(L5) Back Angiology & Neurology

Question 1

What are the main branches of the subclavian A.?

L5 S3

Answer 1

(in order proximally to distally)

• vertebral A.
• internral thoracic A.
• thyrocervical trunk
• costocervical trunk
• dorsal scapular A.

Question 2

What are the landmarks for the subclavian A.?

L5 S3

Answer 2

Arises from aortic arch (left subclavian A. only) and brachiocephalic trunk (right subclavian A. only).

Deep to anterior scalene M.

Continues as axillary A. distal to lateral border of 1st rib

Question 3

What are the main branches of the axillary A.?

L5 S13

Answer 3

(in order proximally to distally)

• superior thoracic A.
• thoracoacromial trunk
• lateral thoracic A.
• subscapular A.
• anterior circumflex humoral A.
• posterior circumflex humoral A.

Question 4

What are the landmarks for the axillary A.?

L5 S13

Answer 4

Continuation of subclavian A. lateral to first rib

Passes under pectoralis minor M.

Continues as brachial A. distal to inferior border of teres major M.

Question 5

What arteries supply the spine and spinal roots?

L5 S17

Answer 5

Spine:

-anterior spinal A. (1) and posterior spinal As. (2) from anterior/posterior segmental medullary arteries

Spinal roots/rootlets:

-anterior/posterior radicular As.

Question 6

What are the sources of paraspinal arteries?

L5 S18

Answer 6

Subclavian A.:

• vertebral A.
• ascending cervical A.
• deep cervical A.

Aorta:

• posterior intercostal A.
• subcostal A.
• lumbar A.

Internal iliac A.:

• iliolumbar A.
• lateral sacral A.

Question 7

What is the result of a spinal cord injury at the level of C1-3?

L5 S24

Answer 7

Quadriplegia and inability to breath without assistance of a ventilator.

Bedbound

Question 8

What is the result of a spinal cord injury at the level of 4-5?

L5 S24

Answer 8

Quadriplegia but able to breath without a ventilator.

Wheelchair bound

Question 9

What is the result of a spinal cord injury at the level of C6-8?

L5 S24

Answer 9

Paraplegia with varibale degree of upper extremity use.

Wheelchair bound

Question 10

What is the result of a spinal cord injury at the level of T1-9?

L5 S24

Answer 10

Paraplegia with full controll of upper extremities. Variable control of trunk.

Wheelchair bound

Question 11

What is the result of a spinal cord injury at the level of T10-L1?

L5 S24

Answer 11

Variable function of thigh.

Possibly able to walk with long leg braces.

Question 12

What is the result of a spinal cord injury at the level of L2-3?

L5 S24

Answer 12

Loss of function of some muscles in lower leg/foot.

Able to walk with short leg braces.

Question 13

What are the filum terminale internum and filum terminale externum?

L5 S26

Answer 13

Filum terminale internm:

-continuation of the pia mater from medullary cone within the subarachnoid space

Filum terminale externum:

-continuation of the of the piamater, arachnoid mater, and dura mater at the termination of the lumbar cistern, no subarachnoid space

Question 14

What are the named posterior rami and what are their spinal levels? (5)

L5 S32

Answer 14

• suboccipital N. (C1)
• greater occipital N. (C2)
• least occipital N. (C3)
• superior cluneal Ns. (L1-3)
• middle cluneal Ns. (S1-3)

Question 15

What are the common structures innervated by posteior rami?

L5 S34

Answer 15

• zygapophysial joint (medial branches only)
• intrinsic muscles of the back (medial and lateral branches)
• overlying skin of the back (medial and lateral branches)

Question 16

What are denticulate ligaments?

L5 S27

Answer 16

Expansion of the pia mater that anchors into the dura mater, suspending the spinalcord in the subarachnoid space.