Somatosensation

Question 1

Encapsulated receptors

Answer 1

Meissner, Merkel, Pacini, Ruffini

Question 2

Proprioception relies on receptors in:

Answer 2

Joints (pacini and ruffini), tendons (Golgi tendon organs), and muscles (muscle spindles)

Question 3

What type of fiber types are and are not myeltinated

Answer 3

A-fiber types are myelinated.

A-alpha is most heavily myelinated followed by A-beta then A-delta.

C-fiber types are not myelinated and the slowest conducting.

Question 4

Lesion of DCML in posterior column causes

Answer 4

ipsalateral deficits

Question 5

Lesions of DCML in medial lemniscus and above cause

Answer 5

contralateral deficits

Question 6

agraphesthesia

Answer 6

inability to identify letters drawn on the skin

Question 7

astereognosia

Answer 7

inability to name objects held against the skin

Question 8

Spinothalamic damage in the lateral funiculus causes

Answer 8

contralateral analgesia (loss of pain sensation)

Question 9

Spinothalamic damage in the anterior white commisure causes

Answer 9

bilateral analgesia in the dermatomes corresponding to the lesion.

Question 10

Right spinal cord hemisection causes

Answer 10

• ipsilateral loss of discriminative touch & proprioception combined with contralateral analgesia.
• Brown-Sequard Syndrome

Question 11

Spinocerebellar pathway controls

Answer 11

Non-concious proprioception

Question 12

Spinocerebellar damage causes

Answer 12

ataxia and ipsalateral deficit