Module 7 - Sensory System Flashcards
1
Q
Sensory Receptor
A
- Detect changes in external environment
- Appropriate reaction to maintain internal environment/homeostasis
2
Q
Adequate Stimulus
A
- Environmental stimulus receptor is most sensitive to
3
Q
Receptor Potentials
A
- Generally depolarizing, can be hyperpolarizing
- Caused by increased permeability to Na+ (K+ in case of hyperpolarization)
- Local, no propagation, decrease with time & distance from stimulus
- Proportional to strength of stimulus
4
Q
Somatosensory system
A
- Detects & processes sensations of skin
- Uses cutaneous receptors
- Touch, vibration, pain & temperature
5
Q
Hair Follicle
A
- Receptors sensitive to touch & vibration
6
Q
Free Nerve Endings
A
- Respond to pain & temperature
7
Q
Pacinian’s Corpuscles
A
- Detect touch & high frequency vibrations
8
Q
Meissner’s Corpuscles
A
- Detect low frequency vibrations
9
Q
Ruffini’s corpuscles
A
- detect touch
10
Q
Receptive Field
A
- Surface area of skin
- Adequate stimulus activates particular receptor
- Action potential is fired
- Any stimulus applied outside field doesn’t generate action potential
11
Q
Spinothalamic Tract
A
- Transmits basic sensations, pain, temperature, touch
- Synapse & cross to contralateral side occurs at base (place of occurrence)
- Travels to somatosensory cortex
12
Q
Dorsal Column
A
- Transmits advanced sensations, fine touch proprioception & vibration
- Synapse & cross to contralateral side occurs at top (travels up spinal cord first)
- Travels to somatosensory cortex
13
Q
Visual System
A
- Detects light
- Converts light to action potentials (photoreceptors of eye)
- Sends information to primary visual areas for processing
14
Q
Retina
A
- Pigment layer back of eye, absorb excess light
- Cells, bipolar, ganglion, horizontal & amacrine
15
Q
Bipolar & Ganglion Cells of Retina
A
- Integration of information from rods & cones
- Fire action potentials
16
Q
Rods
A
- Sensitive to light
- Function best in low light
- Detect shades of grey (no color)
- Located in region of retina outside & around fovea
- 1 type of photopigment, chemical sensitive to light
17
Q
Cones
A
- Sensitive to color
- Function best in bright light (detect detail)
- 3 types of cells, different photo pigments (1 primary color)
- Located in region of fovea (large concentration)
18
Q
Rod & Cone Communication
A
- Generate receptor potentials
- Produce IPSP’s
19
Q
Saccades (Eye Movement)
A
- Jerky, rapid movement
- Rapidly move eye to object of interest
20
Q
Smooth Pursuit (Eye Movement)
A
- Keep moving object focused on fovea
- smooth movement
21
Q
Vestibular Ocular Reflex VOR (Eye Movement)
A
- Focus on object while moving head
- Up/down & back/forth
22
Q
Vergences (Eye Movement)
A
- Object of interest approaching (converge) or moving away (diverge)
23
Q
Inner Ear Components
A
- vestibular apparatus (balance)
- cochlea (process sound)
24
Q
Middle Ear
A
- eardrum
- ear ossicles
- eustachian tube
25
Types of Ear Ossicles
- malleus
- inous
- stapes
26
Outer Ear
- ear (auricle)
- external auditory canal
27
Auditory System
- Converts external soundwaves to action potentials
- Travel to brain, auditory system
28
Organ of Corti
- Converts soundwaves to action potentials by hair cells in tectorial membrane
29
Basilar Membrane Structure
- top of cochlea, wide, thin & loose tension
- base near oval window, thick & tight tension
30
Basilar Membrane Functions
- Separates cochlear duct & tympanic duct
- Soundwaves vibrate membrane, causing hair cells to bend
- detect different frequencies through vibration
- hearing of different frequencies through length & stiffness of hair cells
31
Creation of Sound
- Waves of air pressure hit parts of ear
- Turn air pressure into electrical information
32
Sound Frequency
Sound Frequency
- Number of waves per unit time
- High frequency = low pitch sound
- Low frequency = high pitch sound
33
High Frequencies Stimulation
- hair cells at base, near oval window
34
Low Frequencies Stimulation
- hair cells at top of cochlea
35
Release of Neurotransmitter From Hair Cells
- excites neurons of auditory nerve
- fires action potentials
- attain potentials from to auditory cortex in temporal lobe
36
Sound Intensity
Sound Intensity
- Hight/amplitude of sound wave
- High amplitude = loud sound
- Low amplitude = quiet sound
37
Changes to Sound Amplitude
- tympanic membrane
- incus, malleus & stapes (ear ossicles)
38
Vestibular System
- Located inner ear, next to cochlea
- Responsible for maintaining balance, equilibrium & posture
- Detects linear & rotational motion and position of head
- Responsible for Vestibular Ocular Reflex (VOR)
39
Vestibular Apparatus
- 3 semicircular canals
- 2 otolith organs
40
Cupula Contribution to Balance
- embeds cilia in semicircular canals
- cilia pushed by movement
- endolymph stimulate hair cells
41
Semicircular Canals
- Detect rotational accelerations & decelerations of head
- filled with endolymph fluid
- endolymph fluid bends hair cells
- 3 per apparatus, one for each plane of movement
42
Otolith Organ
- detects linear accelerations & decelerations
- position of head when tilted
- Utricle & saccule act together to detect head tilts
- hair cells, base anchored and cilia embedded in gelatinous membrane
43
Utrcile (Otolith Organ)
- detect horizontal accelerations & decelerations
44
Saccule (Otolith Organ)
- detects vertical accelerations & decelerations
45
Hair Cells
- process sound & balance
- detect loudness/amplitude by weak/strong vibration
- release neurotransmitter from base onto sensory nerve, generating action potentials
- contain stereocilia for neural coding
46
Acceleration
- stereocilia bend toward kinocilium
- more neurotransmitter release
- more action potentials fired on sensory nerve
47
Deceleration
- stereocila bend away from kinocilcum
- less neurotransmitter release
- less action potentials fired on sensory nerve
