Radiology Pt1 Anatomy - Limb Neurovascular

Front 1

Brachial plexus

Back 1

5 Parts -
Roots: C5-T1 (anterior rami)
Trunks: Upper (C5 C6) Middle (C7) Lower (C8 T1)
Divisions: Anterior and posterior divisions of each trunk
Cords: Posterior (all post. divisions C5-T1) Lateral (ant. divisions from upper and middle trunks C5-C7) Medial (ant. division of lower trunk C8-T1)
Branches: Terminal nerves. All but 4 arise from the cords. 2 arise from the roots, 2 from the upper trunk.
There are 3 lateral cord, 5 medial cord and 5 posterior cord branches.

Mnemonic: Radiology trainees drink cold beer

Pre-cord branches:
ROOTS:
Long thoracic nerve runs down the spine, with origins in C5, C6 and C7. Supplies serratus anterior
Dorsal scapula nerve arises from the root of C5, supplying the rhomboids and levator scapulae
TRUNKS:
Nerve to subclavius from upper trunk (C5, C6). Supplies subclavius muscle. Sometimes considered a ROOT branch.
Suprascapular nerve from the upper trunk (C5, C6). Supplies supraspinatus and infraspinatus.

CORD BRANCHES:
LATERAL CORD (C5, C6, C7) -
Lateral pectoral nerve to the pectoralis major. Joins with medial pectoral nerve of medial cord to supply target.
Musculocutaneous nerve to biceps brachii, coracobrachialis and brachialis. Also becomes the sensory lateral cutaneous nerve of the forearm.
Lateral root of the median nerve (which also recieves input from the medial cord). To anterior compartment of forearm, thenar muscles and 2 lateral lumbricals. Sensory to lateral 3 1/2 digits and palm.

POSTERIOR CORD:
Upper subscapular nerve (C5, C6) to subscapularis
Thoracodorsal nerve (C6, C7, C8) to latissimus dorsi
Lower subscapular nerve (C5, C6) to subscapularis and teres major.
Axillary nerve (C5, C6) has two branches (ant and post) supplying deltoid and teres minor. Sensory is tip of shoulder and via upper lateral cutaneous nerve of the arm to inferior lateral/post deltoid.
Radial nerve (C5-T1) to triceps brachii, supinator, anconeus, extensor muscles of forearm and brachioradialis. Sensory via post. cutaneous nerve of arm to triceps, post forearm and back of hand (lateral 3 1/2 fingers).

MEDIAL CORD (C8, T1):
Medial pectoral nerve to pectoralis major and minor (with supply via lateral pectoral nerve)
Medial root of median nerve (as above)
Medial cutaneous nerve of arm sensory to anterior upper arm
Medial cutaneous nerve of forearm sensory to medial forearm
Ulnar nerve to FCU, medial 2 FDP, hypothenars, interossei and medial 2 lumbricals. Sensory to the medial 1 1/2 digits and hand ant and post.

R:
Roots arise from ventral rami after neck branches in the posterior triangle, between scalenus anterior and scalenus medius.
Trunks descend laterally above the clavicle.
Divisions lie behind the clavicle
Cords are named according to their relation to the 2nd part of the axillary artery in the axilla behind pectoralis minor.

Front 2

Subclavian artery

Back 2

O:
On right - brachiocephalic trunk
On left - aortic arch

B: 3 parts
1st part: origin to medial border of scalenus anterior
Vertebral artery
Internal thoracic artery
Thyrocervical trunk
2nd part: behind scalenus anterior
Costocervical trunk
3rd part: Between scalenus ant. lateral border and outer border of 1st rib.
Dorsal scapular artery
Terminal branch: At outer border of 1st rib
Axillary artery

Supply:
Vertebrals - spinal, meningeal, PICA and basilar branches
Internal thoracic - pericardiophrenic, ant. intercostal, musculophrenic and superior epigastric branches (also called internal mammary artery)
Thyrocervical trunk - inferior thyroid, suprascapular and transverse cervical arteries
Costocervical trunk - deep cervical and supreme intercostal arteries
Dorsal scapular - to latissimus dorsi, levator scapulae, rhomboids and trapezius.
Axillary - at edge of 1st rib, many branches down arm.

Mnemonic:
VITamin C+D

Front 3

Axillary artery

Back 3

O: Terminal branch of the subclavian artery at the outer border of the 1st rib.

B: 3 parts:
1st part: Medial to pectoralis minor
Superior thoracic artery
2nd part: Behind pectoralis minor
Thoraco-acromial artery
Lateral thoracic artery
3rd part: Lateral to pectoralis minor
Subscapular artery
Ant humeral circumflex
Post humeral circumflex

Terminal branch -
continues as brachial artery past inferior border of teres minor.

Mnemonic:
She tastes like sweet apple pie

Front 4

Brachial artery

Back 4

O: Terminal branch of axillary artery at lower margin of teres minor.

B:
Profunda brachii
Superior ulnar collateral artery
Inferior ulnar collateral
Radial artery (terminal branch)
Ulnar artery (terminal branch)
Nutrient branches to humerus

Mnemonic: PSIRUN

R:
Lateral to median nerve proximally
Crossed anteriorly by median nerve midway
Medial to median nerve distally

Front 5

Radial artery

Back 5

O: Brachial artery in cubital fossa

B:
3 forearm branches, 1 posterior wrist branch, 3 palmar branches

In the forearm:
Radial recurrent artery back up arm supplying the flexors brachialis and brachioradialis, before anastamosing with profunda brachii
Palmar carpal branch arises near pronator quadratus, runs across carpus and anastamoses with the palmar carpal branch of the ulnar artery
Superficial palmar branch arises before the artery wraps around the wrist, passing through thenar muscles to form the superficial palmar arch with the same branch of the ulnar artery
In the wrist:
Dorsal carpal branch arises as the artery wraps around the wrist through the snuff box, forms the dorsal carpal arch with the same branch of the ulnar artery
In the hand:
Princeps pollicis arises as the artery passes forward between heads of adductor pollicis, and runs up both sides of the thumb as a paired artery, ramifying over the distal phalanx.
Radialis indices arises from a similar location, between dorsal interosseus1 and the oblique head of adductor pollicis, and runs along the lateral side of the index finger to supply it, ramifying with the digital artery on the medial side of the finger.
The deep palmar arch is formed by the radial artery terminally, after passing between the heads of adductor pollicis. It lies on the metacarpal bones and interossei muscles. It runs to the ulnar side, and has a small communication with the deep palmar branch of the ulnar artery. The deep branch of the ulnar nerve runs alongside it.
The deep palmar arch gives rise to the palmar metacarpal arteries.

Front 6

Ulnar artery

Back 6

O: Brachial artery in cubital fossa. Larger than radial artery

B: 3 in forearm, 1 in wrist, 3 in the hand

In the forearm:
Ulnar recurrent (often has ant. and post. branches)
Interosseus (spilts into volar/dorsal branches)
Muscular branches (mutliple)

In the Wrist:
Volar carpal branch ramifies across wrist with same branch of radial.
Superficial palmar arch
Deep palmar arch

R:
Sits on brachialis and FDP proximally. All other flexors are anterior.
Crossed by median nerve ~1/3rd down forearm.
Overlapped by FCU in the mid-third.
Laterally adjacent to ulnar nerve in lower 2/3rds

In the wrist it lies on the flexor retinaculum, under the palmar carpal ligament. Runs lateral to the pisiform bone.
The deep branch passes between adductor digiti minimi and flexor digiti minimi, forming the deep palmar arch.

V: 5-10% have higher or lower origin, even as high as axillary artery. Artery can be more superficial, including subaponeurotic or even occasionally subcutaneous.

Front 7

Profunda brachii

Back 7

O:
Brachial artery posteromedially, just below lower border of teres major.

B: Muscular branches to deltoid
Radial recurrent runs down posteriorly from the spiral groove to anastamose behind the elbow with interosseus recurrent.

R: follows radial nerve - runs in spiral groove posteriorly, then pierces lateral intermuscular septum and curls over the lateral epicondyle between brachialis and brachioradialis.

Front 8

Superior/Inferior ulnar collateral arteries

Back 8

O: Brachial artery sequentially, medially.

R: The superior ulnar collateral passes behind the medial epicondyle, giving a branch to the posterior plexus before anastamosing with the posterior ulnar recurrent.
The inferior ulnar collateral passes anteriorly over the medial epicondyle, also giving a branch that wraps around to enter the posterior confluence of arteries. The inferior ulnar collateral anastamoses with the anterior ulnar recurrent.

Front 9

Superior thoracic artery

Back 9

O: 1st part of axillary artery, prior to pectoralis minor. Runs inferiorly.

S: Runs forward and medial along the upper border of pec minor, then passes between pec major and minor to the side of chest. Supplies upper serratus anterior.

Front 10

Thoraco-acromial artery

Back 10

O: 2nd part of axillary artery, behind pec major. Runs superiorly.

B: Runs forward and splits into 4 branches
Pectoral (supplies pec major and minor)
Acromial (supplies deltoid and acromion)
Clavicular (supplies subclavius and clavicle)
Deltoid (supplies pec major and deltoid)

Mnemonic: ABCD (breast for pectoral)

Front 11

Lateral thoracic artery

Back 11

O: 2nd part of axillary artery, just before lower border of pec minor.

S: Runs along lower border of pec minor and down chest wall. Supplies pec major, serratus anterior and the breast. Sends a small branch to the axilla, supplying the subscapularis medially.

Front 12

Subscapular artery

Back 12

O: 3rd part of the axillary, after pec minor.Runs on lower border of subscapularis to the angle of scapula.

S: subscapularis

Front 13

Ant/Post. circumflex humeral arteries

Back 13

a

Front 14

Internal thoracic artery

Back 14

a

Front 15

Thyrocervical trunk

Back 15

a

Front 16

Costocervical trunk

Back 16

a

Front 17

Dorsal scapular artery

Back 17

a

Front 18

Femoral artery

Back 18

Iliac becomes femoral after inguinal ligament. Passes between the femoral nerve and femoral vein adjacent to the femoral canal.

Gives off 4 branches superficially, including the inferior epigastric artery (anastamoses with the superior epigastric artery from the internal thoracic/subclavian)

In the top of the femoral triangle it bifurcates into profunda and femoral branches.

The profunda gives of anterior and posterior circumflex femoral branches around the trochanteric region, forming the geniculate plexus.

Front 19

Sacral plexus

Back 19

L2 - S4

LUMBAR REGION - L2- L4
Anterior and posterior divisions (of ventral rami)
Anterior: Obturator nerve
Posterior: Femoral nerve

SACRAL REGION:
Upper band and lower band

Upper: L4-S3
Sciatic nerve
Anterior divisions become Tibial nerve
Posterior divisions become Sciatic nerve

Lower S2-S4
Pudendal nerve

There are additional small branches:
L4L5S1 Superior gluteal
L5S1S2 Inferior gluteal
S1S2S3 Cutaneous

And from tibial portion/ant divisions
L4L5S1 Quadratus femoris and inf gemellus
L5S1S2 Obturator internus and sup gemellus