Anatomy and Function of the motor neurone system.

Question 1

White matter is situated where?

Answer 1

Semioval centre below the cortex

Question 2

White matter contains what 3 fibres?

Answer 2

Commisural fibres, Association fibres and Projection fibres

Question 3

Where does the corona radiata converge and what does it form?

Answer 3

Ventrally to form the internal capsule.

Question 4

Internal capsule is compiled by what 3 structures?

Answer 4

The anterior and posterior limb and genticulate fibres.

Question 5

What are the fibres in the geniculate and posterior limb?

Answer 5

Projection fibres.

Question 6

Posterior limb is associated with what tract?

Answer 6

Corticospinal

Question 7

Geniculate fibres are associated with what tract?

Answer 7

Corticobulbar

Question 8

Anterior limb contains what fibres?

Answer 8

Association fibres

Question 9

What are the 2 pyramidal tracts?

Answer 9

Corticobulbar and Corticospinal.

Question 10

Where do the Corticobulbar fibres project and input to?

Answer 10

Project to the brainstem and input to CN nerves.

Question 11

Corticobulbar tract is associated with what movements?

Answer 11

Movements of the head and face.

Question 12

Corticospinal fibres project and input to where?

Answer 12

Project to the spinal cord and input to LMN

Question 13

Corticospinal fibres are associated with movement of what?

Answer 13

Arm, trunk (midline) and leg.

Question 14

Corticospinal tract is split into what?

Answer 14

Lateral and ventral.

Question 15

Ventral synapses with interneurons and motor neurons that innervate what?

Answer 15

Trunk (midline).

Question 16

Lateral synapses with interneurons and motor neurons that innervate what?

Answer 16

Muscles of limbs and digits.

Question 17

What are 3 symptoms of UMN syndrome?

Answer 17

Weakness, stiffness of the contralateral muscles.
Hypertonia
Exaggerated reflexes - spasticity, clonus and babinski reflex.

Question 18

Name 4 other UMN diseases.

Answer 18

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.

Question 19

What are 2 symptoms of LMN diseases?

Answer 19

Flaccid muscles and hypotonia.

Question 20

What are 2 LMN disorders?

Answer 20

Progressive muscular atrophy - degeneration of LMN.

Spinal muscular atrophy - genetic. SMN1 gene.

Question 21

Name 2 skeletal muscle disorders.

Answer 21

Muscular dystrophy and myopathies.

Question 22

Name the disorder affecting the ACh receptors at post-synaptic muscular junctions causing muscle weakness.

Answer 22

Myasthenia Gravis

Question 23

Name 2 disorders affecting the peripheral nerves

Answer 23

Charcot-Marie-Tooth disease and Guillan-Barre syndrome.

Question 24

What is ALS?

Answer 24

Amyloid lateral sclerosis - degeneration of the UMN and LMN.