Exam 2 week 8 ppt 2 Cutaneous Receptors of the Somatic Sensory System Flashcards

Question

which classification system is used only with sensory or afferent fibers?

Answer 1

The Roman Numeral System

Answer 2

the Ia & Ib or A-alpha category They are muscle proprioceptive afferents

Answer 3

IV or C fibers nociceptive afferent fibers

Answer 4

the large and small caliber motor and autonomic efferent fibers

Answer 5

Most articles discussing pain afferents

Answer 6

articles describing muscle afferents commonly use the roman numeral system.

Answer 7

1. •Peritrichial endings - or hair follicle receptors 2. •Meissner's corpuscle 3. •Merkel cell–neurite complex 4. •Pacinian corpuscle 5. •Ruffini ending

Answer 8

•Peritrichial endings 1. –Around base of hair in hair follicle 2. –Respond to hair movement 3. –Light touch, breeze 4. –Rapidly adapting Peritrichial endings are the endings Around base of hair in hair follicle and they respond to hair movement. These are Rapidly adapting receptors that respond to the Light touch of what has been described as a loving caress, or a wafting breeze

Answer 9

1. –Found is superficial cutaneous layers at base of epidermis 2. –Nerve endings surrounded by connective tissue capsule 3. –Responds to light touch 4. –Low threshold and fast adapting Meissner's corpuscle are Low threshold and fast adapting that are Found is superficial cutaneous layers at base of epidermis Nerve endings surrounded by connective tissue capsule. These receptors are specialized to respond to the light touch of passing your hand over an object to get a sense of it s size and shape

Answer 10

1. –At base of epidermal ridges in superficial cutaneous layers 2. –Clustered together in “touch-domes” (lower picture) 3. –Function in sustained light touch 4. –Low threshold and slow adapting Merkel cell–neurite complex are Low threshold and slow adapting cutaneous receptors located at the base of epidermal ridges in superficial cutaneous layers. These are Clustered together in “touch-domes” (as seen in the lower picture) and function in sustained light touch. These are the receptors you use to get a real sense of the texture of an object or to read braille. As David Linden described in his book Touch: The Science of Hand, Heart, you shouldn’t try to read braille with you lips as lips have very few if any Merkel’s touch domes. So even though the lips are highly sensitive and have a high receptor density they do not have these receptors

Answer 11

1. –Meissner respond to onset & release of touch 2. –Merkel respond for entire duration of touch 3. –Both widely distributed but heaviest density at areas of greatest sensitivity - finger tips 4. –Ab or group II afferents 5. –Ascend in dorsal columns Meissner & Merkel receptors are both widely distributed but heaviest density at areas of greatest sensitivity - finger tips and face with Meissner corpuscles responding to onset & release of touch and Merkel receptors responding for entire duration of touch and are responsible for the fine discriminative touch which ascends in the dorsal columns. They both utilize A-beta or group II afferent fibers.

Answer 12

1. –Found in deeper cutaneous layers 2. –Ab nerve endings surrounded by multiple connective tissue layers 3. –Responds to vibratory pressure 4. –High threshold and fast adapting afferents Pacinian corpuscles are High threshold and fast adapting cutaneous receptors found in the deeper cutaneous layers. These are A-beta Nerve ending surrounded by multiple connective tissue layers. These are most sensitive to vibratory pressures felt say through a steering wheel when driving over rough pavement or the lack of vibration when going over ice. It has been speculated that these are useful when using tools to say feel the click of a screwdriver into the notch on the head of the screw or the variation in the vibration felt as a hammer it’s the nail or misses the nail and hits wood.

Answer 13

1. –Spindle shaped, encapsulated Ab endings 2. –Found is deep cutaneous layers 3. –Function in sustained pressure & stretch of skin (object slippage along skin) 4. –High threshold and slow adapting Ruffini ending is a Spindle shaped, encapsulated endings also Found is deep cutaneous layers. It is High threshold and slow adapting A-beta endings and is thought to function in Function in sustained pressure & stretch of skin. Some have speculated that it serves an important role to assess object slippage across the skin such as when you are gripping an object. You need to grip the object enough to prevent slippage of that object but not too hard to cause fatigue

Answer 14

1. –Pacinian respond to onset & release of pressure (vibration) 2. –Ruffini respond for entire duration of pressure 3. –Both widely distributed 4. –Pacinian afferents ascend in dorsal columns 5. –Ruffini afferents ascend in spinothalamic tracts Pacinian respond to onset & release of pressure (vibration) while Ruffini respond for entire duration of pressure Both widely distributed but less densely distributed than the Meissner’s corpuscles and Merkel touch domes. So these may also play a role in non-discriminative touch. The vibratory sense from Pacinian afferents ascend in dorsal columns and the non-discriminative touch and pressure sensations of Ruffini afferents and Pacinian afferents ascend in spinothalamic tracts

Answer 15

* Unencapsulated nerve endings throughout body, most numerous in skin * Are lightly myelinated or unmyelinated primary afferents There are also Pain and thermal receptors. These are Unencapsulated nerve endings which are seen throughout body, but most numerous in skin. They are the terminals of lightly myelinated or unmyelinated primary afferents. Thermal receptors respond to temperature changes of the skin and Nociceptors respond to stimuli that damage tissue.

Answer 16

temperature changes

Answer 17

stimuli that damage tissue

Answer 18

Nociceptors are often classed by the stimulus that they respond to:

Answer 19

1. Thermal 2. Burning heat (\>45° C) 3. Extreme cold (\<15° C) * it says \<5 degrees C in book 4. Strong mechanical stimulation 5. Chemical agents 6. Polymodal – respond to several forms of noxious stimuli, chemical, thermal or mechanical (im not sure the first one was supposed to be separated out)

Answer 20

–Moderate heat (30-45° C) –Moderate cold (10-33° C)

Answer 21

A-delta & C fibers

Answer 22

A-delta fibers