sense organs Flashcards
1
Q
receptors
A
structures that detect stimuli
2
Q
classification of receptors: modality
A
types of stimuli detected:
- thermoreceptors: temperature
- photoreceptors: light
- chemoreceptors: chemicals
- nociceptors: pain
- mechanoreceptors: pressure or stretch
3
Q
classification of receptors: distribution of receptors in body
A
- general senses are widly distributed body senses
- special sense involve cranial nerves (complex)
4
Q
classification of receptors: stimulus origin
A
- exteroceptors: from outside body
- interoceptors: from organs within the body
- proprioceptors: regarding prosition of the body
5
Q
unencapsulated nerve endings
A
dendrites lacking connective wrapping:
6
Q
free nerve endings
A
unencapsulated nerve endings:
- warm receptors
- cold receptors
- nocieptors
7
Q
tactile (merkle) discs
A
unencapsulated nerve endings:
- light touch and pressure
8
Q
hair receptors (pertrichial endings)
A
unencapsulated nerve endings:
- movement of hairs
9
Q
encapsulated nerve endings
A
dendrites wrapped by glia or connective tissue
10
Q
tactile (Meissner) corpusles
A
- encapsulated nerve ending
- oval mass in dermal papillae
- sense light touch and texture perception
11
Q
end bulbs (Krause)
A
- encapsulated nerve ending
- similar to tactile corpuscles but located in mucous membranes
12
Q
bulbous (Ruffini) corpuscles
A
- encapsulated nerve ending
- flat
- sense pressure, skin stretch, and join movement
13
Q
lamellar (pacinin) corpuscles
A
- encapsulated nerve ending
- onion like
- sense deep pressure, stretch, tickle, and vibrations
14
Q
muscle spindles
A
- encapsulated nerve ending
- fusiform
- sense skeletal muscle stretch
15
Q
tendon organs
A
- encapsulated nerve ending
- leaflike
- sense tendon stretch caused by muscle activity
16
Q
receptive field
A
area supplied by a single neuron
17
Q
receptive field sizes
A
- neurons in different regions of body have recieptive fields of different size
- neurons with a small receptive field size (ex: skin of fingers) allow for fine 2-point discrimination
18
Q
somatosensory projection pathways
A
- sensory signals are conveyed through the nervous system by pathways of neurons
- first-, second-, and third-order neurons carry the signals
19
Q
first-order fibers
A
- fibers for touch, pressurem and propriception are large, myelinated, and fast
- fibers for heat and cold are small, unmyleinated and slow
20
Q
second-order fibers
A
terminate in the contralateral thalamus
21
Q
third-order fibers
A
project from thalamus to cerebrum
22
Q
pain
A
- discomfort that makes us aware of injurious situations
- different nociceptors responsible for slow vs fast pain
- third-order neruons end in cerebral cortex
23
Q
pain from the head
A
conducted by cranial nerves to the brain
24
Q
pain from below head
A
travels via spinothalamic and spinoreticular tracts
25
referred pain
| innacturate pain reception
pain from the viscera mistakenly thought to come from more superficial sites
26
gating of pain
| innacturate pain reception
- pain signals from periphery never reach brain
- pain-relieving neurotransmitters can act on first-order neurons
27
taste buds locations
- tongue has the most
- some in soft palate, phsrynx, epiglottis, and cheeks
28
taste (gustation)
- taste buds
- lingual papillae
29
lingual papillae
surface projections on tongue
30
types of lingual papillae
- filiform
- folate
- fungiform
- vallate
31
filiform
- numerous
- tiny spikes
- no buds
32
folate
- ridges on tongue sides
- buds in children
33
fungiform
- mushroom shaped bumps
- have buds
34
vallate
- large bumps in a row at the back of the tongue
- have buds
35
taste buds contain
taste cells and taste pores
36
taste cells
- banana shaped
- taste hairs: receptor for taste modulate
- synapse with sensory nerve
37
taste pore
hole on epithelial surface of tongue
38
gustatory projection pathway to the cerebral cortex
second-order neruons in solitary nucleus of medulla
2 parallel pathways:
- hypothalamus mediates autonomic reflexes (ex: gagging)
- thalamus sends signals to cortex for conscious percetion of taste
39
nerves involved in gustatory projection pathway to the cerebral cortex
- facial (CN VII): anterior tongue
- glossopharyngeal (CN IX): posterior tongue
- vagus: (CN X): palaye, pharynx, epiglottis
40
smell (olfaction) contains
- olfactory mucosa
- olfactory neurons
- olfactory bulbs
41
olfactory mucosa
- roof of nasal canal
- contains 10-20 million olfcatory neruons
42
olfactory neruons
- have olfactory hairs (cilia) with binding site for ordor molecules
- olfactory cell's axons make olfactory nerve (CN I)
43
olfactory bulb
swollen tips of olfactory tracts at base of frontal lobes
44
olfactory projection pathways
- signals do not pass through thalamus before stimulating primary olfactory cortex at medial side of temporal lobe
- secondary areas include insula, orbitofrontal cortex, hippocampus, amygdala, and hypothalamus
- evokes strong memories, emotions, and visceral reactions
45
outer ear
| ear anatomy
- auricle (pinna)
- auditory canal with hairs, cerumen
46
middle ear
| ear anatomy
- tympanic membrane (eardrum)
- tympanic cavity of temporal bone
- auditory (eustachian) tube
- auditory ossicles: malleus, incus, stapes
- oval windo
- muscles: stapedius, tensor tympani
47
inner ear anatomy
| ear anatomy
- bony labyrinth: maze in temporal bone
- membranous labyrinth: tube within maze
- endolymph: fluid in membranous labrynth
- perilymph: fluid between membranous labyrinth and bone
- vestibule: utricle and saccule
- 3 semicircular canals
- cochlea: snal snaped
48
cochlear duct
| inner ear anatomy
organ of hearing
- spirals around modiolus – an axis of spongy bone
- contains spiral organ with four rows of hair cells: one row of inner hair cells, three rows of outer hair cells
- stereocilia of hair cells project into tectorial membrane
- hair cells synapse with sensory neurons that form spiral ganglion and cochlear division of CN VIII
- contains endolymph
49
scala vestibuli
| inner ear anatomy
- chamber above vestibular membrane
- begins near oval window
- contains perilymph
50
scala tympani
| inner ear anatomy
- chamber below basilar membrane
- ends at round window that is covered by secondary tymapnic membrane
- contains perilymph
51
auditory function
52
muscles for eye movements
* Upward: superior rectus
* Downward: inferior rectus
* Lateral: lateral rectus
* Medial: medial rectus
53
rods
- night vision
- monochromatic- rhodopsin in discs in outer membrane
54
cone
- day vision
- trichromatic visions (Blue, green, yellow-orange)- photospins in parallel infolding of the membrane
55
differences between static and dynamic equilibrium and between linear and angular acceleration
- static: still
- dynamic equilibrium: moving
- linear acceleration: moving forwards or backwards
- angular acceleration: moving up and down or spinning
