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Biomedical subjects

B Tillmann

Publications and source records attributed to B Tillmann.

At least 37 records · Page 2Linked to original sources
PubMed2000

Effects of ageing on the insertion zones of the human vocal fold.

The vocal ligaments insert at the anterior and posterior commissures of the larynx. These structures fulfil biomechanical functions, balancing the different elastic moduli of tendon, cartilage or bone and undergo age-related changes that may be responsible for voice changes with increasing age. The aim of this study was to analyse the insertion structures of the vocal ligaments by means of macroscopic, histological, immunohistochemical and electron-microscopic methods and to draw conclusions from age-related structural changes on a functional basis. Investigations were carried out on the larynges of 22 males and 15 females (aged 1-95 y). In adolescence, the insertion zone of the vocal ligament tendon, a dense network of connective tissue rich in sulphated glycosaminoglycans at the thyroid cartilage, is characterised by a layer between tendon and cartilage comparable to fibrocartilage. The insertion zone lacks a perichondrium. Collagen fibrils of the vocal ligament tendon penetrate directly into the thyroid cartilage. In the insertion area, the chondrocytes are surrounded by collagen fibrils, which show positive reactivity to antibodies against type I and type III collagen. Sulphated glycosaminoglycans are integrated between the collagen fibrils. In the area of the posterior glottis, elastic cartilage rests like a cap on the hyaline base of the arytenoid cartilage. There is no distinctive border between the structures. With increasing age, ossification of the laryngeal skeleton occurs, involving hyaline cartilage at the posterior glottis and hyaline and fibrocartilage at the anterior commissure. At the same time, a loss or sulphated glycosaminoglycans is observed inside the vocal ligament tendon. Advanced ossification of the laryngeal skeleton, particularly in the area of the commissures, an increasing loss of glycosaminoglycans in the vocal ligament tendon and changes in the elastic tissue reduce the elastic modulus between tendon, cartilage and bone, thus 'stiffening' the insertion zones, which could be one factor among others favouring voice changes with advancing age.

Aging↗
PubMed2000

Curving and looping of the internal carotid artery in relation to the pharynx: frequency, embryology and clinical implications.

Variations of the course of the internal carotid artery in the parapharyngeal space and their frequency were studied in order to determine possible risks for acute haemorrhage during pharyngeal surgery and traumatic events, as well as their possible relevance to cerebrovascular disease. The course of the internal carotid artery showed no curvature in 191 cases, but in 74 cases it had a medial, lateral or ventrocaudal curve, and 17 preparations showed kinking (12) or coiling (5) out of a total of 265 dissected carotid sheaths and 17 corrosion vascular casts. In 6 cases of kinking and 2 of coiling, the internal carotid artery was located in direct contact with the tonsillar fossa. No significant sex differences were found. Variations of the internal carotid artery leading to direct contact with the pharyngeal wall are likely to be of great clinical relevance in view of the large number of routine procedures performed. Whereas coiling is ascribed to embryological causes, curving is related to ageing and kinking is thought to be exacerbated by arteriosclerosis or fibromuscular dysplasia with advancing age and may therefore be of significance in relation to the occurrence of cerebrovascular symptoms.

Aged↗
PubMed2000

[The joint capsule of the cricoarytenoid joint: biomechanical and clinical aspects].

BACKGROUND: Impaired movement of the cricoarytenoid joint with hoarseness and immobility of the vocal ligament may occur as a consequence of laryngeal trauma and joint disease. Little is known to date about the cricoarytenoid joint capsule and its role in joint pathology. METHODS: The present study analyses the structure of the cricoarytenoid joint capsule by means of histological, immunohistochemical, and scanning electron microscopical methods. Investigations are performed on larynges of 17 male and 16 female. RESULTS: The cricoarytenoid joint was found to be lined by a wide and lax joint capsule consisting of a fibrous and a synovial membrane. The capsule was strengthened posteriorly by the cricoarytenoid ligament. As like the fibrous membrane the cricoarytenoid ligament consisted mainly of collagen types I and III. Moreover the ligament was found to be rich in elastic fibers. Unexpected large and intensively vascularized synovial folds projected into the joint cavity. CONCLUSION: The capsule of the cricoarytenoid joint can be compared with the joint capsules of the limbs despite its structure and its involvement in joint pathology. Based on the laxity of the joint capsule it was concluded that invasive interventions at the respiratory tract with dislocation of the arytenoid cartilage can lead to incarceration of the synovial folds. After a trauma aero-synovitis or formation of hemarthrosis may occur, with subsequent fixation of the arytenoid in an abnormal position.

Adult↗
PubMed2000

Blood supply of the peroneal tendons: injection and immunohistochemical studies of cadaver tendons.

We studied the vascular pattern of human peroneal tendons with injection techniques and immunohistochemically by using antibodies against laminin The main blood supply arises from the peroneal artery. The distal part of the peroneus longus tendon is supplied by branches of the medial tarsal artery. Blood vessels enter the peritenon of both tendons via a mesotenon from the posterior aspect. From the peritenon, the blood vessels penetrate the peroneus brevis and peroneus longus tendons and anastomose with a longitudinally-oriented intratendinous network. The amount of vessels in the tendon substance is consistently less than in the surrounding peritenon. The distribution of blood vessels in the peroneal tendons is not homogeneous. In the region where the peroneus brevis tendon passes through the fibular groove, the longitudinally-oriented intratendinous vascular network is interrupted and the tendon is almost avascular. In this region, the tendon is squeezed between the peroneus longus tendon and the bony slide bearing of the lateral malleolus. The peroneus longus tendon has two avascular zones. In the region where the peroneus longus tendon curves around the lateral malleolus and the peroneal trochlea of the calcaneus, the anterior part of the tendon which is directed towards the pulley is avascular. A second avascular zone is located more distally in the region where the tendon changes direction and wraps around the cuboid.

Adult↗
PubMed2000

Orcein-picroindigocarmine--a new multiple stain.

A new "orcein-picroindigocarmine staining", a colour combination of orcein, indigo carmine, and picric acid, was developed for histological applications. The new technique was tested on different human tissues. Colours ranging from red to brown, yellow, green and blue were observed in paraffine sections of tissues stained by this method. Nuclear structures in all tissues were stained dark brown to dark blue. Squamous epithelium was stained light brown with varying shades of blue in upper horny layers, whereas the ciliated epithelium was tinged blue grey. When connective tissue was stained, collagen fibrils appeared strongly blue next to elastic fibres, which took on a rust brown tinge; cellular components were all coloured brown. The matrix of hyaline cartilage was stained in different shades of blue, with the chondrocytes rust brown. Sections of bone components appeared dark blue to dark green. Skeletal muscle cells were coloured yellow and green with blue collagenous septa. The new staining is useful for distinguishing connective tissue components such as elastic fibres and collagen fibrils. It also demonstrates chondrocytes in favourable contrast to the cartilage matrix. The technique produces aesthetic staining colouring that could supplement histological investigations and provide an alternative to other staining materials.

Adult↗
PubMed1999

[Blood supply of the quadriceps tendon].

Degenerative changes have been considered to be a cause for spontaneous quadriceps tendon rupture. Aim of this study is to investigate the microvasculature of the quadriceps tendon by injection techniques and immunohistochemical methods (antibodies against laminin) with regard to the pathogenesis of tendon degeneration. The blood supply of the quadriceps tendon arises from descending branches of the lateral circumflex femoral artery, by branches of the descending geniculate artery and by branches of the medial and lateral superior geniculate arteries. Blood vessels penetrate the tendon from the surrounding connective tissue and anastomose with a longitudinally orientated intraligamentous network. Compared to the surrounding synovial layer, the amount of vessels in the tendon substance is greatly reduced. The distribution of blood vessels within the quadriceps tendon is not homogenous. The anterior or superficial part of the tendon has a complete vascular network that extends from the musculo-tendinous junction to the patella. Within the deep portion of the quadriceps tendon there is an oval shaped avascular area which measures app. 30 mm in length and app. 15 mm in width. Within this area the immunohistochemical proof of laminin is negative. An explanation for the absence of blood vessels may be compressive stress caused by the patellar groove which serves as hypomochlion for the quadriceps tendon when the knee is flexed. The occurrence of an avascular zone within the deep layer of the tendon that is directed to the joint cavity may explain the frequency of degenerative changes in this region.

Adult↗
PubMed1999

Blood and lymph supply of the posterior cruciate ligament: a cadaver study.

Injection techniques, immunohistochemical (antibodies against laminin), and histochemical (5'-nucleotidase activity) methods were employed to describe the vascular pattern of the human posterior cruciate ligament (PCL); in parallel we used conventional light microscopy and immunohistochemical techniques to visualize the histological structure of the PCL. The blood supply of the PCL mainly arises from the middle geniculate artery. The ligament is covered by a synovial fold where the terminal branches of the middle geniculate artery form a periligamentous network. From the synovial sheath, the blood vessels penetrate the ligament in a horizontal direction and anastomose with a longitudinally orientated intraligamentous network. Within the ligament the blood vessels are located in the loose connective tissue that is sited between longitudinal fibre bundles. Histologically the longitudinal fibre bundles of the ligament consist of dense connective tissue. Lymphatics accompany most of the smaller blood vessels, showing similar regional distribution. Compared to the surrounding synovial layer, the amount of vessels in the substance of the ligament is lower. The distribution of blood vessels within the PCL is not homogenous: we detected three avascular areas within the ligament. Both fibrocartilaginous entheses of the PCL are devoid of blood vessels, and a third avascular zone is located in the central part of the middle third. The histological structure of this zone varies from the rest of the PCL which consists of the characteristic dense connective tissue. In the central part of the PCL the tissue resembles fibrocartilage: the cell shape is round, the pericellular matrix of those cells is rich in acid glycosaminoglycans and the immunohistochemical demonstration of type II collagen is positive. The occurrence of an avascular zone within the central part of the middle third of the PCL where the tissue consists of fibrocartilage has not been described in the literature.

Aged↗
PubMed1999

Blood supply of the tibialis anterior tendon.

Injection techniques and immunohistochemical methods (antibodies against laminin) were performed to uncover the vascular pattern of the human tibialis anterior tendon with regard to spontaneous rupture of this tendon. Proximally, the blood supply of the tibialis anterior tendon mainly arises from the anterior tibial artery. Distally, the tendon is supplied by branches of the medial tarsal artery. Blood vessels enter the peritenon via vinculae from the posterior side. From the peritenon, the blood vessels penetrate the tendon and anastomose with a longitudinally orientated intratendinous network. Compared with the surrounding peritenon, the number of vessels in the tendon substance is greatly reduced. The distribution of blood vessels within the anterior tibial tendon is not homogenous. The posterior part of the tendon has a complete vascular network that extends from the musculotendinous junction to the insertion at the bone. In the anterior half of the tendon, there is an avascular zone between 45 and 67 mm in length. The location of the avascular zone correlates well with the location of the most frequent site of spontaneous rupture of the tibialis anterior tendon reported in the literature. Hypovascularity has to be considered as an etiological cofactor for spontaneous rupture of the tibialis anterior tendon.

Aged↗
PubMed1999

Vascularization and cartilage mineralization of the thyroid cartilage of Munich minipigs and domestic pigs.

Thyroid cartilages of Munich minipigs and domestic pigs were investigated by polychrome sequential labeling, radiography, intravascular injections, histologic examination and scanning electron microscopy in order to gain further insight into the process of vascularization and cartilage mineralization. The relationship between vascularization and cartilage mineralization has only been studied in chondroepiphyses of long bones. Vessels branch off the perichondrial vascular network and enter parts of the thyroid cartilage with a large transverse diameter. Cartilage canals, which are perichondral invaginations, contain an arteriole, a venule, a capillary network and connective tissue. The capillaries form a glomerulus-like structure deep in the matrix of the cartilage. Neighbouring cartilage canals do not display any anastomoses. Cartilage mineralization occurs in large areas of the thyroid cartilage. It is only found in the interterritorial extracellular matrix. Mineralization of the cartilage is evident in areas supplied with cartilage canals as well as in non-supplied areas. Mineralized interterritorial matrix is composed of circular structures of different sizes fusing to form plaques. In scanning electron microscopy circular structures appear as globules. It is possible to visualize the dynamic process of cartilage mineralization with polychrome sequential labeling; it proceeds up to 4 microm per week. Distribution of cartilage canals reveals their nutritional role for the cartilage. According to investigations in chondroepiphyses, cartilage mineralization starts adjacent to the glomerular end of cartilage canals. In contrast, no correlation between cartilage vascularization and the beginning of cartilage mineralization of the thyroid cartilage of Munich minipigs and of domestic pigs has been found.

Animals↗
PubMed1999

Structure and vascularization of the cruciate ligaments of the human knee joint.

The structure and vascularization of the human anterior and posterior cruciate ligament were investigated by light microscopy, transmission electron microscopy,, injection techniques and by immunohistochemistry. The major part of the anterior and posterior cruciate ligament is composed of bundles of type I collagen. Type III collagen-positive fibrils separate the bundles. The major cell type is the elongated fibroblast, lying solitarily between the parallel collagen fibrils. The histologic structure of the cruciate ligaments is not homogeneous. In both ligaments there is a zone where the tissue resembles fibrocartilage. In the anterior cruciate ligament the fibrocartilaginous zone is located 5-10 mm proximal of the tibial ligament insertion in the anterior portion of the ligament. In the posterior cruciate ligament the fibrocartilage is located in the central part of the middle third. Within those zones the cells are arranged in columns and the cell shape is round to ovoid. Transmission electron microscopy reveals typical features of chondrocytes. The chondrocytes are surrounded by a felt-like pericellular matrix, a high content of cellular organelles and short processes on the cell surface. The pericellular collagen is positive for type II collagen. The major blood supply of the cruciate ligaments arises from the middle geniculate artery. The distal part of both cruciate ligaments is vascularized by branches of the lateral and medial inferior geniculate artery. Both ligaments are surrounded by a synovial fold where the terminal branches of the middle and inferior arteries form a periligamentous network. From the synovial sheath blood vessels penetrate the ligament in a horizontal direction and anastomose with a longitudinally orientated intraligamentous vascular network. The density of blood vessels within the ligaments is not homogeneous. In the anterior cruciate ligament an avascular zone is located within the fibrocartilage of the anterior part where the ligament faces the anterior rim of the intercondylar fossa. The fibrocartilaginous zone of the middle third of the posterior cruciate ligament is also avascular. According to Pauwel's theory of the "causal histogenesis" (1960) the stimulus for the development of fibrocartilage within dense connective tissue is shearing and compressive stress. In the anterior cruciate ligament this biomechanical situation may occur when the ligament impinges on the anterior rim of the intercondylar fossa when the knee is fully extended. Compressive and shearing stress in the center of the middle third of the posterior cruciate ligament may result from twisting of the fiber bundles.

Adult↗
PubMed1999

Population pharmacokinetic approach to compare oral and i.v. administration of etoposide.

The antitumor effect of etoposide (ETO) may be related to duration of exposure to a relatively low serum level while myelosuppression may be dependent on peak ETO serum levels. With regard to such therapeutic ranges, duration of exposure to predefined plasma ETO concentration ranges and the related AUC (expressed as percent of total AUC, pAUC) were used to compare pharmacokinetic profiles after oral and short time i.v. (1 h infusion) administration of identical ETO doses (100 mg/m2). Patients included in this study received i.v. (18 patients, short-term infusions) or oral (16 patients) ETO on different treatment schedules. Plasma ETO concentrations were determined by HPLC and population pharmacokinetic parameters were calculated (P-Pharm 1.4). Despite an 'apparent bioavailability' of 59%, oral administration of ETO was associated with the same time of exposure to a predefined 'therapeutic range' of 0.5-3 mg/l and a significantly higher pAUC compared to i.v. administration. By contrast, time of exposure to the probably more myelotoxic concentration range above 3 mg/l was significantly shorter and the related pAUC was highly significantly lower after oral than after i.v. administration. These findings demonstrate that oral ETO therapy is at least equivalent to short time i.v. therapy in terms of achieving specific target concentration ranges and avoiding peak concentrations.

Administration, Oral↗
PubMed1999

Composition of the extracellular matrix in human cricoarytenoid joint articular cartilage.

The extracellular matrix of the human cricoarytenoid joint articular cartilage is involved in different pathological changes. Interestingly, in contrast to the limb joints, the extracellular matrix composition of the healthy cricoarytenoid joint articular cartilage has not yet been elucidated except by some light microscopical investigations. The present study investigates the extracellular matrix components of the cricoarytenoid joint articular cartilage by means of light microscopy, immunohistochemistry, transmission electron microscopy and scanning electron microscopy and compares them with the limb joints for a better understanding of their involvement in joint disease. Chondrocytes near the joint surface of the cricoid and arytenoid cartilage differ from chondrocytes of deeper cartilage layers. The extracellular matrix of the articular cartilage contains chondroitin-4-sulfate, chondroitin-6-sulfate and keratansulfate as well as collagen types II, III, VI, IX and XI. Type-III-collagen shows a special distribution throughout the joint cartilage. In deeper cartilage layers, type-III-collagen occurs only pericellularly; in higher cartilage layers type-III-collagen is also located territorially and interterritorialy in small amounts. Scanning and transmission electron microscopy have revealed the articular surface of the cricoid and arytenoid cartilage to consist of a network of irregularly organized collagen fibrils, which are lined by a layer of electron dense material. The network coats subjacent collagen bundles which descend obliquely downward and intermingle at right angles in the middle part of the articular cartilage with collagen bundles of the deeper cartilage zones. The articular cartilage surface shows structural characteristics which differ from the underlying cartilage. The superficial electron dense layer possibly plays a role in the lubrication of the articular cartilage surface. The alignment of the fibrillar structures in the articular cartilage of the cricoarytenoid joint varies from those of the limb joints based on the different strain occurring during arytenoid movement. Nevertheless, the human cricoarytenoid joint articular cartilage can be compared with the joints of the limbs despite its extracellular matrix composition and its involvement in joint pathology. Evidence of type III collagen in the outermost layer of the articular cartilage of the cricoarytenoid joint presents a peculiarity, which has yet not be demonstrated in the articular cartilage of limb joints.

Adult↗
PubMed1998

Functional anatomy of the human efferent tear ducts: a new theory of tear outflow mechanism.

BACKGROUND: The mechanism of lacrimal drainage under physiological conditions is controversial. The aim of this study was to analyze the three-dimensional architecture of human efferent tear ducts from functional and clinical points of view. A new theory of tear outflow is discussed. METHODS: Thirty-two prepared lacrimal systems of adults were examined by histological, immunohistochemical and scanning electron microscopic techniques. RESULTS: The wall of the lacrimal sac is made up of collagen bundles, elastic and reticular fibers arranged in a helical pattern. Wide luminal vascular plexus are embedded in this helical system and connected to the cavernous tissue of the inferior turbinate in the region of Hasner's valve. Immunohistochemical analysis showed evidence of type I and type III collagen as well as chondroitin 4- and 6-sulfate. CONCLUSION: With blinking, the lacrimal part of the orbicularis muscle contracts. The fornix of the sac moves in a cranial-lateral direction. Thus the lacrimal sac distends and may be "wrung out" due to its medial attachment and helically arranged fibrillar structures. The vascular plexus may play an important role in the absorption and drainage of lacrimal fluid.

Aged↗
PubMed1998

Collagenous fibril texture of the human knee joint menisci.

Anatomical and clinical literature describes the arrangement of collagen fibrils in the human meniscus as being "arcade-like". The "arcade-like" orientation, mainly running in a radial direction in the internal circumference and in a circular direction in the external circumference, was found in polarization light microscopic studies. This, however, does not provide a mechanical explanation for the direction of meniscus tears. In view of this contradiction collagen fibrils in the menisci of adults aged from 18 to 85 years were exposed layer-by-layer to study their arrangement by scanning electron microscopy. The results obtained by this procedure were compared to the path of the split lines. Scanning electron microscopy reveals three distinct layers in the meniscus cross section: (1) The tibial and femoral sides of the meniscus surfaces are covered by a meshwork of thin fibrils with a diameter of approximately 30 nm. (2) Beneath the superficial network there is a layer of lamellalike collagen fibril bundles on the tibial and femoral surface. In the area of the external circumference of the anterior and posterior segments the bundles of collagen fibrils are arranged in a radial direction. In all other parts the collagen fibril bundles intersect at various angles. (3) The main portion of the meniscus collagen fibrils are located in the central region between the femoral and the tibial surface layers. Everywhere in the central main portion of the meniscus the bundles of collagen fibrils are orientated in a circular manner. The split lines in the region of the internal circumference of the menisci are arranged in a circular manner, generally running in a radial direction in the portions adjacent to the base. Scanning electron microscopy reveals that the direction of the split lines depends on the orientation of the collagen fibrils in the superficial lamellar layer. The arcade-like path of the collagen fibrils described in the literature can not be confirmed either by scanning electron microscopy or by the course of the split lines. The circular arrangement of collagen fibrils in the central portion of the meniscus provides a functional explanation for the longitudinal orientation of the majority of tears in the meniscus tissue.

Adolescent↗
PubMed1998

Functional anatomy of human lacrimal duct epithelium.

Resorption of tear fluid in the lacrimal ducts has hitherto been controversial; one reason for this has been insufficient knowledge of the anatomical structure and function of the lacrimal duct epithelium. The present study analyzes the structure of lacrimal duct epithelium by means of histological, histochemical, immunohistochemical and electronmicroscopical methods and draws a conclusion about its physiological function regarding its role in immunodeficiency. Investigations were performed on 31 lacrimal systems of 17 male and 14 female individuals (aged 54-88 years). Lacrimal ducts are surrounded by a wide-ranging cavernous system, which is embedded in an osseous canal between the maxilla and the lacrimal bone. The internal wall of the lacrimal canaliculi is lined by a stratified epithelium. The lacrimal sac and nasolacrimal duct contain a double-layered epithelium, which rests on a broad basement membrane. In their apical part epithelial cells contain large lipid droplets and secretory vacuoles. Epithelial cells are faced by microvilli and some tufts of kinociliae are also visible. Goblet cells are integrated in the epithelium as solitary cells or in a characteristic arrangement of several cells. The secretory product of these cells contains carbohydrates including fucose and sialic acid. Inside the surrounding cavernous system serous glands are found that open their excretory ducts into the lacrimal sac and nasolacrimal duct. Some T- and B-lymphocytes and macrophages may be demonstrated immunohistochemically in the submucosa partly penetrating the epithelium. Synthesized mucins of goblet cells form a specialized protective layer on the epithelium of the lacrimal ducts, which functionally serves for a simplified drainage of tear fluid into the inferior meatus of the nose. Together with immunocompetent cells, the protective layer plays a role in antigen defense and prevents invasion of pathogenic agents. The facing of epithelial cells by microvilli gives hints of re-absorption of lacrimal fluid inside the lacrimal ducts.

Aged↗
PubMed1998

Age-related changes in the articular cartilage of human sacroiliac joint.

Iliac and sacral articular cartilage of 25 human sacroiliac joints (1-93 years) are examined by light microscopy and immunohistochemistry in order to gain further insight into the nature and progress of degenerative changes appearing during aging. These changes can already be seen in younger adults as compared to cartilage degeneration known in other diarthrodial joints. Structural differences between sacral and iliac cartilage can already be observed in the infant: the sacral auricular facet is covered with a hyaline articular cartilage, reaching 4 mm in thickness in the adult and staining intensely blue with alcian blue at pH1. Iliac cartilage of the newborn is composed of a dense fibrillar network of thick collagen bundles, crossing each other at approximately right angles. A faint staining with alcian blue suggests a low content of acidic glycosaminoglycans. In the adult, iliac cartilage becomes hyaline and its maximal thickness reaches 1-2 mm. Both articular facets exhibit morphological changes during aging that are more pronounced in the iliac cartilage and resemble osteoarthritic degeneration; the staining pattern of the extracellular matrix becomes inhomogenous, chondrocytes are arranged in clusters and the articular surface develops superficial irregularities and fissures. Sometimes fibrous tissue fills up these defects. Nevertheless, large areas of iliac cartilage remain hyaline in nature. Sacral articular cartilage often remains largely unaltered until old age. The sacral subchondral bone plate is usually thin and shows spongiosa trabeculae inserted at right angles, suggesting a perpendicular load on the articular facet. Iliac subchondral spongiosa shows no definite alignment and joins the thickened subchondral bone plate in an oblique direction. The iliac cartilage therefore seems to be stressed predominantly by shearing forces, arising from the changing monopodal support of the pelvis during locomotion. The subchondral bone plate on both the iliac and sacral auricular facet is penetrated by blood vessels that come into close contact with the overlying articular cartilage. These vessels may contribute to the high incidence of rheumatoid and inflammatory diseases in the human sacroiliac joint. Immunolabelling with an antibody against type II collagen reveals a diminished immunoreactivity in the upper half of adult sacral cartilage and only a faint and irregular labelling in the iliac cartilage. Type I collagen can be detected in a superficial layer on the sacral articular surface and around chondrocyte clusters in iliac cartilage, as in dedifferentiating chondrocytes during the development of osteoarthritis.

Adolescent↗
PubMed1997

Functional and clinical anatomy of the posterior insertion of the human vocal ligament.

The suggested methods of the formation of intubation granuloma as well as carcinoma invasion in the area of posterior vocal ligament insertion have been controversial. One reason for divergent opinions is possibly based on different judgements of morphology in this region. The present study analyzed structures of the vocal ligament and vocalis muscle insertion at the vocal process by means of histological, immunohistochemical and electron microscopic methods. Investigations were performed in three planes on the vocal cords of 22 men and 19 women (aged 21-97 years). Inside the insertion zone of the vocal ligament at the vocal process three structures could be distinguished: hyaline cartilage at the base of arytenoid cartilage, elastic cartilage at its apex and the posterior elastic nodule in front of them. No perichondrium could be seen around the elastic nodule. In elastic nodules type I and type III collagen fibrils as well as elastic fibers formed a scissor-like meshwork around large fibroblasts. The vocalis muscle inserted at the perichondrium in the lateral part of the arytenoid skeleton by short tendons. At the insertion zone blood vessels of the vocalis muscle penetrated the perichondrium and reached the cartilaginous matrix. At the beginning of osteogenesis, the blood vessels connected with intraosseous blood vessels of the arytenoid. Connective tissue cells of the insertion zone and extracellular matrix components formed by these cells fulfilled a biomechanical function by equalizing the different elastic moduli of tendon, cartilage or bone. The lack of perichondrium around the lengthened posterior elastic nodule made formation of intubation granulomas caused by perichondritis in this area impossible. Loosened perichondrium or periosteum in the area of the insertion of the vocalis muscle at the vocal process, ossification and associated vascularization of the arytenoid skeleton permitted invasion of carcinomas into the arytenoid.

Adult↗