Special senses

Question 1

What does transduce mean?

Answer 1

(=change) environmental info changed into APs – the common language of NS

Question 2

Each type of receptor responds to a particular ______. (define term)

Answer 2

modality (=form of info, e.g. sound, light, pressure)

Question 3

_____ receptors respond at a constant rate as long as stimulus is applied. Example ______

Answer 3

Tonic

Pain

Question 4

_____ receptors respond with a burst of activity but quickly reduce firing rate at constant stimulation (______). Example ____ and _____

Answer 4

Phasic

Adaptation

Smell and touch

Question 5

__________ sense chemical stimuli.

Answer 5

Chemoreceptors

Question 6

What receptor responds to chemicals in external environment?

Answer 6

Exteroceptors

Question 7

What receptor responds to chemicals in the internal environment?

Answer 7

Interoceptors

Question 8

What receptor transduces light?

Answer 8

Photoreceptors

Question 9

What receptor responds to temp. change?

Answer 9

Thermoreceptors

Question 10

What receptor responds to deformation of their cell membrane?

Answer 10

Mechanoreceptors

Question 11

What receptor responds to intense stimuli by signaling pain?

Answer 11

Nociceptors

Question 12

What receptor signals positional info of body parts?

Answer 12

Proprioceptors

Question 13

What receptor are near an epithelial surface and respond to touch, pressure, temp, or pain

Answer 13

Cutaneous Receptors

Question 14

What receptors are part of a sensory organ and respond to hearing, equilibrium, sight, taste, and smell?

Answer 14

Special sense receptors

Question 15

What is the sensation that is produced by a receptors normal stimulus?

Answer 15

Adequate stimulus

Question 16

Mechanism in Mechanoreceptors?

Answer 16

Deformity detected via sensory dendrites or deform hair cells

Question 17

Mechanism in Pain receptors?

Answer 17

Damaged tissues release chemicals that excite sensory endings

Question 18

Mechanism in Chemoreceptors?

Answer 18

Chemical interaction affects ionic permeability of sensory cells

Question 19

Mechanism in Photoreceptors?

Answer 19

Photochemical reaction affects ionic permeability of receptor cell

Question 20

What are generator potentials?

Answer 20

Sensory receptor equivalent of Excitatory postsynaptic potential that is produced in response to adequate stimulus.

Question 21

Generator potentials are proportional to ?

Answer 21

Stimulus intensity

Question 22

AP frequency is proportional to _____ of generator potential.

Answer 22

Amplitude

Question 23

In phasic receptors the generator potential _____ to a constant stimulus and quickly _____ in amplitude

Answer 23

Adapts

diminishes

Question 24

In tonic receptors, generator potential ____ ___ adapt to a constant stimulus

Answer 24

does not

Question 25

Cutaneous receptors such as pain and temp are mediated by ___ and ___ encapsulated nerve endings. They are _____ receptors. ( tonic vs phasic)

Answer 25

free and encapsulated tonic

Question 26

_____ ____ and ____ _____ are slow adapting, expanded free nerve endings that mediate touch

Answer 26

Ruffini endings Merkel's discs

Question 27

Encapsulated nerve endings mediate touch and pressure (Anterior spinothalamic tract) . They are able to ____ quickly and include what two structures?

Answer 27

adapt Messiner's and pacinian corpuscles

Question 28

Cold receptors are located in the ____ ___, while warm receptors are located _____ in ____.

Answer 28

upper dermis deeper in dermis

Question 29

What neurotransmitters are used by nociceptors?

Answer 29

Glutamate and Substance P ( aka Pain NT)

Question 30

Heat elicits pain thru _____ receptors.

Answer 30

Capsaicin

Question 31

Sensations from cutaneous and proprioceptors  Carried by ? and then in ?

Answer 31

large, myelinated nerve fibers in dorsal columns of spinal cord medial lemniscus to thalamus and sensory cortex (postcentral gyrus)

Question 32

A receptive field is a ?

Answer 32

area of skin whose stimulation results in changes in firing rate of sensory neuron.

Question 33

Pattern of receptive fields?

Answer 33

Larger field = less sensory receptors and vice versa

Question 34

Two-Point Touch Threshold

Answer 34

Is minimum distance at which 2 points of touch can be perceived as separate

Question 35

Two-Point Touch Threshold is a measure of ____ ____ or distance between receptive fields

Answer 35

tactile acuity

Question 36

Lateral Inhibition is ?

Answer 36

- CNS process that sharpens sensation  | - Sensory neurons at center of stimulation area inhibit more lateral neurons

Question 37

What are the four papillae and where are they located on the tongue?

Answer 37

Vallate- back of tongue  Fungiform- tip and sides  Foliate- sides  Filiform- tip and anterior 2/3

Question 38

Explain the function of taste.

Answer 38

Receptors on hairs detect dissolved substances

Question 39

What are the 5 taste types?

Answer 39

``` Sour Salty Bitter Sweet  Umami ```

Question 40

What chemical is responsible for the umami taste?

Answer 40

Glutamate (MSG)

Question 41

_____ ___ are modified epithelial cells with microvilli that detect taste. Each on consists of ___ - ___ modified epithelial cells.

Answer 41

taste buds 50 - 100

Question 42

Which taste types don not have receptors and instead act by passing thru channels?

Answer 42

Salty and sour

Question 43

Explain the process of salty taste causing a sensory neuron stimulus.

Answer 43

1. sodium passes through channel into taste bud and cause depolarization. 2. Calcium channels are opened 3. Neurotransmitter is released causing stimulus.

Question 44

Explain the process of sour taste causing a sensory neuron stimulus

Answer 44

1. H+ pass through ion channel and other routes to cause depolarization. 2. Calium channels open. 3. NT is released which causes stimulus

Question 45

Explain the process of sweet and umami taste causing a sensory neuron stimulus

Answer 45

1. sugars and amino acids bind with membrane receptor 2. G proteins cause release of secondary messenger 3. K channels close 4. Depolarization 5. NT released.

Question 46

Explain the process of bitter causing a sensory neuron stimulus

Answer 46

1. Quinine bind with membrane receptor 2. G proteins cause release of secondary messenger 3. K channels close 4. Depolarization 5. NT released.

Question 47

What three cranial nerves are involved with taste?

Answer 47

``` Trigeminal nerve ( CN 5 / lingual branch) ( anterior portion) Glossopharyngeal nerve ( CN 9 and middle portion) Facial nerve ( CN 7 and posterior portion) ```

Question 48

Explain the neuronal pathway of taste from cranial nerves 5/7/9 to brain.

Answer 48

1. CN 5/7/9 relay stimulus to Nucleus of tractus solitaries | 2. Information is relayed from nucleus of tractus solitaries to thalamus, and from thalamus to taste are of cortex.

Question 49

The olfactory apparatus consists of ?

Answer 49

receptor cells supporting cells basal cells

Question 50

What is the olfactory hairs?

Answer 50

Cilia which lies in mucous

Question 51

Receptor cells are bipolar neurons that send axons to _____ ______. (smell)

Answer 51

olfactory bulb

Question 52

____ ___ are stem cells that produce new receptor every 1 -2 months.

Answer 52

Basal cells

Question 53

Supporting cells contain?

Answer 53

detoxifying enzymes

Question 54

Gives the basic process of smell from odors.

Answer 54

1. odorants bind to chemoreceptor molecules and act through G proteins 2. This causes depolarization that leads to initiate action potentials in neurons.

Question 55

What is responsible for extreme sensitivity of smell ? ( humans nose can detect a billionth of ounce of perfume in air.

Answer 55

The high number of G proteins associated with single receptor. ( up to 50)

Question 56

Explain the neuronal pathway of olfaction.

Answer 56

1. Fibers of olfactory nerve receive stimulus | 2. information is relayed from olfactory bulb to Medial , lateral, and intermediate olfactory area.