Ch 46: Sensory Systems

Question 1

Na+/K+ Pump

Answer 1

Actively moves Na+ out and K+ in

Pumps so that more K+ ions are inside the cell

Question 2

Membrane potential

Answer 2

Determined by electric charges
More positive charges are outside and more negative are inside
A rapid, positive going change in charge

Question 3

Hyperpolarization

Answer 3

When the charge of the inside of the cell drops lower than resting potential

Question 4

Sensory system

Answer 4

Sensory cells + sensory organs + neural network

Question 5

Sensory receptors

Answer 5

Receptors that respond to stimuli by directly or indirectly opening or closing ion channels

Question 6

Ionotropic

Answer 6

Directly affect ion channels
Produce small and quick effects
Electro-, mechano-, and thermo-receptors

Question 7

Metabotropic

Answer 7

Indirectly affect ion channels through messengers
Require a G-protein and second messenger
Produce large and long effects because the process is amplified
Chemo- and photo-receptors

Question 8

Intensity of a sensation

Answer 8

Coded as the frequency of action potentials

Question 9

Adaptation

Answer 9

Diminishing response to repeated stimulation

Enable species to ignore background conditions but remain sensitive to new stimuli

Question 10

Taste classes

Answer 10

Salty, sour, sweet, bitter, and umami (MSD taste)

Question 11

-Osmias

Answer 11

Disorders of smell

Question 12

-Geusias

Answer 12

Disorders of taste

Question 13

Somatosensory system

Answer 13

Responds to touch and pressure
Involves mechanoreceptors
Senses position and movement through the stimulation of stretch receptors in muscles and joints

Question 14

Muscle spindles

Answer 14

Mechanoreceptors in muscles
Specialized muscle cells
Have sensory neurons wrapped around them
Stretch triggers a change in the ion channels

Question 15

Golgi tendon organs

Answer 15

Mechanoreceptors in joints
Sense muscle contraction
Is an inhibitor mechanism 
Responds to tendon pulls
Is a balancing point

Question 16

Auditory system

Answer 16

Sound-perceiving system
Hair cells are the mechanoreceptors
Sounds are pressure waves that are converted into changes in resting potentials

Question 17

Stereocilia

Answer 17

Fingerlike extensions of the cell membrane

Receive cilia

Question 18

Tympanic membrane

Answer 18

Eardrum

Converts sound waves to vibrations

Question 19

Ossicles

Answer 19

Stapes + Incus + Malleus

“The little bones”

Question 20

Vestibular system

Answer 20

Equilibrium-maintaining system
Hair cells are the mechanoreceptors
Has 3 semicircular canals at angles to each other
Deal with balance, posture, and acceleration

Question 21

Malleus

Answer 21

“the hammer”

Directly in touch with the tympanic membrane

Question 22

Incus

Answer 22

“the anvil”

Question 23

Stapes

Answer 23

“the stirrup”

Bone that vibrates the oval window

Question 24

Cochlea

Answer 24

A tapered and coiled chamber composed of 3 parallel canals
Full of fluid
When it vibrates, there are waves
Responsible for hearing

Question 25

Oval window

Answer 25

Connects the middle ear to the inner ear

Question 26

Organ of Corti

Answer 26

Transduces pressure waves into action potentials Changes how much chemical is released When the stereocilia bend, the ion channel either fully opens or closes Uses receptor potential

Question 27

Tectorial membrane

Answer 27

Thick membrane that keeps the stereo cilia in place

Question 28

Conduction deafness

Answer 28

Loss of function of the tympanic membrane and/or the middle ear

Question 29

Nerve deafness

Answer 29

Damage to hair cells or auditory nerve pathways

Question 30

Otoliths

Answer 30

``` "ear stones" Calcium carbonate deposits on top of hair cells Help bend hair cells Translate to membrane potential Amplify the force of gravity Respond to process acceleration ```

Question 31

Ciliary muscle

Answer 31

Allows the shape of the eye lens to change

Question 32

Pupil

Answer 32

Allows light to go through to get detected in the eye Size is controlled by the iris Contracts when there is too much light

Question 33

Lens

Answer 33

Projects the image to the back of the eye

Question 34

Fovea

Answer 34

Contains the highest concentration of sensory cells in the eye Where the image seen is projected Cones only Where our highest acuity is

Question 35

Retina

Answer 35

Where photoreceptors are located

Question 36

Myopia

Answer 36

Disease where the lenses cannot adjust appropriately | Nearsighted

Question 37

Hyperopia

Answer 37

Disease where the lens adjusts too much Image gets projected behind the fovea Farsighted

Question 38

Rod cells

Answer 38

Highly light-sensitive cells Black and white vision In the dark, sodium channels are open (depolarization)

Question 39

Cone cells

Answer 39

Function at high light levels | Responsible for color vision