Chapter 18: General and Special Senses Flashcards
(94 cards)
1
Q
What is a sensory receptor?
A
A specialized cell that sends sensations to CNS
2
Q
what are the 2 sensory receptors? describe them
A
tonic: always sending signals to the CNS
phasic: becomes active only with changes in the conditions they monitor
3
Q
What are the five types of receptors? state what they are used to detect
A
- ) Chemoreceptors:
- smell
- taste - ) Nociceptors:
- Cell damage (mechanical, electrical, thermal) - ) Thermoreceptors
- thermal - ) Mechanoreceptors:
- hearing
- stretching
- body position - ) Photoreceptors
- light
4
Q
What is the receptive field?
A
area monitored by a single receptor cell
5
Q
What is receptor specificity?
A
each receptor responds to a specific stimulus
Example: photoreceptor will not respond to a chemical stimulus
6
Q
What is sensation?
A
The sensory information arriving at the CNS
7
Q
What is perception?
A
Conscious awareness of sensation
- All nerve impulses are identical (just action potentials)
- Brain interprets impulses
- “Feeling” that occurs when sensory impulses are interpreted
8
Q
When does sensory adaptation occur?
what does it result in?
A
- Occurs when sensory receptors are subjected to continuous stimulation
- Results in a reduction of sensitivity
- At some point along the pathway, impulses are conducted at a decreased rate
9
Q
What are the two types of sensory adaption?
A
peripheral adaptation:
when sensory receptors decrease their level of activity
central adaptation:
Sensory neurons are still active
CNS causes reduced perception
10
Q
describe sensory limitations
A
Sensory information from receptors is incomplete.
-Do not have receptors for every stimulus
-Other animals can detect things we cannot:
(Infrared, ultraviolet, ultrasonic, magnetism, etc.)
Receptors have limited ranges
Stimulation requires a neural event that is interpreted
11
Q
Compare General and Specialized senses
A
General senses:
-Do NOT have specialized receptor cells or sensory organs
Special senses:
- Can have specialized receptor cells separate from the sensory neuron
- Structurally more complex
- Receptors localized in sense organs
12
Q
What are the three major general senses groups? briefly describe
A
Exteroceptors -Relay info about external environment Proprioceptors -Depict body position in space Interoceptors -Monitor the internal environment
13
Q
describe nociceptors
A
Sense tissue damage perceived as pain free nerve endings with large receptive field -found everywhere except brain -Provide a protective function -do not adapt well
14
Q
What are the three types of pain? (just names)
A
fast pain
slow pain
referred pain
15
Q
describe fast pain
A
Prickling pain
Quick; inducing a reflex usually; end when stimulus ends
16
Q
describe slow pain
A
Burning
Begin later; persist longer; ache
17
Q
describe referred pain
A
- Visceral pain that feels like it is coming from a more superficial region
- Due to superficial structures being innervated by the same spinal nerves as the damaged viscera
- “Brain-freeze”
18
Q
describe thermoreceptors
A
-involve heat & cold
(no difference in structure between the two)
-Free nerve endings in skin
-Quick to adapt
-Felt as pain
(if temp goes above 45 C or if temp goes below 10 C)
19
Q
which receptor type is sensitive to mechanical forces that cause tissues to be deformed?
A
Mechanoreceptors
20
Q
What are the three types of mechanoreceptors? state what they sense
A
Tactile -touch, pressure & vibration Baroreceptors -pressure changes in walls of vessels, etc Proprioceptors -position of joints & muscles
21
Q
There are 6 types of tactile receptors in two categories. What are the two categories?
A
unencapsulated
encapsulated
22
Q
what are the three unencapsulated tactile receptors?
describe them
A
- ) Free nerve endings
- in papillary of dermis
- general touch - ) Root hair
- monitor distortions & movement across body surface - ) Tactile disc
- expanded nerve terminal that synapses with Merkel cell
- sensitive to fine touch
23
Q
what are the three encapsulated tactile receptors?
describe them
A
- ) Tactile (Meissner’s) corpuscles
- found where tactile sensitivities are very well developed - ) Lamellated (Pacinian) corpuscle
- respond to deep pressure - ) Ruffini corpuscle
- in dermis
- detect pressure with little adaptation
24
Q
describe Baroreceptors
A
-Stretch Receptors
-Monitor changes in pressure
-Detect stretching of tissue walls
-Regulates autonomic activities
examples:
digestive tract
bladder
carotid sinus
lung
colon
major arteries
25
describe proprioceptors
- Monitor position of joints, tension in tendons, state of muscle contraction
- No adaptation to stimulus
26
name and describe the two types of proprioceptors
Muscle spindle: monitor length of muscle
| Golgi tendon organ: monitor tension in a tendon during contraction
27
Chemoreceptors respond to _________________ and monitor___________________________________
substances dissolved in surrounding fluids;
| chemical composition of body fluids (ie: sensitive to pH, pCO2 changes)
28
Where are Chemoreceptors found?
inside CNS; medulla
aortic bodies
carotid bodies
29
What is Olfaction?
sense of smell
30
describe the Olfactory organ (3)
- Located within the nasal cavity on either side of nasal septum
- Covers the cribiform plate of ethmoid
- Made up of olfactory epithelium
31
the Olfactory Epithelium consists of what? (3)
```
Olfactory receptors
-chemoreceptors
Supporting cells
-surround the receptors
Basal cells
-stem cells that grow new cells
```
32
The olfactory cells are covered in excretions from_________
olfactory glands
33
describe the olfactory receptors (3)
- Highly modified bipolar neurons
- Have cilia that extend into mucus secreted by olfactory glands
- Odorous particles dissolve into mucus and cause depolarization
34
describe the olfactory pathway (6)
- impulses travel along axons of receptor cells
- Pass through openings in cribiform plate
- Go to olfactory bulb and cranial nerve I
- Unique in that the impulse does NOT go through the thalamus
- Travel along tracts to limbic system (smells can trigger strong emotion_
- Interpreted as smell in temporal lobe & base of frontal
35
How many primary smells do we have?
50
| Refer to slide 26 for last information regarding Olfaction
36
What sense is Gustation?
Taste
37
chemoreceptors in gustation structures are called what?
taste buds
38
Taste buds on superior surface of tongue in __________
papillae
39
what are papillae?
Epithelial projections
40
what are the names of the three types of papillae?
Filiform
Fungiform
Circumvallate
41
slide 29
:)
42
The gustatory pathway uses which cranial nerves?
VII, IX &X
43
In the gustatory pathway, afferent fibers synapse with ________ in _________
nucleus solitarius, medulla
44
The gustatory pathway goes where?
thalamus & cerebral cortex
45
what are the primary tastes? (6)
```
Sour
Sweet
Salt
Bitter
Water
Umami
```
46
true or false: Number & sensitivity decrease with age
true
47
what are the parts of the external ear? describe them
Auricle: external structure supported elastic cartilage
External acoustic meatus: canal to middle ear
Ceruminous glands
Make wax (cerumen)
Hairs
Ends at tympanic membrane
48
what are the functions of the external ear?
Protect middle and inner ear
Limits microorganism growth
Deny access to foreign objects
Funnel vibrations
49
what are the parts of the middle ear?
Tympanic cavity:
-Air filled space between external and inner ear
Tympanic membrane:
-Thin, transparent connective tissue sheet
-Auditory tube
-Ossicles
50
what does the auditory tube do when it is open?
- Middle ear equalized to atmospheric pressure
- Can be induced by chewing or yawning
- Allows for microbes to get in and cause an ‘ear infection’
51
describe the ossicles in the middle ear (not names)
- Tiny bones in middle ear
| - Transfer vibrations from the tympanic membrane to inner ear
52
what are the three ossicles in the middle ear? (names)
Malleus (hammer)
Incus (anvil)
Stapes (stirrup)
53
what are the 2 muscles in the inner ear and where do they insert?
Tensor tympani muscle
-Inserts on malleus
Stapedius muscle
-Inserts on stapes
54
the inner ear is a series of _____ and _________
tubes and cavities
55
the inner ear is split into two sections. What are they? What are they responsible for?
cochlea (hearing) and vestibule (balance)
56
the inner ear consists of several layers. Name them and what they do
1. ) membranous labyrinth
- Contains endolymph fluid
2. ) bony (osseous) labyrinth
- Dense bone layer of the temporal
- Contains perilymph fluid
57
describe the cochlea (3)
- Converts vibrations to ‘sound’
- Contacts the stapes at the oval window
- Coiled tube with cochlear duct
58
the cochlea is divided into 3 ducts. what are they? and what divides them?
```
Vestibular duct
-Divided by vestibular membrane
Cochlear duct
-Divided by basilar membrane
Tympanic duct
```
59
The organ of corti is found in the ________
basilar membrane
60
describe the organ of corti (3)
```
Hair cells
(Mechanoreceptors with stereocilia)
Cranial nerve VIII
(Cochlear branch contacts hair cells)
Tectorial membrane
(Positioned right above hair cell stereocilia)
```
61
describe the steps in the path of vibrations
slide 40-41
62
describe the pathway for auditory sensations (4)
Carried by cochlear branch of cranial nerve VIII
Goes to cochlear nucleus of medulla
Travels through thalamus
Processed in auditory cortex of temporal lobe
63
what does the vestibular complex consist of?
1. ) semicircular canals
| 2. ) utricle and saccule
64
what are the names of the three semicircular canals?
anterior, lateral, and posterior semicircular canals
65
what is located at the base of the semicircular canals?
| what does each posses?
Ampulla; each posses cristae that attaches to a capula
66
the Utricle and Saccule are ___________________ connected by ___________________
paired membranous sacs; endolympthatic duct
67
what does the saccule posses?
maculae
68
in the semicircular canals, the _______ has ________
cupula; hair cells
69
describe what happens in the semicircular canals when your head rotates
- Causes fluid to move through canals
- Fluid moves cupula
- Hair cell stereocilia bends
- Depolarization occurs
70
the maculae of the saccule consists of what 2 things?
hair cells and otolith
71
what is otolith
small calcium carbonate crystals
| gel like substance
72
in the utricle and saccule, head rotation changes what 4 things?
Gravity pulls on crystals
Moves otolith
Deforms hair cell stereocilia
Depolarization occurs
73
For the pathway for balance sensation the hair cells do what two things?
Activate neurons of vestibular branch of cranial nerve VIII
| Synapses with vestibular nuclei
74
what are the names of the 4 eye accessory structures?
1. ) Eyelids or Palpebrae
2. ) Tarsal glands
3. ) Conjunctiva
4. ) lacrimal apparatus
75
what do the eyelids.palpebrae do? what is it made of?
protect & lubricate
| epidermis, dermis, CT
76
what is the function of the tarsal glands?
oily secretions keep lids from sticking together
77
describe the conjunctiva (4)
Thin protective mucus membrane
palpebral & bulbar
stops at corneal edge
dilated BV--bloodshot
78
what does the lacrimal apparatus do?
produce tears
79
what does the lacrimal apparatus consist of? how are they connected?
1. ) Lacrimal Gland
- produces tears
2. ) Lacrimal punctum
- drains tears into the Lacrimal Canaliculi
3. ) Lacrimal canaliculi
- passageway the leads to the lacrimal sac
4. ) Lacrimal sac
- fills grooves on lacrimal bone
- connects to the nasolacrimal duct
5. ) delivers tears to nasal cavity
80
What are the three layers of the eye?
Fibrous Tunic
Vascular Tunic
Neural Tunic
81
describe the fibrous tunic and what it consists of
```
outer
Sclera
-White of eye
-Dense irregular CT
Cornea
-Transparent layer
```
82
what are the four parts of the vascular tunic? (names only)
iris
lens
choroid
ciliary body
83
what is the iris made up of and what does it control?
smooth muscles and pigments; controls the size of the pupil
84
what is the choroid of the eye?
vascularized, pigmented layer
85
the lens is made up of ________ and does what?
layered proteins; refracts light
86
describe the ciliary body of the eye
```
Below the iris
Has ciliary processes
-attach to suspensory ligaments
-Attach to lens
Ciliary muscles change the lens shape
-focus
```
87
what are the functions of the vascular tunic? (4)
Route for BV’s
Regulate amount of light
Secrete & absorb aqueous humor
Control shape of lens
88
describe neural tunic briefly (3 things)
Inner most layer
Retina
5 groups of retinal neurons
89
name and describe the different retinal neurons in the neural tunic of the eye
1. ) Receptor cells
- rods and cones
- detect light
2. ) Bipolar neurons
- synapse with above
3. ) Ganglion cells
- synapse with above
4. )Amacrine cells
- modulate communication between bipolar and ganglion cells
90
describe rods (3)
Very light sensitive
Do not discriminate color
Require less light
91
describe cones (3)
Color vision
Three types
Give sharper image
92
what are the three regions of the retina? describe them
1. ) Macula lutea
- area of no rods
2. ) Fovea centralis
- area of most cones
- within macula
3. ) Optic disc
- beginning of optic nerve
- “blind spot”
93
describe the visual pathway
```
Photoreceptors to…
bipolar cells to…
ganglion axons converge on optic disc into optic nerve (cranial nerve II)
Optic tract to optic chiasm
Relayed to lateral geniculate nucleus
On to visual cortex of occipital lobe
(slide 59)
```
94
what are the two cavities of the eye?
| What does each contain?
Posterior cavity
-contains gelatinous vitreous body
Anterior cavity
-contains clear aqueous humor
