Sensory Physiology

Question 1

how is a physical stimulus converted into a response ?

Answer 1

stimulus -> receptor -> neuron -> CNS (receives, interprets and responds)

Question 2

what are the 6 types of sensory receptors ?

Answer 2

1. photoreceptors
2. mechanoreceptors
3. chemoreceptors
4. nociceptors
5. thermoreceptors
6. osmoreceptors

Question 3

what are nocireceptors ?

Answer 3

pain receptors

Question 4

what are the classes of sensory receptors ?

Answer 4

complex and special

Question 5

what are complex neural receptors ?

Answer 5

olfaction and somatic senses

Question 6

what are the four special senses receptors ?

Answer 6

vision, hearing, balance and taste

Question 7

difference between complex and special receptors ?

Answer 7

• special senses = separate from neutron but still need action potential
• complex receptors = must be sent to neutron and converted to action potentials
  (only difference is the step is how receptor will release neurotransmitters; chemically gates Chanels opening up and ions are flying through it)

Question 8

action potentials vs receptor potentials ?

Answer 8

• action potentials are all or none (once initiated, they will flow down the entire axon) *** once hits threshold action potential must occur
• receptor potentials are graded (they can differ in amplitude and dissipate over time and distance)

Question 9

what type of frequencies of action potentials last longer ?

Answer 9

higher frequency (release of more neurotransmitters)

Question 10

if a receptive field is more sensitive what does this mean ?

Answer 10

more senses present

Question 11

where does smell senses occur (nerve and bulb)

Answer 11

cranial nerve 1 and olfactory bulb

Question 12

about how many odor receptors do we have ?

Answer 12

about 350

Question 13

what are the five taste sensations ?

Answer 13

sweet, sour, salty, bitter and umami

Question 14

around how many taste buds do we have ?

Answer 14

2000-5000

Question 15

how do we specifically taste our food ?

Answer 15

through taste cells “taste buds” that have flavour (each taste bud contains 50-150)

Question 16

what are five important structures of the CNS for sensory physiology ?

Answer 16

1. cerebrum
2. cerebellum
3. brain stem
4. diencephalon
5. spinal cord

Question 17

what three parts make up the cerebrum ?

Answer 17

cortex, basal ganglia and limbic system (main part of brain)

Question 18

what three parts make up the cerebrum ?

Answer 18

cortex, basal ganglia and limbic system (main part of brain)

Question 19

what is the cerebellum responsible for ?

Answer 19

coordination of movement and different procceses

Question 20

what three parts make up the cerebrum ?

Answer 20

medulla oblongata, pons, and midbrain

Question 21

what four parts make up the diencephalon ?

Answer 21

thalamus, hypothalmus, pineal gland, pituitary gland

Question 22

what are the four “lobes” of the brain ?

Answer 22

frontal, parietal, temporal, and occipital

Question 23

what is the frontal lobe responsible for ?

Answer 23

movement and cognition

Question 24

what is the parietal lobe responsible for ?

Answer 24

sensation

Question 25

what is the temporal lobe responsible for ?

Answer 25

hearing and object perception

Question 26

what is the occipital lobe responsible for ?

Answer 26

vision

Question 27

what are the four somatic senses ?

Answer 27

1. touch 2. proprioception 3. temperature 4. nocieception

Question 28

what is proprioception ?

Answer 28

awareness of body movement and location in space

Question 29

how do mechanoreceptors differ ?

Answer 29

1. adaptation rate 2. receptive field size

Question 30

what are the four adaptation rates ?

Answer 30

merkel's disk, meissner's corpuscle, ruffini's ending and pacinian corpuscle

Question 31

which two adaptation rates have small receptive fields ?

Answer 31

merkel's disk and meissner's corpuscle

Question 32

what two adaptation rates have large receptive fields ?

Answer 32

ruffini's ending and pacinian corpuscle

Question 33

which two adaptation rates have slow adaptation ?

Answer 33

merkel's disk and ruffini's ending

Question 34

which two adaptation rates have rapid adaptation ?

Answer 34

meissner's corpuscle and paccinian corpuscle

Question 35

regions with high tactile acuity have what size receptive fields ?

Answer 35

small

Question 36

what is two-point discrimination ?

Answer 36

the smallest seperation between two points on the skin that is perceived as two points rather than one

Question 37

large receptive fields are perceived as ______

Answer 37

one point

Question 38

small receptive fields are perceived as ______

Answer 38

two points

Question 39

between dorsal root and ventral root which is sensory and which is motor ?

Answer 39

sensory = dorsal motor = ventral

Question 40

what is the primary somatosensory cortex (S1) made up of ?

Answer 40

areas 3, 1 and 2 (located on the post central gyrus)

Question 41

what is the primary motor cortex located on ?

Answer 41

the precentral gyrus

Question 42

what is homunculus ?

Answer 42

homunculus represents either the motor or the sensory distribution along the cerebral cortex of the brain.

Question 43

where are thermoreceptors found ?

Answer 43

in the brain

Question 44

what are the three pain fiber types ?

Answer 44

beta, delta and C

Question 45

describe alpha beta fiber type characteristics and associated stimuli ?

Answer 45

large, myelinated and mechanical stimuli (touch)

Question 46

describe alpha delta fiber type characteristics and associated stimuli ?

Answer 46

small, myelinated and intense mechanical or mechanothermal stimuli, fast pain

Question 47

describe C fiber type characteristics and associated stimuli ?

Answer 47

small, unmyelinated and heat, cold, slow pain

Question 48

what has a higher threshold nociceptors or themoreceptors ?

Answer 48

nociceptors have higher than thermoreceptos

Question 49

more pain = higher or lower threshold

Answer 49

higher threshold (higher pain tolerance)

Question 50

name the 7 anatomy parts of the eye

Answer 50

- pupil - cornea - iris - sclera - conjunctive - extraocular muscles - optic nerve

Question 51

what happens at the optic disk ?

Answer 51

no photoreceptors present therefore blind at this spot

Question 52

what is the order of retinal processing cells ?

Answer 52

ganglion cells -- bipolar cells -- photoreceptors

Question 53

what are the two types of photoreceptors ?

Answer 53

cones and rods

Question 54

what are rods ?

Answer 54

highly sensitive to light and responsible for vision at low light levels (night vision)

Question 55

what are cones ?

Answer 55

less sensitive to light, three types of cones; red blue and green (responsible for colour)

Question 56

what happens to light transduction in the darkness ?

Answer 56

rods and cones are depolarized

Question 57

what happens to light transduction in light stimulus ?

Answer 57

rods and cones are hyperpolarized

Question 58

what happens to light transduction at recover phase ?

Answer 58

all channels are closed

Question 59

what is the fovea ?

Answer 59

region of the highest visual acuity very small receptive field

Question 60

which photoreceptors are selectively only present at the fovea ?

Answer 60

cones (for colour vision)

Question 61

what are the four types of eye movement

Answer 61

- saccades - smooth pursuit - vestibule-ocular reflex - vergence

Question 62

what is saccades ?

Answer 62

rapid, jerky eye movements

Question 63

what is smooth pursuit ?

Answer 63

smooth eye movement that keeps the image of a moving object of interest on the fovea

Question 64

what is vestibule-ocular reflex ?

Answer 64

stabilizes the eye during a head movement

Question 65

what is vergence ?

Answer 65

used when the object of interest is approaching or moving away

Question 66

where do fibres from the nasal part of either eye cross over ?

Answer 66

at the optic chiasm

Question 67

what is the order of the visual tract from back to eyes ?

Answer 67

primary visual cortez -- optic tract -- optic chiasm -- optic nerve

Question 68

what region of ear directs the sound into the ear ?

Answer 68

pinna or outer ear

Question 69

which region of ear funnels and conducts the sound to the middle ear ?

Answer 69

ear canal

Question 70

which region of ear separates the external ear from the middle ear

Answer 70

tympanic membrane

Question 71

which region of ear transfers the sound from the external environment to the inner ear ?

Answer 71

small bones

Question 72

what are the three little bones in ear called ?

Answer 72

malleus, incus and stapes

Question 73

what do hair cells in ear do ?

Answer 73

depolarizes the nerve

Question 74

what do fluid waves travel ?

Answer 74

basilar membrane

Question 75

what does tonopoty mean ?

Answer 75

different cells responding to different frequencies

Question 76

slow wave = what frequency ?

Answer 76

low frequency

Question 77

what is the auditory pathway in the CNS ?

Answer 77

ears -> medulla -> midbrain -> thalamus -> auditory cortex

Question 78

where do the nerves cross the body midline in the auditory pathway ?

Answer 78

medulla

Question 79

where do projections to cerebellum come from ?

Answer 79

midbrain

Question 80

what are the three types of hearing loss ?

Answer 80

conductive, sensorineural and central

Question 81

what is sensorineural hearing loss ?

Answer 81

damage to structures of inner ear that affects hair cells, or to auditory nerve

Question 82

what is conductive hearing loss ?

Answer 82

sound is unable to be transmitted through outer or middle ear

Question 83

what is central conductive hearing loss ?

Answer 83

damage to auditory pathways upstream from cochlea (defect in CNS)

Question 84

what does the cochlea in the ear do ?

Answer 84

It changes sounds into nerve messages and sends them to your brain.