Exam #5 Ch. 14 Flashcards
(122 cards)
1
Q
what is sensation the stimulation of?
A
a receptor
2
Q
what is perception?
A
the awareness of a sensation
3
Q
where are general senses?
A
widespread on the body
4
Q
what does general senses include?
A
touch, temperature, pain etc.
5
Q
what are the three types of general senses?
A
1) somatic
2) propicception
3) visceral
6
Q
what does somatic senses provide?
A
information about the body and environment
7
Q
what does proprioception provide?
A
information on body position and movement
8
Q
what does visceral senses provide?
A
information about internal organs
9
Q
where are special senses located/
A
they are localized on the body
10
Q
what senses does special senses include?
A
sight, hearing, balance, smell and taste
11
Q
how are sensory receptors categorized?
A
1) by type of stimulus
2) by location
3) by structure
12
Q
which sensory receptors are categorized by type of stimulus? (5) (MCTPN)
A
1) mechanoreceptors
2) chemoreceptors
3) thermoreceptors
4) photoreceptors
5) nociceptors
13
Q
what do mechanoreceptors respond to?
A
mechanical force such as compression, bending or stretching of cells
14
Q
what do chemoreceptors respond to?
A
chemicals
15
Q
what depends on chemoreceptors?
A
taste and smell
16
Q
what do thermoreceptors respond to?
A
changes in temperature at the site of the receptor
17
Q
what is thermoreceptors necessary for?
A
the sense of temperature
18
Q
what does photoreceptors respond to?
A
light striking the receptor cells
19
Q
what are photoreceptors necessary for?
A
vision
20
Q
what do nociceptors (pain receptors) respond to?
A
extreme mechanical, chemical and thermal stimuli
21
Q
what is unique about nociceptors?
A
most sensory receptors respond to one type of stimulus but nociceptors respond to more than one
22
Q
which sensory receptors are categorized by location? (3) (CVP)
A
1) cutaneous
2) visceroceptors
3) proprioceptors
23
Q
what are cutaneous receptors associated with?
A
skin
24
Q
what are visceroreceptors associated with?
A
the viscera of organs
25
what are proprioceptors associated with?
joints, tendons and other connective tissue.
26
what does cutaneous receptors provide information about?
the external environment
27
which sensory receptors are categorized by structure? (9) (FMHPMRMGO)
1) free nerve endings
2) merkel disks
3) hair follicle receptors
4) pacinian corpuscles
5) meissner corpuscles
6) ruffini end organs
7) muscle spindles
8) golgi tendon organs
9) others
28
what are free nerve endings?
relatively unspecialized neuronal branches similar to dendrites
29
where are free nerve endings distributed?
throughout most parts of the body and especially are abundant in epithelial and connective tissues
30
what are free nerve endings responsible for?
a number of sensations including pain, temperature, itch and movement
31
where are somatic senses (general senses) located?
in skin, muscles and joints
32
where are visceral (general senses) located
in internal organs
33
what senses does somatic senses produce?
touch, pressure, propicopetion, temperature and pain
34
what senses does visceral senses produce?
pain and pressure
35
what are the 3 types of sensations that free nerve endings are responsible for?
1) cold receptor
2) warm receptor
3) pain receptors
36
what does the cold receptors on free nerve endings do?
increase its rate of action potential production as skin is cooled
37
what is cold receptors also activated by?
menthol (gives mint its cool taste)
38
what does the warm receptors on free nerve endings do?
increase its rate of action potential production as skin temperature increases.
39
what do both cold and warm receptors respond most to?
changes in temperature
40
which are more abundant, cold or warm receptors in any given area of the skin?
cold receptors are 10 to 15 more numerous than warm receptors
41
what are pain receptors on free nerve endings stimulated by?
extreme cold or heat
42
at very cold temperatures (0-12 degrees C) what is the only receptor on free nerve endings stimulated?
pain receptors
43
when does the pain sensation end when pain receptors are stimulated by temps 0-12 degree C?
as the temp increases above 15 degrees C
44
what is the structure of free nerve endings?
branching, no capsule
45
what is the function of free nerve endings? (6) (PITTJP)
1) pain
2) itch
3) tickle
4) temperature
5) joint movement
6) proprioception
46
where are the receptors of merkel disks located?
throughout the basal layers of the epidermis just superficial to the basement membrane
47
what does a merkel disk consist of?
axonal branches that end as flattened expansions
48
what are merkel disks associated with?
dome-shaped mounds of thickened epidermis in hair skin
49
what is the structure of merkel disks?
consists of flattened expansions at the end of axons.
50
what is each expansion at the end of axons associated with?
a merkel cell
51
what is the function of merkel disks?
light touch and superficial pressure
52
where are hair follicle receptors (hair end organs) located?
wrapped around hair follicles or extending along the hair axis
53
what does each axon on hair follicle receptors supply?
several hairs
54
what does each hair receive on hair follicle receptors and what does it result in?
branches from several neurons resulting in continuous overlap
55
what is the function of hair follicle receptors?
light touch and responds to very slight bending of hair
56
how is a response elicited in hair follicle receptors?
they are extremely sensitive and require very little stimulation
57
is the sensation in hair follicle receptors localized?
not very well localized
58
what helps explain why light touch is not highly localized in hair follicle receptors?
the considerable overlap in the endings of sensory neurons
59
what makes hair follicle receptors very sensitive?
converging signals within the CNS
60
what is the structure of pacinian corpuscles (lamellated corpuscles)?
onion-shaped capsule composed of several cell layers with a single central nerve process
61
what is the function of the pacinian corpuscle (lamellated corpuscle)?
deep cutaneous pressure, vibration and proprioception
62
what is the structure of meissner corpuscles (tactile corpuscles)?
several branches of a single axon
63
what are the several branches of a single axon on meissner corpuscles associated with?
specialized schwann cells
64
what are the several branches of a single axon on meissner corpuscles surrounded by?
a connective tissue capsule
65
what is the function of meissner corpuscles?
two-point discrimination
66
where are meissner corpuscles distributed?
through the dermal paillae
67
what is two-point discrimination in meissner corpuscles?
the ability to detect simultaneous stimulation at two points on the skin.
68
what is the sensation of meissner corpuscles important for?
evaluating the texture of objects
69
where are meissner corpuscles numerously located and close together?
close together in tongue and fingertips
70
where are meissner corpuscles less numerous and widely separated?
in other areas such as the back
71
what is the structure of ruffini end organs?
branching axon with numerous, small, terminal knobs
72
what are the small terminal knobs of ruffini end organs surrounded by?
a connective tissue capsule
73
what is the function of ruffini end organs?
continous touch or pressure
74
what does ruffini end organs respond to?
depression or stretch of skin
75
where is ruffini end organs located?
in the dermis
76
where in the dermis are ruffini end organs primarily located?
in the fingers
77
what is the structure of muscle spindles?
3-10 striated muscle fibers
78
what are the striated muscle fibers of muscle spindles enclosed by?
a loose connective tissue capsule, striated only at the ends with sensory nerve endings in center
79
what is the function of muscle spindles?
procprioception
80
what is procprioception associated with in muscle spindles?
detection of muscle stretch
81
what are muscle spindles most important for?
control of muscle tone
82
where are muscle spindles located?
in skeletal muscles
83
what do muscle spindles provide information about?
the length of muscle (stretch reflex)
84
what do golgi tendon organs surround?
a bundle of fascili
85
what are golgi tendon organs enclosed by?
a delicate connective tissue capsule
86
what is the structure of nerve terminations in golgi tendon organs?
branched, with small swellings applied to indivisual tendon fasciculi.
87
what is the function of golgi tendon organs?
proprioception
88
what are golgi tendon organs associated with?
stretch of a tendon
89
what is the importance of golgi tendon organs?
for control of muscle contraction
90
what is the increase in tendon tension caused by?
either by contraction of the muscle or by passive stretch of the tendon
91
what does stimulating a receptor produce?
an action potential in the sensory neuron
92
what may produce an action potential?
a graded potential
93
what is a graded potential called?
a receptor potential
94
what is receptor adaptation?
reduced sensitivity to a constant stimulus
95
what do tonic receptors constantly generate?
action potentials
96
what do phasic receptors respond best to?
changes and adapt quickly
97
what are primary receptors?
sensory receptors that conduct action potentials in response to the receptor potential
98
which sensory neurons are primary receptors?
most ofthem
99
what are secondary receptors?
other receptor cells that have no axons or have short, axonlike projections
100
what do secondary receptors generally produce?
receptor potentials
101
what does the production of action potentials by tonic receptors depend on?
as long as a stimulus is being applied
102
why does a stimulus need to be applied to tonic receptors for an action potential to be generated?
so that they adapt very slowly
103
what is an example of tonic receptors?
information from slowly adapting receptors allow us to know where our little finger is at all times without having to look for it
104
how do phasic receptors adapt?
rapidly
105
why do phasic receptor adapt rapidly?
so they are most sensitive to changes in stimuli
106
what is an example of phasic receptors?
information from phasic receptors allow us to iknow where our little finger is as it movses thus we can control its movement through space and predict where it will be in the next moment
107
why are we usually not conscious o tonic or phasic input?
because the higher brain centers ignore it most ofthe time.
108
what type of pathways are sensory pathways/
ascending
109
what do sensory pathways carry?
certain sensory modalities
110
what does the anterolateral system convey?
cutaneous sensory information
111
what does the spinothalmic tract in the anterolateral system carry? (6) (PTLPTI)
1) perceived pain
2) temperature
3) light touch
4) pressure
5) tickle
6) itch
112
where do primary neurons in the spinothalmic tract synapse?
in the posterior gray horn
113
where are the secondary neurons located in the spinothalmic tract?
cross over and ascend in the spinothalmic tract to the thalamus
114
where are the tertiary neurons located in the spinothalmic tract?
they ascend to the somatic sensory cortex
115
what do the spinoreticular and spinomesencephalic tract of the antherolateral system carry?
pain and other touch sensations in the spinothalmic tract to other pats of the brain
116
what does the tactile sensory axons from cranial nerves 7, 9 and 10 in the trigeminothalmic tract in the anetherolateral system join?
the spinothalmic tract in the brainstem
117
what does the dorsal column/medial-lemniscal system carry? (4) (PPPV)
1) perceived 2 point discrimination
2) perceived proprioeption
3) pressure
4) vibration
118
where are most primary neurons in the dorsal column/medial-lemniscal system located?
they enter the spinal cord and ascend in the posterior column to the medulla
119
in primary neurons of the dorsal column/medial-lemniscal system, where does information from the inferior half of the body travel?
in the fasciculus gracillis to the nucleus gracillis
120
in primary neurons of the dorsal column/medial-lemniscal system where does information from the superior half of the body?
in the fasciculus cuneatus to the nucleus cuneatus
121
where are secondary neurons located in the dorsal column/medial-lemniscal system?
they crossover and travel through the medial lemniscus to the thalamus
122
where are tertiary neurons located in the dorsal column/medial-lemniscal system?
they ascend to the somatic sensory cortex
