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Dissection of brachial plexus

Anterior view

Brachial Plexus Nerves

 1 Dorsal scapular nerve

 2 Suprascapular nerve

 3 Nerve to the subclavius muscle

 4 Lateral pectoral nerve

 5 Upper subscapular nerve

 6 Musculocutaneous nerve

 7 Axillary nerve

 8 Radial nerve

 9 Median nerve

10 Ulnar nerve

 11 Lower subscapular nerve

12 Thoracodorsal nerve

The brachial plexus arises from the last four cervical ventral rami and the fi rst thoracic ventral

ramus. The four cervical ventral rami pass laterBrachial Plexus

13 Long thoracic nerve

14 Medial pectoral nerve

15 Superior trunk

16 Middle trunk

17 Inferior trunk

18 Lateral cord

19 Posterior cord

20 Medial cord

Other Nerves and Strucures

21 Phrenic nerve

22 Anterior scalene muscle

23 Middle scalene muscle

ally between the middle and internal layers of the lateral cervical body wall, the middle and

anterior scalene muscles, respectively. As they emerge through the scalenes, they connection with with one another as well as with the ascending branch of the fi rst thoracic ventral

ramus. This is the beginning of the nerve plexus that will innervate almost all the muscles and

associated skin of the upper limb.

24 Levator scapulae muscle

25 Subclavius muscle

26 Pectoralis minor muscle

27 Pectoralis major muscle

28 Deltoid muscle

29 Biceps brachii muscle

30 Subscapularis muscle

31 Teres major muscle

32 Latissimus dorsi muscle

33 Serratus anterior muscle

34 Clavicle

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Lumbar Plexus Nerves

 1 Subcostal nerve

 2 Iliohypogastric nerve

 3 Ilioinguinal nerve

 4 Genitofemoral nerve

 5 Genital branch of genitofemoral nerve

 6 Femoral branch of genitofemoral nerve

 7 Lateral femoral cutaneous nerve

 8 Femoral nerve

 9 Obturator nerve

10 Lumbosacral trunk

Sacral Plexus Nerves

 11 Superior gluteal nerve

12 Inferior gluteal nerve

13 Posterior femoral cutaneous nerve

14 Nerve to the obturator internus muscle

15 Pudendal nerve

16 Perforating cutaneous nerve

17 Inferior cluneal nerve

18 Sciatic nerve

19 Upper bands of sacral plexus

Pelvic dissection exposing lumbar and sacral plexus

Anterior view

Abdominal dissection of lumbar plexus

Anteriorview

The lumbar plexus arises from the ventral rami of the fi rst four

lumbar spinal nerves. The plexus emerges laterally through the

intervertebral foramina to pass anterolateral between the two

Lumbar Plexus

heads of the psoas major muscle. The more superior branches of the plexus enter the abdominal body wall to

innervate the abdominal muscles. The lower nerves of the plexus course into the lower limb as the lateral

femoral cutaneous, femoral, and obturator nerves. The lumbar plexus is a transitory plexus that begins as a

series of body wall nerves and eventually transitions into limb innervation. The fi rst ventral ramus of the plexus

is basically a segmental nerve that follows the basic segmental nerve pattern in the ventral body wall. The

second lumbar ventral ramus forms segmental branches in the body wall and other branches that contribute to

limb innervation. The third and fourth ventral rami contribute solely to innervation of the lower limb anatomy.

Other Structures

20 Diaphragm

21 Psoas major muscle

22 Psoas minor muscle

23 Quadratus lumborum muscle

24 Iliacus muscle

25 Obturator externus muscle

26 Sartorius muscle

27 Tensor fasciae latae muscle

28 Gluteus maximus muscle

29 Gluteus medius muscle

30 Gluteus minimis muscle

31 Piriformis muscle

32 Superior gemellus muscle

33 Obturator internus muscle

34 Inferior gemellus muscle

35 Sacrotuberous ligament

36 Penis

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Dissection of sacral plexus nerves

Posterior view

Dissection of pudendal nerves and vessels

Lateral view

The sacral plexus forms from the ventral rami of the last two

lumbar and the fi rst four sacral spinal nerves. The fourth and

fi fth lumbar spinal nerves form a descending communication,

Sacral Plexus

the lumbosacral trunk, that joins with the upper sacral spinal nerves as they exit the anterior foramina

of the sacrum. On the anterior surface of the sacrum the large roots of the plexus are noticeable

before they exit through the greater sciatic notch on their course into the pelvic wall and lower limb.

This plexus forms the total nerve supply to the pelvic body wall, and, along with the limb branches from

the lumbar plexus, is the nerve supply for the lower limb.

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Dissection of intercostal nerves

Lateral view

Dissection of intercostal space

Lateral view

Intercostal Nerves

costal and subcostal nerves, emerge from the spinal nerve trunk and enter the intercostal space just inferior to each of the

twelve ribs. Each of these segmental nerves has a similar structural design. The main trunk of the nerve runs through the

intercostal space, with the segmental arteries and veins, between the middle and internal muscle layers of the body wall.

Accompanying the main branch is a smaller collateral branch, which emerges from the main branch near the angle of the

rib, and runs inferior to the main branch through the intercostal space. The main branch also gives rise to lateral and anterior cutaneous branches that supply the skin, or dermatome, of each segment.

Unlike the ventral rami in the cervical, lumbar, and sacral regions, which

form plexuses, most of the thoracic ventral rami remain segmental like

their dorsal counterparts. These thoracic ventral rami, called the interIntercostal Nerves

 1 Main trunk

 2 Collateral branch

Other Nerves and Structures

 3 Subcostal nerve

 4 Iliohypogastric nerve

 5 Posterior intercostal vein

 6 Posterior intercostal artery

 7 Innermost intercostal muscle

 8 Transversus abdominis muscle

 9 Gluteus medius muscle

10 Piriformis muscle

 11 Iliocostalis muscles

12 Rib 12

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 1 Greater occipital nerve

 2 Transverse cervical nerves

 3 Supraclavicular nerves

 4 Medial cutaneous branches (dorsal rami)

 5 Lateral cutaneous branches (dorsal rami)

 6 Anterior cutaneous branches (ventral rami)

 7 Lateral cutaneous branches (ventral rami)

Dissections exposing cutaneous nerves

Anterior view to left, Posterior view to right

Many small nerves, named cutaneous nerves, branch from the spinal

and cranial nerves and course through and between muscles to emerge

into the integumentary covering of the body. These detailed dissections

reveal all the cutaneous nerves of the body.

Cutaneous Nerves

 8 Superior lateral brachial cutaneous nerves

 9 Posterior brachial cutaneous nerves

10 Inferior lateral brachial cutaneous nerves

 11 Posterior antebrachial cutaneous nerve

12 Lateral antebrachial cutaneous nerve

13 Medial antebrachial cutaneous nerve

14 Femoral branch of genitofemoral nerve

15 Lateral cutaneous branch of subcostal nerve

16 Anterior cutaneous branch of femoral nerve

17 Lateral femoral cutaneous nerve

18 Superior cluneal nerves

19 Inferior cluneal nerve

20 Posterior femoral cutaneous nerve

21 Saphenous nerve

22 Lateral sural cutaneous nerve

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In contrast to the somatic branches of the

spinal nerve, the visceral branches leave

the body wall to form nerve pathways that

Autonomic Nerves

Autonomic Nerves

 1 Sympathetic trunk nerve

 2 Sympathetic trunk ganglion

 3 White communicating ramus

 4 Gray communicating ramus

 5 Greater splanchnic nerve

 6 Lesser splanchnic nerve

 7 Coeliac ganglion

 8 Superior mesenteric ganglion

 9 Aorticorenal ganglion

10 Vagus nerve

 11 Recurrent laryngeal nerve

12 Anterior vagal trunk

13 Posterior vagal trunk

14 Inferior cardiac plexus

15 Pulmonary plexus

16 Esophageal plexus

Other Structures

17 Intercostal nerve

18 Posterior intercostal artery

19 Posterior intercostal vein

20 Right superior intercostal vein

21 Azygous vein

22 Superior vena cava

23 Aorta

24 Celiac trunk

25 Superior mesenteric artery

26 Renal artery

27 Suprarenal gland

28 Kidney

29 Ureter

30 Diaphragm

30 Esophageal hiatus

32 Subcostal muscle

33 Innermost intercostal muscle

34 Internal oblique muscle

35 Transversus abdominis muscle

36 Psoas major muscle

37 Psoas minor muscle

Deep dissection of sympathetic nerves, callout of communicating rami

Anterolateral view

enter the body cavities. Within the cavities these nerves form the autonomic nerve pathways,

sympathetic and parasympathetic, to the viscera. The autonomic nerves relay input signals from

the wall of the tubular gut and other viscera, while carrying output signals to smooth muscle,

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