Functions Of Descending Motor Tract Flashcards

1
Q

GR: The name of the pyramidal tract

A

Because some fibers arise from the pyramidal (Betz) cells present in motor area 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Functions if pyramidal tract

A
  1. Controls fine skilled motor movements especially in the distal joints
  2. Shares with extrapyramidal tract in gross movements and postural adustment as background for fine movements
  3. Facilitatory to superficial & deep reflexes
  4. Inhibits primitive withdrawal reflex
  5. Conrticobulbar tract controls lateral eye movemts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Mention parts of medial brain stem

A

Work via vertical corticospinal tract
PRS & MRS, vestibulospinal, tectospinal tracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe termination of medial brain stem pathways

A

-Terminate on interneurons in ant horn of spinal cord to control axial & proximal muscles
-Some terminate directly on motor neurons to control axial muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe lateral brain stem pathway

A

Arise from red nucleus of midbrain which has a somatotopic representation like area 4 but less fine, terminate on interneurons in ventral horn of spinal cord controlling distal muscles, it excited flexor & inhibits extensor muscle, may be a weak alternative in fine skilled movement in case of pyramidal lesion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Enumerate functions of extrapyramidal tract

A
  1. Control gross movements if axial & proximal muscles.
  2. Provide postural background for performance of fine skilled movements
  3. Associated with basal ganglia in semiautomatic movements
  4. In selective corticospinal tract lesion, rubrospinal tract can control fine movements of hand & wrist but not fingers.
  5. Regulation of muscle tone
  6. Med tectospinal —reflex head turning in response to sound, lateral tectospinal —protective eye reflexes, head turning in response to visual stimuli.
  7. Vestibulospinal tract activate antigravity muscles.
  8. Autonomic functions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe autonomic functions of extrapyramidal tract

A
  1. Respiratory center to AHCs of respiratory muscles
  2. Vasomotor tract to LHCs in thoraco-Lumbar region
  3. Sweat secretion (from heat regulating center in hypothalamus)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Compare pyramidal to extrapyramidal with respect to termination & when function starts

A

Pyramidal, terminate on cranial nerve nuclei & alpha & gamma (AHCs) , begins one year after birth
Extrapyramidal, terminate on alpha & gamma neurons, during first year

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Mention site of termination of medial & lateral motor systems

A

M, medial or ventral portion of anterior horn
L, lateral portion of anterior horn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly