Sara Paterson-Brown, in straightforward Science in Obstetrics and Gynaecology (Fourth Edition), 2010

The lymphatic system

Lymphatic vessels

The extracellular organization of the body room constantly obtaining fluid and also debris (from capillary leakage, cell death, etc.) and the role of the lymphatics is to eliminate this and also return it to the venous circulation. The lymphatic capillaries have actually the same simple structure as vascular capillaries yet their distribution is not uniform throughout the body. The lymphatics in the limbs tend to it is in superficial, if those the the viscera often tend to drain via networks on the posterior abdominal and thoracic walls.

You are watching: The two collecting ducts that drain the lymphatic trunks are

The lymphatic vessels return the lymph to the venous device via two main channels:

The ideal lymphatic duct drains the right thorax, upper limb, head and also neck

The thoracic duct drains all lymph from the lower half of the body.

The pre- and also para-aortic lymphatics drain into the cisterna chyli which is one elongated sac-like vessel that lies end the body of L1 and also L2 behind the worse vena cava and between the aorta and also the azygous vein. It i do not care the thoracic duct together it ascends with the diaphragm in ~ the level of T12. That starts ~ above the ideal side that the oesophagus, but as it ascends through the thorax the thoracic duct passes behind the oesophagus (at T5) to with its left side, then superiorly it passes over the left subclavian artery and the dome the the left pleura to drainpipe into the confluence of the left subclavian with the left inner jugular veins.

Lymphatics, choose blood ship (and unequal somatic nerves), have the right to cross the midline, but in contrast they pass to and also from lymph nodes (afferent and also efferent lymphatics) and also they make up an anastomosing low-pressure system.

Lymphatic tissue

These comprise concentrations of lymphocytes and occur in mucosal and also submucosal collections in the gut (e.g. Peyer's spot in the ileum) and in the thymus, the spleen and also lymph nodes themselves.

The anatomical clinical prominence of this mechanism relates come the drainage fads of each team of nodes, i m sorry is summary in Table 5.1, but also described because that the individual organs in their relevant local anatomy sections.

View chapterPurchase book

A. Kaipainen, D.R. Bielenberg, in Encyclopedia of the Eye, 2010

Structure and role of the Lymphatic System

The lymphatic system develops a one-way route, carrying lymph native the perimeter of tissues with the thoracic duct or the best lymphatic duct right into the venous blood. These two main lymphatic ducts are connected with the venous mechanism at the junction the the left internal jugular vein and also the left subclavian vein and at the veins of the best jugulo-subclavian confluence, respectively. However, various other potential lymphaticovenous interactions (e.g., iliac and renal areas) may come to be functional when lymphatic pressure rises or in a pathological situation.

Beyond its key function, the drainage that extravasated organization fluid back to the venous circulation, the lymphatic device serves numerous other attributes which include transport for immune defense and also absorption of lipids from the intestine. Practically all vascularized tissues, except the central nervous mechanism (CNS), space invested through lymphatic vessels. The CNS lacks lymphatics since it has a blood-neural barrier that is less permeable than other tissues and is immune-privileged. In the eye, lymph drainage is present in the conjunctiva, sclera, and also choriocapillaris, while there is no lymph drainage because that the anterior chamber, vitreous cavity, subretinal space, or cornea.

In the peripheral tissues, lymphatic vessels and also blood ship are uncovered in close proximity, yet the 2 systems never intermix (Figure 1). Lymphatic functions are reflect in the certain structure that the lymphatic vessels. A main characteristic is the discontinuity of the basement membrane in ~ the interface in between the lymphatic endothelium and also the bordering connective tissue that facilitates active fluid transport. In some tissues, consisting of intestine, lung, and also skin, lymphatic vessels completely lack a basement membrane. A second significant characteristic is the tight link of the lymphatic endothelial cells (LECs) come the bordering matrix through anchoring filaments (AFs). It has been propose that organization expansion because of excess interstitial fluid tightens the AFs, which pull on the lymphatic capillaries, thereby creating gaps between the LEC to rise the intake of fluid. A third characteristic the the lymphatic vessels is the valves in the vessel wall are currently present in ~ the level that capillaries, unequal in the venous blood system where lock are discovered only in venules and also larger vessels. This valves ensure unidirectional flow of the lymphatic fluid, i m sorry starts in the blind-ended capillaries. Furthermore, LECs are considerably larger 보다 the blood endothelial cells; this permits elongation of the cell to accommodate the tissue stretch (see Table 1 because that a perform of differences in between lymphatic vessels and blood vessels).


Blood vesselsLymphatic vessels
Circular systemUnidirectional system
Artery → capillary → veinCapillary → collector → TD → vein
Formed E6.5–9.5 (mice)Sprout native vein at E9.5–12.5 (mice)
Capillaries have BMCapillaries have discontinuous or lack BM
SMC may surround capillariesCapillaries absence SMC
No anchoring filamentsCapillaries have anchoring filaments
Flow is dictated by heart beatFlow is dictated by interstitial pressure
No valves in capillariesCapillaries have actually valves
Blood within the vesselsLymph within the vessels
Contain all the hematopoietic cellsContain immune cells and also no RBC
Retina has actually blood vesselsRetina lacks lymphatic vessels

BM, basement membrane; RBC, red blood cells; SMC, smooth muscle cells; TD, thoracic duct.

David L. Hirsch, Michael J. Spink, in existing Therapy In Oral and Maxillofacial Surgery, 2012

Cervical Lymphatics

Henri Rouvière schematically defined the lymphatic drainage of the head and neck as two concentric narrowing funnels draining caudally come the thoracic duct (left) and lymphatic duct (right). This paradigm is oversimplistic but is still taught in schools today. Regional metastases indigenous the dental cavity often drain to Robbins levels ns to III, therefore the rationale because that supraomohyoid neck dissection. Skip metastases space possible, and also the tongue and soft palate are often uncovered to have actually bilateral local metastases on last pathologic evaluation. Table 53-1 illustrates the anatomic levels of the neck and their importance.

Predictable drainage of the dental cavity come the first echelon that the lymphatic container does exist. However, together a result of data from huge clinical outcome studies and also the ability of lymphoscintigraphy come map sentinel nodes, surgeons currently recognize the drainage can be on an separation, personal, instance basis. Skip metastases to level IV in lateral tongue SCC and also retropharyngeal drainage of the soft palate monitor this paradigm. One more caveat lector is that previously operated necks may have hitherto undiagnosed, nascent, or recurrent metastases. Therefore, lymphatic drainage can be unpredictable after ~ surgery, and also clinically confident (cN+) or negative (cN0) nodes through micrometastases might go undetected.

Radiologists incorporate nodal an essential size and also morphology to recognize “suggestive” cervical adenopathy. Skepticism for local metastases is high in the setup of OSCC if nodes screen a main hypointensity continuous with central necrosis; if they are round and not kidney bean shaped, which represents expansion; if the neighboring fascial aircraft is obliterated, i beg your pardon signifies tissue necrosis or fixation; if their dimensions are greater than 15 mm in ~ level II and also greater than 10 mm elsewhere; or if a spiculated periphery indicative the extracapsular spread is present. This critical characteristic is a far-ranging poor prognostic indicator because that OSCC.

Alfonso López, Shannon A. Martinson, in Pathologic communication of Veterinary condition (Sixth Edition), 2017


The build-up of chyle (lymph affluent in triglycerides) in the thoracic cavity (Fig. 9-116) is a an outcome of the rupture of major lymph vessels, commonly the thoracic duct or the appropriate lymphatic duct. The clinical and also pathologic effects of chylothorax are comparable to those of the other pleural effusions. Reasons include thoracic neoplasia (the many common reason in human beings yet a distant 2nd to idiopathic instances in dogs), trauma, congenital lymph courage anomalies, lymphangitis, dirofilariasis, and also iatrogenic rupture of the thoracic duct throughout surgery. The source of the leakage that chyle is rarely discovered at necropsy. As soon as the leakage the chyle occurs in the abdominal muscle cavity, the problem is described as chyloabdomen. Cytologic and biochemical examination of fluid collected by thoracocentesis frequently reveals huge numbers the lymphocytes, lipid droplets, few neutrophils in chronic cases, and also high triglyceride content.

Robert G. Carroll PhD, in Elsevier's integrated Physiology, 2007


Lymphatics room a network the endothelial tubes that merge to form two large systems that get in the veins. Lymph indigenous the best side that the head, ideal trunk, and also right eight drains right into the best lymphatic duct. Lymph indigenous the remainder of the human body drains into the thoracic duct, i beg your pardon empties right into the thoracic vena cava.

Terminal lymphatics (Fig. 8-3) lack tight junctions, allowing big proteins (and metastasizing cancer cells) to go into the circulatory system through the lymphatic system. Lymph composition very closely resembles interstitial fluid composition. In the GI tract, lymphatics permit digested fats to get in the circulation. Lymph is pushed by (1) massaging from surrounding muscle, (2) organization pressure, and (3) convulsion of the lymph vessels. Valves ensure the the circulation of lymph is toward the vena cava. Over 24 hours, the volume of lymph circulation in the body is same to roughly 5 L, the same as the full blood volume. Lymph is filtered in lymph nodes before progressing back to the circulation.

Mary ann Jackson, J. Christopher Day, in Principles and Practice that Pediatric contagious Diseases (Fifth Edition), 2018

Lymphatic Drainage of the Lungs and also Pleura

As displayed in Fig. 18.1, lymph native the thoracic viscera (heart, pericardium, lungs, pleura, thymus, and esophagus) traverses one of three feasible sets the nodes before entering the thoracic duct or ideal lymphatic duct. Anterior mediastinal nodes are situated anterior come the aortic arch, innominate veins, and large arterial trunks top from the aorta. They obtain afferents indigenous the thymus and pericardium, the sternal nodes, and also the thyroid gland.

Posterior mediastinal nodes lie dorsal come the pericardium and adjacent to the esophagus and descending aorta. They obtain afferents from the esophagus, dorsal pericardium, diaphragm, and convex surface ar of the liver. Middle or mediastinal nodes drainpipe the lungs and pleura. Lymphatic drainage of the lungs is written of superficial and deep plexuses. The superficial plexus lies beneath the visceral pleura. Lymph flows approximately the border that the lung to enter the bronchopulmonary (hilar) nodes. The deep plexus accompanies branches that the pulmonary vessels and also ramifications of the bronchi throughout the lungs.

Lymphatic drainage the the lung overcome through four sets the lymph nodes (Table 18.1). Intrapulmonary lymph nodes are located within the lung, chiefly in ~ the bifurcations of the bigger bronchi. Bronchopulmonary or hilar nodes are situated at the pulmonary hilus in ~ the site of entry of the main bronchi and vessels. Tracheobronchial nodes are split into superior and also inferior groups. The superior group lies in the obtuse angle in between the trachea and bronchi top top both sides. The inferior, or subcarinal, group lies under the carina at the tracheal bifurcation. The 4th group, the tracheal or paratracheal nodes, lies beside and somewhat anterior come the trachea. A fifth group that lymph nodes of prominence in the drainage that the lung is the inferior deep cervical (scalene or supraclavicular) chain, which is located over the lower section of the interior jugular vein, just over the clavicle and also usually under the scalenus anterior muscle. The apical pleurae drain straight to these deep cervical nodes, as do the paratracheal chains. A detect of supraclavicular lymphadenopathy must lead to investigation for intrathoracic or intra-abdominal pathology.

Ultimately, every lymph indigenous the lungs and pleurae will the tracheobronchial and paratracheal lymph nodes. Generally, lymph from the lung flows from left come right, a probable explanation because that the preeminence of right upper paratracheal and also supraclavicular lymphadenopathy in transmittable pulmonary processes, particularly tuberculosis. Lymph from the left reduced lobe (and usually additionally the lingula) flows from the hilar nodes to the reduced tracheobronchial nodes, and then to the ideal paratracheal nodes. Lymph native the best hilar nodes travel to the ideal paratracheal nodes (see Table 18.1).

Lymph vessels from the paratracheal nodes join with lymph trunks indigenous the anterior mediastinum to form the right and left bronchomediastinal trunks. This trunks then join with the lymphatic trunks indigenous the supraclavicular nodes to form the right lymphatic duct and also left thoracic duct.

Bruce H. Culver, Robb W. Glenny, in Clinical Respiratory medicine (Fourth Edition), 2012

Lymphatic Circulation

Pulmonary lymphatics room not discovered in alveolar walls yet originate in interstitial spaces at the level of the respiratory tract bronchioles and also at the pleural surface, then follow the bronchovascular bundles to the hila. The lymph flows through the ideal lymphatic duct and also the thoracic duct into the right and left brachiocephalic veins. The full flow indigenous the lung is quite low under normal problems (less than 0.5 mL/minute in experimental animals) yet can increase many-fold with pulmonary edema. The lymphatics have valves to stop backflow and can generate enough pressures to maintain circulation when systemic venous pressure is together high as 20 cm H2O.

Mary ann Jackson, J. Christopher Day, in Principles and Practice of Pediatric transmittable Diseases (Fifth Edition), 2018

Anatomy and function of Lymphoid Tissue

The lymphoid mechanism is written of comprehensive capillary network that drains lymph into sophisticated systems of collecting vessels. The collecting vessels merge and also empty lymph right into the bloodstream by means of the thoracic duct at its entry right into the left subclavian vein or by the best lymphatic duct, i m sorry empties into the best subclavian vein. Specialized lymphatic structures interspersed follow me the collecting vessels incorporate the tonsillar tissues of the Waldeyer ring, the thymus, the spleen, mucosa-associated lymphoid nodules, and lymph nodes (Table 16.1).

The Waldeyer ring that lymphoid tissue that surrounding the oropharyngeal isthmus and the opening of the nasopharynx into the oropharynx is uniquely positioned to connect with international material entering the nose or mouth. The ring is developed superiorly by the midline pharyngeal (adenoid) tonsil, which is situated in the roof of the nasopharynx, and also inferiorly by the lingual tonsils in the posterior third of the tongue. On either side of the pharynx, the lateral pharyngeal bands the lymphoid tissue attach the adenoid come the tubal tonsils of Gerlach at the openings that the eustachian tubes and also to the faucial (palatine) tonsils. Smaller sized aggregates that lymphoid tissue in this area encompass the posterior pharyngeal granulations and the lymphoid tissue within the laryngeal ventricle.

Small submucosal lymphoid nodules situated throughout the respiratory, gastrointestinal, and genitourinary tracts space composed that phagocytic and also lymphoid cabinet collections there is no a connective organization capsule. These nodules space ideally positioned to respond to mucosal antigens.

The thymus, i m sorry is located over the remarkable vena cava in the anterior mediastinum, is relatively protected from antigens. Surrounding by a slim connective organization capsule, the thymus is uniquely written of epithelial and lymphatic elements.

The spleen is the biggest lymphatic organ in the body and also the just lymphatic tissue specialized to filter blood. Similar to the lymph nodes, the spleen is a component of the peripheral lymphoid system and is written of red pulp (i.e., red blood cells) and an inner of white pulp, which consists of lymphoid nodules v germinal follicles.

Normal lymph nodes space small, oval or bean-shaped bodies that are strategically situated along the course of lymphatic ship to filter lymph ~ above its way to the bloodstream. Lymphatic ship enter roughly the periphery of the nodes. Lymph filters v the cortex to the medulla that the node and exits with the hilum. Blood vessels enter and also leave with the hilum, which is associated to capillaries the course through the node. During this process, lymphocytes can leave the blood and also re-enter the lymphatic circulation.

Nodes room densely packed with lymphocytes the are arranged loosely right into cortical nodules and medullary cords by connective tissue trabeculae and also lymphatic sinuses. The location junxtap of phagocytic cells, antigen-processing cells, and also lymphocytes in an area of slow blood flow is ideally suited to provide the very first line that defense against pathogens. As lymph gradually filters with the well-off reticular network, organisms space trapped and also can be ingested by phagocytic cells, stimulating the relax of cytokines, i m sorry recruits lymphocytes because that immunologic responses. The lymph node groups in the body can be separated into the superficial and peripheral nodes, which commonly are conveniently palpable, and also the deeper groups surrounding to significant vessels and viscera (see Table 16.1).

C.J. Carati, B.J. Gannon, in Encyclopedia of respiratory Medicine, 2006

Lymphatic networks in the lung are discovered in near association v blood vessels and bronchi, and in the pleura. These networks anastomose at the lung surface and interlobular septa, and drain via the hilar an ar into the mediastinal and also tracheobronchial lymphatic system, and also thence to the right lymphatic duct or thoracic duct. Interstitial fluid from the alveolar walls drains into the parenchyma the the alveolar ducts, whereby it beginning blind-ended lymphatic capillaries consist of of an easy discontinuous however overlapping endothelial cells. These in turn drain into collecting lymphatic vessels the contain smooth muscle and one-way valves to aid pump the lymph centrally along the network, considerably aided by respiratory and also vascular movement. This drainage maintains normal tissue hydration, but is get rid of in cardiovascular and also lung an illness resulting in fluid accumulation at the alveolar level. The lymphatics also provide a route of removed of inflammatory and pathological material, consisting of tumor cells, i beg your pardon often finish up in lymph nodes. Determinants that deserve to compromise lymphatic drainage from the lung include reduced lymphatic pump by jeopardized respiratory, vascular, or body movement; inhibition that lymphatic pumping by inflammation cytokines or cells; constriction of lymphatic vessels by exterior forces; obstruction of the lymphatics by tumor; or increased central venous pressure. Pleural fluid drainage is via intercellular gaps called stomata in the pleural mesothelial lining, i beg your pardon directly connect the pleural cavities to lymphatics that drain the dependent areas of the parietal pleura.

The following code and also results space an illustration of just how one could do semantic consistency checking in one ontology choose the FMA. Us specifically focus on the lymphatic system since it will certainly be revisited in section 5.5.3. Below are two particular requirements because that consistency and completeness in the lymphatic system:


Every lymphatic chain should have actually efferent-to relations only to other lymphatic chain or come lymphatic ship such as the Thoracic duct or the best lymphatic duct.


Starting with any kind of lymphatic drainage indigenous an organ or body organ part, all paths using the efferent-to relationship should finish up at either the Thoracic duct or the appropriate lymphatic duct.

The an initial requirement is a slightly an ext stringent need than the present FMA specifies in the “efferent to” relation, however it is necessary in order to get meaningful pathways. In the FMA specification that the “efferent to” relation, the following are enabled classes:

Lymphatic chain

Lymphatic vessel

Anodal lymphatic tree

Lymphatic plexus

Lymph node

The Thoracic duct and Right lymphatic duct are lymphatic trunks, which are subclasses of Lymphatic vessel, so they should be allowed, together with other trunks. Anodal lymphatic tree are tiny networks that lymphatic ship that directly drain structures.

The tests will be performed in a succession of steps. Of course for fully automated checking this steps can easily it is in combined. First, for the lymphatic chains and also vessels, we get all the instances, making use of the all-subclasses role previously defined.

> (setq allchains (all-subclasses "Lymphatic chain"))

("Pulmonary lymphatic chain"

 "Subdivision the pulmonary lymphatic chain"

 "Axillary lymphatic chain" "Subdivision the axillary lymphatic tree"

 "Posterior mediastinal lymphatic chain"

 "Tracheobronchial lymphatic chain"

 "Tributary of tracheobronchial lymphatic chain"

 "Left cardiac tributary that tracheobronchial lymphatic chain"

 "Brachiocephalic lymphatic chain"

 "Right cardiac tributary the brachiocephalic lymphatic chain" …)

> (setq allvessels (all-subclasses "Lymphatic vessel"))

 ("Variant lymphatic vessel" "Lymphatic capillary"

 "Tributary that lymphatic trunk" "Tributary that lymph node"

 "Superficial lymphatic vessel" "Deep lymphatic vessel"

 "Lymphatic trunk" "Incomplete best lymphatic duct"

 "Absent thoracic duct" "Absent cisterna chyli" …)

Checking the lengths of the two lists that result, it shows up there are 353 chains and 670 vessels. Because that each the the item in the 2 lists, we retrieve the worths in the “efferent to” slot. This is conveniently done by writing a role to go through each list, obtain the “efferent to” contents, and also pair it v its chain or vessel.

(defun get-efferents (terms)

(mapcar #’(lambda (x)

(list x (efferent-to x)))


We apply it to both lists, giving the adhering to results.

> (setq chain-slots (get-efferents allchains))

 (("Pulmonary lymphatic chain" ("Bronchopulmonary lymphatic chain"))

("Subdivision of pulmonary lymphatic chain" NIL)

("Axillary lymphatic chain"

("Subclavian lymphatic trunk" "Subclavian lymphatic tree"))

 ("Subdivision of axillary lymphatic tree" NIL)

 ("Posterior mediastinal lymphatic chain"

("Thoracic duct" "Tracheobronchial lymphatic chain"))

 ("Tracheobronchial lymphatic chain"

("Bronchomediastinal lymphatic trunk"

"Bronchomediastinal lymphatic tree"))

 ("Tributary that tracheobronchial lymphatic chain" NIL)

 ("Left cardiac tributary that tracheobronchial lymphatic chain" NIL)

 ("Brachiocephalic lymphatic chain"

("Bronchomediastinal lymphatic trunk"

 "Bronchomediastinal lymphatic tree"))

 ("Right cardiac tributary that brachiocephalic lymphatic chain" NIL)


> (setq vessel-slots (get-efferents allvessels))

 (("Variant lymphatic vessel" NIL) ("Lymphatic capillary" NIL)

 ("Tributary of lymphatic trunk" NIL)

 ("Tributary the lymph node" NIL)

 ("Superficial lymphatic vessel" NIL) ("Deep lymphatic vessel" NIL)

 ("Lymphatic trunk" NIL) ("Incomplete best lymphatic duct" NIL)

 ("Absent thoracic duct" NIL) ("Absent cisterna chyli" NIL) …)

Now we have the right to just iterate with these lists check if the entries complement our criteria above. In every entry, the 2nd item need to be a list of just lymphatic chains or vessels, in which instance we put it top top a “good” list, or the is nil, an interpretation no info is entered, and we put it on a “not done” list, or that is some various other things, in which case we put it on a “bad” list.

(defun check-efferents (termslots allowed)

"termslots is a list of chain or vessels and their efferent to

 slot values. Enabled is the finish list of allowed values"

 (let (good poor not-done)

(dolist (chain termslots)

(let ((efferents (second chain)))

(cond ((null efferents) (push chain not-done))

((every #’(lambda (x)

(find x allowed :test #’string-equal))


(push chain good))

(t (push chain bad)))))

(list good bad not-done)))

Strictly speaking there is nothing in this role about the “efferent to” relation. It can be provided to check any list of (term slot-value) pairs versus a perform of allowed values. Here are the results for the perform of chains:

> (setq chain-checks (check-efferents chain-slots

(append allchains allvessels)))

((("Left submental lymphatic chain"

("Left submandibular lymphatic chain"

"Left jugulo-omohyoid lymphatic chain"))

("Right submental lymphatic chain"

("Right submandibular lymphatic chain"

"Right jugulo-omohyoid lymphatic chain")) …)

 (("Left parasternal lymphatic chain"

("Left bronchomediastinal lymphatic tree"))

("Right parasternal lymphatic chain"

("Right bronchomediastinal lymphatic tree")) …)

 (("Left level through lymphatic chain" NIL)

("Right level using lymphatic chain" NIL)

("Left level V lymphatic chain" NIL) …))

We take into consideration a slot great if its worths come from one of two people the chain perform or the courage list. Now, how many are over there of each?

> (length (first chain-checks))


> (length (second chain-checks))


> (length (third chain-checks))


So, 140 of the chains are correct, 11 have some problem, and also 202 are still no completed. If we look at the 11 that have a problem, the is obvious that these entries are greatly ones whereby a lymphatic tree has actually been entered. It appears problematic the a chain can be efferent come a subtree that the lymphatic system, although this is anatomically correct. A chain the is part of a tree connects come the tree and also the lymphatic liquid flows native the chain right into that branch the the tree. However, for path tracing, the is no useful, because the flow from the chain does not go with the whole tree, yet only v a subset that branches. Therefore this needs to be fixed in order to carry out sound path tracing. There are so couple of that that is relatively easy to solve this modeling problem.

> (pprint (second chain-checks))

(("Left parasternal lymphatic chain"

("Left bronchomediastinal lymphatic tree"))

 ("Right parasternal lymphatic chain"

("Right bronchomediastinal lymphatic tree"))

 ("Left tracheobronchial lymphatic chain"

("Left bronchomediastinal lymphatic trunk"

 "Left bronchomediastinal lymphatic tree"))

 ("Right tracheobronchial lymphatic chain"

("Right bronchomediastinal lymphatic trunk"

 "Right bronchomediastinal lymphatic tree"))

 ("Lymphatic chain of reduced lobe of left lung"

("Left bronchopulmonary lymph node"))

 ("Lymphatic chain of reduced lobe of ideal lung"

("Right bronchopulmonary lymph node"))

 ("Parasternal lymphatic chain"

("Bronchomediastinal lymphatic trunk"

 "Bronchomediastinal lymphatic tree"))

 ("Infraclavicular lymphatic chain"

("Subclavian lymphatic tree" "Apical axillary lymphatic chain"

 "Subclavian lymphatic chain"))

 ("Brachiocephalic lymphatic chain"

("Bronchomediastinal lymphatic trunk"

 "Bronchomediastinal lymphatic tree"))

 ("Tracheobronchial lymphatic chain"

("Bronchomediastinal lymphatic trunk"

 "Bronchomediastinal lymphatic tree"))

 ("Axillary lymphatic chain"

("Subclavian lymphatic trunk" "Subclavian lymphatic tree")))

Now the same checks deserve to be carry out on the vessels list, and also the counts for the 3 categories come out as follows:

> (length (first vessel-checks))


> (length (second vessel-checks))


> (length (third vessel-checks))


On investigate of the 2 that space flagged as bad, the same problem appears. A tree has actually been entered where we would mean a trunk, vessel, or chain.

The second check, to recognize whether all paths terminate in ~ the Thoracic duct or right lymphatic duct, is much more challenging. The fact that countless “efferent to” relationships space still no done makes it very likely the there are countless incomplete paths, so this inspect is more than likely premature. Nevertheless, it need to be clear how to execute it. Native the perform of chains and vessels, one traces the paths, and examines their finish points. Looking earlier to the instance for the Soft palate, you can see that beginning there, a course ends at the Jugular lymphatic trunk. However, there room two jugular lymphatic trunks, a right and also a left. One goes come the thoracic duct and one goes to the right lymphatic duct. So the is exactly to have no entry in ~ the greater level the generality. This is yet another complication in checking consistency and also completeness, as well as in applying the knowledge to clinical problem solving. There are many such places where anatomical frameworks are described as general classes, and then have an ext specific right and also left instances (subclasses). This is an extremely important, due to the fact that geography is important and also (especially v radiation therapy) one should specify on which next the reality of attention are. The presence of the general and also right/left instances makes reasoning difficult to automate. Over there is room because that some more innovation here.

So, no one of the results over should be thought about as deficiencies in the FMA. Rather, our check have established some more complexities in the model itself. An additional possibility is the the path examine may reveal circularities. The route tracing code described previously would certainly not terminate in this case, and a various kind of inspect is needed, wherein one keeps monitor of nodes already visited and also flags any type of returns to together nodes.

The query interface defined here, while quiet operational, is peculiar to the FMA, and also not fine matched come standards and methods offered widely in Semantic internet research and implementation. The FMA can additionally be represented as a graph structure using RDF <271>, and a generalization that the SPARQL questions language <426> has actually been arisen to assistance the facility queries that are becoming important in medicine <90,375>.

See more: An Increase In Net Exports Will Shift The, Reading: Aggregate Demand

Anatomy, important as that is, is periodically viewed as a “dead” subject, with small or nothing new to be discovered. However, in spite of several thousand years of dissection, study, and development of terminology, it seems that lot remains to it is in done. The FMA project, through its goal to construct a consistent computational concept of anatomy, is just one of the many ambitious ontology building projects in biomedical informatics. We have actually learned indigenous it the the expressivity of the metaclass idea, and the representation of relations themselves as entities, are both key elements of complicated biomedical theories. Another an extremely important realization comes out of this occupational as well. Biomedical informatics is not just straightforward applications of well-established computer system science methods. As note Musen has actually said, “ours is the technique that cares around the content” <291>. Biomedical informatics gives formal shape to biomedical content, and also in the battle to gain it right, feeds back to computer science and also information science new ideas and also challenges. This is exactly parallel come the relation in between theoretical physics and mathematics.