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Flashcards in Introduction to sensory systems Deck (58)
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1
Q

What are sensory systems responsible for?

A

1) Collecting information regarding our external and internal environment
2) Conveying that information from the PNS into the CNS
3) Sensory information is utilized by the CNS to:
a) conscious appreciation of the specific qualities of a sensory stimulus
b) appropriate reflex response to a given stimulus

2
Q

What are sensory receptors or ending of the PNS responsible for?

A

1) Monitor changes in one’s external and internal enviornment
2) Serve as biological transducers (change/transduce sensory stimuli into electrical signals = information)
3) Conduct information into the CNS

3
Q

What are sensory neurons (primary sensory neurons) in the PNS?

A

1) Cell bodies of these neurons are almost always located in peripheral ganglia of spinal and cranial nerves
2) Perpheral processes innervate sensory receptors in peripheral tissue
3) Central processes project into the spinal cord or brain

4
Q

What are the 5 different receptor classifications based on stimulus response?

A
Chemoreceptors
Photoreceptors
Thermoreceptors
Mechanoreceptors
Nociceptors
5
Q

What are chemoreceptors?

A

Montior changes in chemical species in a tissue environment

6
Q

What are photoreceptors?

A

Monitor changes in light (rods and cones)

7
Q

What are thermoreceptors?

A

Monitor changes in temperature

8
Q

What are mechanoreceptors?

A

Monitor changes in mechanical and physical stimuli

9
Q

What are nociceptors?

A

Monitor noxious stimuli

Respond to noxious chemical stimulation, noxious thermal extremes, noxious mechanical stimuli

10
Q

What are the different classes of receptors?

A

Encapsulated and nonenscapsulated endings

11
Q

What are nonencapsulated endings?

A

Terminals of axons that lie next to cells or free in the extracellular space

12
Q

What are the different types of nonencapsulated endings?

A

Free nerve endings
Merkel endings
Peritrichial nerve endings

13
Q

What are free nerve endings?

A

Axonal terminal “free” between cells in tissue

14
Q

What are merkel endings?

A

Branched terminals that end as expansions on merkel cells, located in basal layers of skin (mostly in glaborous skin)

15
Q

What are peritrichial nerve endings?

A

Axonal terminal distributed along the root/shaft of hair follicles

16
Q

What are the different types of encapsulated nerve endings?

A
Pacinian corpuscles
Meissner's Corpuscles
Ruffini's Endings
End Bulbs
Neuromuscular spindles
Neurotendinous spindles
17
Q

What are pacinian corpuscles?

A

Single axon that terminate ina capsule made up of collagen and thin flattened cells that are arranged concentrically to the terminal

18
Q

What are Meissner’s corpuscles?

A

encapsulates terminals of several axons

19
Q

What are ruffini endings?

A

thin delicate capsules

single axon that is highly branched

20
Q

What are end bulbs?

A

Single axon that is highly branched

Often spherica most commonly located at musculocutaneous junctions

21
Q

What are neuromuscular spindles?

A

Found in skeletal muscle

22
Q

What are neurotendinous spindles?

A

AKA golgi tendon organs

Found in tendons and ligaments

23
Q

What do nonencapsulated and encapsulated receptors generally monitor?

A

Somatosensory stimuli in cutaneous or other deeper tissues (also monitor various stimuli in visceral tissue

24
Q

What receptors are found in cutaneous areas?

A
Free nerve endings
Peritrichial endings
Merkel's endings
ruffini endings
Meissner's Corpuscles
Pacinian corpuscles
25
Q

What do free nerve endings monitor in cutaneous areas?

A

Monitor thermal, painful (noxious) and tactile stimuli

26
Q

Where are free nerve endings found in cutaneous areas?

A

In deep epidermis, dermis and hypodermis tissue

27
Q

What do peritichial endings monitor in cutaneous areas?

A

Tactile stimuli

28
Q

Where are peritrichial endings found in cutaneous areas?

A

Respond to best of movement of hair

29
Q

Where are merkel’s endings found in cutaneous areas?

A

Deep epidermis

30
Q

What do merkel’s endings monitor in cutaneous areas?

A

Tactile stimuli

31
Q

What do ruffini endings monitor in cutaneous areas?

A

Pressure and stretch (tactile)

32
Q

Where are Ruffini endings found in cutaneous areas?

A

Dermis/hypodermis

33
Q

Where are Meissner’s corpuscles found in cutaneous areas?

A

Dermal papillae, located in glabrous skin

34
Q

What do Meissner’s corpuscles monitor in cutaneous areas?

A

Tactile receptor

35
Q

What do pacinian corpuscles monitor in cutaneous areas?

A

vibration

36
Q

Where are Pacininan corpuscles found?

A

Dermis and hypodermis

37
Q

What are the different nerve endings found in joints?

A

Free nerve endings
small pacinian corpuscles
ruffini-like endings
neurotendinous spindles

38
Q

Where are the free nerve endings found in joints and what do they monitor?

A

In synovial membrane, joint capsule and periarticular CT and they are nocioceptors

39
Q

Where are the small pacinian corpuscles found in joints and what do they monitor?

A

In periarticular CT around the joint capsule and they are proprioceptors

40
Q

Where are the Ruffini-like endings found in joints and what do they monitor?

A

In joint capsular tissue and are proprioceptors

41
Q

Where are the neurotendinous spindles (Golgi tendon organs) found in joints and what do they monitor?

A

In articular ligaments and are proprioceptors

42
Q

What are the receptors found in skeletal muscle?

A

Free nerve endings

Neuromuscular spindles

43
Q

Where are the free nerve endings found in skeletal muscles and what do they monitor?

A

Connective tissue around the muscle and they are nocioceptors

44
Q

Where are the neuromuscular spindles found in skeletal muscles and what do they monitor?

A

Distrbuted mostly in muscle near its junction with tendon and most numerous in muscles that perform highly skilled maneuvers and they are proprioceptors

45
Q

What are the receptors found in tendons?

A

Free nerve endings

Golgi tendon organs (neurotendinous spindles)

46
Q

Where are the neuromuscular spindles found in tendons and what do they monitor?

A

Neuromuscular and proprioceptors

47
Q

What are the receptors found in viscera?

A

Free nerve endings

Pacinian corpuscles

48
Q

What do free nerve endings in tendons monitor?

A

Nocioceptors

49
Q

What do free nerve endings in viscera monitor?

A

Nocioceptors

50
Q

What do pacinian corpuscles in viscera monitor?

A

Stretch and distension

51
Q

What type of nerve fibers are included in peripheral nerves?

A

Peripheral nerves include sensory and motor fibers that are distributed to various end organs or tissues

52
Q

What are the trends from A(alpha) to B in myelinated fibers of peripheral nerves?

A

Thick myelin sheaths move from thick (A-alpha) to thin myelin sheaths
Also, the diameter decreases from A-alpha to B

53
Q

What are the unmyelinated fibers in unmyelinated fibers?

A

C fibers

54
Q

What receptors are type Ia fibers?

A

Neuromuscular spindle

55
Q

What receptors are type Ib fibers?

A

Neurotendinous spindle and Ruffini endings

56
Q

What receptors are type II fibers?

A

Neuromuscular spindle

Meissner’s & Pacinian Corpuscles

57
Q

What receptors are type III fibers?

A

Pain and Temperature receptors

58
Q

What receptors are type IV fibers?

A

Pain & temperature receptors