Anatomic and histologic analysis of paca larynx (Cuniculus paca, Linnaeus 1766) / [Análise anatômica e histológica da laringe da paca (Cuniculus paca, Linnaeus 1766)]

Paca (Cuniculus paca) has encouraged research as an experimental model both in the human medicine and veterinary, as well as the economic exploitation of its meat cuts, which favored its zootechnical use. There are no anatomical, microscopic descriptions and measurements of the larynx in this rodent. Eight pacas were dissected from the wild animal's sector of the Faculty of Agricultural and Veterinary Sciences of the University of the State of São Paulo. The larynx was observed located in the ventral region of the neck, ventral to the esophagus, connecting the pharynx to the trachea, with cylindrical and irregular shape. Laryngeal cartilages (epiglottic, thyroid, cricoid and arytenoid) are interconnected and have different shapes. Thyroid showed greater length and width, compared to the others. Laryngeal cartilages were submitted to histological processing and stained with hematoxylin-eosin and Masson's trichrome. The epiglottic cartilage was stained with toluidine blue. Laryngeal cartilages thyroid, cricoid and the lower portion of the arytenoids are of hyaline origin and, in contrast, the epiglottis and the upper portion of the arytenoids are elastic. This latter cartilage demonstrated taste buds. The results will be able to auxiliate in veterinary care and as well as the conservation programs for this rodent.(AU)

A paca (Cuniculus paca) tem encorajado inúmeras pesquisas, tornando-a modelo experimental tanto em humanos como na veterinária, além da exploração econômica de seus cortes cárneos, que favoreceu diretamente sua importância zootécnica. Não há descrições anatômicas, microscópicas e mensurações da laringe desse roedor. Foram dissecadas oito laringes de pacas, provenientes do setor de Animais Silvestres da Faculdade de Ciências Agrárias e Veterinárias - Universidade Estadual Paulista. Observou-se que a laringe localiza-se na região ventral do pescoço, ventral ao esôfago, conectando a faringe à traqueia, possuindo formato cilíndrico e irregular. As cartilagens laríngeas (epiglote, tireóide, cricóide e aritenóidea) são interligadas e possuem formatos variados. A cartilagem tireóide demonstrou-se maior em comprimento e largura, comparativamente às demais. As cartilagens laríngeas foram submetidas a processamento histológico e coradas em hematoxilina-eosina e tricrômio de Masson. A cartilagem epiglote foi corada em azul de toluidina. As cartilagens laríngeas tireóide, cricóide e a porção inferior das aritenóides são de origem hialina; em contrapartida, a epiglote e a porção superior das aritenóides, de origem elástica. Esta última cartilagem demonstrou corpúsculos gustativos. Os resultados poderão auxiliar tanto nos atendimentos veterinários quanto nos programas de conservação desse roedor.(AU)

Variants of the hyoid-larynx complex, with implications for forensic science and consequence for the diagnosis of Eagle's syndrome.

Thorough anatomic knowledge of the hyoid-larynx complex is necessary for forensic radiologists and ear-nose-throat surgeons, given the many anatomic variations that originate in embryology. In forensics the anomalies must be distinguished from fractures because the latter are indicative of violence on the neck. In this manuscript we describe the anatomical variations that can be found in the hyoid-larynx complex and explain their etiology. 284 radiological scans of excised hyoid-larynx complexes were examined with X-ray and CT. Some rare cases from literature and historical collections were added. Two third of the examined hyoid-larynx complexes deviated from the anatomical standard and showed uni- or bilateral ankylosis in the hyoid bone and/or so-called triticeal cartilages. In one fifth of the cases we found striking anatomical variants, mostly derived from the cartilage of the second pharyngeal arch. Anatomical variations of the hyoid-larynx complex can be explained by embryological development. The aberrant hyoid apparatus and the elongated styloid processes (Eagle syndrome) should be considered as one clinical entity with two different expressions as both anomalies are derived from the cartilage of the second pharyngeal arch. Several variants can mimic fractures in this region, so our study is important for radiologists and forensic experts assessing cases of possible violence on the neck.

Morphology of laryngeal cartilage of the nine-banded armadillo (Dasypus novemcinctus) Linnaeus, 1758.

Armadillos, Xenarthras representatives, known for adaptability to different ecosystems, own specific morphophysiological characteristics that are not known and deserve to be studied. The aim of this study was to describe the morphology of cartilage of the larynx of the nine-banded armadillo (Dasypus novemcinctus). Five dead armadillos were donated by the Chico Mendes Institute of Biodiversity (ICMBio-PI) to the Federal University of Piauí. The animals were fixed and dissected for removal of the larynx. The cartilages were identified and described, photodocumented, and schematized. Fragments with about 0.5 cm of each cartilage were collected and submitted to classical histology for Hematoxylin-Eosin coloring. The slides were assembled in enterlan and analyzed under a light microscope. The larynx of the armadillo (D. novemcinctus) is located in the mentonian region, ventral to the esophagus, and due to the total positioning of the tongue in the oral cavity, there is also a cranial cervical position in this species. The larynx has five cartilages, they are: a cricoid, a thyroid, an epiglottis, and two arytenoids. The corniculate process is present; however, the cuneiform process is absent. The epiglottis has a discrete bifurcation at its apex. In all cartilages epithelial variations are observed. The tissues are varied from squamoso stratified to cylindrical pseudostratified, with propria lamina rich in mucoserosas glands. With the exception of epiglottic cartilage, predominantly elastic, the rest are hyaline. The larynx of D. novemcinctus, although the same number of cartilages, differs morphologically and microscopically from the larynx of other species.

Morfologia da laringe em Cerdocyon thous (Linnaeus, 1766) / Laryngeal morphology in Cerdocyon thous (Linnaeus, 1766)

Cerdocyon thous (cachorro-do-mato) é o canídeo silvestre mais comum em território sul-americano. Objetivou-se com o presente trabalho descrever a morfologia macroscópica, microscópica e comparada da laringe nesta espécie. Para tal, as laringes de dezesseis espécimes (quatro machos e doze fêmeas) foram analisadas quanto à topografia, forma, morfometria, musculatura intrínseca e histologia. A laringe dispôs-se ventralmente ao áxis e foi constituída por uma cartilagem tireoide e outra cricoide (hialinas), uma epiglótica (elástica) e um par de ariteoides (mistas). Um par de cartilagens sesamoides foi identificado entre os processos corniculados e a lâmina da cricoide. A morfometria revelou que a tireoide é a maior cartilagem. Não houve sinais definitivos de dimorfismo sexual na laringe de C. thous. O epitélio predominante foi do tipo pavimentoso estratificado o qual sofreu transição para pseudoestratificado cilíndrico ciliado ao nível do terço caudal da tireoide e rostral da cricoide. A laringe de C. thous mostrou semelhança com a do cão doméstico, ainda que o formato das cartilagens tenha apresentado diferenças.

Cerdocyon thous (crab-eating fox) is the most common wild canid in South American territory. The aim of this paper was to describe macroscopic, microscopic and comparative morphology of the larynx of this species. Analyses of larynges of sixteen specimens (four males and twelve females) revealed the topography, conformation, morphometrics, intrinsic muscles and histological characteristics. The larynx was positioned ventral to the axis and comprised one cricoid and one thyroid cartilage (hyaline), one epiglottis (elastic) and a pair of arytenoids (mixed). A pair of sesamoid cartilages was identified between the corniculate processes and the cricoid lamina. Morphometry revealed that thyroid cartilage was the largest. There were no conclusive signs of sexual dimorphism in the larynx of this species. Squamous stratified epithelium predominated and underwent transition to ciliated pseudo-stratified at the level of caudal thyroid and rostral cricoid portions. By comparison, larynx of C. thous showed similarity with the domestic dog, although the shape of cartilages has shown some variation.

Microcomputed tomography visualization of the cricoarytenoid joint cavity in cadavers.

OBJECTIVES: To visualize the cricoarytenoid joint (CAJ) cavity of the human cadaver and to correlate its appearance to the CAJ capsule. STUDY DESIGN: Prospective. METHODS: A total of 26 cadavers were used for microcomputed tomography arthrography, histology, and epoxy sheet plastination examinations. RESULTS: (1) The dimension of the CAJ cavity was much larger than the articular surfaces; (2) The posterior capsule of the CAJ was significantly strengthened, contained rich elastin fibers, and shared a common attachment with the posterior cricoarytenoid muscle; (3) The arytenoid cartilage was distanced from the cricoid cartilage at the superomedial aspect of the CAJ. CONCLUSIONS: This study demonstrates that the posterior fibrous capsule is the primary passive stabilizer of the CAJ and suggests that in addition to the gliding, rucking, and rotation, a visor-like jumping of the arytenoid cartilage on the cricoid cartilage may provide further adjustments in motions of the vocal fold. The finding of this study has implications for the biomechanics of the CAJ motion; the differential diagnosis of CAJ disorders, such as CAJ dislocation and subluxation; and surgical correction of the CAJ dysfunction.

Percutaneous dilatational tracheostomy: review of technique and evidence for its use.

Tracheostomy is a technique for airway management commonly used by surgeons who care for critically ill patients. Patients with traumatic facial injuries, severe odontogenic infections, and head and neck malignancies are often recipients of tracheostomies. As such, the oral and maxillofacial surgeon who frequently treats such patients should be well-trained in tracheostomy placement. For decades, the standard technique for tracheostomy was the open surgical technique. However, during the past 20 years, the use of percutaneous dilatational tracheostomy has increased. The purpose of the present report is to review the percutaneous dilatational tracheostomy technique, describe the use of intensive care units as proxies for the operating room, and review the available evidence comparing percutaneous dilatational tracheostomy to open tracheostomy.

A new method of reconstructing the human laryngeal architecture using micro-MRI.

OBJECTIVES/HYPOTHESIS: A realistic three-dimentional (3D) model of the larynx could be of value for the understanding of normal laryngeal motion and for studying pathological changes as well as in modeling potential therapy outcomes. The objective of this research was to present a new method of creating a computer model of the human larynx using data obtained through micro-magnetic resonance imaging (MRI) scanning. STUDY DESIGN: Prospective study. METHODS: A 7-T micro-MRI scanner was used to scan an excised larynx obtained postmortem from a 68-year-old woman. MRI data was manually segmented and compiled into 3D images using Mimics12.1 reconstruction software. Measurements of the reconstructed structures were also calculated using Mimics12.1. RESULTS: The 3D laryngeal model contained the thyroid, cricoid, and arytenoid cartilages. Nearly all of the intrinsic muscles could be segmented. Although the cricoarytenoid joint could be visualized, the features of the cricothyroid joint were not clear. Muscle and cartilage volumes and surface areas were calculated from the 3D model. CONCLUSIONS: The combination of MRI and 3D reconstruction generates promising results in the hopes of creating a highly realistic and detailed model of the human larynx.

Short review: field recovery and potential information value of small elements of the skeleton.

The recovery of small elements of the skeleton (e.g. hyoid, carpals, and hand and foot phalanges) is one of the established tasks of the archaeologist and physical anthropologist when working in the field, whether in an archaeological or forensic context. In the present work, we illustrate the field location of ossified laryngeal cartilages, hand sesamoids, and the medial clavicular epiphyses. The potential information offered by these elements is briefly summarized. The frequency of these elements observed in a cemetery dating from 1943 indicates the possibility that these elements could be found in other contexts at a higher frequency than expected.

Biomechanical characterisation of equine laryngeal cartilage.

REASONS FOR PERFORMING THE STUDY: Upper airway obstruction is a common problem in the performance horse as the soft tissues of the larynx collapse into the airway, yet there is a paucity of information on biomechanical properties for the structural cartilage components. OBJECTIVE: To measure the geometry and compressive mechanical properties of the hyaline cartilage to improve understanding of laryngeal function and morphology. METHODS: A total of 11 larynges were harvested from Thoroughbred and Standardbred racehorses. During gross dissection, linear dimensions of the cricoid were obtained. From both the cricoid and arytenoid, specimens were cored to obtain 6 mm disc samples from 3 sites within the dorsal cricoid (caudal, middle and rostral) and 2 central sites in the arytenoids (inner, outer). The specimens were mechanically tested using radial confined compression to calculate the aggregate modulus and permeability of the tissue. The biomechanical data were analysed using a nested mixed effects model. RESULTS: Geometrically, the cricoid has relatively straight walls compared to the morphology of human, ovine and canine larynges. There were significant observations of higher modulus with increasing age (0.13 MPa per year; P = 0.007) and stiffer cricoid cartilage (2.29 MPa) than the arytenoid cartilage (0.42 MPa; P<0.001), but no difference was observed between the left and right sides. Linear contrasts showed that the rostral aspect (2.51 MPa) of the cricoid was 20% stiffer than the caudal aspect (2.09 MPa; P = 0.025), with no difference between the arytenoid sites. CONCLUSIONS: The equine larynx is a well supported structure due to both the geometry and material properties of the cricoid cartilage. The hyaline structure is an order of magnitude higher in compressive modulus compared to the arytenoids and other hyaline-composed tissues. POTENTIAL RELEVANCE: These characterisations are important to understand the biomechanics of laryngeal function and the mechanisms involved with surgical interventions.

Membranous and cartilaginous vocal fold adduction in singing.

While vocal fold adduction is an important parameter in speech, relatively little has been known on the adjustment of the vocal fold adduction in singing. This study investigates the possibility of separate adjustments of cartilaginous and membranous vocal fold adduction in singing. Six female and seven male subjects, singers and non-singers, were asked to imitate an instructor in producing four phonation types: "aBducted falsetto" (FaB), "aDducted falsetto" (FaD), "aBducted Chest" (CaB), and "aDducted Chest" (CaD). The phonations were evaluated using videostroboscopy, videokymography (VKG), electroglottography (EGG), and audio recordings. All the subjects showed less posterior (cartilaginous) vocal fold adduction in phonation types FaB and CaB than in FaD and CaD, and less membranous vocal fold adduction (smaller closed quotient) in FaB and FaD than in CaB and CaD. The findings indicate that the exercises enabled the singers to separately manipulate (a) cartilaginous adduction and (b) membranous medialization of the glottis though vocal fold bulging. Membranous adduction (monitored via videokymographic closed quotient) was influenced by both membranous medialization and cartilaginous adduction. Individual control over these types of vocal fold adjustments allows singers to create different vocal timbres.

The incidence of the foramen thyroideum in the South African population / Incidencia del foramen tiroideo en la población de sudáfrica

The foramen thyroideum is described as an occasional opening existing in one or both laminae of the thyroid cartilage which may or may not contain a neurovascular component. Foramen thryoideum was first described in the literature by Segond in 1847. Some authors consider its existence a structural variation rather than an anomaly, with classical texts of anatomy providing little detail when describing this foramen. This study was undertaken to investigate the incidence and characteristics of the foramen thyroideum in the South African population. A total of 80 formalin fixed cadaveric laryngeal specimens (obtained from the Department of Clinical Anatomy, University of KwaZulu-Natal, South Africa) were dissected. Larynges were dissected with the aid of a Stemi DV 4 light microscope. The incidence, location, dimensions and contents of the foramen thyroideum were recorded. The horizontal and vertical extent of each foramen was measured with a digital caliper. Six of the 80 (7.5 percent) specimens examined had distinctly identifiable foramina. Five of the six cases (4 male, 1 female) displayed bilateral foramina (6.3 percent), with one case (1 female) of a unilateral foramen (1.3 percent). Of the larynges that had bilateral foramina, a single case presented with two foramina on the same (right) thyroid lamina. A total of twelve foramina were observed. Gender distribution of foramen thyroideum was: male: right 5, left 4; female: right 2, left 1. Preceding investigators of the foramen thyroideum have rightly indicated that awareness of its presence is of paramount importance in order to preserve the structures that traverse it and also to comprehensively treat or contain laryngeal cancer.

El foramen tiroideo se describe como una apertura ocasional existente en una o ambas láminas del cartílago tiroides, la cual puede o no contener un componente neurovascular. El foramen tiroideo fue descrito por primera vez en la literatura por Segond en 1847. Algunos autores consideran su existencia como una variación estructural y no una anomalía, los textos clásicos de anatomía proporcionan pocos detalles al describir este foramen. Este estudio se realizó para investigar la incidencia y características del foramen tiroideo en la población Sudafricana. Fueron disecados 80 especímenes cadavéricos de larínge fijados con formalina (obtenidos del Departamento de Anatomía Clínica de la Universidad de KwaZulu-Natal, Sudáfrica). Las laringes fueron disecadas con la ayuda de un microscopio de luz Stemi DV 4. La incidencia, localización, dimensiones y contenido del foramen tiroideo fueron registradas. La extensión horizontal y vertical de cada foramen se midieron con un caliper digital. Seis de los 80 (7,5 por ciento) especímenes examinados tenían foramen tiroideos claramente identificables. Cinco de los seis casos (cuatro hombres y una mujer) mostraron forámenes bilaterales (6,3 por ciento), y un caso (una mujer) foramen unilateral (1,3 por ciento). De las laringes que presentaron forámenes bilaterales, un solo caso presentó dos forámenes en la misma lámina del cartílago tiroides (derecha). La distribución por sexo del foramen tiroídeo en hombres fue 5 derechos y 4 izquierdos, mientras que en mujeres 2 derechos y 1 izquierdo. Los resultados indican que el conocimiento de la presencia del foramen tiroideo es de vital importancia para preservar las estructuras que lo atraviesan y también para el tratamiento de integral o contención del cáncer de laringe.

Relationship between the internal laryngeal nerve and the triticeal cartilage: a potentially unrecognized compression site during anterior cervical spine and carotid endarterectomy operations.

OBJECTIVE: The triticeal cartilage has received scant attention in the literature. To date, its relationship to the nearby internal laryngeal nerve has not been studied. Therefore, to elucidate further this anatomic relationship and its potential surgical implications, this study was performed. METHODS: Eighty-six adult cadaveric sides underwent dissection of the internal laryngeal nerve near its penetration of the thyrohyoid membrane. The relationship of this nerve to the triticeal cartilage was documented. Measurements and histological analysis were performed on all cartilage specimens. RESULTS: We identified triticeal cartilage in 51% of the specimens and found it to be hyaline in nature. The triticeal cartilage was located in the upper, middle, and lower thirds of the thyrohyoid membrane in 14%, 66%, and 20% of sides, respectively. Regardless of the position of the triticeal cartilage within the thyrohyoid membrane, the internal laryngeal nerve crossed directly over the triticeal cartilage on 59% of sides. CONCLUSION: When present, the internal laryngeal nerve will cross over the triticeal cartilage in the majority of individuals. This relationship should be borne in mind during surgical manipulation in this area and when placing retractors during anterior neck operations including cervical discectomy/fusion and carotid endarterectomy. Compression of the internal laryngeal nerve against the solid triticeal cartilage can cause laryngeal nerve palsy and increase the risk of resultant postoperative aspiration.

Implementation of a virtual laryngoscope system using efficient reconstruction algorithms.

BACKGROUND: Conventional fiberoptic laryngoscope may cause discomfort to the patient and in some cases it can lead to side effects that include perforation, infection and hemorrhage. Virtual laryngoscopy (VL) can overcome this problem and further it may lower the risk of operation failures. Very few virtual endoscope (VE) based investigations of the larynx have been described in the literature. MATERIAL/METHODS: CT data sets from a healthy subject were used for the VL studies. An algorithm of preprocessing and region-growing for 3-D image segmentation is developed. An octree based approach is applied in our VL system which facilitates a rapid construction of iso-surfaces. Some locating techniques are used for fast rendering and navigation (fly-through). RESULTS: Our VL visualization system provides for real time and efficient 'fly-through' navigation. The virtual camera can be arranged so that it moves along the airway in either direction. Snap shots were taken during fly-throughs. The system can automatically adjust the direction of the virtual camera and prevent collisions of the camera and the wall of the airway. CONCLUSIONS: A virtual laryngoscope (VL) system using OpenGL (Open Graphics Library) platform for interactive rendering and 3D visualization of the laryngeal framework and upper airway is established. OpenGL is supported on major operating systems and works with every major windowing system. The VL system runs on regular PC workstations and was successfully tested and evaluated using CT data from a normal subject.

Pitch synchronous changes of the anterior cricothyroid gap by using ultrasonography.

OBJECTIVES: The purpose of this study was to describe changes of the anterior cricothyroid space during respiration and phonation by using ultrasonography. Furthermore, to assess and correlate laryngeal dimensions in a large cohort of voice healthy men. STUDY DESIGN: Epidemiological study. METHODS: Ultrasound examinations of the laryngeal skeleton, as well as of the cricothyroid space were performed in 64 voice healthy, elderly male subjects. This was done during respiration, phonation in midrange, and high phonation. RESULTS: We could not find any significant correlation concerning lengths of the cricothyroid space when correlated with voice range, highest or lowest frequency. General anthropometric parameters such as body height, weight, or body mass index did not show any considerable correlation with dimensions of the laryngeal skeleton. CONCLUSION: Functionally orientated surgery of the larynx requires exact knowledge of the anatomy and landmarks of the laryngeal skeleton. Topographic relations and dimensions between the thyroid and cricoid cartilages play an important role in cricoid approximation.

Prenatal and early postnatal morphogenesis and growth of human laryngotracheal structures.

Advances in neonatal medicine have resulted in increased care of fetal and neonatal airways. These advances have required an exhaustive knowledge of fetal airway anatomy and development. The aim of this study was to determine the anatomical development of laryngotracheal structures during the fetal and immediate postnatal period and to correlate these observations with other fetal biometric parameters to estimate developmental particularities of the fetal airway. An anatomical prospective study was based on examination of larynx and trachea from 300 routine autopsies of fetuses and infants, free of malformation and never intubated. Anatomical measurements of cricoid cartilage, thyroid cartilage, glottis, arytenoid cartilage and trachea were performed using a precision calliper and precision divider. Statistical analysis was performed to represent the growth of anatomical structures and to evaluate the correlation with biometric data. Raw data and 10th and 90th percentile curves were fitted satisfactorily with a linear model for gestational age. A linear relationship between laryngotracheal measurement and body weight and height was observed except for glottis length, interarytenoid distance and anterior cricoid height. The diameter of the cricoid lumen was significantly less than that of the trachea and glottis lumen. A sexual dysmorphism was noted for thyroid cartilage measurements and interarytenoid distance, with measurements significantly smaller in females. This study reports the anatomical development of normal laryngotracheal structures during the fetal period. Despite the fact that this study was performed during postmortem examination, these observations can be useful to develop criteria, materials and surgical procedures adapted to fetal and neonatal airways as well as for the purposes of early diagnosis and management of laryngotracheal malformations.

The gross anatomy of larynx, trachea and syrinx in the long-legged buzzard (Buteo rufinus).

Five long-legged buzzards (Buteo rufinus), weighing 475-570 g, were used in this study. It was determined that long-legged buzzards' larynx is composed of three different cartilages. Among these cartilages, the cricoid and procricoid cartilages were single and the arytenoid cartilage was double. The partially ossified corpus and ala of the cricoid cartilage were connected with cartilaginous plate. Trachea was formed up of complete cartilage circles. The tracheal cartilages were notched in dorsal and ventral directions and a number of the tracheal cartilages inter-mingling one another were between 89-96. Syrinx, which was covered with the inter-clavicular air sac, was in contact with basis cordis. It was observed that there is tracheobronchial type syrinx in long-legged buzzard and this syrinx is formed by two different cartilage groups named as the cartt. tracheosyringeales and cartt. bronchosyringeales. The first cartilage rings of the cartt. tracheosyringeales formed the tympanum. The tympanum, cartt. tracheosyringeales and cartt. bronchosyringeales were created of three, two or three and four cartilage rings, respectively. Membrana tympaniformis lateralis and medialis, two pairs of thin membranes constituting voice formation, also determined in long-legged buzzard. Membrana tympaniformis lateralis was observed to be very short between the first and second cartilage rings of cartt. bronchosyringeales. Although the instrictic syringeal muscles were not present in long-legged buzzard, the sternotracheal and tracheolateral muscles, expressed as extrinsic syringeal muscles, were evident. In this study, which is expected to give contribution to veterinary anatomy literature, the similarities and differences in larynx, trachea and syrinx of long-legged buzzard with other bird species were exposed.

[The tensegrity concept applied to the laryngeal biodynamics]. / Du concept de tenségrité à la biodynamique laryngée.

The knowledge of spaces and sliding ways of the forehead part of the neck must be accomplished, however the microscopic observation of these sliding ways shows in fact a real concrete material continuity, through the existence of a binding tissue between the sliding structures. This tissue is shaped in a web form system of multimicrovacuolar collagenic fibers. It respects the functional unit, while saving the relative independance of moving between the different structures concerned. The architectural features of any living tissue may be reported to a tensegrity system. The word of tensegrity is a portmanteau of tensional-integrity, as proposed by the american architect Richard Buckmister Fuller. Following tensegrity the laryngeal biodynamic behaviour is based on two sets of tensions and compressions applied on itself. The laryngeal system is therefore in a constant balance of tissular tensions. The multimicrovacuolar system has a main place. This new point of view may be applied to the laryngeal dysfunctions.

[Visualization and thin sectional anatomy of the laryngeal cartilages].

OBJECTIVE: To establish digitized visible model of the laryngeal cartilages of the visible human, providing morphological data for image diagnosis and laryngectomy. METHODS: Cross-sectional images of fresh tissues from the Chinese visible human data set were reviewed, and the laryngeal cartilages structures data were used, the data was on a section-by-section basis. Three-dimensional computer reconstructions of the laryngeal cartilages were generated from these data by surface rendering on a SGI workstation. RESULTS: The digital images from the visible human offer unique insights into the complex anatomy and ossification of the laryngeal cartilages, the quality of the computerized 3D-reconstructed images was distinct and perfect. CONCLUSIONS: The visible human data set can provide complete and accurate data The digitized model of the laryngeal cartilages offer unique insights into the laryngeal anatomy, could be used for resident education, rehearsal of an unfamiliar surgery and for developing a new surgical approach.