Muscles and fascial elements of the antebrachium and manus of the African elephant (Loxodonta africana, Blumenbach 1797): starring comparative and functional considerations.

The structure of the limbs of elephants is unusual among mammals. In African elephants (Loxodonta africana, Blumenbach 1797), the front limbs serve to support the greatest part of the body mass of the largest land animal. In this study, we present new and detailed anatomical data regarding muscular and specific fascial structures of the lower front limb which were examined by means of standard anatomical and histological techniques. The muscles and tendons of the forearm (antebrachium) and hand (manus) are tightly surrounded by thick, highly elastic fascial layers which fuse with the lacertus (lac.) fibrosus and the so-called ligamentum (lig.) humeroulnare. A well-developed musculus (m.) brachioradialis occupies the proximolateral aspect of the forearm and its tendon inserts together with the lac. fibrosus on the os carpi intermedium. The lac. fibrosus, the lig. humeroulnare and the m. flexor carpi radialis reveal a large proportion of elastic fibres. These three structures may play an important role in storing strain energy thus promoting energy-saving locomotion. On the palmar aspect of the carpus, metacarpus and digits, short flexor, abductor, adductor, lumbricales and interossei muscles are present, whereas supinator muscles are absent in all specimens. The short muscles of the hand together with specific dorsal tendons enable precise movements of specific toes.

Ultrasonographic imaging of the temporomandibular joint in healthy cattle and pathological findings in one clinical case.

AIMS: To describe the normal ultrasonographic appearance of the temporomandibular joint (TMJ) in cattle, and to describe the ultrasonographic pathology of the TMJ as assessed in one cow with TMJ disease. METHODS: The TMJ of 12 healthy Holstein-Friesian cows were examined using a portable ultrasonographic unit with a 7.5 MHz linear probe and a 6.0 MHz convex probe. Each TMJ was scanned in a rostrolateral, lateral and caudolateral plane. In addition, the TMJ of one 2-year-old cow with clinical signs of food retention in the mouth, head tilt, swelling and pain in the right TMJ region and an infected horn fracture was examined ultrasonographically. RESULTS: The bone surfaces of the temporal process, the zygomatic process and the temporal bone, the larger muscles of the TMJ region, the superficial temporal vein, and the parotid salivary gland could be imaged in all normal healthy cattle. Using the linear probe, the joint capsule was visible in 17/24 (71%) cases in the caudolateral plane, but the articular disc could not be visualised. With the convex probe, the joint capsule could be imaged in all cases in the caudolateral plane, and the articular disc in 13/24 (54%) cases in the caudolateral plane. It was never possible to see the synovial pouch in healthy cattle using either probe. By contrast, in the cow diagnosed with septic arthritis of the right TMJ, a marked anechoic and heterogeneous hypoechoic effusion of the TMJ with distension of the joint capsule was visualised. CONCLUSIONS: The results of this descriptive study serve to provide a reference for ultrasonography of pathological conditions of the TMJ region in cattle. CLINICAL RELEVANCE: As many veterinarians are equipped with ultrasound machines with 5-8 MHz linear rectal probes, the authors recommend using these probes for further investigation of clinical cases with swelling of the TMJ region and/or masticatory problems of unclear origin to exclude or diagnose TMJ disorders.

Gross anatomy of the female genital organs of the domestic donkey (Equus asinus Linné, 1758).

Although donkeys play an important role as companion or pack and draught animals, theriogenological studies and anatomical data on the genital organs of the jenny are sparse. To provide anatomical descriptions and morphometric data, the organa genitalia feminina, their arteries and the ligamentum latum uteri of 10 adult but maiden jennies were examined by means of gross anatomical and morphometric techniques. In comparison with anatomical data of horses obtained from literature the genital organs of jennies appear to be more voluminous in relation to the body mass and the position of the ovaries is slightly further cranial than in mares. In asses, the ovaries contain large follicles reaching a diameter of up to 40 mm. The mesosalpinx is much wider than in the horse forming a considerably spacious bursa ovarica. The asinine ligamentum teres uteri reveals a very prominent cranial end, the 'appendix'. Tortuous mucosal folds occur in the wall of the jenny's cervical channel. The vascularization of the female genital organs of asses is very similar to that of horses. One of the examined specimens reveals a large mucosal fold dividing the cranial part of the vagina into a left and right compartment.

Fluctuating asymmetry as an animal welfare indicator -- a review of methodology and validity.

It has been suggested that fluctuating asymmetry (FA) reflects an animal's ability to cope with the sum of challenges during its growing period and, thus, is a potential welfare indicator. In this review we investigate the evidence of associations between FA and other welfare indicators measured at the level of the individual and of effects of welfare-relevant environmental conditions on FA in populations of captive birds and mammals including humans. As the question of validity cannot be treated independently from the quality of the available data, first a checklist for the proper measurement and analysis of FA is drafted and used to evaluate the methodological quality of the various studies. We recommend this checklist to be used as a standard for future FA studies. We found 17 relevant studies on associations between FA and other welfare indicators, and 36 studies on effects of welfare-relevant factors on FA. Frequent methodological shortcomings or insufficient methodological information allow for only cautious conclusions. The proportion of significant results supporting the link between higher FA and poorer welfare is only moderately high. Independent from statistical significance, almost all studies found the relationship between FA and welfare to be prevailingly in the expected direction. FA is a promising measure of animal welfare, despite a great number of open questions, e.g. relating to the ontogeny of FA or its sensitivity to various stressors. The considerable potential of FA as a welfare indicator makes it worthwhile to pursue more intensely validation studies as well as applied studies. These studies should pay particular attention to an appropriate methodological approach.

The structure of the cushions in the feet of African elephants (Loxodonta africana).

The uniquely designed limbs of the African elephant, Loxodonta africana, support the weight of the largest terrestrial animal. Besides other morphological peculiarities, the feet are equipped with large subcutaneous cushions which play an important role in distributing forces during weight bearing and in storing or absorbing mechanical forces. Although the cushions have been discussed in the literature and captive elephants, in particular, are frequently affected by foot disorders, precise morphological data are sparse. The cushions in the feet of African elephants were examined by means of standard anatomical and histological techniques, computed tomography (CT) and magnetic resonance imaging (MRI). In both the forelimb and the hindlimb a 6th ray, the prepollex or prehallux, is present. These cartilaginous rods support the metacarpal or metatarsal compartment of the cushions. None of the rays touches the ground directly. The cushions consist of sheets or strands of fibrous connective tissue forming larger metacarpal/metatarsal and digital compartments and smaller chambers which were filled with adipose tissue. The compartments are situated between tarsal, metatarsal, metacarpal bones, proximal phalanges or other structures of the locomotor apparatus covering the bones palmarly/plantarly and the thick sole skin. Within the cushions, collagen, reticulin and elastic fibres are found. In the main parts, vascular supply is good and numerous nerves course within the entire cushion. Vater-Pacinian corpuscles are embedded within the collagenous tissue of the cushions and within the dermis. Meissner corpuscles are found in the dermal papillae of the foot skin. The micromorphology of elephant feet cushions resembles that of digital cushions in cattle or of the foot pads in humans but not that of digital cushions in horses. Besides their important mechanical properties, foot cushions in elephants seem to be very sensitive structures.

The elephant knee joint: morphological and biomechanical considerations.

Elephant limbs display unique morphological features which are related mainly to supporting the enormous body weight of the animal. In elephants, the knee joint plays important roles in weight bearing and locomotion, but anatomical data are sparse and lacking in functional analyses. In addition, the knee joint is affected frequently by arthrosis. Here we examined structures of the knee joint by means of standard anatomical techniques in eight African (Loxodonta africana) and three Asian elephants (Elephas maximus). Furthermore, we performed radiography in five African and two Asian elephants and magnetic resonance imaging (MRI) in one African elephant. Macerated bones of 11 individuals (four African, seven Asian elephants) were measured with a pair of callipers to give standardized measurements of the articular parts. In one Asian and three African elephants, kinematic and functional analyses were carried out using a digitizer and according to the helical axis concept. Some peculiarities of healthy and arthrotic knee joints of elephants were compared with human knees. In contrast to those of other quadruped mammals, the knee joint of elephants displays an extended resting position. The femorotibial joint of elephants shows a high grade of congruency and the menisci are extremely narrow and thin. The four-bar mechanism of the cruciate ligaments exists also in the elephant. The main motion of the knee joint is extension-flexion with a range of motion of 142 degrees . In elephants, arthrotic alterations of the knee joint can lead to injury or loss of the cranial (anterior) cruciate ligament.

Structure and innervation of the tusk pulp in the African elephant (Loxodonta africana).

African elephants (Loxodonta africana) use their tusks for digging, carrying and behavioural display. Their healing ability following traumatic injury is enormous. Pain experience caused by dentin or pulp damage of tusks seems to be negligible in elephants. In this study we examined the pulp tissue and the nerve distribution using histology, electron microscopy and immunhistochemistry. The results demonstrate that the pulp comprises two differently structured regions. Randomly orientated collagen fibres characterize a cone-like part lying rostral to the foramen apicis dentis. Numerous nerve fibres and Ruffini endings are found within this cone. Rostral to the cone, delicate collagen fibres and large vessels are orientated longitudinally. The rostral two-thirds of the pulp are highly vascularized, whereas nerve fibres are sparse. Vessel and nerve fibre distribution and the structure of connective tissue possibly play important roles in healing and in the obviously limited pain experience after tusk injuries and pulp alteration. The presence of Ruffini endings is most likely related to the use of tusks as tools.

Musculature of the crus and pes of the African elephant (Loxodonta africana): insight into semiplantigrade limb architecture.

The limbs of elephants are designed to support the weight of the largest terrestrial animal, and they display unique morphological peculiarities among mammals. In this article we provide a new and detailed anatomical description of the muscles of the lower hindlimb in African elephants (Loxodonta africana), and we place our observations into a comparative anatomical as well as a functional morphological context. At the cranial aspect of the shank (crus) and the foot (pes), the flexors of the tarsal joint and the extensors of the toes form a flat muscular plate covering the skeletal elements. Caudal to the tibia and the fibula the Musculus (M.) soleus is strongly developed, whereas the M. gastrocnemius and the M. flexor digitorum superficialis are thin. Small flexors, adductors, and abductors of the toes are present. The M. tibialis caudalis as well as the Mm. fibularis longus and brevis mainly support the tarsal joint. The design of the muscular structures matches the specific requirements of heavy-weight bearing as well as of proboscidean limb posture and locomotion patterns.

Anatomical description of the muscles of the pelvic limb in the ostrich (Struthio camelus).

Dissections of 12 formalin-fixed ostriches were performed to give anatomical descriptions of the muscles and tendons of the pelvic, femoral, tibiotarsal, tarsometatarsal and digital regions. In the pelvic limb of the ostrich, 36 muscles can be determined. The ostrich lacks those muscles to the first and second toes (with exception of the M. flexor hallucis longus), which can be found in birds with four toes. The Mm. iliotrochantericus medius, plantaris, extensor proprius digiti IV and adductor digiti IV, which are present in other birds, are also absent, whereas the Mm. pectineus and femorotibialis accessorius additionally occur in the ostrich. The Pars supramedialis is a tendineous part of the M. gastrocnemius, on which the Mm. flexor cruris lateralis and flexor cruris medialis insert by means of a fascial sheet. The caudal part of the M. iliofibularis terminates within the caudal aspect of the superficial fascia cruris. The caudal heads of the Mm. flexor perforatus digiti III and flexor perforatus digiti IV as well as the M. flexor hallucis longus have a common origin on the Fossa poplitea of the femur. The lateral head of the M. flexor perforatus digiti IV and the femoral head of the M. flexor perforans et perforatus digiti III originate on the tendon of origin of the Caput laterale of the M. flexor perforatus digiti III. Furthermore, the last named tendon fuses with the tendon of insertion of the M. ambiens. The M. extensor proprius digiti III originates on a plate-like fascial sheet part of the dorsal joint capsule of the intertarsal joint.

Hyoid apparatus and pharynx in the lion (Panthera leo), jaguar (Panthera onca), tiger (Panthera tigris), cheetah (Acinonyxjubatus) and domestic cat (Felis silvestris f. catus).

Structures of the hyoid apparatus, the pharynx and their topographical positions in the lion, tiger, jaguar, cheetah and domestic cat were described in order to determine morphological differences between species or subfamilies of the Felidae. In the lion, tiger and jaguar (species of the subfamily Pantherinae) the Epihyoideum is an elastic ligament lying between the lateral pharyngeal muscles and the Musculus (M.) thyroglossus rather than a bony element like in the cheetah or the domestic cat. The M. thyroglossus was only present in the species of the Pantherinae studied. In the lion and the jaguar the Thyrohyoideum and the thyroid cartilage are connected by an elastic ligament, whereas in the tiger there is a synovial articulation. In adult individuals of the lion, tiger and jaguar the ventral end of the tympanohyal cartilage is rotated and therefore the ventral end of the attached Stylohyoideum lies caudal to the Tympanohyoideum and the cranial base. In newborn jaguars the Apparatus hyoideus shows a similar topographical position as in adult cheetahs or domestic cats. In adult Pantherinae, the Basihyoideum and the attached larynx occupy a descended position: they are situated near the cranial thoracic aperture, the pharyngeal wall and the soft palate are caudally elongated accordingly. In the Pantherinae examined the caudal end of the soft palate lies dorsal to the glottis. Differences in these morphological features between the subfamilies of the Felidae have an influence on specific structural characters of their vocalizations.

Occurrence and structure of epipharyngeal pouches in bears (Ursidae).

The infrequent mention of epipharyngeal pouches occurring in some species of bears indicates the scarcity of morphological and functional knowledge about these structures. In order to provide precise morphological data on the structure of these remarkable formations and to verify their taxonomic utility, the pharyngeal regions of 1 spectacled bear and 3 brown bears were examined. All these individuals possessed epipharyngeal pouches, which are tubular, blind-ending outpouchings of the caudodorsal pharyngeal wall equipped with respiratory epithelium and a thick layer of elastic fibres. While the spectacled bear and Ursus arctos syriacus possessed a single pouch on the caudodorsal wall of the nasopharynx, in Ursus arctos and Ursus arctos beringianus 2 unequally sized pouches were present. Two additional sacs of smaller size, representing outpouchings of the lateral pharyngeal wall, occurred in the spectacled bear. These findings prove epipharyngeal pouches to be constant and unique morphological features of the family Ursidae, the anatomical features suggesting involvement in the respiratory system most probably in important aspects of ursid phonation. This is the first description of epipharyngeal pouches in the spectacled bear.

[Anatomic-topographic description of the stomach, small intestine, large intestine and their arteries of the greater mara (Dolichotis patagonum Desmarest 1820)]. / Anatomisch-topographische Darstellung des Magens, des Dünndarmes, des Dickdarmes sowie deren arterielle Gefässversorgung beim Grossen Mara (Dolichotis patagonum Desmarest 1820).

The abdominal parts of the alimentary canal and the associated arteries from seven male and nine female maras are described. The mara possesses a stomach with a single cavity and a glandular mucosa lining. The large stomach is situated caudal of the liver at right-angles to the longitudinal body axis. The long jejunum is located on the left side of the body caudal of the stomach. The cecum has two teniae and numerous haustra which are proximal larger than distal. The smooth colon ascendens runs proximal parallel to the cecum and describes distal an U-shaped double-loop. The internal surface of the proximal part of the colon ascendens is characterized by two parallel mucosal ledges. Cecum and colon ascendens lie right caudal of the liver. The colon descendens is coiled and situated on the left body side. The A. gastrica sinistra and branches of the A. lienalis and the A. hepatica supply the stomach. The A. mesenterica cranialis which branches of separately from the A. coeliaca is a large and long vessel that supplies the major parts of the small intestine and the colon. The A. mesenterica caudalis supplies parts of the colon desendens and of the rectum.