Sensory lecture

Question 1

ANTERIOR LATERAL TRACT

Answer 1

primary afferents will travel and synapse on this same side After the first synapse, the ascending information decussates

Question 2

Discriminative touch

Answer 2

Localization of touch and vibration

Ability to discriminate between two closely spaced points touching the skin

Question 3

Conscious proprioception

Answer 3

Awareness of the movements and relative position of body parts

Question 4

Stereognosis

Answer 4

Ability to use touch and proprioceptive information to identify an object

Question 5

Dorsal column/Medial lemniscus system

Answer 5

Cross the midline
transmits discriminative touch, proprioception, vibration, 2 pt discrimination to consciousness into the CNS and up to the thalamus

Question 6

Anterolateral column/Spinothalamic pathway

Answer 6

Crosses midline via anterior white commissure and ascend to thalamus as spinothalamic tract
transmits pain, temperature and poor localization into the CNS and up to the thalamus

Question 7

Spinocerebellar projections

Answer 7

these relay information about muscle tension, limb position and spinal cord level of activity to the cerebellum for planning of movements

Question 8

Brown-Sequard Syndrome

Answer 8

Loss of pain and temp.side opposite and below
Loss of light touch and 2-point ipsilateral and below the lesion
Upper motor lesion ipsilateral below the level of the lesion
Lower motor lesion at the level of the lesion due to the injury of cells directly and not axons

Question 9

Speed of information processing is determined by the following

Answer 9

Diameter of the axons
Degree of axonal myelination
Number of synapses in the pathway

Question 10

Tonic receptors

Answer 10

Do not adapt to the stimulus
Light on a photoreceptor, pressure, chemoreception
either on or off

Question 11

Phasic receptors

Answer 11

Adapt to the stimulus

Some types of pain, noise, vibration

Question 12

Mechanoreceptors

Answer 12

Respond to mechanical deformation of touch, pressure, stretch, or vibration.

Question 13

Chemoreceptors

Answer 13

Respond to released substances by cells, including damaged cells after injury or infection.

Question 14

Thermoreceptors

Answer 14

Respond to heat or cold.

Question 15

Nociceptors

Answer 15

Stimulation results in the sensation of pain.
Example: Pressure mechanoreceptors are stimulated by stubbing a toe; the sensation experienced is pain rather than pressure.
Usually activated when cell damage/death might occur

Question 16

What does distribution pattern tell you?

Answer 16

Spinal level of impairment
Brain involvement
Peripheral nerve damage

Question 17

Ways to test for spinothalamic tract damage

Answer 17

sharp object and use of cold object

Question 18

Ways to test for dorsal column tract damage

Answer 18

cotton swab and filament testing

Question 19

Meissner corpuscles

Answer 19

a cutaneous nerve ending responsible for transmitting the sensations of fine, discriminative touch and vibration.

Question 20

Pacinian corpuscles

Answer 20

sensory nerve that acts as a receptor for pressure and vibration.

Question 21

Vibration: discriminative

Answer 21

30 Hz stimulates Meissner corpuscles

256 Hz stimulates Pacinian corpuscles

Question 22

Two-point Discrimination

Answer 22

Accuracy of sensory fields
Can 2 points be detected
Differing sizes in different areas of the body
Back are the largest
Face and fingers are the smallest

Question 23

Stereognosis: discriminative

Answer 23

Requires cortical processing and interpretation
Can objects be recognized by touch only
Difficult to test if patient has expressive aphasia or anomia

Question 24

Diabetic neuropathy

Answer 24

Primarily loss of vibratory and position sense
Muscle denervation can occur
Paresthesia, numbness, coldness, other distortions of thermal sensations

Question 25

Why have a NCS?

Answer 25

In addition to determining the location of peripheral nervous system lesions, a primary diagnostic value of NCS is to determine whether the neuropathic lesion is one of axonal loss or demyelination.