Descneding tracts

Question 1

بسم الله الرحمن الرحيم وبه نستعين
UMN IS ?

Answer 1

Nerves from cortex and subcortical Nuclei to the AHCs of spinal cord or Cranial Motor Nuclei

Question 2

LMN IS ?

Answer 2

AHCs a motor neurons of spinal cord and Cranial motor Nuclei and their Axons

Question 3

Some characteristic of UMNs pYRAMIDAL TRACT

Answer 3

From cortex
To a motor neurons of AHCs + Cranial Nerve Nuceli
60% Develops after 1 year
3%From betz cells of area 4
It is Well developed

Question 4

Functions of Pyramidal Tracts

Answer 4

-Movements:-
Gross + Fine movements
Gross for positioning and fixation
postural background for fine movments.
To perform Fine skilled Movements in distal limb muscles
Faciltatory to Superfical and deep reflexes
______________________
-Reflexes:-
Inhibits Babinski reflex
_______________________
-According to areas :-
-Area 4 fine
-Area 6 and supplemental gross
-Area 8 contral lateral volunary lateral conjugate eye movements

Question 5

Extrapyramidal tracts in brief

Answer 5

From cortex motor mainly area 6
to basal ganglia which Is Distrubitive Center to the Nuceli of Extra pyarmidal tracts :
Red Nucleus = Rubrospinal
Tectum of mid brain = Tectospinal
Vestibular nucleus= Vestibulopsina;
Retiuclar formation = Reticulospinal
Inferior olivary nucleus = Olivospina

Question 6

Lateral brainstem pathway in Extrapyramidals ?

Answer 6

Rubrospinal tract for fine movements

Question 7

Medial brains stem pathaway for extrapyramidals ?

Answer 7

Tectospinal
Vestibulospinal
Reticulospina;l

Question 8

other area that has a map for motor movemnts than area 4 ?

Answer 8

Red nucleus im mid brain

Question 9

Termination and control of medial brainstem extrapyramidals ?

Answer 9

Ends on medial AHCs alpha motor neurons for ?
Axial and proximal limb muscles for gross movments and postural background for fine movements

Question 10

Termination and controol of lateral brainsterm extrapyramidals ?

Answer 10

Ends on lateral AHCs alpha notor neurion for ?
Distal limb Muscles for Fine movements
It faciltate flexor parts of AHCs and inhivits externsors

Question 11

How to compare between medial and lateral brainstem extrapyrmaidals ?

Answer 11

in Tracts + Termination + Control(function)

Question 12

Mnetion functions of Extrapyramidal tracts

Answer 12

Coorfination of Voluntary movements gross and fine:
Gross movemnts for fixation and posistioningg and postural background for
Fine movements alternative pathway in rubrospinal alternative to Lateral coritcospinal in lesion
_________________________
Facilitatory and inhibtory to SR
Functional regulation of Automnomic function in CVS resp
_________________________
Tectospinal : Medial Aduial reflex
Larteal : visual reflex eye protective reflexes
Vestibulospinal Activating Alpha motor neurons for antigravity extensors muscles

Question 13

How to compare between pyrmaidal and ExtraPyramidal Tracrts

Answer 13

Origin
tract

Crossing
Termination
Start of function
funciton

Question 14

Compare between Pyramidal and Extrapyramidal tracts

Answer 14

Pyramidal : from cortex - One neuron from cortex to Anterior HOrn cells of spinal cord of Cranial motor nuclei one synapse -90 % crossing -start function after year - function for fine movements and gross and for ++SR
___________________
ExtraPyramidal : cortical subcortical - Polysynaptic as go to basal ganglia then ditrbted - terminates in AHCs of spinal cord only - start during first year - Function gross movments + alternative fine movements may be
++ or– for SR

Question 15

How to compare between descneding Tracts ?

Answer 15

TRACTS
Termination
COntrol
Lesion

Question 16

Compare between descending Tracts

Answer 16

Lateral descneding :
Rubrsospinal-Lateral Corticospinal
Terminates in the lateral motor neurons of the AHCs in 1 or 2 segments for precise movements as it is responsible for distal limb muscles fine movements and its lesion causes loss of Fine movements in fingers and wrist with preservations of gross moveents
lesion to LCS only casues loss of finger fraction finve movments with perservation of wrist function by rubrospinal tract
__________________________
Medial descending :Ventral CS
Retuclospinal–Tectospinal-Vestibulospinal
Terminates in medial AHCs of the Spinal cord in multiple segments intersegmental for Control of movments of group of muscles
for axial and proximal limb muscles gross movements for Stabilization and Fixation and Postural Backgroung for fine movments and its lesion causeS ?
Loss of Gross movements posttural backgoround gfor fine movemetns
dfffiuvlt in sitting standing walking

Question 17

Medial descending tracts desvribe

Answer 17

Medial descending :Ventral CS
Retuclospinal–Tectospinal-Vestibulospinal
Terminates in medial AHCs of the Spinal cord in multiple segments intersegmental for Control of movments of group of muscles
for axial and proximal limb muscles gross movements for Stabilization and Fixation and Postural Backgroung for fine movments and its lesion causeS ?
Loss of Gross movements posttural backgoround gfor fine movemetns
dfffiuvlt in sitting standing walking

Question 18

Lateral descneding tracts :
desvribe

Answer 18

Lateral descneding :
Rubrsospinal-Lateral Corticospinal
Terminates in the lateral motor neurons of the AHCs in 1 or 2 segments for precise movements as it is responsible for distal limb muscles fine movements and its lesion causes loss of Fine movements in fingers and wrist with preservations of gross moveents
lesion to LCS only casues loss of finger fraction finve movments with perservation of wrist function by rubrospinal tract

Question 19

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