Neurophys I

Question 1

Labeled line principle

Answer 1

Gives sensory modality telling the “what”

Question 2

Define Lateral inhibition

Answer 2

A way to enhance boundary contrasts to improve two point discrimination.

Question 3

What is the frequency code?

Answer 3

Signal strength increase by frequency of nerve impulses.

Question 4

What s the population code?

Answer 4

Increasing the number of fibers that are activated to increase the strength of a signal.

Question 5

Merkel cels, Ruffini end organs, and Baroreceptors are all part of what adaptation class?

Answer 5

Slowly adapting also known as tonic.

Question 6

Pacinian corpuscles, and meissers corpuscles are all known as what class of adapting cells?

Answer 6

Rapidly adapting aka phasic.

Question 7

Aalpha Type I nerve fibers have what function?

Answer 7

These are the axons to:
motor neuron muscles
spindle primary endings (1a) and
Golgi tendon organ afferent.

Question 8

A-Beta type II nerve fibers have what function?

Answer 8

Muscle spindle secondary endings
Axons of cutaneous mechanoreceptors.
“Touch receptors”

Question 9

A-Gamma nerve fibers have what function?

Answer 9

Axons of gamma motor neuron to muscle spindle fibers.

Question 10

A-Delta (type III) nerve fibers have what function?

Answer 10

Fast Pain information 
Some temp (Group III)

Question 11

B type nerve fibers have what function?

Answer 11

Sympathetic preganglionic axons.

Question 12

C type IV fibers have what function?

Answer 12

UNMYELINATED 
Slow pain
Some temperature
and
Sympathetic postganglionic axons.

Question 13

which cell type is non-adapting?

Answer 13

Nociceptors!

Question 14

Which receptors are involved in proprioception?

Answer 14

Joint receptors
Muscle spindle and golgi tendon organs
Skin tactile receptors.

Question 15

What information is carried by the dorsal column?

Answer 15

Temperature
Vibration
Fine touch
Proprioception
Visceral pain

Question 16

Where does the dorsal column cross the midline?

Answer 16

In the descussation of the medial lemniscus in the brainstem.

Question 17

What deficits are seen with lesion to dorsal columns?

Answer 17

Tactile discrimination loss
Graphesthesia
Stereognosis
Vibratory sence
Proprioception

Question 18

What sort of information is carried by the Anterolateral spinal cord pathways?

Answer 18

Nociception and temperature
Some tactile info
(Lesions of dorsal columns will not eliminate all tactile sensation)

Question 19

Where does the anterolateral spinal cord pathway cross?

Answer 19

In the spinal cord

Question 20

What deficits are seen in the enterolateral spinal cord pathway is damaged?

Answer 20

Loss of pain sense
Loss of thermal sense
Diminished tactile sense.

Question 21

Where is the somatosensory cortex located?

Answer 21

Parietal lobe.

Foot is always in medial cortex!!!