Anatomy and Function of the motor neurone system. Flashcards
White matter is situated where?
Semioval centre below the cortex
White matter contains what 3 fibres?
Commisural fibres, Association fibres and Projection fibres
Where does the corona radiata converge and what does it form?
Ventrally to form the internal capsule.
Internal capsule is compiled by what 3 structures?
The anterior and posterior limb and genticulate fibres.
What are the fibres in the geniculate and posterior limb?
Projection fibres.
Posterior limb is associated with what tract?
Corticospinal
Geniculate fibres are associated with what tract?
Corticobulbar
Anterior limb contains what fibres?
Association fibres
What are the 2 pyramidal tracts?
Corticobulbar and Corticospinal.
Where do the Corticobulbar fibres project and input to?
Project to the brainstem and input to CN nerves.
Corticobulbar tract is associated with what movements?
Movements of the head and face.
Corticospinal fibres project and input to where?
Project to the spinal cord and input to LMN
Corticospinal fibres are associated with movement of what?
Arm, trunk (midline) and leg.
Corticospinal tract is split into what?
Lateral and ventral.
Ventral synapses with interneurons and motor neurons that innervate what?
Trunk (midline).
Lateral synapses with interneurons and motor neurons that innervate what?
Muscles of limbs and digits.
What are 3 symptoms of UMN syndrome?
Weakness, stiffness of the contralateral muscles.
Hypertonia
Exaggerated reflexes - spasticity, clonus and babinski reflex.
Name 4 other UMN diseases.
Primary lateral sclerosis - corticospinal tract degeneration
Pseudobulbar palsy - corticobulbar tract degeneration.
Cerebral Palsy - damage to motor centres of the developing brain. Symptoms non-progressive
Multiple Sclerosis - immune disorder that destroys the myelin. Inflammation reaction to myelin therefore neurons very slow.
What are 2 symptoms of LMN diseases?
Flaccid muscles and hypotonia.
What are 2 LMN disorders?
Progressive muscular atrophy - degeneration of LMN.
Spinal muscular atrophy - genetic. SMN1 gene.
Name 2 skeletal muscle disorders.
Muscular dystrophy and myopathies.
Name the disorder affecting the ACh receptors at post-synaptic muscular junctions causing muscle weakness.
Myasthenia Gravis
Name 2 disorders affecting the peripheral nerves
Charcot-Marie-Tooth disease and Guillan-Barre syndrome.
What is ALS?
Amyloid lateral sclerosis - degeneration of the UMN and LMN.
