The lumbar plexus (plexus lumbalis) is formed by the anterior branches of the three upper lumbar, partly the XII thoracic and IV lumbar spinal nerves. Part of the anterior branch of the IV lumbar spinal nerve descends into the pelvic cavity, forming with the anterior branch of the V lumbar spinal nerve the lumbosacral trunk, connecting the lumbar and sacral plexuses. The sacral plexus (plexus sacralis) is formed by the lumbosacral trunk and the anterior branches of the upper four sacral spinal nerves.
The lumbar plexus is located anterior to the transverse processes of the lumbar vertebrae in the thickness of the psoas major muscle, from under the lateral edge of which (or perforating it) its branches emerge. Muscular branches arise from all anterior branches that form the plexus (even before they are connected to each other); they innervate the psoas major and minor, quadratus muscle and intertransverse lateral lumbar muscles.
The iliohypogastric nerve, formed by the anterior branches of ThXII-LI, emerges from the thickness (or behind) the psoas major muscle, descends along the anterior surface of the quadratus muscle and laterally (parallel to the hypochondrium nerve), stretches along inner surface transverse abdominal muscle, pierces it above the iliac crest, follows between the named muscle and the internal oblique abdominal muscle to the rectus muscle of the latter.
It innervates all abdominal muscles and the skin of the superolateral parts of the gluteal region and thigh area, as well as the anterior abdominal wall above the pubic area. The ilioinguinal nerve (ThXII-LIV) goes under the previous one (parallel and similar to it), innervates the abdominal muscles, enters the inguinal canal (located in front of the spermatic cord in men or the round ligament of the uterus in women), exits through its external opening, where with its its terminal branches innervate the skin of the pubis and groin area, the root of the penis and the anterior parts of the scrotum (or labia majora in women). The genitofemoral nerve (LI-LII) pierces the psoas major muscle at level III lumbar vertebra, divided into genital and femoral branches.
The genital branch follows in front of the external iliac artery, enters the inguinal canal (lies behind the spermatic cord in men or the round ligament of the uterus in women). In men, it innervates the muscle that lifts the testicle, the skin of the scrotum and its fleshy membrane, and the skin of the superomedial surface of the thigh. In women, this branch innervates the round ligament of the uterus, the skin of the labia majora and the superomedial surface of the thigh (in the area of the outer ring of the femoral canal). The femoral branch passes through the vascular lacuna to the thigh, adjacent to the anterolateral semicircle of the femoral artery, pierces the ethmoidal fascia and innervates the skin in the area of the subcutaneous fissure and under the inguinal ligament.
The lateral cutaneous nerve of the thigh (LI-II) emerges from under the lateral edge of the psoas major muscle (or pierces it), descends along iliacus muscle towards the inguinal ligament, passes under its lateral part to the thigh, where its terminal branches innervate the skin of the posteroinferior surface of the gluteal region and the lateral surface of the thigh (to the level knee joint). The obturator nerve (LII-IV) is a large nerve that runs along the medial edge of the psoas major muscle and descends into the pelvic cavity. joins the blood vessels of the same name, and together with them passes through the obturator canal to the thigh, where it is located between the adductor muscles. It has two terminal branches: the anterior one innervates the adductor brevis and longus, the pectineus and gracilis muscles, and gives the cutaneous branch to the skin of the lower sections of the medial surface of the thigh; the posterior branch innervates the obturator externus and adductor magnus muscles, as well as the capsule of the hip joint.
The femoral nerve is the largest branch of the lumbar plexus. It is formed at the level of the V lumbar vertebra on the anterior internal surface of the psoas major muscle from three roots, crosses this muscle, descends along the iliacus muscle to the inguinal ligament, passes under it through the muscle lacuna to the thigh. In the femoral triangle it is located lateral to the femoral vessels, separated from the femoral artery by a deep layer of the fascia lata of the thigh. Below the inguinal ligament it divides into its terminal branches: muscular, anterior cutaneous and saphenous nerve of the thigh. The muscle branches innervate the sartorius, quadriceps and pectineus muscles of the thigh. The anterior cutaneous branches branch in the skin of the anteromedial surface of the thigh.
The saphenous nerve - the longest branch of the femoral nerve - goes along with the femoral artery into the adductor canal, exits through its anterior opening together with the descending genicular artery, and descends between the adductor magnus and the medial broad muscles thigh to the medial surface of the leg, gives off a popliteal branch along the way, innervating the skin of the knee joint, stretches down next to the great saphenous vein, innervating the skin of the anteromedial surface of the leg and the medial edge of the foot (to the big toe).
The sacral plexus has the appearance of a triangular plate, the base of which is located at the pelvic openings of the sacrum, and the apex is directed towards the greater sciatic foramen. Through it, both short and long branches of this plexus leave the pelvis. Almost all short branches exit the pelvis through the infrapiriform foramen and innervate the muscles of the same name. These are the obturator internal and piriformis nerves, the quadratus femoris nerve and the inferior gluteal nerve (LIII-SI, II), which innervates the gluteus maximus muscle.
Only the superior gluteal nerve (LIV, V-SI) emerges through the suprapiriformis foramen, which branches into the gluteus medius and minimus and the tensor fascia lata muscle. The pudendal nerve (SI-SIV) occupies a special place among the short branches. This is a mixed nerve that innervates the skin, perineal muscles and external genitalia. The pudendal nerve leaves the pelvic cavity through the infrapiriform foramen, bends around the sciatic spine from behind and enters the ischiorectal fossa through the lesser sciatic foramen. Along the lateral wall of this fossa, it reaches the pubic symphysis and passes to the dorsum of the penis (or clitoris) in the form of a terminal branch - the dorsal nerve of the penis (clitoris). The lateral branches of the pudendal nerve are located in this way: the lower rectal branches go to the external sphincter of the anus and to the skin of the area adjacent to it; perineal nerves - to the skin of the perineum and scrotum or labia majora; posterior scrotal (labial) nerves - to the muscles of the genitourinary diaphragm.
The long branches of the sacral plexus leave the pelvic cavity through the infrapiriform foramen. The posterior cutaneous nerve of the thigh (SI-SIII) emerges from under the lower edge of the gluteus maximus muscle, giving the inferior nerves of the buttocks to the skin covering it, and the perineal branches to the skin of the perineum. It descends under the fascia lata between the semitendinosus and biceps femoris muscles to the popliteal fossa, innervating the skin of the thigh and popliteal region with its lateral branches. The sciatic nerve receives fibers from all the roots of the sacral plexus and is a mixed nerve.
It descends along the thigh between its posterior muscles, gives them its branches and in the popliteal fossa (or not reaching it) is divided into two branches: the thicker tibial and relatively thin common peroneal nerves; these branches sciatic nerve innervates all the muscles of the leg and foot and all the skin of these areas, excluding the area of the skin in which the saphenous nerve of the thigh branches. The tibial nerve is a continuation of the trunk of the sciatic nerve in the lower leg. In the popliteal fossa lies behind the vein of the same name; passes down between the heads of the gastrocnemius muscle (together with the posterior tibial artery and vein), under the tendinous arch of the soleus muscle, enters the ankle-popliteal canal, leaves it behind the medial malleolus and divides there into its terminal branches - the medial plantar nerve and the lateral plantar nerve.
The first of them innervates the skin of the plantar surface of three and a half fingers (I-IV), as well as the muscles of the sole: the short flexor and abductor muscles of the thumb, the short flexor of the fingers, the I and II lumbrical muscles. The second of these nerves innervates the skin of the IV-V fingers, interosseous muscles, III and IV lumbricals, adductor muscle thumb, quadratus plantae and muscles of the little finger; in addition, both plantar nerves innervate the joints of the foot. The common peroneal nerve curves around the head fibula and in the thickness of the long peroneal muscle it is divided into the superficial and deep peroneal nerves.
The first of them innervates the long and short peroneal muscles, and with its cutaneous branches the skin of the dorsal surface of the toes (except for the surfaces of the I-II fingers facing each other). The second of these nerves branches in the muscles of the anterior group of the leg and foot (extensors and the tibialis anterior muscle) and innervates the skin of the sides of the first and second toes facing each other. The tibial nerve and peroneal nerve give off the medial and lateral cutaneous nerves of the calf to the lower leg; connecting with each other, they form the sural nerve, which innervates the skin of the lateral edge of the foot and little toe.
Pathology:
The lumbosacral plexus is affected by gunshot wounds, compression by bone fragments during fractures of the spine, pelvic bones, tumors of the abdominal and pelvic organs, aneurysms of the abdominal aorta and hypogastric arteries, the fetal head during prolonged labor, etc. Secondary lumbosacral plexitis can develop when inflammatory processes in the ovaries, uterus, appendix, peritoneum, pelvic tissue. This plexus is sometimes affected by certain infectious diseases (influenza, tuberculosis, syphilis, brucellosis, etc.). Lumbosacral plexitis is most often unilateral.The clinical picture of lesions of the lumbosacral plexus is characterized by pain when pressing in the lower abdomen, in the gluteal region. The pain radiates to the lower back and leg to the innervation zone of the obturator, femoral and sciatic nerves. Rectal examination reveals pain when pressing on the anterior wall of the sacrum. Spontaneous pain is also localized in these areas. With total damage to the lumbosacral plexus, flaccid paralysis or paresis of the muscles of the pelvic girdle and legs with areflexia, peripheral sensitivity disorders and trophic disorders. The function of the pelvic organs may be impaired.
With partial damage to the lumbosacral plexus, the clinical picture varies depending on the location of the pathological process, for example, with damage to the upper trunks of the lumbar plexus, the function of the iliopsoas, long and short adductor muscles is impaired, sensitivity is impaired on the anterior and anterior inner surface of the thigh, partially in the buttock area . Damage to the lower trunks of the lumbar plexus leads to paresis of the quadriceps femoris, gluteal, and twin muscles, which impairs walking and makes it difficult to straighten the leg; The knee reflex decreases or disappears. Sensitivity on the front surface of the thigh, inner surface of the leg and foot is impaired.
With isolated damage to individual branches of the lumbar plexus, a clinical picture appears similar to manifestations of dysfunction of the roots or nerves: iliohypogastric and ilioinguinal (hypoesthesia in the lower parts of the anterior abdominal wall), lateral cutaneous nerve of the thigh (anesthesia on the outer surface of the thigh or painful paresis ), femoral-genital (hypoesthesia in the scrotum and upper thigh), obturator (hypoesthesia on the inner surface of the thigh, paresis of the muscles that adduct the thigh).
Damage to the sacral plexus is manifested by dysfunction of the sciatic nerve, atrophic paralysis of the muscles of the posterior thigh, leg and foot, reduction or disappearance of the Achilles reflex, anesthesia back surface thighs, legs and feet, causalgia, vegetative-trophic disorders of the legs and feet. When the inferior gluteal nerve is damaged, paresis of the gluteus maximus muscle is observed (it is difficult to straighten the hip, straighten the body from the position of bending the body forward, climb stairs, jump); superior gluteal nerve - difficulty abducting and rotating the hip, duck gait; posterior cutaneous nerve of the thigh - hypoesthesia in the lower parts of the buttock and posterior surface of the thigh.
Damage to the genital and coccygeal plexuses is accompanied by dysfunction of the sphincters of the bladder and rectum (urinary and fecal incontinence), hypoesthesia on the inner half of the buttock, the perineum and anus, and the posterior surface of the genitals. Irritation of these plexuses causes coccydynia (see Neuralgia).
The diagnosis of damage to the lumbosacral plexus is based on a characteristic clinical picture: paresis of the corresponding muscle groups, a certain area of sensitivity disorders and vegetative-trophic disorders. Differential diagnosis is carried out with discogenic radiculitis, circulatory disorders in the radiculomedullary arteries with symptoms of radiculomyeloischemia, ankylosing spondylitis, etc.
In the treatment of lesions of the lumbosacral plexus, painkillers, decongestants, B vitamins, physiotherapy and balneotherapy, reflexology, massage, and exercise therapy are used. In some cases, surgical intervention is indicated; sanatorium-resort treatment is important in the complex of rehabilitation measures.
genitofemoral nerve
pudendal nerve
posterior cutaneous nerve of the thigh
lateral cutaneous nerve of the thigh
Specify the muscles innervated by the ilioinguinal nerve
rectus abdominis muscle
transverse abdominis muscle
internal oblique muscle
external oblique muscle
Specify the muscles innervated by the iliohypogastric nerve
transverse abdominis muscle
internal oblique muscle
diaphragm
rectus abdominis muscle
Specify the nerves involved in the innervation of the quadriceps femoris muscle
femoral nerve
sciatic nerve
obturator nerve
common peroneal nerve
Specify the nerve from which the saphenous nerve arises
obturator nerve
sciatic nerve
femoral nerve
genitofemoral nerve
Specify the anatomical structures that the saphenous nerve innervates
skin of the anterior surface of the leg
skin of the lateral edge of the foot
skin of the medial surface of the knee joint
skin of the medial edge of the foot
Specify the nerves that are short branches of the sacral plexus
pudendal nerve
genitofemoral nerve
superior gluteal nerve
inferior gluteal nerve
Indicate the nerves passing through the infrapiriform foramen
obturator internal nerve
piriformis nerve
sciatic nerve
quadratus femoris nerve
Specify the nerve that innervates the gluteus maximus muscle
sciatic nerve
inferior gluteal nerve
superior gluteal nerve
femoral nerve
Specify the nerves involved in the innervation of the gluteus minimus and gluteus medius muscles
inferior gluteal nerve
obturator nerve
sciatic nerve
superior gluteal nerve
1137. Specify the anatomical formations that belong to the peripheral part of the autonomic nervous system
large celiac knot
pterygopalatine ganglion
sympathetic trunk nodes
intermediolateral nuclei in the spinal cord
Specify the anatomical structures related to the sympathetic nervous system
white connecting branches
deep petrosal nerve
superficial petrosal nerve
accessory nucleus of the oculomotor nerve
Indicate the branches that approach the sympathetic trunk
white connecting branches
gray connecting branches
internodal branches
lesser splanchnic nerve
Indicate the branches that arise from the sympathetic trunk
white connecting branches
splanchnic nerves
meningeal branches
gray connecting branches
Specify the branches that arise from the superior cervical ganglion of the sympathetic trunk
internal carotid nerve
spinal nerve
inferior cervical cardiac nerve
gray connecting branches
Specify the branches that arise from the cervicothoracic (stellate) ganglion of the sympathetic trunk
jugular nerve
spinal nerve
inferior cervical cardiac nerve
external carotid nerves
Indicate the branches that arise from the thoracic ganglia of the sympathetic trunk
pulmonary nerves
esophageal nerves
phrenic nerves
thoracic cardiac nerves
Indicate the nerves that approach the celiac plexus
great splanchnic nerves
hypogastric nerves
small splanchnic nerves
lumbar splanchnic nerves
Specify the vegetative node from which secretory fibers are directed to the lacrimal gland
pterygopalatine ganglion
ciliary node
submandibular ganglion
ear node
What are the main parts included in each analyzer?
peripheral section
nerve center in the cerebral cortex
descending pathway
ascending pathway
1147. Indicate the anatomical formations that are part of eyeball
ocular nucleus
eye socket
optic nerve
membranes of the eye
Specify the membranes that make up the eyeball
mucous membrane
fibrous membrane
retina
serosa
1149. Specify the anatomical formations that make up the choroid of the eye
ciliary belt
iridocorneal angle
ciliary body
Specify smooth muscle choroid
meridional fibers of the ciliary muscle
sphincter pupil
muscle that dilates the pupil
circular fibers of the ciliary muscle
Which of the following components pigment is concentrated in the eyeball
ciliary body
retina
fibrous membrane
1152. Specify the anatomical structures that limit the anterior chamber of the eyeball
lens
cornea
1153. Specify the formations that limit the posterior chamber of the eyeball
ciliary body
vitreous
lens
Where does aqueous humor drain from the anterior chamber of the eye?
into the venous sinus of the sclera
into the veins of the iris
into the episcleral space
into the lacrimal sac
Indicate the muscles that begin deep in the orbit from the common tendon ring
inferior oblique muscle of the eyeball
superior oblique muscle of the eyeball
muscle that lifts the upper eyelid
lateral rectus muscle of the eyeball
What parts make up the auricle?
antitragus
helix legs
Indicate the lateral and posterior walls of the tympanic cavity
mastoid wall
labyrinth wall
membranous wall
sleepy wall
What anatomical structures belong to the sound-conducting apparatus of the hearing organ?
auditory ossicles
eardrum
oval window membrane
perilymph of the scala vestibularis of the cochlea
1159. Specify the anatomical structures that are connected by the auditory tube
oropharynx
nasopharynx
tympanic cavity
membranous labyrinth
Indicate the location of the vestibule of the labyrinth
in front of the cochlea
behind the snail
anterior to the semicircular canals
posterior to the semicircular canals
Indicate the papillae of the tongue that do not contain taste buds
leaf-shaped papillae
circumvallate papillae
filiform papillae
fungiform papillae
On which wall of the heart is the fossa ovalis located?
Septum unterventriculare
Auricula sinistra
Septum interatriale
Specify the parts of the septum interventriculare
Pars muscularis
Pars endocardialis
Pars membranecea
What openings are there in the walls of the atrium dextrum?
Foramina venarum minimarum
Ostium venae cavae superioris
Ostium venae cavae inferions
Ostium venarum pulmonalium
What openings are there in the walls of the ventriculus dexter?
Ostium venae cavae inferioris
Ostium trunci pulmonalis
Foramina venarum minirnarum
What openings are there in the walls of the atrium sinistrum?
Ostia venarum pulmonalium dextrarum
Ostia venarum pulmonalium sinistrarum
Ostium venae cavae superioris
Ostium sinus coronarii
What openings are there in the walls of the ventriculus sinister?
Ostium sinus coronarii
Ostia venarum pulmonalium
Ostium trunci pulmonalis
Specify the outer boundaries of the right ventricle of the heart
Sulcus coronarius
Sulcus interventricularis anterior
Sulcus interventricularis posterior
Sulcus terminalis
Indicate the direction of orientation of the longitudinal axis of the heart
Right to left
Front to back
Top down
Back to front
Specify the layers of the heart wall
What anatomical structures make up the heart skeleton?
Trigonum fibrosum dextrum
Trigonum fibrosum sinistrum
Anulus fibrosus dexter
Anulus fibrosus sinister
Where is the nodus sinuatrialis of the cardiac conduction system located?
Atrium sinistrum
Septum interatriale
Septum interventriculare
Specify the elements of the conduction system of the heart
Fasciculus atrioventricularis
Nodus sinuatrialis
Nodus atrioventricularis
1174. What anatomical formations are there on the inner surface of the walls of the atrium dextrum?
Musculi papillares
Musculi pectinati
Trabeculae carneae
Chodae tendineae
1175. What anatomical formations are there on the inner surface of the walls of the ventriculus sinister?
Chordae tendineae
Musculi papillares septales
Trabeculae carneae
Musculus parallaris posterior
The sacral plexus (Latin name - plexus sacralis) is formed by the 4th and 5th abdominal branches of the lumbar and spinal sacral nerves. They are formed into a bundle, which is called the lumbosacral trunk (in Latin - truncus lumbosacralis) and is part of the plexus sacralis. This plexus includes fibers from the nodes of the lower lumbar and sacral sympathetic trunk. The branches of the sacral plexus are located on the piriformis muscle (Latin name - m. piriformis) in the pelvis and converge to the openings located above and below the piriformis muscle. Through the above openings, the branches go to the dorsum of the pelvis.
Plexus with short mixed branches
The spine is functionally important for humans. Due to the lumbar vertebra, lordosis is formed. This part of the spine experiences the greatest load.
The sacral plexus is located anterior to the transverse processes. Its anatomy is unique and has been studied for a long time.
Muscular branches
The muscular branches (Latin name - rr. musculares) are formed by fibers L 4 and L 5, as well as S 1 and S 2, supplying nerves to the pelvic area m. piriformis, obturatorius internus. After passing through the hole under the piriformis muscle, they connect the quadriceps femoris muscle (m. quadratus femoris) with the central nervous system. Receptors for other fibers are present in these soft tissues. For example, femoral nerve tissue.
Superior gluteal
The superior gluteal nerve (in Latin - n.gluteus superior) is formed by fibers L 2 - L 5 and S 1 and is represented by a short trunk. It follows through the supragiriform foramen from the small pelvis to the dorsum of the pelvis. At the same time, it is united into a joint bundle with arteries and a vein of the same name. The nerve is divided into 3 branches, which supply sensory fibers to the small and medium muscles of the buttocks and thighs. Receptors are located in small, medium muscle tissue and connective membrane. The nerves of the sacral plexus are important.
Inferior gluteal
The inferior gluteal nerve (Latin name - n.gluteus inferior), which is formed by fibers L 5 and S 1 -S 2, is represented by a short trunk, passing to the dorsum of the pelvis through a slit-like gap in the lower part of the large paired opening of the posteroinferior section of the pelvic wall, like and blood vessels. The psoas major muscle is supplied by nerves. The receptors are located in hip joint, and in large muscle buttocks. There is a connection between sensory nerve fibers and motor fibers. They then move together to the nuclei of the spinal cord.
Sacral plexus and long branches
Muscular branches arise from all the anterior rami, which form the plexus (before they are united). They are responsible for the innervation of the psoas minor and major muscles, the quadratus muscle and the intertransverse lateral lumbar muscles. Damage to branches can lead to serious consequences.
The nerve located behind (Latin name - n. cutaneus femoris posterior), thin, long and sensitive. Receptors are located within the skin and connective membrane of the back of the thigh, the fossa of the knee joint, in the perineum and at the bottom of the gluteal muscle. The nerve endings and trunk are located under the fatty tissue on the connective tissue membrane of the thigh. Then in the middle, in the fold of the buttocks at the lower edge (m. gluteus maximus), the fiber passes through the connective tissue membrane. Here, covered by the greater gluteal nerve, it accompanies the sciatic nerve. Passes through the hole under the piriformis muscle into the recess of the pelvis and forms the posterior roots L 1 - L 3.
The roots L 4—L 5 take part in the formation of the sciatic nerve (in Latin - n. ischiadicus). S 1 - S 3 is the thickest and longest fiber in the human body, it is also called mixed. The abdominal branches emerge from the nerve, which is formed on the wall near the paired foramen in the posteroinferior section of the pelvic wall, passes through a slit-like gap in the lower part of the paired foramen from the pelvic recess and lies in the cavity between the ischial tubercle and the trochanter of the femoral tubular bone on the femoral muscle, which has a quadrate shape, under the gluteal muscle. This is where the femoral nerve is located.
Sciatic nerve
This part of the system is located in the dorsal part of the thigh on the medial muscle and the long head of the biceps femoris muscle. It is directed downwards between the semimembranosus and semitendinosus muscles. The moving branches of the long head of the biceps, semitendinosus and semimembranosus muscles of the thigh depart from the sciatic nerve in the thigh area. The sciatic nerve enters at the upper corner of the fossa located under the knee, or into the opening of the thigh. Here it divides into the tibial and peroneal nerves. Let us consider the further structure of the system.
The tibial nerve (in Latin - n. tibialis) is located at the top of the popliteal fossa between the fascia and popliteal vessels, continuing its plexus between the gastrocnemius muscles into the ankle-popliteal canal (Latin name - canalis cruropopliteus). Lower on the lower leg it is located between the long soft tissues of the lower leg of the posterior group. The tibial nerve in the foot divides into the median and lateral plantar nerve endings.
Tibial fiber branches
The mixed muscular branches have the Latin name rr. musculares). The first group arises where the tibial nerve passes through the ankle-popliteal canal. They are used to provide sensitive connections to the gastrocnemius, soleus, and plantaris muscles. The second group goes to the bottom of the lower leg. They are designed to provide a neural connection to the posterior tibial, long muscle shins back group. All these tissues have receptors from which smaller fibers extend. They go along muscle branches to the tibial nerve.
Plantar mixed (Latin name - n. plantaris medialis) is located on the middle edge of the sole in the groove between the muscle that abducts the first toe and the muscle of the plantar part of the foot. It provides motor cells that respond to any stimulus. These muscles contain receptors associated with sensory fibers that participate in the formation of the median plantar nerve.
On the middle part of the foot, a lateral branch (in Latin - r. lateralis) departs from the median plantar fiber to provide sensory cells to the 1st and 2nd lumbrical muscles. The sensory part of the lateral branch has receptors in the skin of the first, second and third fingers, the lateral half of the fourth finger and in the palmar interosseous muscles. The fibers take part in the formation of nerves on the sole, which connect into 3 common plantar nerves. They, in turn, find a connection with the lateral branch. The tibial nerve is directed in the direction from the cutaneous receptors of the middle surface of the first toe. It connects to the medial branch of the median fiber of the plantar, located lateral to the muscle that abducts the big toe. But this is not all the features of the structure. What other nerves does the lumbosacral region contain?
Lateral plantar
The lateral mixed plantar nerve (Latin name - n. plantaris lateralis) is located on the lateral edge of the foot in the groove between the plantar muscle and the quadratus pes muscle, then goes into the groove, which is formed by the muscles of the 5th toe and the foot muscle. Its deep branch at the level of the metatarsal curves towards the middle. Here it provides nerve cells to the muscles of the fifth digit (abductor digitorum brevis, flexor brevis, adductor digitorum brevis, the third and fourth gracilis brevis between the tendons of the flexor digitorum longus and the interosseous muscles). Receptors are located in the skin and subcutaneous fat. You can find them in the area of the 4th and 5th fingers. It is from them that the nerves come, connecting into a large nerve that goes to the upper branch of the lateral nerve of the plantar. They form the lumbosacral plexus.
Median gastrocnemius
The median sural nerve has the Latin name n. cutaneus surae medialis. Its endings are located on the dorsum of the lower leg on the medial side. At the same time, they alternate with receptors of the femoral nerve. The fibers, reaching the bottom of the popliteal fossa, pierce the fascia of the leg. Here they enter the tibial nerve.
There are other fragments of this system. For example, the sural nerve with the Latin name n. suralis. It is sensitive and contains endings in the skin and subcutaneous fatty tissue on the dorsum of the leg, heel and side of the foot. It is from them that the dorsal nerve begins. The fibers, reaching the lateral malleolus, transition to the main tibial nerve. Sensitive tissues are located in the subcutaneous tissue in the lower third of the lower leg on the lateral side. They are then sent along two nerve trunks: one along the tibial nerve, the other along the common peroneal nerve. It is worth listing other features of the system. What nerves does the lumbosacral region have?
Sensory fibers of the lower leg
The nerve of the lower leg is also sensitive. They are located between the bones (Latin name - n. interosseus cruris). The endings are located in the membrane between the bones, in the areas above the bones of the leg and in the ankle joint. At the same time, it connects with other fibers. It runs along the membrane and enters the tibial nerve at the place where there is an opening in the membrane between the bones.
Articular branches (in Latin - rr. articulares) are formed from the ends of the capsule of the joints of the ankle and knees. They unite with the greater tibial nerve as it passes near them.
The lesser tibial nerve (Latin name - n. fibularis communis) is mixed, separated from the ischial nerve in the thigh area. It is located on the lateral side of the fossa under the knee and the head of the fibula. Its sensitive fiber goes around the back. In this case, the nerve is located between the neck of the fibula and the beginning of the peroneus longus muscle.
What else does the sacral plexus include? This will be discussed further.
Branches of the peroneal nerve
The lateral sural nerve (Latin name - n. cutaneus surae lateralis) is very sensitive. The endings are located in the skin, tissue and connective tissue membrane of the posterolateral part of the leg. Fibers with high sensitivity go under the connective sheath. It forms a sheath for the lower leg. Here the nerve connects with the fibers of the tibial nerve. In the hole under the knee they emerge from under the connective membrane. At this point there is a merger with the small tibial nerve.
The articular branches (Latin name - rr. articulares) are sensitive and have endings in the capsule between the tibia and knee joints. The branches from this section are short. Especially those that are located between the tibia joint and have an entrance to the lesser nerve. Fusion occurs when it is located close to the head of the fibula. The nerve branches from the knee joint are thick. They enter the system in the corner of the popliteal fossa. What else is included in the sacrococcygeal plexus?
Muscle branches (in Latin - rr. musculares) are motor nerves of short length. Provide sensory cells to the head of the biceps femoral muscle.
The superficial peroneal nerve (Latin name - n. fibularis superficialis) is mixed and widely supplied with nerve cells. Receptors are located on the foot in the skin of the dorsum and interdigital spaces of the third, fourth and median surface of the fifth toe. From them the posterior nerves are formed, which unite into the intermediate dorsal cutaneous nerve of the foot.
So, we examined the anatomy of the sacral plexus in detail.
The sacral plexus (plexus sacralis) is formed by part of the anterior branch of the fourth and fifth lumbar (LIV-LV) and first-third sacral (SI-SIII) spinal nerves. The plexus is located in the pelvic cavity, directly on the fascia covering the anterior surface of the piriformis muscle. The base of the plexus corresponds to the line connecting the pelvic sacral foramina. The branches of the sacral plexus are directed to the greater sciatic foramen. There are short and long branches of the sacral plexus. Short branches end in the pelvic girdle. Long branches go to the muscles, joints, bones and skin of the free part lower limb.
Short branches. The short branches of the sacral plexus include the obturator internal nerve (from LIV-SII), the piriformis nerve (from SI-SII), the quadratus femoris nerve (from LIV-SII, going to the muscles of the same name, as well as the superior and inferior gluteal and pudendal nerves.
The superior gluteal nerve (n. gluteus superior) is formed by fibers of the anterior branches of the fourth and fifth lumbar (LIV-LV) and first sacral (SI) spinal nerves. Together with the artery of the same name, the nerve leaves the pelvic cavity through the supragiriform foramen. Upper branch This nerve goes forward to the gluteus minimus muscle and innervates it. The inferior branch of the superior gluteal nerve passes between the gluteus minimus and medius muscles, innervates them, and also gives off a branch to the tensor fascia lata muscle.
The inferior gluteal nerve (n. gluteus inferior) consists of fibers of the anterior branches of the fifth lumbar (LV) and the first and second sacral (SI-SII) spinal nerves. The nerve exits the pelvic cavity through the infrapiriform foramen along with the artery of the same name. With fan-shaped diverging short branches, the nerve enters the gluteus maximus muscle, innervates it, and also gives off branches to the capsule of the hip joint.
The pudendal nerve (n. pudendus) is formed by the anterior branches of the SIII-SIV, partially SII spinal roots. It is located below the sacral plexus on the anterior surface of the sacrum at the lower edge of the piriformis muscle. From this nerve, motor fibers extend to the levator ani muscle and the coccygeus muscle. The largest branch of the pudendal plexus is the nerve of the same name - n. Pudendus. This nerve exits the pelvic cavity under the piriformis muscle, bends around the ischial tuberosity and passes through the lesser sciatic foramen to the lateral wall of the ischiorectal fossa. Here it is divided into branches:
- inferior rectal nerves (pass to the muscle that compresses the anus and to the skin of the anterior part of the anus);
- the perineal nerve passes to the superficial transverse muscle perineum, bulbocavernosus muscle, as well as to the skin of the back of the scrotum or labia majora.
The dorsal nerve of the penis/clitoris - n. - also departs from the pudendal nerve. dorsalis penis (clitoridis). Its branches supply the deep transverse perineal muscle and the constrictor urethra, as well as the skin of the penis/clitoris and the urethra.
In the ischiorectal fossa, the pudendal nerve gives off the inferior rectal and perineal nerves. The lower rectal nerves (nn. rectales inferiores) penetrate the ischiorectal fossa and innervate the external anal sphincter and the skin of the anal area. Perineal nerves (nn. perineales) innervate the muscles and skin of the perineum of the scrotum in men and the labia majora in women. The final branch of the pudendal nerve is the dorsal nerve of the penis or clitoris (n. dorsalis penis, s. clitoridis). This nerve passes through the urogenital diaphragm next to the artery of the same name on the dorsum of the penis (clitoris), gives branches to the cavernous bodies, the head of the penis (clitoris), the skin of the penis in men, the labia majora and minora in women, as well as branches to deep transverse perineal muscle and urethral sphincter.
Long branches of the sacral plexus. The long branches of the sacral plexus include the posterior cutaneous nerve of the thigh and the sciatic nerve.
The posterior cutaneous nerve of the thigh (n. cutaneus femoris posterior) is formed by fibers of the anterior branches of the first to third sacral spinal nerves (SI-SIII). The nerve exits the pelvic cavity through the infrapiriform foramen and descends next to the sciatic nerve. Next, the posterior cutaneous nerve of the thigh goes down in the groove between the semitendinosus and biceps femoris muscles. Its branches pass through the fascia lata of the thigh, branching in the skin of the posteromedial surface of the thigh up to the popliteal fossa and the upper part of the leg. Near the lower edge of the gluteus maximus muscle, the lower nerves of the buttocks (nn. clunium inferiores) and perineal branches (rr. perineales) extend to the skin of the perineum from the posterior cutaneous nerve of the thigh. The inferior nerves of the buttocks innervate the skin of the lower part of the gluteal region.
The sciatic nerve (n. ischiadicus) is the largest nerve of the human body. It is formed by fibers of the anterior branches of the fourth and fifth lumbar (LIV-LV), first and second sacral (SI-II) spinal nerves. The nerve exits the pelvic cavity through the infrapiriform foramen along with the inferior gluteal and pudendal nerves, arteries of the same name and the posterior cutaneous nerve of the thigh. The sciatic nerve then runs approximately midway between the ischial tuberosity and the greater trochanter of the femur along the posterior surface of the gemellus, obturator internus and quadratus femoris muscles. Under the inferior border of the gluteus maximus muscle, the sciatic nerve passes along the posterior surface of the adductor magnus muscle and anterior to the long head of the biceps femoris muscle. At the level of the upper angle of the popliteal fossa, and sometimes higher, it is divided into the tibial and common peroneal nerves.
In the pelvis and thigh, the sciatic nerve gives off muscle branches to the obturator internus, gemellus, quadratus femoris, semitendinosus and semimembranosus muscles, the long head of the biceps femoris and the posterior part of the adductor magnus muscle.
The tibial nerve (n. tibialis) is much thicker than the common peroneal nerve. It descends vertically in the popliteal fossa, passes between the heads of the gastrocnemius muscle, posteriorly and slightly lateral to the popliteal artery and vein. Together with the posterior tibial artery, the nerve goes under the soleus muscle into the ankle-popliteal canal. In the lower leg, the tibial nerve is located between the flexor hallucis longus muscle laterally and the flexor digitorum longus muscle medially. In the lower parts of the ankle-popliteal canal, the tibial nerve passes more superficially. In the groove at the posterior edge of the medial malleolus, the tibial nerve divides into its terminal branches, the medial and lateral plantar nerves.
The tibial nerve along its length gives numerous muscular branches to the triceps surae muscle, long flexors fingers and big toe, to the plantar and popliteal muscles. Sensitive branches The tibial nerve innervates the capsule of the knee joint, the interosseous membrane of the leg, the capsule of the ankle joint, and the bones of the leg. The largest sensory branch of the tibial nerve is the medial cutaneous nerve of the calf (n. cutaneus surae medialis). It arises from the tibial nerve at the level of the popliteal fossa, then, in the form of a long and thin branch, passes first under the fascia of the leg, between the heads of the gastrocnemius muscle. At the level of the origin of the distal gastrocnemius tendon, this nerve pierces the fascia and exits under the skin and connects with the lateral cutaneous nerve of the calf (from the common peroneal nerve). When these two nerves merge, the sural nerve (n. suralis) is formed, which passes first behind the lateral malleolus, then along the lateral edge of the foot called the lateral dorsal cutaneous nerve (n. cutaneus dorsalis lateralis). This nerve innervates the skin of areas adjacent to the nerve, and near the calcaneus it gives off cutaneous lateral calcaneal branches (rr. calcanei laterales).
The medial plantar nerve (n. plantaris medialis), which is one of the terminal branches of the tibial nerve, on foot goes along the medial edge of the flexor digitorum brevis tendon in the medial plantar groove, adjacent to the medial plantar artery. On the foot, the nerve gives off muscle branches to the short flexor of the fingers and big toe, to the abductor pollicis muscle, as well as to the two medial lumbrical muscles. At the level of the base of the metatarsal bones, the medial plantar nerve gives off the first proper plantar digital nerve (n. digitalis plantaris proprius) to the skin of the medial edge of the foot and big toe, as well as three common plantar digital nerves (nn. digitales plantares communes). These digital nerves pass under the plantar aponeurosis along with the plantar metatarsal arteries. Each common plantar digital nerve at the level of the metatarsophalangeal joints is divided into two own plantar digital nerves (nn. digitales plantares proprii), which innervate the skin of the I-IV fingers facing each other.
The lateral plantar nerve (n. plantaris lateralis) is thinner than the medial one. It is located in the lateral plantar groove between the quadratus plantaris muscle and the flexor digitorum brevis muscle. At the proximal portion of the fourth intermetatarsal space, the lateral plantar nerve divides into deep and superficial branches. deep branch(r. profundus) gives branches to the quadratus plantae muscle, the abductor little finger muscle, the flexor little finger brevis muscle, the 3rd and 4th lumbrical muscles, and the interosseous muscles; to the adductor hallucis muscle and to the lateral portion of the flexor hallucis brevis muscle. Superficial branch(r. superficialis) of the lateral plantar nerve gives off cutaneous branches to the lateral side of the little finger and the sides of the IV and V fingers facing each other (common plantar digital nerve, n. digitalis plantaris communis), dividing into two own plantar digital nerves (nn. digitales plantares propria).
The common peroneal nerve (n. fibularis communis) is the second major branch of the sciatic nerve, directed obliquely downward and laterally. The nerve occupies the lateral part of the popliteal fossa, giving branches to the knee and tibiofibular joints, to short head biceps femoris muscle. At the level of the popliteal fossa, the lateral cutaneous nerve of the calf (n. cutaneus siirae lateralis) departs from the common peroneal nerve, which gives off cutaneous branches to the lateral side of the leg, and at the level of the middle of the back side of the leg it pierces the fascia, exits under the skin and connects with the medial cutaneous nerve of the calf (forms sural nerve).
The common peroneal nerve, near the lateral angle of the popliteal fossa, bends around the neck of the fibula on the lateral side. The nerve then pierces the initial part of the peroneus longus muscle and divides into the superficial and deep peroneal nerves.
The superficial peroneal nerve (n. fibularis superficialis, s. peroneus superficialis) runs down and laterally in the superior musculofibular canal, innervating the short and long peroneus muscles. At the border of the middle and lower thirds of the leg, the nerve leaves the superior musculofibular canal, pierces the fascia of the leg, goes down and medially towards the dorsum of the foot. In the superolateral region of the foot (or just above) it is divided into the medial and intermediate dorsal cutaneous nerves. The medial dorsal cutaneous nerve (n. cutaneus dorsalis medialis) innervates the skin of the dorsum of the foot near its medial edge and the skin of the dorsum of the II and III fingers facing each other. The intermediate dorsal cutaneous nerve (n. cutdneus dorsalis intermedius) innervates the skin of the superolateral surface of the dorsum, as well as the sides of the third, fourth and fifth fingers facing each other (dorsal digital nerves of the foot, nn. digitales dorsales pedis).
The deep peroneal nerve (n. fibularis profundus, s. peroneus profundus) from its origin goes in the medial direction, passes through the hole in the anterior intermuscular septum of the leg. Next, the nerve goes through the thickness of the long muscle that extends the fingers. Together with the anterior tibial artery and veins, the nerve descends along the anterior surface of the interosseous membrane of the leg. For some distance, the neurovascular bundle passes between the tibialis anterior muscle medially and the extensor digitorum longus muscle laterally. Next, the deep peroneal nerve runs down next to the extensor pollicis longus tendon (foot). On the dorsum of the foot, the nerve passes under the short extensor of the big toe, then in the first intermetatarsal groove. At the level of the distal part of the first intermetatarsal space, the deep peroneal nerve is divided into two terminal branches - the dorsal digital nerves (nn. digitales dorsales), innervating the skin of the sides of the first and second toes facing each other.
Sacral plexus(plexus sacralis) is formed on the anterior side of the sacrum and pear-
Rice. 499. Cutaneous nerves of the lower limb. Front view.
1 - anterior cutaneous branches of the femoral nerve, 2 - infrapatellar branch, 3 - saphenous nerve, 4 - superficial peroneal nerve, 5 - lateral cutaneous nerve of the thigh, 6 - femoral branch of the femoral-genital nerve, 7 - femoral cutaneous branch of the ilioinguinal nerve, 8 - cutaneous branch of the obturator nerve.
Rice. 500. Femoral and obturator nerves and their branches. Front view. Superficial muscles have been removed. 1 - femoral nerve, 2 - anterior cutaneous branches of the femoral nerve, 3 - obturator nerve, 4 - femoral artery, 5 - saphenous nerve, 6 - great saphenous vein of the leg, 7 - muscular branches of the femoral nerve.
prominent muscle part of the anterior branches of the fourth and fifth lumbar nerves and the anterior branches of the first-third sacral (S I -S III) spinal nerves (Fig. 498). The short branches of the plexus end in the pelvic girdle, the long branches go to the muscles, joints, bones and skin of the free part of the lower limb.
To the short branches of the sacral plexus include the internal obturator and piriformis nerves, the nerve of the quadratus femoris muscle, as well as the upper and lower gluteal and pudendal nerves (Fig. 501).
Superior gluteal nerve(n. gluteus superior) leaves the pelvic cavity through the supragiriform foramen, goes to the gluteus minimus and medius muscles, and also gives off a branch to the tensor muscle of the fascia lata.
Inferior gluteal nerve(n. gluteus inferior) leaves the pelvic cavity through the infrapiriform foramen (together with the sciatic and pudendal nerves), innervates the gluteus maximus muscle, and also gives off a branch to the capsule of the hip joint.
Pudendal nerve(n. pudendus) leaves the pelvic cavity through the infrapiriform foramen, then goes around the sciatic spine and through the lesser sciatic foramen penetrates the ischiorectal fossa, giving off the lower rectal and perineal nerves (Fig. 502). Inferior rectal nerves(nn. rectales inferiores) innervate the external anal sphincter and the skin of the anal area. Perineal nerves(nn. perineales) innervate the muscles and skin of the perineum and scrotum in men or the labia majora in women. The terminal branch of the pudendal nerve is dorsal nerve of the penis (clitoris)(n. dorsalis penis, s. clitoridis), which gives branches to the cavernous bodies, the head of the penis (clitoris), the skin of the penis in men, the labia majora and minora (in women), as well as branches to the deep transverse muscle of the perineum and urethral sphincter.
To the long branches of the sacral plexus include the posterior cutaneous nerve of the thigh and the sciatic nerve (Fig. 501).
Posterior cutaneous nerve of the thigh(n. cutaneus femoris posterior) leaves the pelvic cavity through the infrapiriform opening and goes down next to the sciatic nerve, gives off inferior nerves of the buttocks(nn. dunium inferiores), which innervate the skin of the lower part of the gluteal region, and perineal nerves(rr. perineales) to the skin of the perineum. Next, the posterior cutaneous nerve of the thigh goes down, pierces the fascia lata and branches in the skin of the posteromedial side of the thigh up to the popliteal fossa (Fig. 503).
Sciatic nerve(n. ischiadicus) exits the pelvic cavity through the infrapiriform foramen along with the inferior gluteal, pudendal nerves, posterior cutaneous nerve of the thigh and internal pudendal artery, along the posterior side of the adductor magnus muscle. At the level of the upper angle of the popliteal fossa or above, the sciatic nerve is divided into the tibial and common peroneal nerves (Fig. 504). Muscle branches extend from the sciatic nerve to the obturator internus, gemellus, quadratus femoris, semitendinosus, semimembranosus, long head of the biceps femoris, and posterior portion of the adductor magnus.
Tibial nerve(n. tibialis) descends vertically downwards, goes under the soleus muscle into the tibial-popliteal canal. Behind the medial malleolus, this nerve divides into its terminal branches - the medial and lateral plantar nerves (Fig. 505). The tibial nerve gives off muscle branches to the triceps surae muscle, to the long flexor muscles of the fingers and big toe, to the plantar and popliteal muscles. The sensory branches of the tibial nerve go to the capsule of the knee joint, the interosseous membrane of the leg, ankle joint, bones of the lower leg. The major sensory branch of the tibial nerve is medial cutaneous nerve of the calf(n. cutaneus surae medialis), which pierces the fascia and exits under the skin, where it connects with the lateral cutaneous nerve of the calf (from the common peroneal nerve). When these two nerves connect, it forms sural nerve(n. suralis), which
Rice. 501. Superior and inferior gluteal nerves. Posterior cutaneous nerve of the thigh and sciatic nerve. Rear view. Big gluteal muscle cut and turned upward, part of the gluteus medius muscle was removed.
1 - superior gluteal nerve, 2 - sciatic nerve, 3 - inferior nerve of the buttock, 4 - posterior cutaneous nerve of the thigh, 5 - inferior gluteal nerve.
Rice. 502. The pudendal nerve and its branches in the male perineum. View from below.
1 - pudendal nerve, 2 - internal pudendal artery, 3 - anus, 4 - dorsal nerve of the penis, 5 - artery of the bulb of the penis, 6 - bulbospongiosus muscle, 7 - posterior scrotal nerves, 8 - ischiocavernosus muscle, 9 - external anal sphincter, 10 - levator ani muscle, 11 - gluteus maximus muscle, 12 - inferior rectal artery, 13 - inferior rectal nerves.
Rice. 503. Cutaneous nerves of the gluteal region and the free part of the lower limb. Rear view.
1 - superior nerves of the buttock, 2 - middle nerves of the buttock, 3 - lower branches of the buttock, 4 - posterior cutaneous nerve of the thigh, 5 - medial cutaneous nerve of the calf, 6 - lateral cutaneous nerve of the calf, 7 - sural nerve.
Rice. 504. Tibial and common peroneal nerves. Rear view. Triceps tibia removed.
1 - sciatic nerve, 2 - tibial nerve, 3 - common peroneal nerve, 4 - medial calf cutaneous nerve, 5 - lateral calf cutaneous nerve, 6 - sural nerve.
innervates the skin of the lateral side of the dorsum of the foot (Fig. 504).
Medial plantar nerve(n. plantaris medialis) on the foot runs along the medial plantar groove and gives off muscle branches to the flexor digitorum brevis and the medial head of the flexor hallucis, to the abductor hallucis muscle, as well as to the two medial lumbrical muscles (Fig. 505 ). The medial plantar nerve gives off own plantar digital nerve(n. digitalis plantaris proprius) to the skin of the medial edge of the foot and big toe, as well as three common plantar digital nerves(nn. digitales plantares communes), each of which is divided into two proper plantar digital nerves(nn. digitales plantares proprii), innervating the skin of the first to fourth toes facing each other.
Lateral plantar nerve(n. plantaris lateralis) goes in the lateral plantar groove, gives branches to the quadratus plantar muscle, to the short flexor of the little finger and to the muscle opposing the little finger, to the third and fourth lumbrical muscles, to the interosseous muscles, to the muscle that adducts the big toe , and to lateral head flexor hallucis brevis. The lateral plantar nerve also innervates the skin of the lateral side of the little toe and the sides of the fourth and fifth toes facing each other.
Common peroneal nerve goes obliquely downwards and laterally, giving branches to the knee and tibiofibular joints, to the short head of the biceps femoris muscle. Its branch is lateral cutaneous nerve of the calf(n. cutaneus surae lateralis), which innervates the skin of the lateral side of the leg, and at the level of the middle of the leg it exits under the skin and connects with the medial cutaneous nerve of the calf (forms the sural nerve).
The common peroneal nerve near the lateral angle of the popliteal fossa is divided into the superficial and deep peroneal nerves (Fig. 506).
Rice. 505. Plantar nerves and their branches. The muscles of the sole of the foot are partially removed. 1 - common digital nerves, 2 - plantar metatarsal arteries, 3 - medial plantar nerve, 4 - lateral plantar nerve, 5 - medial plantar artery, 6 - posterior tibial artery, 7 - calcaneal branch, 8 - lateral plantar artery, 9 - plantar arterial arch, 10 - proper digital nerves.
Rice. 506. Common peroneal nerve and its branches. Front and side views.
1 - common peroneal nerve, 2 - superficial peroneal nerve, 3 - peroneus longus, 4 - extensor digitorum longus, 5 - fascia of the leg, 6 - superficial peroneal nerve, 7 - intermediate dorsal cutaneous nerve, 8 - sural nerve, 9 - lateral dorsal cutaneous nerve, 10 - dorsal digital nerves of the foot, 11 - deep peroneal nerve, 12 - dorsal artery of the foot, 13 - medial dorsal cutaneous nerve, 14 - anterior tibial muscle, 15 - anterior tibial artery, 16 - deep peroneal nerve, 17 - muscle branches, 18 - knee joint network.
Superficial peroneal nerve(n. peroneus superficialis) goes laterally and downward in the superior musculofibular canal, innervates the short and long peroneus muscles. At the border of the middle and lower third of the leg, the nerve leaves the superior musculofibular canal and goes to the dorsum of the foot, where it divides into the medial and intermediate dorsal cutaneous nerves. Medial dorsal cutaneous nerve(n. cutaneus dorsalis medialis) innervates the skin of the medial edge of the dorsum of the foot and the skin of the second and third toes facing each other. Intermediate dorsal cutaneous nerve(n. cutaneus dorsalis intermedius) innervates the skin of the superolateral side of the dorsum of the foot, as well as the sides of the third to fifth toes facing each other (dorsal digital nerves of the foot, nn. digitales dorsales pedis).
Deep peroneal nerve(n. fibularis, profundus, s. fibularis profundus) passes through the hole in the anterior intermuscular septum of the leg, descends along the front side of the interosseous membrane of the leg and gives branches to the anterior tibial and other muscles of the leg (Fig. 506). The nerve on the dorsum of the foot innervates short muscles, which extend the fingers and thumb, gives off sensitive branches to the ankle joint, to the joints and bones of the foot.
Coccygeal plexus(plexus coccygeus) is located on the anterior side of the coccygeus muscle and on the sacrococcygeal ligament. Originating from the coccygeal plexus antococcygeal nerves(nn. anococcygei) innervate the skin in the area of the coccyx and anus. Muscular branches(rami musculares) of this plexus innervate the coccygeus muscle and back levator ani muscle.
Autonomic (autonomic) nervous system
Autonomic (autonomic) nervous system(systema nervosum autonomicum) is the part of the nervous system that controls the functions internal organs, glands, heart and blood vessels, exercises an adaptive-trophic effect on all human organs, maintains the constancy of the internal environment of the body (homeostasis). The functions of the autonomic (autonomic) nervous system are not controlled by consciousness, but they are subordinate to the spinal cord and brain.
The autonomic (autonomous) system is divided into central and peripheral sections. TO central department include: parasympathetic autonomic nuclei of the oculomotor, facial, glossopharyngeal and vagus cranial nerves lying in the brain stem (midbrain, pons and medulla oblongata); parasympathetic sacral nuclei (nuclei parasympathici sacrales), located in the gray matter of the three sacral segments of the spinal cord (S II - S iv), as well as the autonomic (sympathetic) thoracic nucleus (nucleus thoracicus), located in the lateral column of the eighth cervical, all thoracic and two upper lumbar segments of the spinal cord (C IIX, Th I - Th XII, L I - L II).
TO peripheral department The autonomic (autonomic) nervous system includes autonomic (autonomic) nerves, branches and nerve fibers emerging from the brain and spinal cord, autonomic (autonomous) visceral nerve plexuses, nodes of the autonomic (autonomous, visceral) plexuses, autonomic fibers (parasympathetic and sympathetic), going from the vegetative nodes to the organs and tissues of the human body, nerve endings involved in autonomic reactions.
Autonomic (autonomous) nerve fibers emerging from the spinal cord and brain as part of the roots of the spinal and cranial nerves, and then their branches, are formed by processes of neurons in the lateral horns of the spinal cord or autonomic nuclei of the cranial nerves. The axons of these neurons (efferent) are directed to the periphery to the nodes of the autonomic nerve plexuses, on the cells of which these fibers end. The processes of cells located in the vegetative nodes are sent to organs, tissues, blood and lymphatic vessels for their innervation. The path of autonomic innervation from the brain to the working organ consists
Rice. 507. Autonomic reflex arc.
1 - posterior root of the spinal nerve, 2 - intermediate lateral nucleus of the lateral horn of the spinal cord, 3 - preganglionic (prenodal) fibers of the intercalary neuron (as part of the anterior root of the spinal nerve), 4 - spinal ganglion, 5 - spinal nerve, 6 - white connecting branch, 7 - node of the sympathetic trunk, 8 - gray connecting branch, 9 - postganglionic (post-nodal) nerve fibers of the effector neuron as part of the spinal nerve, 10 - postganglionic (post-nodal) fibers of the effector neuron (as part of the splanchnic nerve), 11 - nerve node autonomic plexus, 12 - postganglionic (post-nodal) nerve fibers of the effector neuron (as part of the visceral and choroid plexuses), 13 - postganglionic fibers to the blood vessel, 14 - blood vessel, 15 - postganglionic (post-nodal) nerve fibers (to the sweat glands of the skin, muscles hair and to blood vessels).
of two neurons (Fig. 507). The axons of a neuron extending from the vegetative nucleus in the brain to the vegetative ganglion in the periphery are called prenodal (preganglionic) nerve fibers(neurofibrae preganglionares). The axons of neurons whose bodies are located in the peripheral vegetative node are called postnodal (postganglionic) nerve fibers(neurofibrae postganglionares). Autonomic nerve fibers are part of the cranial and spinal nerves and their branches.
Based on the topography of the vegetative nuclei and nodes, differences in the length of the fibers of the first and second neurons of the efferent pathway, as well as the characteristics of the autonomic functions nervous system divided into sympathetic and parasympathetic parts.
