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Flashcards in Lecutre 3 Deck (77)
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0
Q

mechanoreceptor expanded tip endings

A

merkel’s discs

1
Q

include both free and encapsulated endings receiving skin tactile sensidbility

A

mechanoreceptors

2
Q

mechanoreceptors spray endings

A

ruffini’s corpuscles

3
Q

Name the two specific mechanoreceptors which feature encapsulated endings:

A

meissner’s corpuscles kraus corpuscles

4
Q

mechanoreceptors hearing

A

sound receptors of cochlea

5
Q

mechanoreceptors with encapsulated endings, responsible for sensitivity to pressure and vibrations

A

pacinian corpuscles

6
Q

mechanoreceptors equilibrium

A

vestivular receptors

7
Q

mechanorepectors arterial pressure

A

baroreceptors

8
Q

cold and warm receptors

A

thermoreceptors

9
Q

free nerve endings responding to pain

A

nociceptors

10
Q

include rods and cones of the eye for vision

A

electromagnetic receptors

11
Q

taste, smell, arterial oxygen, osmolarity, blood CO2, Blood glucose, amino acids, fatty acids

A

chemoreceptors

12
Q

each type of receptor is highly sensitive to one type of stimulus and is almost nonresponsive to toher types

A

differential sensitiivty

13
Q

refers to each of the principal types of sensation

A

modality

14
Q

adaption of receptors

A

-all sensory receptors adapt either partially or completly to any constant stiumuls after a period of time -some receptors adapt to a far greater extent than others

15
Q

the specificity of nerve fibers for transmitting only on modality of sensation

A

Labeled Line Principle

16
Q

characteristics of tonic receptors

A

-slow adapting -detect continous stimulus strength -transmit impulses as long as stimulus is present

17
Q

Types of tonic receptors

A

muscle spindles golgi tendon organs macula and vestibular receptors baroreceptors chemoreceptors

18
Q

characteristics of phasic receptors

A

rapidly adapting do no transmit a continuous signal stiumlated only when stimulus strength changes transmit informaiton regarding rate of change

19
Q

Type A fibers

A

further subdivided into, alpha, gamma, beta, delta lg and medium sized myelinated fibers of spinal nerves

20
Q

Type C

A

small, unmyelinated fibers conduct signals at low velocity make up more than half of all sensory fibers in most peripheral nerves and all post ganglionic autonomic fibers

21
Q

fibers from annulospiral endings of muscle spindles

A

Group Ia (Type Aalpha fibers)

22
Q

Fibers from golgi tendon organs

A

Group Ib (Type Aalpha fibers)

23
Q

from cutaneous tactile receptors and flower spray

A

group II ( type Abeta, gamma fibers)

24
Q

carry temp, crude touch, and pricking pain

A

group III (type A delta fibers)

25
Q

carry pain, itch temperature, and crude tough

A

group IV (type C fibers)

26
Q

Temporal summation

A

-increase signal strength by increasing frquencey of nerve impulses in each fiber

27
Q

Explain/describe the concept of Spatial summation

A

increasing signal strenth in transmittted by using progressively greater number of fibers -entire cluster of nerve endings from one pain fiber covers an area of skin referred to as the receptor field for that fiber -number of endings is lg in center of field buy is reduced in periphery -nerve endings from one pain fiber overlap those of other pain fibers

28
Q

stimulatory field of nueronal pool

A

-stimuatled by each incoming nerve fiber -terminals for each input fiber lie on the nearest neuron in its field - fewer terminals for each input fiber lie on neurons further away

29
Q

give examples of a neuronal pool

A

cerebral cortex basal nuclei thalmaic nuclei cerebellum mesencephalon pons medulla gray matter of spinal cord

30
Q

includes all the output fibers stimulated by the incoming fiber

A

discharge zone

31
Q

faciliated inhibition zone

A

-neurons further from the discharge zone that are facilitated but not excited -may be inhibitory or excitatory depending on the input fiber

32
Q

diverging neuronal pathways

A

may result in amplification of initial signal may allow transmission of original signal to separte areas

33
Q

converging neuronal pathways

A

multiple input fibers converge onto a single output neuron input fibers may be from a single source or from multiple separate sources

34
Q

Reverberatory circuits or oscillatory circuits

A

caused by postivie feedbback within neuronal circuit circuit once stimulated may discharge repetitively for a long time

36
Q

What are somatic senses?

A

collect sensory information from all over the body

37
Q

What are three types of somatic senses?

A

mechanoreceptive thermoreceptive pain

38
Q

What are some examples of special senses?

A

vision, hearing, smell, taste, equilibrium

39
Q

What are exteroreceptive sensations?

A

From the surface of the body

40
Q

What is proprioceptive sensations?

A

refer to physical state of the body -position sensations -muscle and tendon sensations -pressure sensations -equilibrium

41
Q

What are deep sensations

A

deep pressure, pain, and vibrations

42
Q

What are mechanoreceptive somatic senses?

A

include both tactile and position senses that are stimulated by mechanical displacement of some tissue of the body

43
Q

What are physiological types of somatic senses?

A

mechanoreceptive somatic senses thermoreceptive senses pain sense

44
Q

What are three neuron ascending pathways?

A

primary sensory neurons secondary neurons tertiary neurons

45
Q

What are primary sensory neurons?

A

from external receptors travel through dorsal roots of spinal cord

46
Q

What are secondary neurons?

A

make up tracts in spinal cord and brainstem

47
Q

What are tertiary neurons?

A

from thalamus to primary sensory cortex travel through internal capsule

48
Q

What are two examples of ascending pathways for conscious perception?

A

spinothalamic system medial lemniscal system

49
Q

What are ascending pathways that are unconscious perception?

A

spinocerebellar spino olivary spinotectal spinoreticular

50
Q

What makes up the spinothalmaic system?

A

lateral spinothalamic tract anterior spinothalamic tract

51
Q

What does the lateral spinothalamic tract

A

-carries pain and temperature -primary fibers ascend or descend 1-2 spinal cord segments before synapsing with secondary fibers -secondary axons decussate through anterior gray and white commissures -secondary axons make up the lateral spinothalamic tract traveling in the lateral column of the spinal cord

52
Q

Where are the secondary fibers in the lateral spinothalamic tract joined?

A

in brainstem by fibers of the trigeminothalamic tract -pain and temperature from face an teeth

53
Q

Where do secondary fiber collaterals project for the lateral spinothalamic tract?

A

stimulate wakefulness and consciousness

54
Q

Where do secondary fibers project of the lateral spinothalamic tract?

A

to ventral posterolateral (VPL) nucleus of thalamus

55
Q

Where do secondary fibers synapse in the lateral spinothalamic tract?

A

with tertiary fibers in VPL

56
Q

Where does tertiary fibers (corticopetal fibers) of the lateral spinothalamic tract synapse?

A

in postcentral gyrus: somatic sensory areas 3,1,2

57
Q

What does the tertiary fibers of the lateral spinothalamic tract form?

A

internal capsule

58
Q

What caries light touch(crude touch), pressure, tickle, itch?

A

anterior spinothalamic tract

59
Q

What is the medial lemniscus system also called?

A

posterior column system

60
Q

What does the medial lemniscus system carry sensation for?

A

two point sensation (Fine touch), pressure, and vibration

61
Q

Where does primary fibers ascend for medial lemniscus system?

A

entire length of spinal cord and synapse with secondary neurons in medulla

62
Q

What are the secondary neurons in medulla?

A

fasciculus gracilis fasciculus cuneatus

63
Q

Where do fibers of fasciculus gracilis synapse?

A

in nucleus gracilis -convey sensations from below midthoracic level

64
Q

Where doe fibers of fasciculus cuneatus synapse?

A

in nucleus cuneatus -convey sensations from above midthoracic level -also conveys proprioceptive sensation from arms to cerebellum

65
Q

What do medial lemniscus system secondary fibers do?

A
  • decussate - ascend to synapse in VPL of thalamus, and then the tertiary will ascend through the internal capsule to the primary sensory cortex.
66
Q

What do medial lemniscus system tertiary fibers do?

A

ascend through internal capsule to primary sensory cortex

67
Q

What do the anterior spinothalamic tract primary neurons?

A

may ascend 8-10 spinal cord segments before synapsing with secondary neurons

68
Q

What do the anterior spinothalamic tract secondary fibers do?

A

-decussate in anterior gray or white commissures - ascend to synapse with tertiary fibers in VPL nucleus of thalamus

69
Q

What do the anterior spinothalamic tract tertiary fibers do?

A

ascend through internal capsule to primary sensory cortex.

70
Q

All of the output neurons that are stimulated by an incoming fiber comprise the __________. A) Neuronal Pool B) Discharge Zone C) Zone of Facilitation D) Stimulatory field

A

Ans: B) Discharge Zone

71
Q

Which tract is known for ascending or descending 1 to 2 vertebral segments before synapsing on a secondary neuron in the CNS? a) Anterior Spinothalamic Tract b)Medial Lemniscus System c) the Fasciculus Cuneatus d)the Fasciculus gracilis e) the Lateral Spinothalamic Tract

A

e) the Lateral Spinothalamic Tract

72
Q

Which Tract system is sensitive to vibration, pressure and 2 point sensation? a) Anterior Spinothalamic Tract b)Medial Lemniscus System c) the Fasciculus Cuneatus d)the Fasciculus gracilis e) the Lateral Spinothalamic Tract

A

b)Medial Lemniscus System

73
Q

Which specific tract conveys proprioceptive sensation from the arms to the cerebellum? a) Anterior Spinothalamic Tract b)Medial Lemniscus System c) the Fasciculus Cuneatus d)the Fasciculus gracilis e) the Lateral Spinothalamic Tract

A

c) the Fasciculus Cuneatus

74
Q

Which tract specifically synapses in the nucleus gracilis and conveys sensations from below the mid thoracic level? a) Anterior Spinothalamic Tract b)Medial Lemniscus System c) the Fasciculus Cuneatus d)the Fasciculus gracilis e) the Lateral Spinothalamic Tract

A

d)the Fasciculus gracilis

75
Q

T/F: The Temporal Summation is when an increased signal strength is increased by the number of neurons synapsing and thereby increasing the frequency of nerve impulses.

A

FALSE. The Temporal Summation is when there is an increase in signal strength by increasing the frequency of nerve impulses, but it will be from THE SAME presynaptic fibers… not additional ones

76
Q

Define Discharge Zone:

A

includes all the output fires stimulated by incoming fibers

77
Q

Ruffini Corpuscles can be remembered because “Ruffles have ridges.” What type of endings do these Free Mechanoreceptors have?

A

Free expanded spray endings.