Ministry of Health of the Republic of Uzbekistan Teaching and Methodological Cabinet for Higher and Secondary Medical Education Tashkent Medical Academy Department of Human Anatomy and Okhta. Reticulospinal tract
1) Bone as an organ, its development, structure, growth. Classification of bones. Osteon.
Each bone,os, is an independent organ and consists of bone tissue. The outside of the bone is covered periosteum, periosteum, inside of her marrowy cavities, cavitas medullares, is the bone marrow. Bones vary in size and shape and occupy a specific position in the body. For convenience of study, the following groups of bones are distinguished: long (tubular), short (spongy), flat (wide), abnormal (mixed), air-bearing (Fig. 15).
Long(tubular) bone,os longum, has an elongated, cylindrical or triangular middle part - the body of the bone, the diaphysis, diaphysis(from Greek dia - between, phyo - I grow). Its thickened ends are called epiphyses, epiphysis(from Greek epi - over). Each epiphysis has an articular surface, fades articuldris, covered with articular cartilage, which serves to connect with adjacent bones. The part of the bone where the diaphysis passes into the epiphysis is isolated as the metaphysis, metaphysis. This area corresponds to the epiphyseal cartilage ossified in postnatal ontogenesis. Tubular bones make up the skeleton of the limbs, act as levers. There are long bones (humerus, femur, bones of the forearm and lower leg) and short bones (metacarpal, metatarsal, phalanges of the fingers).
short(spongy) bone,os Breve, has the shape of an irregular cube or polyhedron. Such bones are located in areas of the skeleton where the strength of the bones is combined with mobility - in the joints between the bones (carpal bones, tarsus).
flat(wide) bones,ossa plana, participate in the formation of body cavities and also perform the function of protection (bones of the skull roof, pelvic bones, sternum, ribs). At the same time, they provide extensive surfaces for muscle attachment.
Abnormal(mixed) bones,ossa irregularia, complex, their shape is varied. For example, the vertebral body in shape (and structure) refers to spongy bones, the arc, processes - to flat ones.
air bones,ossa pneumatica, have a cavity in the body lined with a mucous membrane and filled with air. These include some bones of the skull: frontal, sphenoid, ethmoid, upper jaw.
OSTEON (from the Greek osteon - bone) (Haversian system) - a structural unit of the compact substance of bones in vertebrates and humans. The osteon consists of bony plates arranged concentrically around the Haversian canals, which gives the bone exceptional strength.
2) Language development, structure, functions, its blood supply, innervation. Regional lymph nodes.
Filiform and cone-shaped papillae, papillae filiformes et papillae conicae, the most numerous, located over the entire surface of the back of the tongue anterior to the border groove.
fungiform papillae, papilla fungiformes, localized mainly at the top and along the edges of the tongue. Taste buds (bulbs) are located in the papillae, to which the nerves that conduct taste sensitivity approach.
Grooved papillae(surrounded by a rampart) papillae vallatae. In the center of the papilla there is an elevation bearing taste buds (bulbs), and around it there is a roller, separated from the central part by a narrow groove.
Foliate papillae, papillae foliatae, in the form of flat elongated plates are located on the edges of the tongue.
Superior longitudinal musclet. longitudinalis superior begins in the thickness of the root of the tongue, and in some bundles - from the anterior surface of the epiglottis, small horns of the hyoid bone and ends in the region of the apex of the tongue. Function: shortens the tongue, raises its top up.
lower longitudinal muscle,t. longitudinalis inferior n It starts at the root of the tongue and ends at its apex. Function: shortens the tongue, lowers the top of the tongue.
transverse muscle of the tonguet. transversus linguae, consists of bundles running transversely from the septum of the tongue in both directions to its edges. Muscle bundles end in the mucous membrane of the right and left edges of the tongue. Function: reduces the transverse dimensions of the tongue, raises the back of the tongue.
Vertical muscle of the tonguet. verticalis linguae, located mainly in the lateral sections of the tongue between the mucous membrane of the back and the lower surface of the tongue. Function: flattens the tongue.
genio-lingual muscle,t. genioglossus, starts from the mental spine of the lower jaw. Its fibers run back and up the sides of the septum of the tongue and end in the thickness of the tongue. Function: pulls the tongue forward and down.
hyoid-lingual muscle,t. hyoglossus, starts from the large horn and the body of the hyoid bone, goes forward and upward; ends in the lateral sections of the tongue. Function: pulls the tongue back and down.
styloglossus muscle,t. styloglossus, originates from the styloid process of the temporal bone and the stylohyoid ligament, goes down, forward and medially, enters the thickness of the tongue from the side. Function: pulls the tongue back and up; with unilateral contraction, it pulls the tongue to the side.
Vessels and nerves of the tongue. Blood to the tongue comes from the lingual artery (from the external carotid artery). Venous blood flows to the vein of the same name, which flows into the internal jugular vein. Lymphatic vessels from the tongue are sent to the submandibular, mental and lateral deep cervical lymph nodes.
The nerves of the tongue come from various sources. The motor innervation of the muscles of the tongue is carried out by the hypoglossal nerve (XII pair). Sensitive innervation of the mucous membrane is performed by the endings of the lingual nerve, the glossopharyngeal nerve (IX pair), and the laryngeal nerve. Gustatory innervation is carried out by the glossopharyngeal nerve, the facial nerve through the tympanic string, the fibers of which are suitable as part of the lingual nerve.
The lymph nodes:
Nodi lymphatici submandibulares - submandibular lymph nodes. Nodi lymphatici cervicales laterales profundi - deep cervical (internal jugular),
Nodus lumphaticus jugulodigastricus - jugular-bigastric nodes
Nodus lymphaticus juguloomohyoideus - jugular - scapular - sublingual nodes.
3) External carotid artery, its topography, branches and areas, blood supply to them.
external carotid artery, a. carotis externa, is one of the two terminal branches of the common carotid artery. The artery divides into its terminal branches - the superficial temporal and maxillary arteries. On its way, the external carotid artery gives off a number of branches that radiate from it in several directions. The anterior group of branches is made up of the superior thyroid, lingual, and facial arteries. The posterior group includes the sternocleidomastoid, occipital, and posterior auricular arteries. The ascending pharyngeal artery is directed medially.
Anterior branches of the external carotid artery:
1. superior thyroid artery,a. thyreoidea superior, departs from the external carotid artery at its beginning, is divided into anterior and back branch, rr. anterior and posterior. The anterior and posterior branches are distributed in the thyroid gland. The following lateral branches depart from the artery:
1) superior laryngeal artery, a. laryngea superior, which supplies blood to the muscles and mucous membrane of the larynx;
2) sublingual branch, g. infrahyoideus; 3) sternocleidomastoid branch, g. sternocleidomasto-ideus, and 4) cricothyroid branch, g. cricothyroideus, blood-supplying muscles of the same name.
2. lingual artery,a. lingudlis, branches off from the external carotid artery. The artery gives dorsal branches, rr. dorsales linguae. Its terminal branch is deep artery of the tongue, a. profunda linguae. Two branches depart from the lingual artery: 1) thin suprahyoid branch, g. suprahyoideus and 2) hypoglossal artery, a. sublingualis, going to the sublingual gland and adjacent muscles
3. Facial artery,a. facialis, departs from the external carotid artery. The lingual and facial arteries may begin in common linguofacial trunk, truncus linguofacialis. The artery is adjacent to the submandibular gland, giving it glandular branches, rr. glanduldres.
Branches on the neck depart from the facial artery: 1) ascending palatine artery, a. palatina ascendens, to the soft palate;
2) tonsil branch, g. tonsillaris, to the palatine tonsil;
3) submental artery, a. submentalis, to the chin and neck muscles. four) inferior labial artery, a. labialis inferior, and 5) superior labial artery, a. labialis superior. 6) angular artery a. apgularis.
Posterior branches of the external carotid artery:
1. Occipital artery,a. occipitdlis, departs from the external carotid artery, branches in the skin of the occiput to occipital branches, rr. occipitdles. Lateral branches depart from the occipital artery: 1) sternocleidomastoid branches, rr. sternocleidomastoidei, to the muscle of the same name; 2) ear branch, rr. auriculdris, to the auricle; 3) mastoid branch, g. mas-toideus, to the hard shell of the brain; four) descending branch, r. dissidents, to the muscles of the back of the neck.
2. posterior ear artery,a. auricularis posterior, departs from the external carotid artery. Her ear branch, gg. auricularis, and occipital branch, r. occipitdlis, blood supply to the skin of the mastoid process, the auricle and the back of the head. One of the branches of the posterior auricular artery - stylomastoid artery, a. stylomastoidea, gives back posterior tympanic artery, a. tympanica posterior, to the mucous membrane of the tympanic cavity and the cells of the mastoid process.
Medial branch of the external carotid artery - ascending pharyngeal artery,a. pharyngea ascendens. They depart from it: 1) pharyngeal branches, rr. pharyngeales, to the muscles of the pharynx and to the deep muscles of the neck; 2) posterior meningeal artery, a. meningea posterior, follows into the cranial cavity through the jugular foramen; 3) inferior tympanic artery, a. tympanica inferior, through the lower opening of the tympanic tubule penetrates into the tympanic cavity.
Terminal branches of the external carotid artery:
1. superficial temporal artery,a. temporalis superficialis, divided by frontal branch, g. frontalis, and parietal branch, g. parietalis, feeding the supracranial muscle, the skin of the forehead and crown. A number of branches depart from the superficial temporal artery: 1) under the zygomatic arch - branches of the parotid gland, rr. parotidei, to the salivary gland of the same name; 2) transverse artery of the face, a. transversa faciei, to facial muscles and skin of the buccal and infraorbital regions; 3) anterior ear branches, gg. auriculares anteriores, to the auricle and external auditory canal; 4) above the zygomatic arch - zygomatic-orbital artery, a. zygomaticoorbitalis, to the lateral corner of the orbit, blood supply to the circular muscle of the eye; 5) middle temporal artery, a. temporalis media, to the temporalis muscle.
2. maxillary artery,a. maxillaris, splits into its terminal branches. It is divided into three sections: maxillary, pterygoid and pterygopalatine.
4) Parasympathetic innervation of the pelvic organs.
The sacral SM is represented by the sacral PS nuclei , located in the lateral intermediate substance II-IV of the sacral segments. The fibers form the pelvic splanchnic nerves, pp. splanchnici pelvini. These nerves reach the intramural or intraorgan nodes of the descending colon, sigmoid and rectum, bladder, internal and external genital organs. Intramural nodes are located in organ plexuses (rectal, bladder, utero-vaginal, prostate, etc.). Short postganglionic fibers depart from them to the glands of the mucous membranes, smooth muscles, blood vessels of the cavernous bodies). The pelvic organs receive afferent innervation from the neurons of the sacral spinal nodes (only "spinal"), sympathetic - from the neurons of the upper and lower hypogastric plexuses.
1) The development of the skull in ontogenesis. Individual, age and sex characteristics of the skull.
Cerebral region of the skull develops from the mesenchyme surrounding the rapidly growing brain. The mesenchymal cover turns into a connective tissue membrane - the stage of the membranous skull. In the region of the arch, this shell is subsequently replaced by bone. Cartilaginous tissue appears only at the base of the skull, near the anterior chord, which ends dorsal to the pharynx, posterior to the future pituitary stalk. The sections of cartilage lying next to the chord are called the perichordal (parachordal) cartilages, and in front of the chord, the prechordal plates and cranial crossbars. Subsequently, the cartilage at the base of the skull is replaced by bone, with the exception of small areas (synchondrosis), which persist in adults until a certain age.
Thus, in humans, the vault (roof) of the skull in its development goes through two stages: membranous (connective tissue) and bone, and the base of the skull - three stages: membranous, cartilaginous and bone.
Facial region of the skull develops from the mesenchyme adjacent to the initial section of the primary intestine.
Features of the skull. For an individual characteristic of the shape of the skull (brain), it is customary to determine its following dimensions (diameters): longitudinal, transverse, height. The ratio of the longitudinal size (diameter) to the transverse one, multiplied by 100, is the cranial index (longitudinal-latitudinal index). When the value of the cranial index is up to 74.9, the skull is called long (dolichocrania); an index equal to 75.0-79.9 characterizes the average size of the skull (mesocrania), and with an index of 80 or more, the skull will be wide and short (brachycrania). The shape of the head corresponds to the shape of the skull. In this regard, long-headed people (dolichocephalus), medium-headed (mesocephalic) and broad-headed (brachycephalic) people are distinguished.
Looking at the skull from above (vertical norm), one can note the variety of its shapes: ellipsoid (with dolichocrania), ovoid (with mesocrania), spheroid (with brachycrania), etc.
Sex differences human skulls are small, so it is sometimes difficult to distinguish a male skull from a female one. At the same time, it is necessary to point out the following not always clearly expressed sex differences in the skull. In the male skull, tuberosities (muscle attachments) are usually better visible; the occipital protuberance, superciliary arches protrude more strongly. The eye sockets are relatively large, the paranasal sinuses are more pronounced. The bones are usually somewhat thicker than those of the female skull. The longitudinal (anteroposterior) and vertical dimensions of the male skull are large. The male skull is more capacious (by 150-200 cm 3) than the female one: the capacity of the skull in men is on average 1450 cm 3, and in women - 1300 cm 3. The difference can be explained by the smaller body size in women.
2) Pleura, its departments, borders; pleural cavity, pleural sinuses.
Pleura , pleura, which is the serous membrane of the lung, is divided into visceral (pulmonary) and parietal (parietal). Each lung is covered with a pleura (pulmonary), which, along the surface of the root, passes into the parietal pleura.
Visceral (lung) pleurapleura visceralis (pulmonalls). Down from the root of the lung forms lung ligament,lig. pulmonale.
Parietal (parietal) pleura,pleura parietalis, in each half of the chest cavity forms a closed bag containing the right or left lung, covered with a visceral pleura. Based on the position of the parts of the parietal pleura, the costal, mediastinal and diaphragmatic pleura are distinguished in it. costal pleura, pleura costalis, covers the inner surface of the ribs and intercostal spaces and lies directly on the intrathoracic fascia. mediastinal pleura, pleura mediastindlis, adjoins from the lateral side to the organs of the mediastinum, on the right and on the left it is fused with the pericardium; on the right, it also borders on the superior vena cava and unpaired veins, on the esophagus, on the left - on the thoracic aorta.
Above, at the level of the upper aperture of the chest, the costal and mediastinal pleura pass into each other and form dome of the pleuracupula pleurae, bounded on the lateral side by the scalene muscles. In front and medially to the dome of the pleura, the subclavian artery and vein are adjacent. Above the dome of the pleura is the brachial plexus. diaphragmatic pleura, pleura diafragmatica, covers the muscular and tendon parts of the diaphragm, with the exception of its central sections. Between the parietal and visceral pleura there is pleural cavity,cavitas pleuralis.
Sinuses of the pleura. In places where the costal pleura passes into the diaphragmatic and mediastinal, pleural sinuses,recessus pleurdles. These sinuses are reserve spaces of the right and left pleural cavities.
Between costal and diaphragmatic pleura costophrenic sinus , recessus costodiaphragmaticus. At the junction of the mediastinal pleura to the diaphragmatic pleura is phrenomediastinal sinus , recessus phrenicomediastinalis. A less pronounced sinus (depression) is present at the point of transition of the costal pleura (in its anterior section) into the mediastinal one. Here is formed costomediastinal sinus , recessus costomediastinalis.
Pleura borders. Right anterior border of the right and left costal pleura from the dome of the pleura descends behind the right sternoclavicular joint, then goes behind the handle to the middle of its connection with the body and from here descends behind the body of the sternum, located to the left of the midline, to the VI rib, where it goes to the right and passes into the lower border of the pleura. Bottom line pleura on the right corresponds to the line of transition of the costal pleura to the diaphragmatic.
Left anterior border of the parietal pleura from the dome goes, as well as on the right, behind the sternoclavicular joint (left). Then it goes behind the handle and the body of the sternum down to the level of the cartilage of the IV rib, located closer to the left edge of the sternum; here, deviating laterally and downward, it crosses the left edge of the sternum and descends close to it to the cartilage of the VI rib, where it passes into the lower border of the pleura. Inferior border of the costal pleura on the left is slightly lower than on the right side. Behind, as well as on the right, at the level of the XII rib, it passes into the posterior border. pleural border at the back corresponds to the posterior line of the transition of the costal pleura to the mediastinal.
3) Femoral artery: its topography, branches and areas supplied with blood. Blood supply to the hip joint.
femoral artery,a. femoralis, is a continuation of the external iliac artery. Branches from the femoral artery:
1. Superficial epigastric artery,a. epigastric superficialis, blood supply to the lower part of the aponeurosis of the external oblique muscle of the abdomen, subcutaneous tissue and skin.
2. Superficial artery, envelope of the ilium,a. circumflexa iliaca superjicialis, goes in a lateral direction parallel to the inguinal ligament to the superior anterior iliac spine, branches in the adjacent muscles and skin.
3. External pudendal arteries,aa. pudendae externa, exit through the subcutaneous fissure (hiatus saphenus) under the skin of the thigh and go to the scrotum - anterior scrotal branches, rr. scrotdles anteriors, in men or to the labia majora anterior labial branches, rr. labidles anteriores, among women.
4. Deep artery hips, a. profunda femoris, supplies blood to the thigh. The medial and lateral arteries depart from the deep artery of the thigh.
1) Medial circumflex artery of the femur a. circumflexa femoris medialis, gives back ascending and deep branches, rr. ascendens et profundus, to iliopsoas, pectineus, obturator externus, piriformis and quadratus femoris muscles. The medial circumflex artery of the femur sends acetabular branch, g. acetabuldris, to the hip joint.
2) Lateral circumflex artery of the femur, a. circumflexa femoris latertis, his ascending branch, r. ascendens, blood supply to the gluteus maximus muscle and tensor fascia lata. Descending and transverse branches, rr. descendens and transversus, blood supply to the muscles of the thigh (tailor and quadriceps).
3) Perforating arteries, aa. perfordntes(first, second and third), supply blood to the biceps, semitendinosus and semimembranosus muscles.
5. Descending genicular artery, a. Genus descendens, departs from the femoral artery in the adductor canal, takes part in the formation knee articular network, rete articuldre genus.
4) Medulla. The position of the nuclei and pathways in the medulla oblongata.
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The body of the first neuron is the giant pyramidal Betz cell of the cortex of the anterior central gyrus. Through the internal capsule, axons go to the bodies of the second neurons - the cells of the motor nuclei of the cranial nerves.
Starting from the midbrain and further, in the bridge and in the medulla oblongata, the fibers of the cortical-nuclear pathway pass to the opposite side to the motor nuclei of the cranial nerves: to the nuclei of III and IV pairs - in the midbrain; to the nuclei V, VI, VII pairs - in the bridge; to the nuclei IX, X, XI, XII pairs - in the medulla oblongata.
Rice. 38. Pyramidal pathways (anterior and lateral cortical-spinal tracts) ( O . Feitz , 2009).
III- alpha motor neurons of the anterior horns of the spinal cord
Their axons as part of the cranial nerves go to the muscles of the head and neck (Fig. 39).
Rice. 39. Pyramidal pathways (cortical-nuclear tracts)
(O. Feitz, 2009).
I- Betz giant pyramidal cells;II- nuclei of cranial nervesIII- XIIcouple).
Extrapyramidal pathways
Extrapyramidal pathways conduct impulses to the muscles from the basal nuclei, thalamus, red nucleus, substantia nigra, olive nucleus, vestibular nerve, reticular formation. The extrapyramidal system maintains the tone of the skeletal muscles automatically.
The extrapyramidal pathways include:
- red nuclear-spinal path (tractus rubrospinalis);
- pre-door-spinal path (tractus vestibulospinalis);
- reticulo-spinal tract (tractus reticulospinalis);
- tractus tectospinalis;
Red nuclear-spinal tract (Monakova)
The red nuclear-spinal tracts originate from the red nucleus, pass to the opposite side (Forel's cross), pass in the tire of the bridge, in the lateral sections of the medulla oblongata and descend as part of the lateral funiculus of the spinal cord to the motor neurons of the spinal cord.
Their axons leave the spinal cord in the anterior roots and are sent as part of the spinal nerves to the skeletal muscles (Fig. 40).
Rice. 40. Extrapyramidal pathways
(Red nuclear-spinal tract (Monakova) (Fr. Feitz, 2009)
I- red nucleus of the midbrain;II- anterior horns of the spinal cord.
Vestibulo-spinal tract
In the coordination of the motor functions of the body, the pre-door-spinal path is important. It connects the nuclei of the vestibular nerves with the motoneurons of the anterior horns of the spinal cord and is involved in controlling the body's adjusting reactions in case of imbalance. The axons of the neurons of the lateral vestibular nucleus (Deiters' nucleus), as well as the lower vestibular nucleus (descending root) of the vestibulocochlear nerve, take part in the formation of the vestibulospinal tract.
These fibers descend as part of the anterior funiculus of the spinal cord and end on the motor neurons of the anterior horns of the spinal cord. The nuclei that form the pre-door-spinal path are in direct connection with the cerebellum, as well as with the medial longitudinal bundle, which is associated with the nuclei of the oculomotor nerves. The presence of such a connection makes it possible to maintain the direction of the visual axis when turning the head and neck (Fig. 41).
The tractus tectospinalis is a descending motor path related to the extrapyramidal system. It carries out unconditional reflex motor reactions in response to sudden strong visual, auditory, tactile and olfactory stimuli. The first neurons of the operculospinal tract are located in the superior colliculi of the midbrain in the subcortical integration center of the midbrain. Information enters this integration center from the subcortical centers of vision (the core of the upper colliculus), from the subcortical center of hearing (the core of the lower colliculus), from the subcortical center of smell (the core of the papillary body) and collaterals from the pathways of general sensitivity (lemniscus spinalis, lemniscus medialis, lemniscus trigeminalis).
The axons of the first neurons are directed ventrally and upward, bypass the central gray matter of the midbrain and pass to the opposite side. The intersection of the fibers of the tectospinal tract with the tract of the same name on the opposite side is called the dorsal decussation of the tegmentum, decussatio tegmenti dorsalis. This decussation is also called the fountain-shaped, or Meinert's decussation, which reflects the nature of the course of the nerve fibers. Further, the tract passes in the dorsal part of the bridge next to the medial longitudinal bundle. Along the tract in the brainstem depart
fibers that terminate on the motor neurons of the motor nuclei
cranial nerves. These fibers are combined under the name of the tegmental bundle, fasciculus tectonuclearis. They provide protective reactions involving the muscles of the head and neck.
In the region of the medulla oblongata, the tectospinal
the path approaches the dorsal surface of the pyramids and goes to the anterior funiculus of the spinal cord. In the spinal cord, it occupies
the most medial part of the anterior funiculus, limiting the anterior
middle slot.
The tectospinal tract can be traced throughout the entire spinal cord. Gradually thinning, it gradually gives off branches to the alpha-small motor neurons of the motor nuclei of the anterior horns of the spinal cord of its side. Axons of motor neurons conduct nerve impulses to the muscles of the trunk and limbs.
With the defeat of the occlusal-spinal tract disappear
starting reflexes, reflexes to sudden sound, auditory,
olfactory and tactile stimuli.
Reticular-spinal tract
The reticular-spinal path, tractus reticulospinalis - descending, efferent path of the extrapyramidal system - is designed to perform complex reflex acts (breathing, grasping movements, etc.) that require the simultaneous participation of many groups of skeletal muscles. Therefore, it performs a coordinating role in these movements. The reticular-spinal tract conducts nerve impulses that have an activating or, conversely, inhibitory effect on the motor neurons of the motor nuclei of the anterior horns of the spinal cord. Except
In addition, this pathway transmits impulses to gamma motor neurons that provide skeletal muscle tone.
The first neurons of the reticular-spinal tract are located in the reticular formation of the brain stem. The axons of these
neurons go in a downward direction. In the spinal cord, they form a bundle, which is located in the anterior funiculus. The bundle is well expressed only in the cervical and upper thoracic regions of the spinal cord. Segmentally, it becomes thinner, giving fibers to the gamma motor neurons of the motor nuclei of the anterior horns of the spinal cord. The axons of these neurons travel to the skeletal muscles.
Vestibulo-spinal tract
The vestibulo-spinal path, tractus vestibulospinalis, is a descending, motor path of the extrapyramidal system. It provides unconditional flexor motor acts in violation of the balance of the body. The vestibulospinal tract is formed by the axons of the cells of the lateral and inferior vestibular nuclei (the nuclei of Deiters and Roller). In the medulla oblongata, it is located in the dorsal region. In the spinal cord, it passes at the border of the lateral and anterior cords, therefore it is penetrated by horizontally oriented fibers of the anterior roots of the spinal nerves.
The fibers of the vestibulo-spinal tract end in segments on the alpha motor neurons of the motor nuclei of the anterior horns of the spinal cord. Axons of motor neurons as part of the roots of the spinal nerves leave the spinal cord and go to the skeletal muscles.
Olivo-spinal tract
Olivo-spinal tract, tractus olivospinalis, - descending
motor pathway of the extrapyramidal system It provides unconditional reflex maintenance of the tone of the muscles of the neck and motor acts aimed at maintaining the balance of the body.
The olivo-spinal tract starts from the neurons of the inferior olive nucleus of the medulla oblongata. Being a phylogenetically new formation, the lower olive nucleus has direct connections with the cortex of the hemispheres of the frontal lobe (cortical-olive path, tr. corticoolivaris), with the red nucleus (red-olive path, tr. rubroolivaris) and with the cortex of the cerebellar hemispheres (olive-cerebellar path, tr olivocerebellatis). The axons of the cells of the inferior olive nucleus are assembled into a bundle - the olive-spinal tract, which runs in the anterior-medial section of the lateral funiculus. It can be traced only at the level of the six upper cervical segments of the spinal cord.
The fibers of the olivo-spinal tract terminate in segments on the alpha motor neurons of the motor nuclei of the anterior horns of the spinal cord.
brain. Axons of motor neurons as part of the roots of the spinal nerves leave the spinal cord and go to the muscles of the neck.
Medial longitudinal bundle
Medial longitudinal bundle, fasciculus longitudinalis medialis
is a combination of descending and ascending
fibers that carry out coordinated movements of the eye
block and head. This function is necessary to maintain equilibrium
this body. The execution of this function becomes possible only
as a result of the morphofunctional connection between the nerve centers
ramie, providing innervation of the muscles of the eyeball (motor
body nuclei III, IV and VI pairs of cranial nerves), centers,
responsible for the innervation of the muscles of the neck (the motor nucleus of the XI pair
and motor nuclei of the anterior horns of the cervical segments of the spinal
brain), the center of balance (the nucleus of Deiters). The work of these centers is coordinated by neurons of large nuclei of the reticular formation -
intermediate nucleus, nucleus interstitialis (Kahal's nucleus), - and the nucleus of the posterior commissure, nucleus commissuraeposterior (Darkshevich's nucleus).
Intermediate nucleus and nucleus of the posterior commissure of the brain are located
and the rostral midbrain, in its central gray matter. The axons of the neurons of these nuclei form a medial longitudinal bundle that passes under the central gray matter.
near the midline. Without changing its position, it continues in the dorsal part of the bridge and deviates ventrally in the medulla oblongata. In the spinal cord, it is located in
anterior funiculus, in the angle between the medial surface of the anterior
horns and front white commissure. The medial longitudinal fasciculus is traced only at the level of the upper six cervical segments.
Within the midbrain to the medial longitudinal fasciculus
fibers come from the posterior longitudinal bundle, which unites
reproductive centers. This connection between the medial and posterior longitudinal bundles explains the resulting autonomic reactions.
with vestibular stress. From the medial longitudinal bundle, fibers are directed to the motor nucleus of the oculomotor nerve.
This nucleus has five segments, each of which is responsible for the innervation of certain muscles: neurons of the upper segment
(1st) innervate the muscle that lifts the upper eyelid; 2nd - rectus eye muscle; 3rd - the lower oblique muscle of the eye; 4th - lower rectus muscle of the eye; 5th - medial rectus muscle of the eye.
The neurons of the 1st, 2nd and 4th segments receive fibers from the medial longitudinal bundle of their side, the neurons of the 3rd segment from the opposite side. The neurons of the 5th segment are also closed on
the central unpaired nucleus (convergence) and are connected with the medial longitudinal bundle of its side. They provide the possibility of movement of the eyeball to the medial side and the simultaneous convergence of the eyeballs (convergence).
Further, within the midbrain, from the composition of the medial longitudinal bundle, fibers are sent to the neurons of the motor nucleus of the trochlear nerve of the opposite side. This nucleus is responsible for the innervation of the superior oblique muscle of the eyeball.
In the bridge, the axons of the cells of the nucleus of Deiters enter into the composition of the medial longitudinal bundle (VIII pair - the vestibulocochlear nerve),
which go in an upward direction to the neurons of the intermediate
kernels. From the medial longitudinal bundle fibers depart to neurons
motor nucleus of the abducens nerve (VI pair), which is responsible for the innervation of the lateral rectus muscle of the eyeball. And finally
within the medulla oblongata and spinal cord from the medial longitudinal bundle, the fibers are directed to the neurons of the motor nucleus
accessory nerve (XI pair) and motor nuclei of the anterior horns
six upper cervical segments responsible for the work of the neck muscles.
In addition to the general coordination of the work of the muscles of the eyeball and head, the medial longitudinal bundle performs an important integrative function.
role in the activity of the muscles of the eye. Communicating with the cells of the nucleus
oculomotor and abducens nerves, it ensures the coordinated function of the external and internal rectus muscles of the eye, manifested in the combined turn of the eyes to the side. In this case, there is a simultaneous contraction of the external rectus muscle of one eye and the internal rectus muscle of the other eye.
With damage to the intermediate nucleus or the medial longitudinal bundle, there is a violation of the coordinated work of the muscles of the eyeball. Most often, this manifests itself in the form of nystagmus (frequent contractions of the muscles of the eyeball, directed in the direction of movement, when the gaze stops). Nystagmus can be horizontal, vertical, and even rotatory (rotational). Often these disorders are supplemented by vestibular disorders (dizziness) and autonomic disorders (nausea, vomiting, etc.).
Posterior longitudinal beam
The posterior longitudinal bundle, fasciculus longitudinalis dorsalis, is a collection of descending and ascending fibers that make connections between the autonomic centers of the brain stem and spinal cord. The posterior longitudinal bundle (Schütz's bundle) originates from the cells of the posterior nuclei of the hypothalamus. The axons of these cells unite into a bundle only at the border of the diencephalon and midbrain. Further, it passes in close proximity to the aqueduct of the midbrain. Already in the midbrain, part of the fibers of the posterior longitudinal bundle goes to the accessory nucleus of the oculomotor nerve. In the region of the bridge, fibers depart from it to the lacrimal and
to the inferior salivary nuclei of the facial nerve. In the medulla oblongata, fibers branch off to the lower salivary
nucleus of the glossopharyngeal nerve and dorsal nucleus of the vagus nerve.
In the spinal cord, the posterior longitudinal bundle is located in the form of a narrow ribbon in the lateral funiculus, next to the lateral cortical-spinal tract. The fibers of the Schutz bundle end in segments on the neurons of the lateral intermediate nucleus, which are the autonomic sympathetic centers of the spinal cord. Only a small part of the fibers of the dorsal longitudinal bundle separates at the level of the lumbar segments and is located near the central canal. This bundle is called near-ependymal. The fibers of this bundle end on the neurons of the sacral parasympathetic nuclei. The axons of the cells of the parasympathetic and sympathetic nuclei leave the brainstem or spinal cord as part of the cranial or spinal nerves and go to the internal organs, vessels and glands. So the rear
longitudinal bundle plays a very important integrative role in the regulation
of the vital functions of the organism.
News about the cerebrospinal tract
- Professor V.A. Parfenov MMA named after I.M. Sechenova T.T. Batysheva Rehabilitation Clinic No. 7, Moscow Back pain, or dorsalgia, can be a symptom of various diseases. Back pain is one of the most common complaints in general medical practice. Main reasons b
- Yu. A. Zozulya, Yu. A. Orlov Institute of Neurosurgery. AP Romodanova Academy of Medical Sciences of Ukraine, Kyiv Congenital malformations are one of the main causes of infant mortality and disability. Almost 400,000 children were born in Ukraine in 2001, of which 48,000 had deformities. Significant places
Discussion
- Dear... My daughter Katya was born with a tumor on her back in the thoracic spine, on the right. The nature of the tumor, subcutaneous size 3 x 4 x 0.7 as a small pillow and liquid consistency, body color. When Katya cried, the tumor tightened up; in a calm state, the tumor was compared with the surface with
tectospinal path) projection descending nerve path, starting in the upper mounds of the roof of the midbrain, passing through and anterior, ending in its anterior horns.
1. Small medical encyclopedia. - M.: Medical Encyclopedia. 1991-96 2. First aid. - M.: Great Russian Encyclopedia. 1994 3. Encyclopedic dictionary of medical terms. - M.: Soviet Encyclopedia. - 1982-1984.
See what the "Tube-spinal tract" is in other dictionaries:
- (tractus tectospinalis, PNA, BNA, JNA; syn. tectospinal path) projection descending nerve path, starting in the upper mounds of the roof of the midbrain, passing through the brainstem and anterior cord of the spinal cord, ending in its ... ... Big Medical Dictionary
Big Medical Dictionary
- (tractus tectospinalis; anat. tectum mesencephali the roof of the midbrain) see Tire spinal tract ... Medical Encyclopedia
- (medulla spinalis) part of the central nervous system located in the spinal canal. S. m has the appearance of a strand of white color, somewhat flattened from front to back in the area of thickenings and almost round in other departments. In the spinal canal ... ... Medical Encyclopedia
Spinal cord- (medulla spinalis) (Fig. 254, 258, 260, 275) is a strand of brain tissue located in the spinal canal. Its length in an adult reaches 41 45 cm, and its width is 1 1.5 cm. The upper section of the spinal cord smoothly passes into ... ... Atlas of human anatomy
Pathways of the nervous system- Conscious sensory pathways are conductors that conduct nerve impulses to the cerebral cortex. Depending on the localization of the receptors, which determines the nature of the impulses, the pathways are divided into ... ... Atlas of human anatomy
Diagram of the arrangement of pathways in the white matter and nuclei in the gray matter on a cross section of the spinal cord- thin and wedge-shaped bundles; thin and wedge-shaped bundles; own (rear) beam; posterior spinal cerebellar pathway; lateral pyramidal (cortical spinal) path; own bundle (lateral); red nuclear spinal tract; ... ... Atlas of human anatomy
The central nervous system (tractus sistematis nervosi centralis) is a group of nerve fibers that are characterized by a common structure and functions and connect various parts of the brain and spinal cord. All nerve fibers of one path start from ... Medical Encyclopedia
- (ki) (fasciculus, i, PNA, BNA, JNA) in anatomy, a collection of fibers (nerve, connective tissue or muscle), anatomically and functionally combined. Arnold's bundle, see Fronto bridge path. Atrioventricular bundle (f. atrioventricularis ... Medical Encyclopedia
Brain: Mesencephalon Latin name Mesencephalon Mesencephalon ... Wikipedia
