information travels through the nervous system as nerve impulses. A sensory receptor generates action potentials that travel along an axon extending into the CNS. A non-neuronal sensory receptor does not itself generate action potentials, but instead conveys information to an afferent neuron via a chemical synapse.

Question 9

Perception

Answer 9

The interpretation of sensory system input by the brain. Perceptions such as colors, smells, and sounds are constructions formed in the brain and don’t exist outside of it. Action potentials from sensory receptors travel along neurons that are dedicated to a particular stimulus; these dedicated neurons form synapses with particular neurons in the brain or spinal cord. Then, the brain distinguishes stimuli such as sight and sound solely by the path along which the action potentials have arrived.

Question 10

Adaptation

Answer 10

The tendency of sensory neurons to become less sensitive when they are stimulated repeatedly.

Question 11

Mechanoreceptors

Answer 11

Sense physical deformation caused by forms of mechanical energy. Some consists of ion channels that are linked to a hairlike extension of the cell (cilium). Bending of the cilium generates tensions that change the shape of the ion channel, either opening or closing it.

Question 12

Electromagnetic receptors

Answer 12

Detect electromagnetic energy in forms such as light, electricity, and magnetism.

Question 13

Thermoreceptors

Answer 13

Detection of hot and cold

Question 14

Pain receptors

Answer 14

Animals and humans rely on nociceptors, a receptor that responds to harmful or painful stimuli.

Question 15

Chemoreceptors

Answer 15

the perception of smell and taste both depend on chemoreceptors. Mammals can distinguish thousands of different odors, each caused by a structurally distinct odorant (smells that are carried through the air).

Question 16

How are taste receptor cells organized?

Answer 16

They are organized into taste buds. Each taste cell has just a single receptor type, programming the cell to detect only one of the five tastes. (bitter, sweet, sour, salty, and savory)

Question 17

Explain how the eyes and brain work together to integrate visual information

Answer 17

Axons of ganglion cells form the optic nerves that transmit action potentials from the eyes to the brain. Axons in the optic nerves are routed at the optic chiasm that sensations from the left visual field are transmitted to the right side of the brain, and sensations from the right visual field are transmitted to the left side of the brain.

Question 18

Describe the function of the ear in hearing and balance

Answer 18

To sense gravity and maintain equilibrium most invertebrates rely on statocysts. In statocysts granules formed by grains of dense materials sit in a chamber lined with ciliated receptor cells.