UMN & LMN Lesions

Question 1

Main motor function of the somatic nervous system

Answer 1

Produce smooth coordinated voluntary movement

Question 2

Things needed to perform smooth coordinate voluntary movement

Answer 2

Intact motor cortex
Intact motor pathways :
UMN
LMN

Intact subcortical centers :
The cerebellum
The basal ganglia

Question 3

UMN :

Answer 3

From the motor cortex to anterior horn cell AHC

Pyramidal and extrasoyramidal tracts

Question 4

LMN :

Answer 4

From AHC to skeletal muscles

Called alpha motor neuron

Question 5

Role of the cerebellum in the performing of motor function

Answer 5

Coordinating the movements through braking, damping, prediction

Question 6

Role of the basal ganglia in performing motor functions

Answer 6

Shares in production and control the rapidity and intensity of movements

Question 7

Effects of UMNL :

Answer 7

1) Paralysis or paresis
2) Hypertonia
3) Hyperreflexia
4) Change in Superficial reflexes

Question 8

Type of paralysis or paresis depending on the site of UMNL

Answer 8

Lesion in cortex and corona radiata > Monoplegia
Lesion in internal capsule > Uncrossed hemiplegia
Lesion in brain stem > Crosses hemiplegia
Lesion in upper spinal cord > Ipsilateral Hemiplegia in limbs
Lesion in lower spinal cord > Ipsilateral Monoplegia in one lower limb

Question 9

What’s the changes that occur on superficial reflexes in UMNL

Answer 9

Plantar reflex > Babinski’s sign

Abdominal reflex > Absent