THE LYMPHATIC SYSTEM consists (1) of advanced capillary networks which gather the lymph within the varied organs and tissues; (2) of an elaborate system of gathering vessels which conduct the lymph from the capillaries to the massive veins of the neck on the junction of the inner jugular and subclavian veins, the place the lymph is poured into the blood stream; and (3) lymph nodes or nodes that are interspaced within the pathways of the gathering vessels filtering the lymph because it passes by them and contributing lymphocytes to it. The lymphatic capillaries and gathering vessels are lined all through by a steady layer of endothelial cells, forming thus a closed system. The lymphatic vessels of the small gut obtain the particular designation of lacteals or chyliferous vessels; they differ in no respect from the lymphatic vessels usually excepting that through the strategy of digestion they comprise a milk-white fluid, the chyle.

The Improvement of the Lymphatic Vessels.—The lymphatic system begins as a collection of sacs on the factors of junction of sure of the embryonic veins. These lymph-sacs are developed by the confluence of quite a few venous capillaries, which at first lose their connections with the venous system, however subsequently, on the formation of the sacs, regain them. The lymphatic system is due to this fact developmentally an offshoot of the venous system, and the liner partitions of its vessels are at all times endothelial.

  Within the human embryo the lymph sacs from which the lymphatic vessels are derived are six in quantity; two paired, the jugular and the posterior lymph-sacs; and two unpaired, the retroperitoneal and the cisterna chyli. In decrease mammals a further pair, subclavian, is current, however within the human embryo these are merely extensions of the jugular sacs.

  The place of the sacs is as follows: (1) jugular sac, the primary to seem, on the junction of the subclavian vein with the primitive jugular; (2) posterior sac, on the junction of the iliac vein with the cardinal; (3) retroperitoneal, within the root of the mesentery close to the suprarenal nodes; (4) cisterna chyli, reverse the third and fourth lumbar vertebrae. From the lymph-sacs the lymphatic vessels bud out alongside mounted traces corresponding roughly intently to the course of the embryonic bloodvessels. Each within the body-wall and within the wall of the gut, the deeper plexuses are the primary to be developed; by continued progress of those the vessels within the superficial layers are steadily fashioned. The thoracic duct might be fashioned from anastomosing outgrowths from the jugular sac and cisterna chyli. At its reference to the cisterna chyli it’s at first double, however the two vessels quickly be part of.

  All of the lymph-sacs besides the cisterna chyli are, at a later stage, divided up by slender connective tissue bridges and remodeled into teams of lymph nodes. The decrease portion of the cisterna chyli is equally transformed, however its higher portion stays because the grownup cisterna.

Lymphatic Capillaries.—The advanced capillary plexuses which include a single layer of skinny flat endothelial cells lie within the connective-tissue areas within the varied areas of the physique to which they’re distributed and are bathed by the intercellular tissue fluids. Two views are at current held as to the mode through which the lymph is fashioned: one being by the bodily processes of filtration, diffusion, and osmosis, and the opposite, that along with these bodily processes the endothelial cells have an lively secretory perform. The colorless liquid lymph has about the identical composition because the blood plasma. It comprises many lymphocytes and ceaselessly crimson blood corpuscles. Granules and micro organism are additionally taken up by the lymph from the connective-tissue areas, partly by the motion of lymphocytes which go into the lymph between the endothelial cells and partly by the direct passage of the granules by the endothelial cells.

  The lymphatic capillary plexuses range vastly in kind; the anastomoses are normally quite a few; blind ends or cul-de-sacs are particularly widespread within the intestinal villi, the dermal papillae and the filiform papillae of the tongue. The plexuses are sometimes in two layers: a superficial and a deep, the superficial being of smaller caliber than the deep. The caliber, nonetheless, varies vastly in a given plexus from a couple of micromillimeters to 1 millimeter. The capillaries are with out valves.

Distribution.—The Pores and skin.—Lymphatic capillaries are considerable within the dermis the place they kind superficial and deep plexuses, the previous sending blind ends into the dermal papillae. The plexuses are particularly wealthy over the palmar floor of the fingers and fingers and over the plantar floor of the toes and toes. The dermis is with out capillaries. The conjunctiva has an particularly wealthy plexus.

  The subcutaneous tissue is with out capillaries.

  The tendons of striated muscle and muscle sheaths are richly provided. In muscle, nonetheless, their existence remains to be disputed.

  The periosteum of bone is richly provided they usually have been described within the Haversian canals. They’re absent in cartilage and possibly in bone marrow.

  The joint capsules are richly provided with lymphatic capillaries, they don’t, nonetheless, open into the joint cavities.

  Beneath the mesothelium lining of the pleural, peritoneal and pericardial cavities are wealthy plexuses; they don’t open into these cavities.

  The alimentary canal is provided with wealthy plexuses beneath the epithelium, usually as a superficial plexus within the mucosa and a deeper submucosal plexus. Cul-de-sacs prolong into the filiform papillae of the tongue and the villi of the small gut. These parts of the alimentary canal lined by peritoneum, have as well as a subserous lymphatic capillary plexus beneath the mesothelium.

  The salivary nodes are provided with lymphatic capillaries.

  The liver has a wealthy subserous plexus within the capsule and in addition intensive plexuses which accompany the hepatic artery and portal vein. The lymphatic capillaries haven’t been adopted into the liver lobules. The lymph from the liver kinds a big a part of that which flows by the thoracic duct. The gall-bladder and bile ducts have wealthy subepithelial plexuses and the previous a subserous plexus.

  The spleen has a wealthy subserous set and a capsular set of lymphatic capillaries. Their presence within the parenchyma is unsure.

  The nasal cavity has intensive capillary plexuses within the mucosa and submucosa.

  The trachea and bronchi have plexuses within the mucosa and submucosa however the smaller bronchi have solely a single layer. The capillaries don’t prolong to the air-cells. The plexuses across the smaller bronchi join with the wealthy subserous plexus of the lungs in locations the place the veins attain the floor.

  Lymphatics have been described within the thyroid node and within the thymus.

  The adrenal has a superficial plexus divided into two layers, one within the unfastened tissue in regards to the node and the opposite beneath the capsule. Capillaries have additionally been described inside the parenchyma.

  The kidney is provided with a rough subserous plexus and a deeper plexus of finer capillaries within the capsule. Lymphatics have been described inside the substance of the kidney surrounding the tubules.

  The urinary bladder has a wealthy plexus of lymphatic capillaries simply beneath the epithelial lining, additionally a subserous set which anastomoses with the previous by the muscle layer. The submucous plexus is steady with the submucous plexus of the urethra.

  The prostate has a wealthy lymphatic plexus surrounding the node and a wide-meshed subcapsular plexus.

  The testis has a wealthy superficial plexus beneath the tunica albuginea. The presence of deep lymphatics is disputed.

  The uterus is supplied with a subserous plexus, the deeper lymphatics are unsure. Subepithelial plexuses are discovered within the vagina.

  The ovary has a wealthy superficial plexus and a deep interstitial plexus.

  The coronary heart has a wealthy subserous plexus beneath the epicardium. Lymphatic capillaries have additionally been described beneath the endocardium and all through the muscle.

  Lymphatic capillaries are in all probability absent within the central nervous system, the meninges, the eyeball (besides the conjunctiva), the orbit, the inner ear, inside striated muscle, the liver lobule, the spleen pulp and kidney parenchyma. They’re fully absent in cartilage. In lots of locations additional investigation is required.

Lymphatic Vessels.—The lymphatic vessels are exceedingly delicate, and their coats are so clear that the fluid they comprise is instantly seen by them. They’re interrupted at intervals by constrictions, which give them a knotted or beaded look; these constrictions correspond to the conditions of valves of their inside. Lymphatic vessels have been present in practically each texture and organ of the physique which comprises bloodvessels. Such non-vascular constructions as cartilage, the nails, cuticle, and hair have none, however with these exceptions it’s possible that finally all elements might be discovered to be permeated by these vessels.

Construction of Lymphatic Vessels.—The bigger lymphatic vessels are every composed of three coats. The inside coat is skinny, clear, barely elastic, and consists of a layer of elongated endothelial cells with wavy margins by which the contiguous cells are dovetailed into each other; the cells are supported on an elastic membrane. The center coat consists of clean muscular and wonderful elastic fibers, disposed in a transverse course. The exterior coat consists of connective tissue, intermixed with clean muscular fibers longitudinally or obliquely disposed; it kinds a protecting masking to the opposite coats, and serves to attach the vessel with the neighboring constructions. Within the smaller vessels there are not any muscular or elastic fibers, and the wall consists solely of a connective-tissue coat, lined by endothelium. The thoracic duct has a extra advanced construction than the opposite lymphatic vessels; it presents a definite subendothelial layer of branched corpuscles, just like that discovered within the arteries; within the center coat there’s, along with the muscular and elastic fibers, a layer of connective tissue with its fibers organized longitudinally. The lymphatic vessels are provided by nutrient vessels, that are distributed to their outer and center coats; and right here even have been traced many non-medullated nerves within the type of a wonderful plexus of fibrils.

  The valves of the lymphatic vessels are fashioned of skinny layers of fibrous tissue lined on each surfaces by endothelium which presents the identical association as on the valves of veins. In kind the valves are semilunar; they’re hooked up by their convex edges to the wall of the vessel, the concave edges being free and directed alongside the course of the contained present. Normally two such valves, of equal measurement, are discovered reverse each other; however sometimes exceptions happen, particularly at or close to the anastomoses of lymphatic vessels. Thus, one valve could also be of small measurement and the opposite elevated in proportion.

  Within the lymphatic vessels the valves are positioned at a lot shorter intervals than within the veins. They’re most quite a few close to the lymph nodes, and are discovered extra ceaselessly within the lymphatic vessels of the neck and higher extremity than in these of the decrease extremity. The wall of the lymphatic vessel instantly above the purpose of attachment of every section of a valve is expanded right into a pouch or sinus which supplies to those vessels, when distended, the knotted or beaded look already referred to. Valves are wanting within the vessels composing the plexiform net-work through which the lymphatic vessels normally originate on the floor of the physique.

Lymph Nodes (lymphonodeulae).—The lymph nodes are small oval or bean-shaped our bodies, located in the middle of lymphatic and lacteal vessels in order that the lymph and chyle go by them on their solution to the blood. Every usually presents on one facet a slight despair—the hilus—by which the bloodvessels enter and depart the inside. The efferent lymphatic vessel additionally emerges from the node at this spot, whereas the afferent vessels enter the organ at completely different elements of the periphery. On part a lymph node shows two completely different constructions: an exterior, of lighter colour—the cortical; and an inside, darker—the medullary. The cortical construction doesn’t kind an entire funding, however is poor on the hilus, the place the medullary portion reaches the floor of the node; in order that the efferent vessel is derived straight from the medullary constructions, whereas the afferent vessels empty themselves into the cortical substance.

Construction of Lymph Nodes.—A lymph Node consists of (1) a fibrous envelope, or capsule, from which a frame-work of processes (trabeculae) proceeds inward, imperfectly dividing the Node into open areas freely speaking with one another; (2) a amount of lymphoid tissue occupying these areas with out utterly filling them; (3) a free provide of bloodvessels, that are supported within the trabeculae; and (4) the afferent and efferent vessels speaking by the lymph paths within the substance of the node. The nerves passing into the hilus are few in quantity and are mainly distributed to the bloodvessels supplying the node.

  The capsule consists of connective tissue with some plain muscle fibers, and from its inside floor are given off a lot of membranous processes or trabeculae, consisting, in man, of connective tissue, with a small admixture of plain muscle fibers; however in lots of the decrease animals composed virtually fully of involuntary muscle. They go inward, radiating towards the middle of the node, for a sure distance—that’s to say, for about one-third or one-fourth of the house between the circumference and the middle of the node. In some animals they’re sufficiently well-marked to divide the peripheral or cortical portion of the node into a lot of compartments (so-called follicles), however in man this association isn’t apparent. The bigger trabeculae springing from the capsule break up into finer bands, and these interlace to kind a mesh-work within the central or medullary portion of the node. In these areas fashioned by the interlacing trabeculae is contained the right node substance or lymphoid tissue. The node pulp doesn’t, nonetheless, utterly fill the areas, however leaves, between its outer margin and the enclosing trabeculae, a channel or house of uniform width all through. That is termed the lymph path or lymph sinus. Working throughout it are a lot of finer trabeculae of retiform connective tissue, the fibers of that are, for essentially the most half, lined by ramifying cells.

  On account of the peculiar association of the frame-work of the organ, the node pulp within the cortical portion is disposed within the type of nodules, and within the medullary half within the type of rounded cords. It consists of unusual lymphoid tissue, being made up of a fragile net-work of retiform tissue, which is steady with that within the lymph paths, however marked off from it by a better reticulation; it’s possible, furthermore, that the reticular tissue of the node pulp and the lymph paths is steady with that of the trabeculae, and in the end with that of the capsule of the node. In its meshes, within the nodules and cords of lymphoid tissue, are intently packed lymph corpuscles. The node pulp is traversed by a dense plexus of capillary bloodvessels. The nodules or follicles within the cortical portion of the node ceaselessly present, of their facilities, areas the place karyokinetic figures point out a division of the lymph corpuscles. These areas are termed germ facilities. The cells composing them have extra considerable protoplasm than the peripheral cells.

  The afferent vessels, as said above, enter in any respect elements of the periphery of the node, and after branching and forming a dense plexus within the substance of the capsule, open into the lymph sinuses of the cortical half. In doing this they lose all their coats besides their endothelial lining, which is steady with a layer of comparable cells lining the lymph paths. In like method the efferent vessel commences from the lymph sinuses of the medullary portion. The stream of lymph carried to the node by the afferent vessels thus passes by the plexus within the capsule to the lymph paths of the cortical portion, the place it’s uncovered to the motion of the node pulp; flowing by these it enters the paths or sinuses of the medullary portion, and eventually emerges from the hilus by way of the efferent vessel. The stream of lymph in its passage by the lymph sinuses is far retarded by the presence of the reticulum, therefore morphological parts, both regular or morbid, are simply arrested and deposited within the sinuses. Many lymph corpuscles go with the efferent lymph stream to affix the overall blood stream. The arteries of the node enter on the hilus, and both go directly to the node pulp, to interrupt up right into a capillary plexus, or else run alongside the trabeculae, partly to provide them and partly working throughout the lymph paths, to help in forming the capillary plexus of the node pulp. This plexus traverses the lymphoid tissue, however doesn’t enter into the lymph sinuses. From it the veins begin and emerge from the organ on the similar place as that at which the arteries enter.

  The lymphatic vessels are organized right into a superficial and a deep set. On the floor of the physique the superficial lymphatic vessels are positioned instantly beneath the integument, accompanying the superficial veins; they be part of the deep lymphatic vessels in sure conditions by perforating the deep fascia. Within the inside of the physique they lie within the submucous areolar tissue, all through the entire size of the digestive, respiratory, and genito-urinary tracts; and within the subserous tissue of the thoracic and stomach partitions. Plexiform networks of minute lymphatic vessels are discovered interspersed among the many correct parts and bloodvessels of the a number of tissues; the vessels composing the net-work, in addition to the meshes between them, are a lot bigger than these of the capillary plexus. From these net-works small vessels emerge, which go, both to a neighboring node, or to affix some bigger lymphatic trunk. The deep lymphatic vessels, fewer in quantity, however bigger than the superficial, accompany the deep bloodvessels. Their mode of origin might be just like that of the superficial vessels. The lymphatic vessels of any half or organ exceed the veins in quantity, however in measurement they’re much smaller. Their anastomoses additionally, particularly these of the massive trunks, are extra frequent, and are effected by vessels equal in diameter to these which they join, the continual trunks retaining the identical diameter.

  Hemolymph nodes or nodes and hemal nodes that are so considerable in some mammals are in all probability not current in man.

Lymph.—Lymph, discovered solely within the closed lymphatic vessels, is a clear, colorless, or barely yellow, watery fluid of particular gravity about 1.015; it intently resembles the blood plasma, however is extra dilute. When it’s examined underneath the microscope, leucocytes of the lymphocyte class are discovered floating within the clear fluid; they’re at all times elevated in quantity after the passage of the lymph by lymphoid tissue, as in lymph nodes. Lymph must be distinguished from “tissue fluid” which is discovered exterior the lymphatic vessels within the tissue areas.

The Thoractic Duct

The thoracic duct (ductus thoracicus) conveys the larger a part of the lymph and chyle into the blood. It’s the widespread trunk of all of the lymphatic vessels of the physique, excepting these on the proper facet of the pinnacle, neck, and thorax, and proper higher extremity, the proper lung, proper facet of the guts, and the convex floor of the liver. Within the grownup it varies in size from 38 to 45 cm. and extends from the second lumbar vertebra to the basis of the neck. It begins within the stomach by a triangular dilatation, the cisterna chyli, which is located on the entrance of the physique of the second lumbar vertebra, to the proper facet of and behind the aorta, by the facet of the proper crus of the diaphragm. It enters the thorax by the aortic hiatus of the diaphragm, and ascends by the posterior mediastinal cavity between the aorta and azygos vein. Behind it on this area are the vertebral column, the proper intercostal arteries, and the hemiazygos veins as they cross to open into the azygos vein; in entrance of it are the diaphragm, esophagus, and pericardium, the final being separated from it by a recess of the proper pleural cavity. Reverse the fifth thoracic vertebra, it inclines towards the left facet, enters the superior mediastinal cavity, and ascends behind the aortic arch and the thoracic a part of the left subclavian artery and between the left facet of the esophagus and the left pleura, to the higher orifice of the thorax. Passing into the neck it kinds an arch which rises about 3 or 4 cm. above the clavicle and crosses anterior to the subclavian artery, the vertebral artery and vein, and the thyrocervical trunk or its branches. It additionally passes in entrance of the phrenic nerve and the medial border of the Scalenus anterior, however is separated from these two constructions by the prevertebral fascia. In entrance of it are the left widespread carotid artery, vagus nerve, and inside jugular vein; it ends by opening into the angle of junction of the left subclavian vein with the left inside jugular vein. The thoracic duct, at its graduation, is about equal in diameter to a goose-quill, nevertheless it diminishes significantly in caliber in the midst of the thorax, and is once more dilated simply earlier than its termination. It’s usually flexuous, and constricted at intervals in order to current a varicose look. Not occasionally it divides in the midst of its course into two vessels of unequal measurement which quickly reunite, or into a number of branches which kind a plexiform interlacement. It sometimes divides at its higher half into two branches, proper and left; the left ending within the ordinary method, whereas the proper opens into the proper subclavian vein, in reference to the proper lymphatic duct. The thoracic duct has a number of valves; at its termination it is supplied with a pair, the free borders of that are turned towards the vein, in order to stop the passage of venous blood into the duct.

  The cisterna chyli (receptaculum chyli) receives the 2 lumbar lymphatic trunks, proper and left, and the intestinal lymphatic trunk. The lumbar trunks are fashioned by the union of the efferent vessels from the lateral aortic lymph nodes. They obtain the lymph from the decrease limbs, from the partitions and viscera of the pelvis, from the kidneys and suprarenal nodes and the deep lymphatics of the larger a part of the stomach wall. The intestinal trunk receives the lymph from the abdomen and gut, from the pancreas and spleen, and from the decrease and entrance a part of the liver.

Tributaries.—Opening into the graduation of the thoracic duct, on both facet, is a descending trunk from the posterior intercostal lymph nodes of the decrease six or seven intercostal areas. Within the thorax the duct is joined, on both facet, by a trunk which drains the higher lumbar lymph nodes and pierces the crus of the diaphragm. It additionally receives the efferents from the posterior mediastinal lymph nodes and from the posterior intercostal lymph nodes of the higher six left areas. Within the neck it’s joined by the left jugular and left subclavian trunks, and generally by the left bronchomediastinal trunk; the last-named, nonetheless, normally opens independently into the junction of the left subclavian and inside jugular veins.

  The proper lymphatic duct (ductus lymphaticus dexter), about 1.25 cm. in size, programs alongside the medial border of the Scalenus anterior on the root of the neck and ends in the proper subclavian vein, at its angle of junction with the proper inside jugular vein. Its orifice is guarded by two semilunar valves, which forestall the passage of venous blood into the duct.

Tributaries.—The best lymphatic duct receives the lymph from the proper facet of the pinnacle and neck by the proper jugular trunk; from the proper higher extremity by the proper subclavian trunk; from the proper facet of the thorax, proper lung, proper facet of the guts, and a part of the convex floor of the liver, by the proper bronchomediastinal trunk. These three gathering trunks ceaselessly open individually within the angle of union of the 2 veins.

Lymphatic vessels and regional lymphatic nodes

The Lymphatics of the Decrease Extremity

The superficial and deep vessels are distinguished in decrease limb. The superficial vessels are located over superficial fascia and deep vessels positioned intently to deep blood vessels. Popliteal nodes and inguinal nodes are distinguished in decrease limb. Final one subdivide into deep inguinal nodes and superficial inguinal nodes. Superficial inguinal nodes dispose alongside inguinal ligament and lie on superficial sheet of fascia lata femoris. Their efferent vessels go to exterior iliac nodes, which accompany similar title artery.

The superficial vessels of decrease limb fashioned from capillary pores and skin networks and subcutaneous mobile tissue and kind medial, lateral and posterior vessel teams.

Medial group of superficial vessels fashioned in pores and skin of I, II and III fingers, medial a part of foot and medial floor of shin. These vessels run alongside vena saphena magna and empty into superficial inguinal nodes.

Lateral group of superficial vessels of decrease limb fashioned laterally in space of fingers in dorsal foot floor and lateral floor of shin. These vessels beneath knee be part of to medial group.

Posterior group of superficial vessels of decrease limb begins in pores and skin of heel and plantar floor of lateral foot margin, passes alongside the vena saphaena parva and runs into popliteal lymphatic nodes.

Deep vessels of decrease limb drainage muscle tissue, joints, synovial sheaths, bones, nerves, accompany deep arteries and veins and empty into deep inguinal nodes.

The Lymphatics of the Pelvis

In pelvic space differ the visceral and parietal lymphatic nodes.

The visceral lymphatic nodes dispose close to pelvic organs and they’re: paravesical, prevesical and retrovesical nodes, lateral vesical nodes, parauterine nodes, paravaginal nodes and pararectal or anоrectal nodes. The efferent vessels from these nodes go into iliac nodes, primarily to widespread iliac nodes and to retroaortic nodes. Lymph flows from ovaries into lumbar nodes.

The parietal lymphatic nodes disposed alongside the course of huge vessels widespread iliac nodes; inside iliac nodes, which unite gluteal and sacral nodes. Exterior iliac nodes be part of obturator nodes. The efferent vessels from these nodes go first into widespread iliac nodes, then into retroaortic nodes, and from them – into lumbar lymphatic nodes.

The Lymphatics of the Stomach

In stomach cavity, as and in pelvis, lymphatic nodes could also be divided into two units, parietal and visceral.

The Visceral lymphatic nodes dispose alongside the course of huge vessels come away from stomach aorta, they obtain lymph from all inside stomach organs: coeliac nodes, proper/left gastric nodes, lymphatic unnulus of cardia, proper/left gastroepiploic nodes, pyloric nodes, pancreatic nodes, splenic nodes, pancreatoduodenal nodes, hepatic nodes, superior mesenteric nodes and inferior mesenteric nodes. The lymphatic vessels of the small gut obtain the particular designation of lacteals or chyliferous vessels; they differ in no respect from the lymphatic vessels usually excepting that through the strategy of digestion they comprise a milk-white fluid, the chyle.The lymphatic vessels and nodes of the small gut positioned in mesentery and empty into intestinal trunk. The vessels take away lymph from these nodes, go to lumbar nodes. Efferent vessels of final kind the lumbar trunks, which flowing collectively kind a thoracic duct.

The parietal lymphatic nodes disposed round aortae and inferior vene cava  – proper/left and intermidiate lumbar nodes, lateral aortic nodes, preaortic nodes, retroaortic nodes, lateral caval nodes, precaval nodes, retrocaval nodes, inferior phrenic nodesand inferior epigastric nodes.

Lymphatic vessels of superior half of stomach wall go upward to the axillar lymphatic nodes. The vessels of inferior half of stomach wall go downward to inguinal lymphatic nodes.

The Lymphatic Vessels of the Thorax

Lymphatic nodes of the thorax could also be divided into two units, parietal and visceral.There distinguish the next parietal nodes of thorax:

1. Parasternal nodes gather lymph from pericardium, pleura, anterior thoracic wall, diaphragmatic floor of liver, mammary gland. The vessels from these nodes carry lymph into proper and left venous angles.
2. Intercostal nodes empty lymph into thoracic duct, and from superior nodes – into deep lateral jugular lymphatic nodes.
3. Superior phrenic nodes carry lymph into parasternal nodes, nodes inferior tracheobronchic and into bronchоpulmonary nodes.
4. Prepericardial nodes transport lymph into parasternal nodes, nodes inferior tracheobronchic and into bronchоpulmonary nodes.
5. Prevertebral nodes are disposed between spine and esophagus.
6. Paramammary nodes are disposed laterally from breasts and drain them.

The visceral lymph nodes embrace the next teams:

1. paraesophageal nodes
2. paratracheal nodes
3. tracheobronchic nodes
4. bronchоpulmonary nodes

All foregoing visceral nodes of thorax in accordance outdated anatomic nomenclature, belong to anterior and, particularly, posterior mediastinal lymphatic nodes (nodi lymphatici mediastinales anteriores et posteriores). Left half of thoracic cavity is drained to thoracic duct, proper half – into proper lymphatic duct.

The Lymphatics of the Head, Face, and Neck

Lymph from head and neck gathers into proper and left jugular lymphatic trunks, which go on all sides close to inside jugular vein and fall: proper – into proper lymphatic duct or into proper venous angle and left – into thoracic duct or instantly into left venous angle. Earlier than duct lymph passes by regional lymphatic nodes.

Lymph from head runs into nodes positioned on boundary between head and neck. They embrace the next: 1) occipital nodes, 2) mastoid nodes, 3) superficial parotid nodes, 4) deep parotid nodes, 5) submandibular nodes, 6) facial nodes, 7) submental. Efferent vessels from these nodes prolong in deep cervical nodes.

There are two teams of lymphatic nodes on neck – anterior cervical nodes and lateral cervical nodes, which subdivide into superficial and deep. Anterior deep lymphatic nodes: prelaryngeal nodes, thyroid nodes, pretracheal nodes, paratracheal nodes. The superficial lateral nodes lie alongside exterior jugular vein, and deep – alongside inside jugular vein.

The Lymphatics of the Higher Extremity

Lymphatic nodes of higher limb could also be divided into two units, superficial and deep.

The superficial vessels and nodes of higher limb go alongside the course of vena basilica and vena cephalica and compose lateral, medial and center teams. Lateral group of superficial vessels carries lymph from pores and skin of I-ІІІ fingers, lateral forearm floor and arm to axillar lymphatic nodes. Medial group of superficial vessels carries lymph from IV-V fingers, hand, medial forearm facet and brachium to cubital and axillar lymphatic nodes. Center group carries lymph from palmar forearm floor to cubital fossa and right here a part of vessels joins to lateral grand, and half to medial group. The superficial lymphatic nodes accompany the superficial hand veins. They gather lymph from pores and skin and subcutaneous tissue. From them lymph passes to cubital nodes and axillar nodes.

Deep vessels and nodes of higher limb accompany the deep huge vessels and carry lymph into deep nodes and superficial nodes, and from right here – into cubital nodes and axillar lymphatic nodes. Axillar nodes obtain the vessels from higher limb, thoracic wall, and mammary gland. The efferent vessels from axillar nodes kind a subclavian trunk (left and proper).

Lymphatic annulus of pharynx belongs to secondary lymphatic organs and consists of lingual tonsil, palatine tonsil, pharyngeal tonsil and tubarius tonsil. They’ve tonsillar cryptae and tonsillar fossulae and lymphatic nodules. These tonsils are described partly “pharynx”. Tonsils are agglomerations of lymphoid tissue, which is disposed in space of entrance to pharynx and nasopharynx. They’re positioned round preliminary parts of excessive respiratory and digestive paths (lymphoepithelial ring of Pyrohov-Valdeyer).

The Lymphatic follicles of gastrointestinal tract are agglomeration lymphoid tissue in mucous membrane of the abdomen (the gastric lymphatic follicles), small gut (solitary lymphatic follicles and mixture lymphatic follicles – Payer patches), giant gut (solitary lymphatic follicles and mixture lymphatic follicles of vermiform processes). The most important quantity of Payer patches is located in distal portion of iliac bowel. Т-lymphocytes migrate freely from lymphatic follicles by epithelium of mucous membrane into intestinal shaft of sunshine.

The SPLEEN belongs to secondary lymphatic organs and is a giant lymphatic node. Spleen is disposed in left hypochondriac on the extent of Sept. 11 ribs. Spleen has inferior margin and superior margin, anterior extremity and posterior extremity. It has a diaphragmatic floor (superior) and visceral floor (inferior). To the final adjoin abdomen (facies gastrica), left kidney with suprarenal gland (facies renalis), left colic flexure (facies colica) and tail of pancreas (facies pancreatica). Place on visceral floor, the place vessels and nerves enter and depart, is known as as splenic hilus. Spleen is roofed by peritoneum from all sides (lies intraperitoneally).

Spleen is roofed by fibrous capsule, from which quite a few small fibrous bands, trabeculæ are given off in all instructions into parenchyma, these uniting, and represent the framework of the spleen. Parenchyma consists of splenic pulp, which has a white pulp and crimson pulp and its construction described intimately in histology course.

ORGANS of IMMUNE SYSTEM and HAEMOPOESIS

Immune system unites organs and tissues, which give protection from genetically overseas cells or issues, that acquired from out or are generated contained in the organism, offering fidelity of inside organism setting. Organs of immune system could also be divided into central and peripheral half.

To central organs of immune system belong thymus gland and crimson marrow.

To peripheral organs of immune system unite organs are usually not enveloped in capsule (tonsils, lymphoid follicles, which might be located in partitions of hole organs of digestive and respiratory techniques and lymphocytes, that are located in blood, lymph, connective and epithelial tissue) and capsulated organs (lymphatic nodes and spleen).

Thymus is positioned in entrance a part of superior mediastinum and consists of lobes, extra frequent two. Outdoors this gland is tunicate by fibrous capsule that provides off septa, which cut up up lobes on lobules. They comprise reticular cells with lymphocytes between them (known as as ‘thymocytes’). The lobules of gland have a cortex and medulla thymi. May be equipment lobules of thymus. Fundamental perform of thymus maturation and supporting of effector cells (killer) and regulatory cells (helper and supressor) Т-lymphocytes populations. Additionally thymus takes half into regulation of neuro-muscular transmission, phosphoric-calcium metabolism, carbohydrate and peptide metabolism, interplay with different endocrine glands (that is why one could be take into account thymus gland as a endocrine organ).

Crimson marrow is sole haemopoetic organ in grownup and central organ of immune system. Stem cells are generated in it, they’re like lymphocytes as a result of their morphology and through cell-fission give starting to all formal blood parts, additionally together with cells offering immunity – to leukocytes and lymphocytes. Crimson marrow in grownup is located in cells of spongy matter of flat and brief bones, in epiphysis of lengthy tubular bones. Yellow marrow is located in diaphysis of lengthy tubular bones. Largest quantity of crimson marrow is located into epiphysis of femoral and tibiae bones.