28 Neurovasculature

Arteries of the Upper Limb

Fig. 28.1 Arteries of the upper limb
Right limb, anterior view.

Fig. 28.2 Branches of the arteria subclavia
Right side, anterior view.

Fig. 28.3 Scapular arcade
Right side, posterior view.

Fig. 28.4 Arteries of the forearm and hand
Right limb. The aa. ulnaris and radialis are interconnected by the arcus palmares superficialis and profundus, the rr. perforantes, and the rete carpale dorsale.

Veins & Lymphatics of the Upper Limb

Fig. 28.5 Veins of the upper limb
Right limb, anterior view.

Fig. 28.6 Veins of the dorsum manus
Right hand, posterior view.

Fig. 28.7 Fossa cubitalis
Right limb, anterior view. The subcutaneous veins of the fossa cubitalis have a highly variable course.

Clinical box 28.1

Venipuncture
The veins of the fossa cubitalis are frequently used when drawing blood. In preparation, a tourniquet is applied above the fossa cubitalis. This allows arterial blood to flow, but blocks the return of venous blood. The resulting swelling makes the veins more visible and palpable.

Lymph from the upper limb and mamma drains to the nll. axillares. The superficial lymphatics of the upper limb lie in the subcutaneous tissue, while the deep lymphatics accompany the arteries and deep veins. Numerous anastomoses exist between the two systems.

Fig. 28.8 Lymphatics of the upper limb
Right limb.

Fig. 28.9 Lymphatic drainage of the hand
Right hand, radial view. Most of the hand drains to the nll. axillares via nll. cubitales. However, the pollex, index, and dorsum manus drain directly.

Fig. 28.10 Nodi lymphoidei axillares
Right side, anterior view. For surgical purposes, the nll. axillares are divided into three levels with respect to their relationship with the m. pectoralis minor: lateral (level I), posterior (level II), or medial (level III). They have major clinical importance in breast cancer (see p. 77).

Nerves of the Upper Limb: Plexus Brachialis

Almost all muscles in the upper limb are innervated by the plexus brachialis, which arises from segmenta C5–T1 medullae spinalis. The rr. anteriores of the nn. spinales give off direct branches (pars supraclavicularis of the plexus brachialis) and merge to form three trunci, six divisiones (three anteriores and three posteriores), and three fasciculi. The pars infraclavicularis of the plexus brachialis consists of short branches that arise directly from the fasciculi and long (terminal) branches that traverse the limb.

Fig. 28.11 Plexus brachialis
Right side, anterior view.

Pars Supraclavicularis & Fasciculus Posterior

Fig. 28.12 Supraclavicular branches
Right shoulder.

The supraclavicular branches of the plexus brachialis arise directly from the radices plexus brachialis (rr. anteriores of the nn. spinales) or from the trunci plexus brachialis in the regio cervicalis lateralis.

Table 28.2 Pars supraclavicularis plexus brachialis

Nerve	Level	Innervated muscle
N. dorsalis scapulae	C4–C5	M. levator scapulae Mm. rhomboidei major et minor
N. suprascapularis	C4–C6	M. supraspinatus M. infraspinatus
N. subclavius	C5–C6	M. subclavius
N. thoracicus longus	C5–C7	M. serratus anterior

Fig. 28.13 Fasciculus posterior plexus brachialis: Short branches
Right shoulder.

The fasciculus posterior gives off three short branches (arising at the level of the fasciculi plexus brachialis) and two long branches (terminal nerves, see pp. 368–369).

Table 28.3 Branches of the fasciculus posterior

Nerve	Level	Innervated muscle
Short branches
Upper n. subscapularis	C5–C6	M. subscapularis
Lower n. subscapularis		M. subscapularis M. teres major
N. thoracodorsalis	C6–C8	M. latissimus dorsi
Long (terminal) branches
N. axillaris	C5–C6	See p. 368
N. radialis	C5–T1	See p. 369

Fasciculus Posterior: Nervus Axillaris & Nervus Radialis

Fig. 28.14 Nervus axillaris: Cutaneous distribution
Right limb.

Clinical box 28.2

The n. axillaris may be damaged in a fracture of the collum chirurgicum of the humerus. This results in limited ability to abduct the arm and may cause a loss of profile of the shoulder.

Fig. 28.15 Nervus axillaris
Right side, anterior view, stretched for clarity.

Table 28.4 Nervus axillaris (C5–C6)

Motor branches	Innervated muscles
Rr. musculares	M. deltoideus M. teres minor
Sensory branch
N. cutaneus brachii lateralis superior

Fig. 28.16 Nervus radialis: Cutaneous distribution

Fig. 28.17 Nervus radialis
Right limb, anterior view with forearm pronated.

Table 28.5 Nervus radialis (C5–T1)

Motor branches	Innervated muscles
Rr. musculares	M. brachialis (partial)
	M. triceps brachii
	M. anconeus
	M. brachioradialis
	Mm. extensores carpi radialis longus and brevis
R. profundus (terminal br.: n. interosseus antebrachii posterior)	M. supinator
	M. extensor digitorum
	M. extensor digiti minimi
	M. extensor carpi ulnaris
	Mm. extensores pollicis brevis and longus
	M. extensor indicis
	M. abductor pollicis longus
Sensory branches
Rr. articulares from n. radialis: Capsula articularis of the art. humeri
Rr. articulares from n. interosseus antebrachii posterior: Capsula articularis of the carpus and four radial artt. metacarpophalangeae
N. cutaneus brachii posterior
N. cutaneus brachii lateralis inferior
N. cutaneus antebrachii posterior
Rr. superficiales	Nn. digitales dorsales
	R. communicans ulnaris

Clinical box 28.3

Chronic n. radialis compression in the axilla (e.g., due to extended/improper crutch use) may cause loss of sensation or motor function in the hand, forearm, and posterior arm. More distal injuries (e.g., during anesthesia) affect fewer muscles, potentially resulting in wrist drop with intact m. triceps brachii function.

Fasciculus Medialis & Fasciculus Lateralis

The fasciculi medialis and lateralis plexus brachialis give off four short branches. The nn. intercostobrachiales are included with the short branches of the plexus brachialis, although they are actually the cutaneous branches of the nn. intercostales 2 and 3.

Fig. 28.18 Fasciculi medialis et lateralis: Short branches
Right side, anterior view.

Fig. 28.19 Short branches of fasciculi medialis et lateralis: Cutaneous distribution

Fig. 28.20 Nervus musculocutaneus
Right limb, anterior view.

Table 28.7 Nervus musculocutaneus (C5–C7)

Motor branches	Innervated muscles
Rr. musculares	M. coracobrachialis
	M. biceps brachii
	M. brachialis
Sensory branches
N. cutaneus antebrachii lateralis
Rr. articulares: Capsula articularis of the art. cubiti (anterior part)
Note: N. musculocutaneus innervation of the arm is purely motor; innervation of the forearm is purely sensory.

Fig. 28.21 Nervus musculocutaneus: Cutaneous distribution

Nervus Medianus & Nervus Ulnaris

The n. medianus is a terminal branch arising from both the fasciculi medialis and lateralis plexus brachialis. The n. ulnaris arises exclusively from the fasciculus medialis.

Fig. 28.22 Nervus medianus
Right limb, anterior view.

Fig. 28.23 Nervus medianus: Cutaneous distribution

Clinical box 28.4

N. medianus injury caused by fracture/dislocation of the art. cubiti may result in compromised grasping ability and sensory loss in the fingertips (see Fig. 28.23 for territories). See also carpal tunnel syndrome (p. 387).

Table 28.8 Nervus medianus (C6–T1)

Motor branches	Innervated muscles
Direct rr. musculares	M. pronator teres
	M. radialis flexor carpi
	M. palmaris longus
	M. flexor digitorum superficialis
Rr. musculares from n. interosseus antebrachii anterior	M. pronator quadratus
	M. flexor pollicis longus
	M. flexor digitorum profundus (radial half)
Thenar r. muscularis	M. brevis abductor pollicis
	Caput superficiale musculi flexoris pollicis brevis
	M. opponens pollicis
Rr. musculares from nn. digitales palmares communes	Mm. lumbricales I and II
Sensory branches
Rr. articulares: Capsulae articulares of the artt. cubiti and carpi
R. palmaris of n. medianus (eminentia thenaris)
R. communicans cum nervo ulnari
Nn. digitales palmares communes
Nn. digitales palmares proprii

Fig. 28.24 Nervus ulnaris: Cutaneous distribution

Fig. 28.25 Nervus ulnaris
Right limb, anterior view.

Table 28.9 Nervus ulnaris (C7–T1)

Motor branches	Innervated muscles
Direct rr. musculares	M. flexor carpi ulnaris
	M. flexor digitorum profundus (ulnar half)
R. muscularis from superior n. ulnaris	M. palmaris brevis
Rr. musculares from r. profundus	M. abductor digiti minimi
	M. brevis flexor digiti minimi
	M. opponens digiti minimi
	Mm. lumbricales III and IV
	Mm. interossei palmares and dorsales
	M. adductor pollicis
	Caput profundum musculi flexoris pollicis brevis
Sensory branches
Rr. articulares: Capsulae articulares of the artt. cubiti, carpi, and metacarpophalangeae
R. dorsalis (terminal brs.: nn. digitales dorsales)
R. palmaris
Nn. digitales palmares proprii (from r. superficialis)
N. digitales palmares communes (from r. superficialis; terminal brs.: nn. digitales palmares proprii)

Clinical box 28.5

Ulnar nerve palsy is the most common peripheral nerve damage. The n. ulnaris is most vulnerable to trauma or chronic compression in the art. cubiti and ulnar tunnel (see p. 387). Nerve damage causes “clawing” of the hand and atrophy of the mm. interossei. Sensory losses are often limited to the 5th digit.

Superficial Veins & Nerves of the Upper Limb

Fig. 28.26 Superficial cutaneous veins and nerves of the upper limb

Fig. 28.27 Cutaneous innervation of the upper limb

Fig. 28.28 Dermatomes of the upper limb

Posterior Shoulder & Arm

Fig. 28.29 Posterior shoulder
Right shoulder, posterior view. Raised: M. trapezius (pars transversa). Windowed: M. supraspinatus. Revealed: Suprascapular region.

Fig. 28.30 Triangular and quadrangular spaces

Anterior Shoulder

Fig. 28.31 Anterior shoulder: Superficial dissection
Right shoulder.

Fig. 28.32 Shoulder: Transverse section
Right shoulder, inferior view.

Fig. 28.33 Anterior shoulder: Deep dissection
Right limb, anterior view. Removed: Mm. sternocleidomastoideus, omohyoideus, and pectoralis major. This dissection reveals the neurovascular contents of the regio cervicalis lateralis (see p. 642) and axilla (see pp. 380–381).

Axilla

Fig. 28.34 Axilla: Dissection
Right shoulder, anterior view.

Table 28.11 Walls of the axilla

Anterior wall	M. pectoralis major M. pectoralis minor Fascia clavipectoralis
Lateral wall	Sulcus intertubercularis of humerus
Posterior wall	M. subscapularis M. teres major M. latissimus dorsi
Medial wall	Lateral thoracic wall M. serratus anterior

Anterior Arm & Regio Cubitalis

Fig. 28.35 Regio brachialis
Right arm, anterior view. Removed: Mm. deltoideus, pectorales major et minor. Revealed: Sulcus bicipitalis medialis.

Fig. 28.36 Regio cubitalis
Right cubitus, anterior view.

Regio Antebrachii Anterior & Regio Antebrachii Posterior

Fig. 28.37 Regio antebrachii anterior
Right forearm, anterior view.

Fig. 28.38 Regio antebrachii posterior
Right forearm, anterior view during pronation. Reflected: Mm. anconeus and triceps brachii. Removed: Mm. extensor carpi ulnaris and extensor digitorum.

Regio Carpalis

Fig. 28.39 Regio carpalis anterior
Right hand, anterior (palmar) view.

Fig. 28.40 Canalis ulnaris
Right hand, anterior (palmar) view.

Fig. 28.41 Canalis carpi: Cross section
Right hand, proximal view. The tight fit of sensitive neurovascular structures with closely apposed, frequently moving tendons in the canalis carpi often causes problems (carpal tunnel syndrome) when any of the structures swell or degenerate.

Palm of the Hand

Fig. 28.42 Superficial neurovascular structures of the palm
Right hand, anterior view.

Fig. 28.43 Neurovasculature of the digitus manus
Right digitus manus III, lateral view.

Fig. 28.44 Deep neurovascular structuresof the palm
Right hand, anterior view.

Fig. 28.45 Innervation patterns in the palm
Right hand, anterior view.

Dorsum of the Hand

Fig. 28.46 Cutaneous innervation of the dorsum of the hand (dorsum manus)
Right hand, posterior view.

Fig. 28.47 Anatomic snuffbox
Right hand, radial view. The three-sided “anatomic snuffbox” is bounded by the tendons of insertion of the m. abductor pollicis longus and mm. extensores pollicis brevis and longus.

Fig. 28.48 Neurovascular structures of the dorsum