Thoracic limb vessels and nerves

Main arteries of thoracic limb (proximal-distal)

• Subclavian

• Axillary

• Brachial

• Median

Subclavian artery branches

• Left subclavian

• Right subclavian

Left subclavian

• Arises from aorta

• Continues into axillary

Right subclavian

• arises from brachiocephalic trunk (from aorta)

Axillary a

• Continuation of subclavian a, after it passes the first rib

superficial cervical a supplies…..

• branch of subclavian that supplies blood to the superficial muscles at the base of the neck, superficial cervical LN, muscles of scapula, shoulder

Branches of the axillary (proximal-distal)

• external thoracic a (may not be seen in specimens)

• lateral thoracic a (may not be seen in specimens)

  • sub scapular a

• cranial circumflex humeral a

• brachial a

External thoracic a supplies…..

superficial pectoral

Lateral thoracic a supplies….

• deep pectoral m

• latissimus dorsi m

• cutaneous trunci m

• skin

• mammae (in females)

Subscapular branches

• thoracodorsal a

• caudal circumflex humeral a

subscapular supplies…..

• scapula

• shoulder muscles

• long head of triceps

• rhomboideus

• trapezius

thoracodorsal a supplies…..

• latissimus dorsi

• teres major

• skin

caudal circumflex humeral a supplies…..

• triceps brachii

• deltoideus

• coracobrachialis

• infraspinatus

• shoulder joint

caudal circumflex anastamosis

anastomosis with cranial circumflex humeral and suprascapular a

cranial circumflex humeral a supplies

• biceps brachii

• shoulder joint

cranial circumflex humeral anastomosis

anastomosis with caudal circumflex humeral and suprascapular

brachial a

• main artery in the trunk of the brachial region

• continuation of axillary after the branch of the cranial circumflex humeral a

branches of the brachial a

• deep brachial

• bicipital

• collateral ulnar

• superficial brachial

• transverse cubital

• common interosseous

• median

deep brachial a supplies….

triceps brachii

bicipital a supplies…..

biceps brachii

collateral ulnar a supplies….

• triceps brachii

• ulnar nerve

• elbow

superficial brachial a

gives rise to cranial superficial antebrachial

transverse cubital a supplies….

• elbow

• adjacent mm

common interosseous a branches

• ulnar a

• cranial and caudal interosseous a

median a

• principle source of blood supply for the manus

• forms a superficial palmar arch with a branch of the caudal interosseous s

median a branches

• deep antebrachial

• radial

dorsal common digital a supplies….

dorsal superficial portion of manus

palmar common digital supplies…

superficial palmar portion of the manus

Dorsal metacarpal a supplies….

Deep dorsal portion of the manus

palmar metacarpal a supplies….

deep palmar portion of the manus

abaxial/axial dorsal/palmar proper digital aa

• supplies blood flow to the digits

• continuation of dorsal and palmar common digital aa

deep veins of thoracic limb (distal-proximal)

• median v

• brachial v

• axillary v

• subclavian v

Superficial veins of thoracic limb (distal-proximal)

• accessory cephalic v

• cephalic v

• median cubital v

• axillobrachial v

• omobrachial v

cephalic vein drains into…..

external jugular vein

omobrachial v

• passes superficial to the brachiocephalicus m

• from the axillobrachial v to the external jugular

axillobrachial v

• from cephalic v to the axillary v

accessory cephalic v

• arises from veins on dorsal surface of the manus (common digital veins)

• joins cephalic vein on the cranial aspect of the antebrachium

median cubital v

• connects brachial/median vein with cephalic vein

lymph nodes of the antebrachium

• superficial cervical (pre-scapular) lymph nodes

• axillary lymph node

• accessory axillary lymph node

thoracic limb nerves (of the brachial plexus)

• suprascapular n

• subscapular n

• musculocutaneous n

• axillary n

• radial n

  • superficial branch —> antebrachiocutaneous nn

  • deep branch

• median n

• ulnar n

  • caudal antebrachial cutaneous n

sensory nerves

General somatic afferent (GSA) - bring the somatic stimuli from the environment towards the central nervous system

• also have postganglionic sympathetic general visceral efferent fibers (GVE-sympathetic)

motor nerves

General somatic efferent (GSE) - fibers from the CNS towards the skeletal muscle to perform voluntary control of movement

• GSA proprioceptive fibers

• postganglionic sympathetic general visceral efferent (GVE-sympathetic)

GSA proprioceptive fibers

bring sensory information from stretch receptors located in joints, capsules, ligaments, tendons, skeletal muscles to the central nervous system

postganglionic sympathetic general visceral efferent fibers

motor fibers for the smooth muscle in vessels, piloerector muscle, and glands located in the skin

suprascapular n

• C6-C7

• motor nerve

  • innervates supraspinatus and infraspinatus

• found cranial to the scapular notch

subscapular n

• C6-C7

• motor nerve

  • innervates subscapularis

• found in a medial view in sub scapular m

musculocutaneous n

• C6, C7, C8

• motor nerve

  • innervates biceps brachii, brachialis, coracobrachialis

• sensory nerve

  • innervates medial aspect of antebrachium

• found cranial to biceps brachii, between brachial a in a medial view

axillary n

• C7, C8

• motor

  • innervates teres major, teres minor, deltoids, caudal part of subscapularis

• sensory

  • innervates craniolateral shoulder area, cranial aspect of antebrachium

• Found caudal to the neck of the scapula

radial n

• C7, C8, T1, T2

• motor nerve - Deep branch

  • innervates triceps brachii, tensor fascia antebrachii, anconeus, brachioradialis, extensor muscles of the antebrachium

• sensory nerve - sensory branch

  • cranial and lateral aspect of the antebrachium, medial and dorsal aspect of the manus

• find innervating the triceps in a medial view, branches into deep and superficial on the lateral side deep to the triceps

radial nerve deep branch

• motor

  • innervates extensors and supinator

• found deep to the carporadialis m

radial nerve superficial branch

• sensory

  • cranial and lateral aspect of the antebrachium

  • medial and dorsal aspect of the manus

• Divides into to antebrachiocutaneous nn

• runs parallel with cephalic vein

median n

• C8, T1, T2

• motor

  • innervates the antebrachial flexors

• sensory

  • innervates palmar aspect of the manus

• originates from a common trunk with the ulnar nerve, runs caudal to the brachial a

ulnar n

• C8, T1, T2

• motor

  • innervates flexor carpi ulna's , deep digital flexor, interossei

• sensory

  • innervates caudal aspect of the antebrachium, palmar aspect of the manus, lateral side of 5th digit

• originates from trunk with median n, runs caudal in the brachium into two branches, continues to run distally through the groove formed by medial epicondyle of the humerus and the olecranon

caudal antebrachial cutaneous n

• superficial branch of the ulnar nerve

axillary a

cranial circumflex humeral a

bicipital a

superficial brachial a

collateral ulnar a