spinal cord anatomy: descending tracts and spinal cord blood supply

Question 1

What part of the internal capsule of the ganglia contains the sensory fibers along with the corticospinal/pyramidal system (leg, trunk, arm, face)?

Answer 1

posterior limb

Question 2

Once the corticospinal tract reaches the medulla, 85% of the fibers branch off and become the ____.

Answer 2

Lateral corticospinal tract

Question 3

Once the corticospinal tract reaches the medulla, 15% of the fibers branch off and become the ____.

Answer 3

anterior corticospinal tract

Question 4

What does the lateral corticospinal tract supply?

Answer 4

Everything except the axial muscles.

Question 5

What does the anterior corticospinal tract supply?

Answer 5

axial muscles

Question 6

Where does the rubrospinal tract originate?

Answer 6

red nucleus of the midbrain

Question 7

The rubrospinal tract (does/does not) receive input from the cortex.

Answer 7

It does

Question 8

What pathway is only found in the cervical segments?

Answer 8

rubrospinal tract

Question 9

What does the rubrospinal tract innervate?

Answer 9

Flexors of the UE

Question 10

Where does the medial vestibulospinal tract originate?

Answer 10

medial vestibular nucleus

Question 11

What does the medial vestibulospinal tract innervate?

Answer 11

Head and neck muscles

Question 12

Does the medial vestibulospinal tract become bilateral or does it stay unilateral?

Answer 12

It becomes bilateral for the cervical spine

Question 13

Where does the lateral vestibulospinal tract originate?

Answer 13

lateral vestibular nucleus

Question 14

Does the lateral vestibulospinal tract become bilateral or does it stay unilateral?

Answer 14

It stays unilateral

Question 15

What pathways are believed to have involvement with muscle spasticity?

Answer 15

Reticulospinal tract

Question 16

What do the reticulospinal tracts do as a whole?

Answer 16

Provide postural control/tone

Question 17

Where does the medial reticulospinal tract originate?

Answer 17

Reticular formation in the PONS

Question 18

Does the medial reticulospinal tract become bilateral or does it stay unilateral?

Answer 18

It stays unilateral

Question 19

What does the medial reticulospinal tract do?

Answer 19

excites the extensors and axial muscles

Question 20

Where does the lateral reticulospinal tract originate?

Answer 20

reticular formation of the MEDULLA

Question 21

Does the lateral reticulospinal tract become bilateral or does it stay unilateral?

Answer 21

It is bilateral at ALL levels

Question 22

What does the lateral reticulospinal tract do?

Answer 22

It excites the flexor muscles

Question 23

What does the reticular formation receive information from?

Answer 23

cortex and basal ganglia

Question 24

(true/false) The anterior spinal artery only goes down to the thoracic level.

Answer 24

False (it travels down the whole spinal cord)

Question 25

What is considered as the “watershed of the spinal cord?”

Answer 25

anterior spinal artery

Question 26

What arteries supply blood to the anterior spinal artery at every level?

Answer 26

anterior radicular arteries

Question 27

where do the anterior radicular arteries branch off of?

Answer 27

the aorta

Question 28

What level(s) of the spinal cord have the least amount of blood going to the anterior spinal artery?

Answer 28

T4-T8

Question 29

The anterior spinal artery provides blood to ___ of the spinal cord.

Answer 29

2/3

Question 30

The posterior spinal artery provides blood to __ of the spinal cord.

Answer 30

1/3 (dorsal columns)

Question 31

Where is the venous plexus found in the vertebral column?

Answer 31

Epidural space

Question 32

What is unique about the venous plexus in the vertebral column?

Answer 32

They do not have valves