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Introduction

The history of modern anatomical terminology starts with the Basler Nomina Anatomica (BNA), published in Latin by the Anatomische Gesellschaft (Society of German-speaking anatomists) under the leadership of Wilhelm His (His 1895). It was not accepted worldwide, in particular not in France and Great Britain. In 1903, the International Federation of Associations of Anatomists (IFAA) was founded and started to work on a revision of the BNA from 1905 onwards. Since this work took so much time, the Anatomical Society of Great Britain and Ireland (1933) published its own modification as Birmingham Revision (BR). In 1935, the Anatomische Gesellschaft approved an extensive modification of the BNA, the Jenaer Nomina Anatomica (JNA), published in 1936 (Stieve 1936). The JNA was focused on veterinary anatomy as well, preferred the horizontal position of the body, and included many language corrections.

In 1936, the IFAA established the International Anatomical Nomenclature Committee (IANC) to revise the BR and the JNA, but due to World War II, it began to operate not before 1952. Its main task was to create an anatomical nomenclature in Latin, which could be accepted worldwide. The IANC took the BNA as its starting point and strictly refused to accept the JNA changes. In 1955, at the sixth IFAA Congress in Paris, the IANC proposal was discussed and accepted as the Paris Nomina Anatomica (PNA 1955). Various revisions were approved and published from 1961 to 1983 as the Nomina Anatomica (NA) that is why the PNA is also known as NA1. The fourth edition (NA4 1977) included the first histological and embryological nomenclatures in Latin, the Nomina Histologica and the Nomina Embryologica. A fifth edition (NA5) appeared in 1983. In 1989, the IANC published a sixth edition (NA6) without the approval of the IFAA. Then, at its meeting in Rio de Janeiro in 1989, the IFAA decided to appoint a new commission, Federative Committee on Anatomical Terminology (FCAT). FCAT took the NA5 as its starting point (Kachlik et al. 2008).

Eight years later, the IFAA approved the Terminologia Anatomica (TA) in São Paulo. It was published in 1998 in Latin and English (TA 1998). The Chairman of FCAT, Ian Whitmore, explained the intentions of the committee (Whitmore 1999). Apart from continuing the elaboration of histological, cytological, embryological, odontological, and anthropological terminology, FCAT proposed to produce a dictionary of anatomical terms, an illustrated terminology, and an electronic version of the whole series. Later, it changed name to Federative International Committee on Anatomical Terminology (FICAT) and published the Terminologia Histologica (TH) in 2008.

This brief overview of the history of anatomical terminology clearly shows that to reach a worldwide accepted anatomical nomenclature, many hurdles have to be taken. After FICAT, the IFAA founded a new programme for anatomical terminology, Federative International Programme for Anatomical Terminology (FIPAT) with new sections on Anthropology, Odontology and Neuroanatomy, aiming at electronic, online versions. It issued the Terminologia Embryologica (TE) in 2013 and already in 2017, the second edition of the Terminologia Embryologica (TE2) and also the Terminologia Neuroanatomica (TNA) went online at FIPAT’s Dalhousie’s website (https://fipat.library.dal.ca/). A full version of TNA was finally made available in December 2021 (https://ifaa.unifr.ch). The second edition of the Terminologia Anatomica (TA2) went online not before 2019, among others due to the inclusion of the Regular Anatomical Terms (RAT) rules (Neumann et al. 2017). FIPAT suggested to use the RAT in the synonym column, but its Gross Anatomy Working Group decided otherwise, after which the IFAA suggested a Referendum among its Member Associations. At the Referendum on Regular Anatomical Terms versus traditional, standard Latin for the TA2, in Autumn 2020, the final vote was: 40 votes for RAT and 30 votes for standard Latin. Forty associations took part in the referendum, 20 voted for RAT and 18 voted for standard Latin. Two societies’ votes were considered spoilt ballots. It appeared that Societies in parts of America and the Far East, not using Latin in their teaching, voted for RAT, while Societies in parts of Europe, using Latin in their teaching, voted to maintain standard Latin. Fortunately, while RAT became the primary set of terms used in the terminologies, it is still permissible to use the Latin terminology, as standard Latin became the first synonym (Table 1).

Table 1 Abbreviations used for terminologies
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Some notes on the regular anatomical terms

As to the implementation of the human anatomy nomenclature rules for the computer age (Neumann et al. 2017), there may be some truth in these, but the Anatomical Societies using proper Latin in their teaching, textbooks, and atlases will hardly follow these rules. It is good that generic rules for the word order are set up, but especially Rules 10 and 11 met great resistance within European Anatomical Societies in particular, and no one of their members is willing to use terms following such rules. For the TA 1998 and earlier versions, the word order followed a general rule for adjectives: the more general term should be first and the more specific term should be second, e.g., fossa cranii anterior and not fossa anterior cranii, arteria cerebri media and not arteria media cerebri, and flexura coli sinistra and not flexura sinistra coli. The nonconcordant adjective must be stated first, followed by a concordant positional adjective (Kachlik et al. 2015). This was applied in the TNA for the TA terms Venae superficiales cerebri and comparable terms (TNA 2017b; ten Donkelaar et al. 2017, 2018). Otherwise, the terms will produce confusion. This way seems the most reasonable from linguistic, rational, and traditional points of view. A more widespread discussion on the preferred word order would be advisable to come up with regular rules that also seem intuitive, before implementing these rules that change such a vast amount of the terminology. Major changes in anatomical nomenclature on the basis of logic and intuitiveness should have broad support. There can be a beautiful list of seemingly logic terminology but if the majority of anatomists do not support it, the majority will not use it. This would downgrade the status of the TA.

As a possible solution and to increase the acceptance of the TA2, following earlier suggestions by FIPAT, we propose to have two equivalent columns in the six-column format, one with the traditional Latin terms as in TA98, the other with the Regular Anatomical Terms. In the current form, the long-standing presently used terms have to be looked for under synonyms and other columns, even in the column “Other”. Given the not too major differences between the UK-English and the US-English columns, these may be combined again to one as in TA98. The RAT should remain “considered alternatives” until the recommended wider discussion of the RAT rules has taken place. As will be shown below, the automatic generation of Latin terms by the Terminologia Anatomica Humana (TAH; see below) is done in a standard way. It is obvious that the generated terms may have two variants: the traditional term and an RAT compliant term.

Notes on other changes in the TA2

In the TA2, many other changes are apparent:

  1. 1.

    The use of full terms, not the short terms as usual (TA98). Extending the terms to complete (stand-alone) terms, so not anymore needing to extend terms with part of parent terms such as in TA98, which led to uncertainty about the stand-alone term, is a major and very welcomed improvement.

  2. 2.

    Grouping together bony and cartilaginous structures, joints, and muscles. This certainly has its advantages.

  3. 3.

    A large number of adjectives have been changed as compared to the earlier version sent to the Member Societies (November 2016). Most of these are not explained and seem to be unnecessary: why Os sphenoideum instead of Os sphenoidale, why Articulatio radiocarpea instead of Articulatio radiocarpalis; this applies to all terms involved (…-carpalis or …-tarsalis). We are not impressed by all these unnecessary corrections in Latin terms. The traditional terms better resemble the terms in various vernacular languages. To quote the late Roger Warwick in his introduction to the NA4 (1977): “The more the Latin term can be made to resemble its vernacular language, the easier it is to guess the significance of the Latin term”.

  4. 4.

    Neither is the reintroduction of diphthongs as in thyreoid… and all the “prae’s” explained. Diphthongs were deleted since the PNA, by now also from the second edition of the Terminologia Embryologica (TE2 2017a). Such diphthongs would better be presented in the column “Other” or as historical terms.

  5. 5.

    Given the fact that the TNA 2017, available on the FIPAT website since February 23, 2017, and accepted by the General Assembly as the official terminology for the nervous system and the sense organs at the 19th IFAA World Congress (August 9–11, 2019, London), the TNA should be the basis for Capita XIV and XV of TA2. In the TA2, several entities in neuroanatomy received different TA2 terms besides the yet accepted TNA terms. This is counter to FIPAT’s core goal of anatomical nomenclature unification and hence, if ratified, would seriously undermine FIPAT’s credibility. Moreover, the TA2 apparently does not accept modern views on the subdivision of the central nervous system applied in the TE2 and the TNA. The TNA is increasingly accepted, for instance in the TA2023AG of the Anatomische Gesellschaft (see below).

  6. 6.

    TA98 used plural and singular terms, seemingly random (Gobée et al. 2011). TA2 appears to have made improvements in this respect. We recommend all terms to be made singular.

The current situation

Several Anatomical Societies, using standard Latin in their teaching, will continue using the TA98 as well as the TNA 2021, officially accepted at IFAA’s 19th World Congress in London, August 9, 2019. Since the TA2 often contains more Latin synonyms than one, and the first official terms are often replaced without apparent reasoning, it is difficult to see which entity in TA2 is new and which entity is deleted. Therefore, these Anatomical Societies prefer TA98. Recently, the Anatomische Gesellschaft announced the usage of the TA2023AG, based on the TA98 and incorporating the TNA. The TA2023AG is a descriptive nomenclature following the evolution of anatomical knowledge and language in the scientific literature and in current practice rather than introducing linguistic modifications (Anatomische Gesellschaft 2023).

It might be useful to go back to the first FIPAT Meeting in Beijing (August 7, 2014), where an internal document ‘Anatomical Terminologies for Tomorrow’ by Robert Baud, Tom Gest, Paul Neumann, and Pierre Sprumont was discussed. In its introduction, FIPAT’s goals for the revision of the TA98 were mentioned:

  1. 1.

    To merge the TA98 and the TH 2008 to form a single terminology for adult human anatomy, provisionally abbreviated TAH for Terminologia Anatomica Humana.

  2. 2.

    To conservatively revise the terminology to ensure uniqueness and clarity of terms: (a) to improve compliance of the Latin terms to the traditional rules; (b) to improve the precision of the terminology; (c) to adopt and apply new naming rules (Regular Anatomical Terminology); and (d) to use terms in the singular throughout.

  3. 3.

    To make the hierarchical relationships between terms explicit.

  4. 4.

    To develop definitions of terms.

  5. 5.

    To encourage the use of the preferred terms in Latin and equivalent terms in other languages.

The Terminologia Anatomica Humana

The TAH is a nomenclature based on scientific criteria, which are commonly accepted in biological domains such as in the Foundation Model of Anatomy (FMA; Rosse and Mejino 2003). Both the FMA and the TAH are compatible with the essentials of database development in life sciences as recommended by the OBO Foundry (Smith et al. 2007), and we adopt the basic principles of the Basic Formal Ontology 2.0 (Smith et al. 2015). The size of the terminology, which amounts to more than a hundred thousand terms, and the complexity of interlanguage concordance and coordination, makes such a scientific background strictly necessary. The support of dedicated computer applications for the implementation of the terminology is, therefore, a must.

The following specifications are mandatory for the TAH:

  1. 1.

    The terminology is based in two hierarchies, partonomy and taxonomy, with permanent bridges between the two.

  2. 2.

    The terminology is language-independent, which means that no language can impose whatever rules or concepts that are specific or local. A special position is given to Latin, considered as a reference model for all vernacular languages.

  3. 3.

    The terminology must be formally multilingual with guidance rules for the translation in any language. This means that the translation is computer-generated.

  4. 4.

    The inter-entities relations must be made explicit using pointers, not by linguistic clues.

  5. 5.

    All terms are defined as singular and plural forms when necessary are exclusively computer-generated.

  6. 6.

    The terminology is publicly available in three forms: web pages, PDFs, and tables. The PDF files replace the published book.

  7. 7.

    Definitions must be included in the terminology.

  8. 8.

    The new version of the terminology must be traced back to earlier versions, including the TA98. Links must be provided between corresponding identifiers in each version.

  9. 9.

    The management of the terminology must be documented.

These specifications need the following explanations:

  1. 1.

    In the TA98, a general partonomy of the human body was used with taxonomic aspects under Nomina generalia (General terms), but it lacks an explicit taxonomy. The FMA has a complete coverage of the TA98 and supplies the missing taxonomy. From then on, new versions of the nomenclature must contain both hierarchies with permanent connections between the two.

  2. 2.

    A terminology dominated by a preferred language is not acceptable at an international level, not even Latin. Therefore, a language-independent reference is necessary to make the terminology shared by all countries. A universal representation is the recipient of what is common to everyone: each entry of the terminology is formulated as a sequence of abstract words, each one having a defined representation in all languages. From the universal formulas, an automated process generates the terminology in any language, including Latin. However, each language must be in the position to save its specificity and its traditional aspects. To do that, every universal term is accepted by a given language or is replaced by a typical term at will of the native speakers of this language. This process must be performed without restriction. The experience with five languages in the TNA (Latin, English, French, Spanish, and Russian) shows that 95% of the universal terms are accepted as they are. This means that the universal representation is clearly the skeleton for the terminology of the future.

  3. 3.

    Once it has been defined by universal terms or their language exceptions, the terminology must be translated in any language by automatic translation. In fact, the language of anatomy is a simplified subset of the human languages. The automatic translation is fully mastered today for at least the five languages mentioned above and may be extended at the cost of a manageable availability of manpower.

  4. 4.

    Most entities in the terminology are in the form A of B or equivalent, for instance tunica mucosa gastris, where A stands for tunica mucosa and B for gaster. This means several thousands of relations that must be made explicit. The generation of the term for such an entity is realized using a pointer to gaster, without duplicating this term.

  5. 5.

    This rule follows the decision of the IFAA General Assembly in Beijing. By definition, the terms of the taxonomy are always singular. Presenting sets at plural is possible in the partonomy and the corresponding terms are computer-generated from the singular form.

  6. 6.

    The minimal presentation of the terminology has three forms in parallel. Web pages allow the presentation on the Internet, the PDF format allows anyone to make a personal copy, whereas the table form is an invitation to any casual user to experiment with the terminology, building his/her proper database and new applications.

  7. 7.

    Definitions are the core of the terminology. Many controversial entities must be explicitly defined to clear what we are talking about. Due to the immense task of building definitions for the entire terminology, a partial automation is necessary. The website AnatomicalTerms.Info (https://www.anatomicalterms.info) provides a good beginning for definitions. The TAH has developed the taxonomic definitions which are a disciplined approach of this task without the comfortable feeling of encyclopaedic definitions, but with a significant degree of automatic generation. Some 2000 definitions are present, considered today as an experimental trial.

  8. 8.

    Tracing the terminology from TA98 to any successor is essential. Often, users of the terminology are used to previous versions and hesitate to move to a new version. Therefore, tracing of the terms in successive versions must be a basic service.

  9. 9.

    Documentation, help systems, and guidance within the terminology are keys to the success. As a general point of view, users of the terminology are mostly not specialists in ontology, linguistic, or other scientific domains. Therefore, a didactic approach is welcome. The value of the terminology relies on the capability to transfer the whole application from one actor to another.

Progress on the TAH so far

As to the first of FIPAT’s goals in Beijing, merging of TA98 and TH2008, so far this has only been accomplished in the TNA, of which an illustrated version with definitions was published (ten Donkelaar et al. 2018). In December 2021, a digital version of the TNA was prepared in five languages (Latin, English, French, Spanish, and Russian) and became available at the IFAA’s Fribourg website (https://ifaa.unifr.ch). This digital version may be viewed as the first part of the TAH as suggested in 2014 and will form Chapters 14 (The Central and Peripheral nervous system) and 15 (The Senses) of the TAH. The TAH has 16 Chapters as in TA98 and TA2. It contains unique, computer-generated identifiers. For the changes made, see ‘About the Terminologia Neuroanatomica: Past, Presence and Future’ (ten Donkelaar and Baud 2021). In the digital version of the TNA, the following major changes were made in its presentation: (1) presenting the terms in a top-down approach, i.e., from telencephalon to spinal cord, to make terms compatible with the FMA and other parts of the TA98; (2) a new view on the presentation of tracts was implemented (Baud et al. 2018); and (3) the universal model for terms was applied. Because of its clinical and functional significance, the TNA includes the blood supply to the brain and spinal cord (Vasa sanguinea encephali and Vasa sanguinea medullae spinalis). Clinically relevant subdivisions of the large vessels to the brain are included. The document is divided into three Chapters: (1) Chapter 1 (Central Nervous System); (2) Chapter 2 (Peripheral Nervous System), and (3) Chapter 3 (The Senses).

Following the digitalization of the TNA, we started an initiative to prepare a digital version of the other Chapters of an updated TA98, in which improvements and new items of the TA2 and from the literature have been included, and inconsistencies in the TA98 have been corrected. First, the Systema musculare (Muscular system) has been updated and included as part of the TAH (its Chapter 4). Like in the TA98 and TA2, the following parts are discussed in a partonomic hierarchy:

  1. 1.

    Pars capitis systematis muscularis;

  2. 2.

    Pars cervicalis systematis muscularis;

  3. 3.

    Pars dorsalis systematis muscularis;

  4. 4.

    Pars thoracica systematis muscularis;

  5. 5.

    Pars abdominalis systematis muscularis;

  6. 6.

    Pars pelvica systematis muscularis;

  7. 7.

    Systema musculare membri superioris;

  8. 8.

    Systema musculare membri inferioris.

All parts comprise Musculi, Fasciae, Bursae and Vaginae tendinum, where appropriate. For the limbs a section Compartimenta is included. Compartments for hand and foot were added. For all terms, unlike TA2, comparison with the Foundation Model of Anatomy (FMA) and TA98 is given. New terms from TA2 and some from the literature (Kachlik et al. 2015, 2016) were added with explanatory notes, particularly for the Fascia capitis (Stecco et al. 2011, 2013; Herlin et al. 2015), the Fascia cervicalis (Fig. 1), the Fascia pelvis (Fritsch et al. 2004), and the Diaphragma pelvis (Fig. 2). In a recent study on a large series embalmed with Thiel’s method (Thiel 1992), Feigl et al. (2020) clarified aspects of the sometimes confusing terminology for the Fascia cervicalis. Their proposal largely follows Hafferl’s approach (Hafferl 1969). In brief (Figs. 1 and 3), the term Fascia cervicalis superficialis stands for the TA98 term Lamina superficialis fasciae cervicalis; the term Fascia buccopharyngea (fascia cervicalis visceralis) replaces the TA98 term Lamina pretrachealis fasciae cervicalis. In TA2, Fascia visceralis colli is used. The Fascia cervicalis media (TA2: Fascia musculorum infrahyoideum) is formed by the fascia of the infrahyoid muscles. The Fascia cervicalis profunda is subdivided into three layers: (a) the Lamina superficialis or Fascia intercarotica; (b) the Lamina profunda or Fascia prevertebralis (former Lamina prevertebralis fasciae cervicalis); and (c) the Septum sagittale cervicale or Fascia alaris (TA98 and TA2). This septum forms a sagittal membrane in the neck, described as ‘cloisons sagittales’ by Charpy (1912).

Fig. 1
figure 1

Fascia cervicalis. In this and the other tables, a partonomic list is presented with reference to the FMA, the TA98, and the TAH. UID means Unit identifier in the TAH

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Fig. 2
figure 2

Diaphragma pelvis

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Fig. 3
figure 3

Overview of the Fascia cervicalis: drawings of a median (mediosagittal) and transverse cross-section: fascia cervicalis superficialis (light green), fascia cervicalis media (blue), fascia buccopharyngea (green), fascia intercarotica (orange), fascia prevertebralis (pink), and fascia alaris (turkoise). The fascia alaris is marked by arrows as well (Feigl et al. 2020)

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For the Diaphragma pelvis, new terms are available for the Musculus levator ani going back to DeLancey (1996) and Shafik (1999), but it would be wise to keep the term Musculus levator ani as the primary term with the following subdivision (Fig. 2): (a) Musculus pubovisceralis, consisting of the Musculus iliococcygeus, the Musculus pubococcygeus with the Musculus puboprostaticus in males, the Musculus pubovaginalis in females, and the Musculus puboperitonealis; (b) the Musculus puborectalis seu puboanalis (TA2), subdivided into a Pars profunda and a Pars superficialis. It should be emphasized that (a) the Musculus puboprostaticus and the attachment of the Musculus pubovaginalis to the vagina could not be demonstrated (Dorschner et al. 2001; Fritsch et al. 2002; Wu et al. 2015) and (b) that the Musculus puborectalis colocalizes with the Pars profunda and Pars superficialis of the Musculus sphincter ani externus (Wu et al. 2017, 2020).

The presentation of Musculi largely follows the subdivision as found in most atlases and textbooks as exemplified in Fig. 4 for the muscles of the upper limb, but is different from TA98, in which most terms were grouped as a single section. The discrepancy between the use of English and half English/half Latin terms was solved by presenting an English term with the English term from TA98 as synonym. For example: long flexor muscle of great toe versus flexor hallucis longus muscle. We kept the use of the term muscle in all muscles as accepted at the 2nd FIPAT Meeting in Istanbul (August 31/September 1, 2015). Anglicizing of terms such as Spinotransversales muscles into Spinotransversal muscles as in Transversospinal muscles has been done. The same holds for Interspinales and Intertransversarii muscles, for the muscles of the tongue and the palate. The revised terminology for the muscular system can be viewed on the Fribourg website (https://ifaa.unifr.ch).

Fig. 4
figure 4

Musculi membri superioris

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The next part concerns the Systema cardiovasculare (Cardiovascular system). It forms Chapter 12 of the TAH. Again, the following parts are discussed in a partonomic hierarchy:

  1. 1.

    Cor: following the TA2, (a) the importance of an attitudinal appropriate description was emphasized (Anderson and Loukas 2009); (b) we reordered terms so that the atrioventricular valves are considered in the context of a ‘valvar complex’ (Complexus valvaris cordis); (c) the section on fibrous skeleton of heart (Skeleton fibrosum cordis) has been extended according to recent studies (Mori et al. 2016; Saremi et al. 2017); and (d) the conducting system of the heart (Systema conducens cordis) is listed separately, to which the internodal tracts were added (James 1963, 2001; Seo et al. 2022).

  2. 2.

    Systema arteriosum commune following TA98 with some additions from the literature (Kachlik et al. 2015, 2017, 2018, 2021). The intrarenal arteries have also been added.

  3. 3.

    Systema arteriosum cerebrospinale (from TNA).

  4. 4.

    Systema venosum commune following TA98 with some additions from the literature, in particular the veins of the lower limb (Caggiatti et al. 2002, 2005, 2018, 2021; Kachlik et al. 2010, 2012). Sections on the portocaval anastomoses (Anastomoses portocavales) and the cavocaval anastomoses (Anastomoses cavocavales) have been added as well as the intrarenal veins.

  5. 5.

    Systema venosum cerebrospinale (from TNA).

  6. 6.

    Vasa lymphatica following TA98 with superficial and deep trunks for the limbs added (Kachlik et al. 2017, 2018, 2021).

In Fig. 5, the Anastomoses portocavales are presented. Under pathological conditions, veno-venous ‘bypasses’ open to decrease hypertension in the hepatic portal vein system. These are enlarged existing veno-venous anastomoses. The following major routes can be distinguished (Luzsa 1972; Kachlik et al. 2021) between: (a) the left gastric vein and the oesophageal veins; (b) the inferior mesenteric vein (and its superior rectal vein) and the middle and inferior rectal veins; (c) the paraumbilical veins and tributaries of the superficial epigastric and thoracoepigastric veins; (e) the paraumbilical veins and tributaries of the inferior and superior epigastric veins within both rectus abdominis muscles; (f) the paraumbilical veins and tributaries of the vesical venous plexus running in the midline along the median umbilical ligament; (g) the splenic, superior and inferior mesenteric veins and retroperitoneal veins and veins of the posterior abdominal wall; (h) between veins of the hepatic capsule and veins of the diaphragm at the area nuda of the liver.

Fig. 5
figure 5

Anastomoses portocavales

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For the Systemata visceralia (Chapters 5–10) of the TAH, we largely followed the TA98. Again, new data from the literature are added (Kachlik et al. 2015; Musil et al. 2019; TA2) and, where appropriate, the layers of the various structures were brought in line with the TH. For Chapter 5 (Systema digestorium), we decided to present the Teeth as a separate section Dentition (in progress; Chapter 6). The recently published Oroanatomical Terminology with Russian Equivalents, which was approved by the Working Group Terminologia Oroanatomica (TOA) of FIPAT, will be consulted (Nikityuk 2023). The muscles of the tongue, palate, and pharynx are listed under Systema musculare with a reference in this chapter. For all parts of the digestive system, the presentation of the various layers follows the TH as exemplified for the Laminae intestini tenuis in Fig. 6. In Chapter 7 (Systema respiratorium), the Cartilagines laryngis and Articulationes laryngis were kept in this chapter. The laryngeal muscles, however, are listed under Systema musculare. The section Cavitas thoracis follows TA98, as did TA2, but will be included in a new Chapter 10. In Chapter 8 (Systema urinarium), the process of removing microscopic features to the TH as in TA2 is not followed. For all parts, layers are included again as shown for the Vesica urinaria in Fig. 7. Chapter 9 (Systemata genitalia) in fact consists of two separate sections: Systema genitale femininum and Systema genitale masculinum. The hotly debated term Pudendum femininum was replaced by Vulva, although in the BNA Regio pudendalis was used for both sexes. For further discussion, see Moxham and Sprumont (2016) and Kachlik (2021). The terms on the Perineum are largely included in the Systema musculare (Fascia pelvis, Diaphragma pelvis). Remaining terms such as Fossa ischioanalis are together with the Cavitas thoracis and the Cavitas abdominopelvica covered in Chapter 10 (Systema trunci).

Fig. 6
figure 6

Laminae intestini tenuis

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Fig. 7
figure 7

Laminae vesicae urinariae

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Remaining short Chapters, including Chapter 11 (Glandulae endocrinae), Chapter 13 (Systema lymphaticum), and Chapter 16 (Integumentum commune) will be included shortly. The large Chapters 2 (Systema skeletale) and 3 (Systema articulare) will be dealt with in the first half of 2024.

Conclusions

The long-awaited revision of the official anatomical nomenclature, the second edition of the Terminologia Anatomica (TA2), issued in 2019, breaks with many traditional views of terminology. These changes in the TA98 met great resistance in many European Anatomical Societies who decided to keep using the TA98. We felt that the TA98 certainly needs updating but especially a digital version. The Terminologia Anatomica Humana project incorporates the recent digital version of the Terminologia Neuroanatomica from 2017 as its Chapters 14 and 15. The TAH is expanded with many new terms, including those in TA2, along with their definitions, relevant references, and clinical terms as shown in the various tables. Inconsistencies in the TA98 were corrected. Although the TAH is still in progress, many chapters are already available at the IFAA Website in Fribourg (https://ifaa.unifr.ch) as is the digital version of the TNA (2022).