Spinal nerves

The number of pairs of spinal nerves of the brain and their localization correspond to segments of the spinal cord: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal pair. All of them are moving away from the spinal cord posterior and anterior sensitive motor rootlets. Spines are merged into one barrel and out of the spinal canal through the intervertebral opening. In the area of the intervertebral openings are spinal units (ganglion spinale), representing a cluster of sensory cells and are part of the posterior roots. Cells from the spinal unit start-sensitive fibers and cells of the anterior horn-motor. Together, the nerves are mixed. After exiting the intervertebral openings spinal nerves are divided into front and rear mixed branches. Rear sent to the muscles and skin of the posterior trunk and anterior muscles innervated by the anterior trunk and limbs. By uniting with each other in other departments, the nerves form a neck, shoulder, lumbar and sacral plexus.

Cerviciplex (plexus cervicalis) is formed through the merger of four branches of the upper cervical nerves and is located in the deep muscles of the neck. Coming out from under the posterior edge of sternocleidomastoid muscle, branches of cervical plexus are divided into sensory, motor or mixed.

Sensitive branch include:

- Small occipital nerve (n. occipitalis minor), bound to the skin of the nape;

- Great auricular nerve (n. auricularis magnus), which innervate the skin of the ear lobe and a convex side of the ear;

- Cross-Neck nerve (n. transversus colli), bound to the skin of the neck;

- Supraclavicular nerves (nn. supraclaviculares), passing under the clavicle and over the deltoid muscle.

The motor branch directed to the deep muscles of the neck and the muscles beneath it the hyoid bone, as well as innervate the sternocleidomastoid and trapezius muscles.

Mixed branch of cervical plexus is the phrenic nerve (n. phrenicus). Motor fibers are sent to the phrenic nerve to the diaphragm, and sensitive innervate the pleura and pericardium.

 In Fig. 268.
Scheme of spinal nerves
1 - great auricular nerve;
2 - small occipital nerve;
3 - supraclavicular nerves;
4 - the nerves of the cervical plexus;
5 - subclavian nerve;
6 - suprascapular nerve;
7 - brachial plexus;
8 - phrenic nerve;
9 - subscapular nerve;
10 - the median nerve;
11 - musculo-cutaneous nerve;
12 - grudospinnoy nerve;
13 - axillary nerve;
14 - long thoracic nerve;
15 - medial cutaneous nerve of the shoulder;
16 - great splanchnic nerve;
17 - the radial nerve;
18 - ulnar nerve;
19 - medial cutaneous nerve of forearm;
20 - intercostal nerves;
21 - small splanchnic nerve;
22 - the nerves of the lumbar plexus;
23 - ilio-hypogastric nerve;
24 - ilio-inguinal nerve;
25 - nerve sacral plexus;
26 - sex-femoral nerve;
27 - upper gluteal nerve;
28 - lower gluteal nerve;
29 - posterior cutaneous nerve of the thigh;
30 - obturator nerve;
31 - sciatic nerve

Brachial plexus (plexus brachialis) formed branches of the lower four cervical nerves and the anterior branch of the 1st thoracic nerve. The branches of the plexus emerge at the neck between the anterior and middle scalene muscles and sent to the armpit. Plexus consists of a supraclavicular department, formed short branches, heading for the shoulder girdle, chest and back, and subclavian department, which consists of long branches that innervate the skin and muscles of the free portion of the upper extremity (axillary nerve with the exception of (n. axillaris), walking the shoulder belt).

 In Fig. 269.
Plexus spinal nerves, front view
1 - cervical plexus;
2 - phrenic nerve;
3 - sympathetic trunk;
4 - the median nerve;
5 - intercostal nerves;
6 - medial cutaneous nerve of the shoulder;
7 - cerebral cone;
8 - ilio-inguinal nerve;
9 - lumbar plexus;
10 - lateral cutaneous nerve of the thigh;
11 - sacral plexus;
12 - femoral nerve;
13 - obturator nerve;
14 - anterior cutaneous branch of femoral nerve
 In Fig. 270.
Plexus spinal nerves, rear view
1 - great occipital nerve;
2 - small occipital nerve;
3 - great auricular nerve;
4 - the nerves of the cervical plexus;
5 - lateral cutaneous nerve of the shoulder;
6 - posterior cutaneous branch of the thoracic nerves;
7 - the nerves of the lumbar plexus;
8 - sacral plexus nerves
In Fig. 271.
nerves of the diaphragm
1 - muscle lifting the spine;
2 - external oblique muscle of abdomen;
3 - the internal oblique muscle of abdomen;
4 - thoracic aorta;
5 - esophagus;
6 - the right phrenic nerve;
7 - lower hollow Vienna;
8 - left phrenic nerve
Supraclavicular department includes:

- The dorsal nerve of scapula (n. dorsalis scapulae), which is sent to the rhomboid muscles and muscles, levator scapulae;

- Long thoracic nerve (n. thoracicus longus), innervating the anterior serratus muscle;

- Medial and lateral pectoral nerves (nn. pectorales medialis et lateralis), going to the major and minor pectoral muscles;

- Subclavian nerve (n. subclavius), which innervates the subclavian muscle;

- Suprascapular nerve (n. suprascapularis) next to the supraspinatus and infraspinatus muscles;

- Subscapular nerve (n. subscapularis), bound to the subscapularis muscle and the large circular muscle;

- Grudospinnoy nerve (n. thoracodorsalis), which is a branch of the subscapular nerve and innervates the latissimus dorsi.

Subclavian department is located in the underarm area and consists of three bundles: the medial, lateral and posterior. The trunks of these bundles innervate the axillary artery and is the beginning of long branches.

The medial trunk includes:

- Medial cutaneous nerve of arm (n. cutaneus brachii medialis), bound to the skin of the medial surface of the shoulder;

- Medial cutaneous nerve of forearm (n. cutaneus antebrachii medialis), innervating the skin medial surface of the forearm;

- Ulnar nerve (n. ulnaris), which is mixed. Its sensory fibers directed to the skin of the medial wrist. On the palmar surface of the skin, they innervate the V finger and ulnar side of finger IV, on the back surface - the skin IV and V fingers and ulnar side of finger III. Motor fibers to the ulnar forearm flexors are sent to the wrist and the medial deep flexor of fingers. On the hand they innervate the muscle, resulting in thumb, hypothenar muscles, as well as the 3-4th lumbrical.

In Fig. 272.
Nerves of the shoulder girdle
1 - lateral pectoral nerve;
2 - subscapular nerve;
3 - axillary nerve;
4 - grudospinnoy nerve;
5 - musculo-cutaneous nerve;
6 - medial cutaneous nerve of the shoulder;
7 - the radial nerve;
8 - the median nerve;
9 - medial cutaneous nerve of forearm;
10 - ulnar nerve;
11 - lateral cutaneous nerve of forearm

Lateral trunk includes:

- The median nerve (n. medianus), which also applies to mixed. He leaves the lateral and medial trunks. Sensory fibers are directed to the skin of the lateral palmar surface of the skin and I, II and III of the fingers, as well as the radial side of finger IV and partly to the rear surface of the fingers. Motor fibers innervate the forearm flexor forearm, elbow flexor except wrist and finger flexor deep and sent to the square and round pronator. On the hand motor part innervates the muscles of the elevation of the thumb;

- Musculo-cutaneous nerve (n. musculocutaneus), which is mixed. Its branches are sent to the front of the shoulder flexor;

- Lateral cutaneous nerve of forearm (n. cutaneus anterbrachii lateralis), which is the terminal branch of the preceding nerve and innervates the forearm.

The rear trunk includes:

- The radial nerve (n. radialis), which is mixed. Sensory fibers are directed to the skin of the lateral parts of the dorsum of the hand and I, II fingers, and radial side of finger III. Motor fibers innervate the extensors of the arm and forearm;

- Posterior cutaneous nerve of arm (n. cutaneus brachii posterior), which is a sensitive branch of the radial nerve and sent to the skin of the back of the shoulder;

- Posterior cutaneous nerve of forearm (n. cutaneus anterbrachii posterior), which is also a sensitive branch of the radial nerve innervating the skin and the back surface of the forearm.

Anterior branches of thoracic nerves do not form a plexus. Intercostal nerves (nn. intercostales) are mixed and depart from the rear of the branches. These sensory fibers are directed to the skin of the chest and abdomen, and motor - to the intercostal muscles, the muscles, lifting the edges, posterior serratus, lateral chest muscles, as well as the transverse and rectus abdominis, external and internal oblique abdominal muscles.

In Fig. 273.
Diagram of the nerves of the upper extremity
1 - supraclavicular nerve;
2 - brachial plexus;
3 - musculo-cutaneous nerve;
4 - axillary nerve;
5 - medial cutaneous nerve of the shoulder;
6 - lateral cutaneous nerve of the shoulder;
7 - ulnar nerve;
8 - the median nerve;
9 - the radial nerve;
10 - lateral cutaneous nerve of forearm;
11 - medial cutaneous nerve of forearm;
12 - superficial branch of ulnar nerve;
13 - deep branch of ulnar nerve;
14 - common palmar finger nerves;
15 - Finger palmar own nerves

Lumbar plexus (plexus lumbalis) formed by the branches of the 12th thoracic nerve and the 1-4th lumbar nerves and lies behind and partly in the interior of a large psoas muscle, from the lateral edges of which are beyond branches of the lumbar plexus:

- Iliac hypogastric nerve (n. iliohypogastricus), relating to mixed. Its sensory fibers going to the skin over the tensor fasciae latae, and hip middle gluteal muscle, as well as to the suprapubic skin. Motor fibers are sent to external and internal oblique and rectus abdominis muscle;

- Ilio-inguinal nerve (n. ilioinguinalis), who is also mixed, sensory fibers which innervate the skin of the scrotum in men and labia in women, and the motor are sent to the iliac muscle and the lumbar muscle of a square;

- Sex-femoral nerve (n. genitofemoralis), which is mixed and consists of two branches. Ramifications of sexual branches (r. genitalis) innervate the dartos muscle and that lifts the egg. The femoral branch (r. femoralis) is sent to the skin below the inguinal ligament;

- Lateral femoral cutaneous nerve (n. cutaneus femoris la-teralis), which relates to sensitive skin and supplies the lateral surface of the femur;

- Obturator nerve (n. obturatorius), which is mixed. Its sensory fibers to the skin are the lower part of the medial surface of the femur, and the movement - the muscles of the medial thigh;

- Femoral nerve (n. femoralis), which refers to the mixed and is the largest nerve of the lumbar plexus. The anterior cutaneous branches (rr. cutanei anteriores)  are sensitive and forwarded to the skin anterior thigh. Subcutaneous nerve (n. saphenus) - the longest branch of the femoral nerve - goes along the great saphenous vein and gives lots of branches, reaching to the skin of the anteromedial tibia and the medial dorsum of the foot. Muscular branches (rr. musculares) the femoral nerve are directed to a large psoas muscle, iliacus, quadriceps and sartorius muscles of the thigh.

In Fig. 274.
Nerves of the brush
1 - ulnar nerve;
2 - the median nerve;
3 - superficial branch of ulnar nerve;
4 - common palmar finger nerves;
5 - palmar finger nerves own
In Fig. 275.
Intercostal nerves
1 - the spinal cord;
2 - cerebral spinal nerve;
3 - central intercostal nerves;
4 - thoracic aorta;
5 - lateral cutaneous branch of the breast;
6 - external intercostal muscles;
7 - front chest cutaneous branch;
8 - the internal intercostal muscle

Sacral plexus (plexus sacralis) form the anterior branch of the 4-5th lumbar nerves, anterior branches of the sacral nerves and coccygeal nerve. The branches are divided into short and long, and sent to the great sciatic opening, forming a triangular plate, located on the front surface of the pyriform muscle.

In Fig. 276.
Diagram of the nerves of the lower extremity
1 - ilio-hypogastric nerve;
2 - obturator nerve;
3 - ilio-inguinal nerve;
4 - the femoral nerve;
5 - sex-femoral nerve;
6 - lateral cutaneous nerve of the thigh;
7 - the sciatic nerve;
8 - posterior cutaneous nerve of the thigh;
9 - the common peroneal nerve;
10 - tibial nerve;
11 - medial cutaneous nerve of calf;
12 - deep peroneal nerve;
13 - subcutaneous nerve;
14 - superficial peroneal nerve;
15 - lateral cutaneous nerve of calf;
16 - sural nerve;
17 - medial and lateral plantar branches

Short branches include:

- Muscular branches (rr. musculares), innervate the square muscle of the thigh, the upper and lower twin muscle, pear and internal obturator muscle;

- The upper gluteal nerve (n. gluteus superior), which innervates the tensor fasciae latae thigh, middle and small gluteal muscles;

- The lower gluteal nerve (n. gluteus inferior), bound to the gluteus maximus;

- Genital nerve (n. genitalis) refers to mixed. Sensory fibers innervate the skin of the perineum and external genitalia, and movement - the muscles of the perineum.

Long branches include:

- Posterior cutaneous nerve of thigh (n. cutaneus femoris posterior), which is sensitive and bound to the skin of the back of the thigh;

- Sciatic nerve (n. ischiadicus), which refers to the mixed and is the largest nerve in the human body. It departs from many branches of traveling to the muscles of the back of the thigh. The very nerve descends to the upper part of the popliteal fossa, which is divided into the tibial and peroneal nerves.

Tibial nerve (n. tibialis) passes along the posterior tibial artery between deep and superficial flexors and leg behind the medial malleolus of the tibia goes to the plantar surface of the foot. In the popliteal fossa the tibial nerve gives the following branches:

- Medial cutaneous nerve of calf (n. cutaneus surae medialis) is sent to the skin surface of the posteromedial tibia. In the lower part of the tibia combined with the lateral cutaneous nerve of the calf. Together they form the sural nerve (n. suralis), runs behind the lateral malleolus and the lateral units innervating the dorsum of the foot;

- Muscular branches (rr. musculares) innervate the muscles of the back of the leg.

In Fig. 277.
The projection of the nerve plexus on the vertebral column
1 - cervical plexus;
2 - brachial plexus;
3 - intercostal nerves;
4 - lumbar plexus;
5 - sacriplex

On the tibia the tibial nerve gives the following branches:

- Medial calcaneal branch (rr. calcanei medialis) are sent to the skin of the medial heel;

- Muscular branches (rr. musculares) innervate the deep layer of posterior leg muscles.

At the foot tibial nerve divides into medial and lateral plantar branches (rr. plantares medialis et lateralis), which are mixed and are in the same direction as the plantar artery. Medial plantar sensory nerve fibers are directed to the skin of medial sole of the foot and the skin I, II, III, IV fingers.

Motor fibers are sent to the short flexors, muscle, abductor big toe and a 2-D worm-like muscles. Motor fibers of the lateral plantar nerve innervate the flexor short little finger of the foot, muscle, abductor little finger of the foot, the muscle that causes the big toe, square foot muscles, intercostals muscles, and 3-4th lumbrical.

Common peroneal nerve (n. fibularis communis) belongs to the mixed and in the lateral popliteal fossa department is divided into superficial and deep peroneal nerve. The main branches of the common peroneal nerve are:

- Lateral cutaneous nerve of calf (n. cutaneus surae late-ralis), bound to the skin of posterolateral parts of the tibia and the medial cutaneous integrated with ner-tion of eggs;

- Superficial peroneal nerve (n. fibularis superficialis), is mixed. Its sensory fibers innervate most of the dorsum of the foot skin, and the motor - long and short peroneal muscle;

- The deep peroneal nerve (n. fibularis profundus), following along the tibial artery. His sensitive branch offers a number of branches in the skin of the dorsum of the foot in the first interdigital gap. Motor fibers innervate the anterior group of leg muscles and the muscles of the dorsum of the foot.

In Fig. 278.
The area of innervation of the trunk, front view
I - cutaneous branches of the cervical plexus;
II - supraclavicular nerves;
III - the lateral cutaneous nerve of forearm;
IV - the medial cutaneous nerve of the shoulder;
V - front cutaneous branches of intercostal nerves;
VI - lateral cutaneous branches of intercostal nerves;
VII - the lateral cutaneous branch of the ilio-hypogastric nerve;
VIII - front cutaneous branches ilio-hypogastric nerve;
IX - ilio-inguinal nerve;
X - the lateral cutaneous nerve of the thigh;
XI - the branch sex-femoral nerve;
XII - the branches of the sacral plexus;
XIII - front cutaneous branches femoral nerve;
XIV - cutaneous branch of the obturator nerve
In Fig. 279.
Innervation of the trunk area of the rear view
I - suprascapular nerve;
II - lateral cutaneous nerve of forearm;
III - the lateral thoracic cutaneous branches of the nerves;
IV - the medial cutaneous nerve of the shoulder;
V - posterior cutaneous nerve of the shoulder;
VI - lateral cutaneous branches of intercostal nerves;
VII - medial cutaneous branches of thoracic nerves;
VIII - branches of lumbar nerves;
IX - medial cutaneous branches of the sacral nerves;
X - the lateral cutaneous branch of the ilio-hypogastric nerve;
XI - the lateral cutaneous nerve of the thigh;
XII - branches of posterior femoral cutaneous nerve
In Fig. 280.
The area of innervation of the upper extremity
A - palmar surface;
B - back of the surface:
I - transverse nerve of neck;
II - subclavian nerves;
III - the lateral cutaneous nerve of forearm;
IV - branches of thoracic nerves;
V - medial cutaneous nerve of the shoulder;
VI - posterior cutaneous nerve of the shoulder;
VII - the lateral cutaneous nerve of forearm;
VIII - the medial cutaneous nerve of forearm;
IX - the branch of the median nerve;
X - the branches of the ulnar nerve;
XI - the branch of radial nerve;
XII - the deep branch of the median nerve;
XIII - the deep branch of ulnar nerve;
XIV - the branches of the intercostal nerves;
XV - posterior cutaneous nerve of forearm;
XVI - the deep branch of radial nerve

In Fig. 281.
The area of innervation of the lower extremity
A - anterior surface;
B - back side:
I - lateral cutaneous branch of the ilio-hypogastric nerve;
II - the branch sex-femoral nerve;
III - ilio-inguinal nerve;
IV - the lateral cutaneous nerve of the thigh;
V - cutaneous branch of the obturator nerve;
VI - anterior cutaneous nerve of the thigh;
VII - the branch of subcutaneous nerve;
VIII - the branch of the common peroneal nerve;
IX - the branches of superficial peroneal nerve;
X - branches of sural nerve;
XI - the branch of deep peroneal nerve;
XII - branches of lumbar nerves;
XIII - medial cutaneous branches of the sacral nerves;
XIV - posterior cutaneous nerve of the thigh;
XV - the branch of the tibial nerve
 
In Fig. 282.
The area of innervation of the head and neck
I - the branches of the frontal, orbital, and the trigeminal nerve;
II - the branches of the malar, infraorbital, maxillary, and the trigeminal nerve;
III - a large branch of the occipital nerve;
IV - branch ushno-occipital, chin, jaw, and the trigeminal nerve;
V - a small branch of the occipital nerve;
VI - the branch of a large ear nerve;
VII - the subcutaneous branches of the dorsal nerve blades;
VIII - the transverse nerve of neck;
IX - supraclavicular nerves
   







List of Abbreviations

a., aa. — arteria, arteriae (artery, the artery)

lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)

m., mm. — musculus, musculi (muscle, the muscle)

n., nn. — nervus, nervi (nerve, the nerve)

r., rr. — ramus, rami (branch)

s. — seu (or)

v., vv. — vena, venae (vienna)