Terminologia anatomica: new terminology for the new anatomist.

Over many years, anatomical terminology has been the subject of much controversy and disagreement. Previously, the International Anatomical Nomenclature Committee has been responsible for the production of six editions of Nomina Anatomica. In 1989 a new committee, the Federative Committee on Anatomical Terminology (FCAT), was created by its parent body, the International Federation of Associations of Anatomists (IFAA). FCAT has worked for 9 years and published Terminologia Anatomica (TA) in 1998. FCAT's aim has been to democratize the terminology and make it the internationally accepted, living language of anatomy. The worldwide adoption of the same terminology would eliminate national differences, which were causing extreme confusion in instances where the same structure was known by several names. The new terminology is thus the result of worldwide consultation and contains Latin and equivalent English terms. It is indexed in Latin and English and contains an index of eponyms in order to find the correct non-eponymous term. The future goal of FCAT is to continue to improve the terminology-new structures are described, different terms come into use, and the terminology needs to be expanded to include terms used by clinicians for structures that currently do not appear in the list. Future versions of the terminology must accommodate the needs of all who use it, both in the clinical and scientific worlds.

Career progress of temporary lecturers in anatomy: a surgical success story.

A questionnaire concerning career progress was sent to 159 previous holders of temporary lecturer posts in anatomy (TLAs) at the University of Manchester (UK) between 1975 and 1992. Replies were received from 123 TLAs, of whom 90% were male and 71% had achieved Fellowship(s) of a Royal College of Surgeons. Of the 86 respondents who had reached career appointments, 72% held surgical posts, 16% were in general practice, 6% were in nonsurgical hospital specialties, and 6% in nonclinical careers. The duration of training for the surgical specialties overall had been 12 years. Postgraduate diplomas and degrees had been obtained by 93% of career post holders. Most respondents (87%) had found the posts to be useful for their ongoing careers, citing improved communication skills and teaching. The positive values of temporary lecturer posts in anatomy are discussed in relation to the declining numbers of medically qualified anatomists, and the implications of changes in postgraduate surgical training in the UK are highlighted.

Endoscopic visualisation of the human nasolacrimal system: an experimental study.

Orthograde and retrograde endoscopy of the upper and lower nasolacrimal system was performed using two prototype ultrathin (0.5 mm and 1.1 mm diameter) fibrescopes on four cadaver heads. Appearances were verified by subsequent dissection. The procedure, which we term 'dacryocystoscopy' is described. With modifications this technique may have clinical applications in the treatment of nasolacrimal disorders.

A quantitative study of the histochemical and morphometric characteristics of the human cricopharyngeus muscle.

Samples of human cricopharyngeus muscles obtained at postmortem were assessed for fibre type composition and fibre size. Fibre type was determined using serial cryostat sections exposed to several histochemical reactions; narrow fibre diameter and fibre area were measured from photomicrographs using a digitiser interfaced to a microcomputer. Results were compared with values from samples of vastus lateralis obtained from the same subjects. Cricopharyngeus muscle, in comparison with vastus lateralis, contained significantly more oxidative fibres but fewer glycolytic fibres and significantly more Type I fibres but fewer Type IIB. Cricopharyngeal fibres were significantly smaller than the fibres in vastus lateralis and in neither muscle were fibre sizes normally distributed. In each muscle most Type I fibres were oxidative, and the ratio of oxidative: glycolytic fibres was similar for Type IIA and IIB fibres. The fibre type proportions and fibre sizes in cricopharyngeus did not vary significantly with age or between males and females. The composition of cricopharyngeus--mostly Type I oxidative fibres and few Type II glycolytic fibres--correlated well with the functions of sustained tonicity to prevent aerophagia and occasional forceful contraction during deglutition.

A histological and histochemical study of the cricopharyngeus muscle in man.

The human cricopharyngeus muscle was investigated by dissection and by histological, histochemical and morphometric methods. Muscle fibres in the cricopharyngeus were found to be similar in appearance to those of the lateral part of the quadriceps femoris, although they were generally much smaller and more variable in size. The endomysial connective tissue was markedly increased in the cricopharyngeus and muscle spindles were not found. Certain features normally considered to be pathological were also noted in the cricopharyngeus muscles. The fibre type population consisted mainly of histochemically 'slow-twitch' richly oxidative fibres. This finding is consistent with the proposed function of this muscle in its sphincteric role in deglutition, vomiting, eructation and in the control of aerophagia.

A quantitative investigation into some ultrastructural characteristics of guinea-pig oesophageal striated muscle.

Electron micrographs of guinea-pig oesophageal striated muscle have been subjected to quantitative assessment. The results show that whereas the motor end-plates are considerably simpler than those of control hindlimb muscles, the Z-line width and M-line bridges are those of fast-twitch, oxidative and glycolytic fibres. Guinea-pig oesophageal striated muscle continues to defy classification into the normally accepted subtypes for skeletal muscle and should thus be considered as an example of 'visceral striated muscle'.

A histological and histochemical study of the cricopharyngeus muscle in the guinea-pig.

Histological, histochemical and morphometric methods were used to investigate the cricopharyngeus muscle in the guinea-pig and to compare it with the extensor digitorum longus and soleus muscles. The cricopharyngeus comprised uniformly small diameter fibres otherwise similar in appearance to those found in skeletal limb muscles. Several fibre type profiles were distinguished within the cricopharyngeus, all of which had homogeneously high oxidative activity, whilst the majority were histochemically fast (Type II). Muscle spindles were not observed in the cricopharyngeus muscles. Compared to the surrounding musculature the cricopharyngeus has a higher oxidative activity and may thus be suitably adapted for the maintenance of tonic contraction, forming a part of the upper oesophageal sphincter.

A comparison between the physiological and histochemical characterisation of urethral striated muscle in the guinea pig.

In this in vitro study comparison has been made between the actomyosin ATPase activity and the contractile properties of the external urethral sphincter in the guinea pig. Histochemical analysis showed the external urethral sphincter to contain a mixture of alkali and acid stable actomyosin ATPase positive fibres in the ratio of 3:1. External urethral sphincter isometric contraction measurements were undertaken using specimens mounted transversely or longitudinally with respect to the urethral lumen. These contraction parameters have shown that the majority of fibres which constitute the external urethral sphincter correspond to the fast twitch type. In order to determine whether the relatively small fibre diameter of urethral striated muscle influenced the contraction results, when compared with controls, corrections for different volume ratios of slow and fast fibres were applied to the results. These modified values revealed close correlation between muscle fibre actomyosin ATPase content and isometric contraction responses.

The ultrastructure of oesophageal striated muscle in the guinea-pig and marmoset.

The ultrastructural characteristics of oesophageal striated muscle from guinea-pig and marmoset have been examined using transmission electron microscopy and compared with ultrastructural features of skeletal muscle. The findings show that, although similar to skeletal muscle, oesophageal striated muscle exhibits important differences in the arrangement of its muscle fibres and their motor innervation. It was also found impossible to classify oesophageal striated muscle according to the usual ultrastructural criteria since its motor endplates bore a greater resemblance to those of intrafusal skeletal muscle fibres. The consideration of these differences in conjunction with characteristics revealed elsewhere by other techniques confirms the unique nature of oesophageal striated muscle.

A comparison of the mechanical properties of oesophageal striated muscle with skeletal muscles of the guinea pig.

An in vitro comparative study has been made of the contractile properties of guinea pig oesophageal striated muscle with fast twitch (extensor digitorum longus) and slow twitch (soleus) muscles. Histochemical analysis of sections showed oesophageal fibres to react in a manner typical of fast twitch muscles. Isometric measurements made at 23 and 37 degrees C indicated that oesophageal striated muscle contracts at speeds similar to, but still significantly faster than soleus. Isotonic measurements of oesophageal preparations made at 23 degrees C gave an intrinsic speed of shortening and an a/Po value derived from Hill's equation, comparable with that obtained for soleus. The reason for the contradiction between the results from histochemistry, and the results from isometric and isotonic contractions are not apparent, but may be due to differences in fibre arrangement between oesophagus and the two skeletal muscles.

Oesophageal striated muscle arrangement and histochemical fibre types in guinea-pig, marmoset, macaque and man.

The muscularis externa of the oesophagus was examined histologically and histochemically in the guinea-pig, marmoset, and man. It was found that the transition from striated muscle to smooth occurred more gradually and at a more proximal level in the primates than in the guinea-pig. In addition, minor differences in fibre lay-out were observed between the four species examined. Guinea-pig oesophageal striated muscle was all found to be of one type, 'fast twitch' oxidative and glycolytic. The marmoset oesophageal muscle, also unitypical, was 'slow twitch' and oxidative. Both the macaque and man each revealed two types: 'slow twitch' oxidative glycolytic and 'fast twitch' oxidative glycolytic, and concluded that these differences represent species variation.