| cerebellar efferents in the lizard varanus exanthematicus. i. corticonuclear projections. | the organization of the cerebellar corticonuclear projections, i.e., the projections from the purkinje cell layer to the cerebellar nuclei and the vestibular nuclear complex, was investigated with the horseradish peroxidase (hrp) technique in the lizard varanus exanthematicus. after hrp slow-release gels were implanted in the cerebellar nuclei or various parts of the vestibular nuclear complex, the following longitudinally oriented zones of labeled purkinje cells could be distinguished: a medial ... | 1984 | 6480921 |
| cerebellar efferents in the lizard varanus exanthematicus. ii. projections of the cerebellar nuclei. | the projections of the cerebellar nuclei have been studied in the lizard varanus exanthematicus with various experimental anatomical techniques. in anterograde degeneration experiments (lesions of the cerebellar peduncle) both ascending and decending contralateral projections were found. ascending fibers which could be traced from the cerebellar commissure ventralward decussated at the level of the trochlear and oculomotor nuclei. these fibers coursed rostralward to the mesodiencephalic junction ... | 1984 | 6512019 |
| eat and run: prioritization of oxygen delivery during elevated metabolic states. | the principal function of the cardiopulmonary system is the matching of oxygen and carbon dioxide transport to the metabolic requirements of different tissues. increased oxygen demands (vo2), for example during physical activity, result in a rapid compensatory increase in cardiac output and redistribution of blood flow to the appropriate skeletal muscles. these cardiovascular changes are matched by suitable ventilatory increments. this matching of cardiopulmonary performance and metabolism durin ... | 2004 | 15556104 |
| [transfer of exotic ticks (acari: ixodida) on reptiles (reptilia) imported to poland]. | in the of period 2003-2007, a total of 382 specimens of reptiles belonging to the following genera were investigated: testudo, iguana, varanus, gongylophis, python, spalerosophis, psammophis. the material for the present study was a collection of reptiles owned by the "animals" ltd from swietochłowice (upper silesia, poland), specialising in import of exotic animals to poland, as well as the reptile collections of private breeders. the reptiles that turned out to be the most heavily infected wit ... | 2009 | 20066784 |
| parasitisation and localisation of ticks (acari: ixodida) on exotic reptiles imported into poland. | as a result of examinations, the following species of ticks have been found parasitising on python regius brought from africa to poland: amblyomma latum, amblyomma transversale, amblyomma spp., on varanus exanthematicus: amblyomma exornatum, amblyomma flavomaculatum, amblyomma latum, amblyomma nuttalli, amblyomma spp., on varanus salvator brought from indonesia to poland: amblyomma varanensis. there were 58 specimens of monitor lizard (v. salvator and v. exanthematicus) and 92 specimens of pytho ... | 2010 | 21186765 |
| first reports of ectoparasites collected from wild-caught exotic reptiles in florida. | we collected ectoparasites from 27 of 51 wild-caught, free-ranging exotic reptiles examined in florida from 2003 to 2008. sampled animals represented eight species, five of which yielded ectoparasites. reported new parasite distribution records for the united states include the following: the first collection of the african tick amblyomma latum (koch) from a wild-caught animal [ball python, python regius (shaw)] in the united states; the first collection of the lizard scale mite hirstiella stami ... | 2011 | 21337954 |
| brain stem afferents to the anterior dorsal ventricular ridge in a lizard (varanus exanthematicus). | the anterior dorsal ventricular ridge (advr), a large intraventricular protrusion in the reptilian forebrain, receives information from many different sensory modalities and in turn, projects massively onto the striatum. the advr possesses functional similarities to the mammalian isocortex and may perform complex sensory integrations. the advr in lizards is composed of three longitudinal zones which receive visual, somatosensory and acustic information, respectively. these projections are relaye ... | 2012 | 3364750 |
| terrestrial locomotion does not constrain venous return in the american alligator, alligator mississippiensis. | the effects of treadmill exercise on components of the cardiovascular (heart rate, mean arterial blood pressure, central venous pressure, venous return) and respiratory (minute ventilation, tidal volume, breathing frequency, rate of oxygen consumption, rate of carbon dioxide production) systems and on intra-abdominal pressure were measured in the american alligator, alligator mississippiensis, at 30 degrees c. alligators show speed-dependent increases in tidal volume and minute ventilation, demo ... | 2005 | 16109894 |
| afferent connections of the cerebellum in various types of reptiles. | the origin of cerebellar afferents was studied in various types of reptiles, viz., the turtles pseudemys scripta elegans and testudo hermanni, the lizard varanus exanthematicus, and the snake python regius, with retrograde tracers (the enzyme horseradish peroxidase and the fluorescent tracer "fast blue"). projections to the cerebellum were demonstrated from the nucleus of the basal optic root, the interstitial nucleus of the fasciculus longitudinalis medialis, the vestibular ganglion, and the ve ... | 1982 | 7107986 |
| propriospinal fibers interconnecting the spinal enlargements in some quadrupedal reptiles. | the cells of origin, course and site of termination of long propriospinal fibers interconnecting the intumescences have been studied with the aid of the horseradish peroxidase technique, as well as with anterograde degeneration techniques, in some quadrupedal reptiles (the lizards tupinambis nigropunctatus and varanus exanthematicus, and the turtles testudo hermanni and pseudemys scripta elegans). the anterograde degeneration findings suggest that long descending propriospinal fibers from the ce ... | 1980 | 6933169 |
| lung ventilation during walking and running in four species of lizards. | the relationship between locomotion and aspiration breathing was investigated in the lizards iguana iguana, ctenosaura similis, varanus exanthematicus and varanus salvator, and the quail coturnix coturnix. respiratory air-flow during walking and running on a 7.3 m track or on a treadmill was measured with a bidirectional flow meter attached to one nostril. in all four species of lizards, lung ventilation drops markedly during locomotion. tidal volume decreases as speed increases, often by more t ... | 1987 | 3666097 |
| hypoxic pulmonary vasoconstriction in reptiles: a comparative study of four species with different lung structures and pulmonary blood pressures. | low o2 levels in the lungs of birds and mammals cause constriction of the pulmonary vasculature that elevates resistance to pulmonary blood flow and increases pulmonary blood pressure. this hypoxic pulmonary vasoconstriction (hpv) diverts pulmonary blood flow from poorly ventilated and hypoxic areas of the lung to more well-ventilated parts and is considered important for the local matching of ventilation to blood perfusion. in the present study, the effects of acute hypoxia on pulmonary and sys ... | 2005 | 15961533 |
| basal ganglia projections to the brain stem in the lizard varanus exanthematicus as demonstrated by retrograde transport of horseradish peroxidase. | | 1981 | 7266879 |
| ascending projections of the brain stem reticular formation in a nonmammalian vertebrate (the lizard varanus exanthematicus), with notes on the afferent connections of the forebrain. | in the present study an attempt has been made to analyze the ascending reticular projections in the lizard varanus exanthematicus by means of the horseradish peroxidase (hrp) technique. reticular projections ascending to the telencephalon were found to arise in the mesencephalon, but not caudal to the mesorhombencephalic border. hrp injections into the dorsal thalamus have demonstrated retrogradely labeled cells in the mesencephalic reticular formation, particularly at the level of the oculomoto ... | 1981 | 7263959 |
| the fasciculus longitudinalis medialis in the lizard varanus exanthematicus. 1. interstitiospinal, reticulospinal and vestibulospinal components. | with the horseradish peroxidase (hrp) technique the various descending components of the medial longitudinal fasciculus (flm) have been studied in the lizard varanus exanthematicus. after wheat germ agglutinin conjugated hrp injections at the spinomedullary border, retrogradely labeled fibers passing via the flm could be traced to various parts of the magnocellular rhombencephalic reticular formation, the descending and ventromedial vestibular nuclei and the interstitial nucleus of the flm. by i ... | 1984 | 6547576 |
| the motor nuclei and sensory neurons of the iiird, ivth, and vith cranial nerves in the monitor lizard, varanus exanthematicus. | the motor nuclei of the oculomotor, trochlear, and abducens nerves of the reptile varanus exanthematicus and the neurons that subserve the sensory innervation of the extraocular muscles were identified and localized by retrograde and anterograde transport of horseradish peroxidase (hrp). the highly differentiated oculomotor nuclear complex, located dorsomedially in the tegmentum of the midbrain, consists of the accessory oculomotor nucleus and the dorsomedial, dorsolateral, intermediate, and ven ... | 1988 | 3343406 |
| synaptic connections between primary trigeminal afferents and accessory abducens motoneurons in the monitor lizard, varanus exanthematicus. | we studied the anatomical pathway underlying the nictitating reflex in the monitor lizard varanus exanthematicus by the anterograde degeneration technique combined with retrograde transport of horseradish peroxidase (hrp) and electron microscopy. after application of hrp to the abducens nerve, retrogradely labeled neurons were observed in the ipsilateral principal and accessory abducens motor nuclei. the transection, in the same experiments, of the root of the trigeminal nerve resulted in massiv ... | 1988 | 3343407 |
| mixed-junction axon terminals on identified principal abducens motoneurons in the monitor lizard. | motoneurons in the principal abducens nucleus of the monitor lizard varanus exanthematicus were identified by retrograde labeling following application of horseradish peroxidase to the abducens nerve. the ultrastructure and synaptology of thirty labeled neurons were studied. we observed a type of axon terminal which forms mixed junctions with the cell bodies and the initial axon segments of labeled motoneurons. the juxtaposed membranes of the terminals and the motoneurons display gap junctions a ... | 1988 | 3196908 |
| further serial transmission electron microscopy studies of auditory hair cell innervation in lizards and in a snake. | auditory hair cells of three lizard and one snake species were studied by serial transmission electron microscopy (tem) sections of two unidirectional hair cells (uhc) and two bidirectional hair cells (bhc) and by nonserial section montages of each entire papilla cut at 2-microns intervals across the papillar width. the unidirectional hair cell region of the agamid lizard, acanthosaura crucigera, lacked efferent innervation. another agamid lizard, agama agama, studied by nonserial section only, ... | 1990 | 2375282 |
| primary structure of hemoglobin from monitor lizard (varanus exanthematicus albigularis--squamata). | the primary structure of the major hemoglobin component from the monitor lizard varanus exanthematicus albigularis is presented. the polypeptide subunits were separated by reversed-phase high-performance liquid chromatography on nucleosil c-4 column. the amino-acid sequence was established by automatic edman degradation of the native polypeptide and its tryptic and hydrolytic cleavage products in a spinning cup sequencer. the structural data are discussed with reference to other reptiles. | 1991 | 1930730 |
| distribution patterns and predilection muscles of <i>trichinella zimbabwensis</i> larvae in experimentally infected nile crocodiles (<i>crocodylus niloticus</i> laurenti). | no controlled studies have been conducted to determine the predilection muscles of trichinella zimbabwensis larvae in nile crocodiles (crocodylus niloticus) or the influence of infection intensity on the distribution of the larvae in crocodiles. the distribution of larvae in muscles of naturally infected nile crocodiles and experimentally infected caimans (caiman crocodilus) and varans (varanus exanthematicus) have been reported in literature. to determine the distribution patterns of t. zimbabw ... | 2014 | 28235274 |
| distribution patterns and predilection muscles of trichinella zimbabwensis larvae in experimentally infected nile crocodiles (crocodylus niloticus laurenti). | no controlled studies have been conducted to determine the predilection muscles of trichinella zimbabwensis larvae in nile crocodiles (crocodylus niloticus) or the influence of infection intensity on the distribution of the larvae in crocodiles. the distribution of larvae in muscles of naturally infected nile crocodiles and experimentally infected caimans (caiman crocodilus) and varans (varanus exanthematicus) have been reported in literature. to determine the distribution patterns of t. zimbabw ... | 2014 | 24833069 |
| the fasciculus longitudinalis medialis in the lizard varanus exanthematicus. 2. vestibular and internuclear components. | in the present study the vestibular components of the fasciculus longitudinalis medialis (flm) were investigated in the lizard varanus exanthematicus with various tracing techniques: anterograde transport of horseradish peroxidase to study vestibulo-oculomotor and vestibulospinal projections, the multiple retrograde fluorescent tracer technique for the cells of origin of such projections. internuclear projections between the oculomotor and abducens nuclei could also be studied in this way. rathe ... | 2010 | 2996380 |
| the brain stem in a lizard, varanus exanthematicus. | | 2012 | 3318284 |
| scanning electron microscope study of the morphology of the reptilian lung: the savanna monitor lizard varanus exanthematicus and the pancake tortoise malacochersus tornieri. | the morphology of the lungs of two reptilian species, varanus exanthematicus and malacochersus tornieri, have been studied on gross preparations, latex casts, and critical-point-dried tissues. the shape of these lungs was observed to conform with that of the body, the lung of the monitor lizard (varanus) being long and ovoid while that of the pancake tortoise (malacochersus) was rounded and laterally indented. with respect to the size distribution of the gas exchange compartments, the lungs were ... | 2009 | 2782631 |
| melanophoromas and iridophoromas in reptiles. | chromatophoromas are tumours of pigment-producing cells of the skin and are rarely reported in reptiles. these tumours are subclassified on the basis of the type of pigment. the present study characterizes chromatophoromas arising in 26 reptiles, including six snakes, 19 lizards and a tortoise. these include the first reports of melanophoromas in a yellow anaconda (eunectes notaeus), pigmy rattlesnake (sistrurus spp.), southern water snake (nerodia fasciata), veiled chameleon (chamaeleo calyptra ... | 2011 | 21864845 |
| the international trade in reptiles (reptilia)--the cause of the transfer of exotic ticks (acari: ixodida) to poland. | the problem of the unnatural transfer of exotic ticks (acari: ixodida) on reptiles (reptilia) imported to poland is presented. in the period from 2003 to 2007, 382 specimens of reptiles belonging to the following genera were investigated: testudo, iguana, varanus, gongylophis, python, spalerosophis, psammophis. the reptiles most infested with ticks are imported to poland from ghana in africa, and are the commonly bred terrarium reptiles: varanus exanthematicus and python regius. as a result of t ... | 2010 | 20153933 |
| detection of anaplasma phagocytophilum in amblyomma flavomaculatum ticks (acari: ixodidae) collected from lizard varanus exanthematicus imported to poland. | adults and nymphs of amblyomma exornatum, a. flavomaculatum, a. latum, amblyomma spp. and hyalomma aegyptium, were collected from savannah monitors, royal python (africa, ghana) and marginated tortoises (europe, greece) imported to poland, in 2004-2007. altogether 345 ticks were examined by polymerase chain reaction for rickettsial agents. none of the tested ticks was positive for the glta gene of rickettsia spp. dna of 16s rrna gene from anaplasma phagocytophilum was amplified and sequenced fro ... | 2010 | 20084536 |
| trichinella papuae and trichinella zimbabwensis induce infection in experimentally infected varans, caimans, pythons and turtles. | the discovery of trichinella zimbabwensis in farm crocodiles of zimbabwe has opened up a new frontier in the epidemiology of the trichinella genus. the objective of the present study was to investigate the infectivity of encapsulated species (t. spiralis, t. nativa, t. britovi, t. murrelli and t. nelsoni) and non-encapsulated species (t. pseudospiralis, t. papuae and t. zimbabwensis) in caimans (caiman crocodilus), varans (varanus exanthematicus), pythons (python molurus bivittatus) and turtles ... | 2004 | 15074882 |
| scaling of rotational inertia in murine rodents and two species of lizard. | because the force required to rotate a body about an axis is directly proportional to its rotational inertia about the axis, it is likely that animals with high rotational inertia would be constrained in their turning abilities. given that rotational inertia scales with mass(1.67) in geometrically similar animals, whereas the ability to apply torque scales with mass(1.00), larger animals would be expected to have more difficulty turning than smaller animals of similar shape. to determine how rot ... | 2002 | 12089217 |
| successful hyperimmune bovine colostrum treatment of savanna monitors (varanus exanthematicus) infected with cryptosporidium sp. | therapy based on the protective passive immunity of hyperimmune bovine colostrum (hbc) (raised against cryptosporidium parvum in cows) was applied to 4 savanna monitors (varanus exanthematicus) with gastric cryptosporidium sp. infections. all lizards were moderately emaciated, and their fecal and gastric lavage samples contained moderate numbers of cryptosporidium sp. oocysts. the first 3 of 7 gastric hbc treatments at 1-wk interval each decreased the numbers of oocysts in the fecal and gastric ... | 2000 | 10864270 |
| effect of bacterial pyrogen on three lizard species. | 1. three lizard species (callopistes maculatus, gerrhosaurus major, and varanus exanthematicus) were tested for their response to intraperitoneal injection of alcohol-killed aeromonas sobria. 2. a paired experimental design, in which each animal received an injection of sterile saline and 1 x 10(10) a. sobria, was utilized. 3. c. maculatus demonstrated a statistically significant increase in mean selected body temperature (msbt) after bacteria injection. 4. g. major and v. exanthematicus did not ... | 1990 | 1976479 |
| pulmonary oxygen transport during activity in lizards. | oxygen consumption (mo2), effective alveolar ventilation (veff), arterial and alveolar po2 (pao2, pao2) and the alveolar-arterial po2 difference [(a--a)po2] were determined in the lizards varanus exanthematicus and iguana iguana at rest and during treadmill exercise at 35 degrees c. in both species, veff increased more rapidly than mo2 giving rise to an increased pao2. in contrast, pao2 remained unchanged through the highest levels of mo2 attained. as a result, the (a--a)po2 increased with incre ... | 1981 | 7280383 |
| use of ultrasonography in the diagnosis of hepatic spindle-cell sarcoma in a savannah monitor (varanus exanthematicus). | | 2002 | 11918052 |
| postprandial exercise: prioritization or additivity of the metabolic responses? | monitor lizards (varanus exanthematicus) were used to examine the prioritization or additivity of the metabolic responses associated with exercise and digestion, either of which can elevate metabolic rate independently. rates of oxygen consumption (v(o2)) and ventilation (v(e)) were measured in lizards during fasting exercise, postprandial rest and postprandial exercise. in fasting animals, v(o2) increased with walking speed to a maximal value of 15.9 ml o(2)kg(-1)min(-1) at 1.25 km h(-1). postp ... | 2001 | 11441054 |
| ventilation and gas exchange in lizards during treadmill exercise. | the extent to which lizards ventilate their lungs during locomotion is controversial. direct measurements of airflow across the nostrils suggest a progressive reduction in tidal volume and minute ventilation with increased running speed, while other studies have demonstrated that arterial po2 remains constant during exercise. to resolve these conflicting findings, we measured minute ventilation and gas exchange rate in five specimens of varanus exanthematicus and five specimens of iguana iguana ... | 1997 | 9359369 |
| fiber-type composition in the perivertebral musculature of lizards: implications for the evolution of the diapsid trunk muscles. | the perivertebral musculature of lizards is critical for the stabilization and the mobilization of the trunk during locomotion. some trunk muscles are also involved in ventilation. this dual function of trunk muscles in locomotion and ventilation leads to a biomechanical conflict in many lizards and constrains their ability to breathe while running ("axial constraint") which likely is reflected by their high anaerobic scope. furthermore, different foraging and predator-escape strategies were sho ... | 2013 | 23115131 |
| in situ cardiac perfusion reveals interspecific variation of intraventricular flow separation in reptiles. | the ventricles of non-crocodilian reptiles are incompletely divided and provide an opportunity for mixing of oxygen-poor blood and oxygen-rich blood (intracardiac shunting). however, both cardiac morphology and in vivo shunting patterns exhibit considerable interspecific variation within reptiles. in the present study, we develop an in situ double-perfused heart approach to characterise the propensity and capacity for shunting in five reptile species: the turtle trachemys scripta, the rock pytho ... | 2016 | 27207643 |
| lymphosarcoma with leukemic blood profile in a savannah monitor lizard (varanus exanthematicus). | a 6-mo-old male savannah monitor lizard (varanus exanthematicus) was presented for lethargy and anorexia of 7 days duration. physical examination revealed a slightly raised subcutaneous mass (1 cm diameter) in the left scapular area. fine-needle aspiration cytology of the mass revealed a population of immature, pleomorphic lymphoid cells consistent with lymphosarcoma. a hemogram indicated marked leukocytosis (465,000 cells/microl) characterized by extreme lymphocytosis and many circulating lymph ... | 1999 | 10367659 |
| ventilation and pulmonary gas exchange during exercise in the savannah monitor lizard (varanus exanthematicus). | during exercise, pulmonary gas exchange in reptiles was predicted to differ from that in mammals because of their less complex lung structure, which might reduce ventilation-perfusion heterogeneity (v/ql) at the expense of pulmonary diffusion limitation. to investigate this, the multiple inert gas elimination technique was used in six varanus exanthematicus at rest and during maximal exercise. trace amounts of six inert gases were infused into the external jugular vein and blood samples were col ... | 1995 | 7636447 |
| stable isotopes may provide evidence for starvation in reptiles. | previous studies have attempted to correlate stable isotope signatures of tissues with the nutritional condition of birds, mammals, fishes, and invertebrates. unfortunately, very little is known about the relationship between food limitation and the isotopic composition of reptiles. we examined the effects that starvation has on delta13c and delta15n signatures in the tissues (excreta, carcass, scales, and claws) of six, distantly related squamate reptiles (gaboon vipers, bitis gabonica; ball py ... | 2008 | 18613003 |
| fatty acid analyses may provide insight into the progression of starvation among squamate reptiles. | fasting-induced changes in fatty acid composition have been reported to occur within the body lipids of several types of animals; however, little is known about the changes in fatty acid profiles exhibited by reptiles subjected to prolonged fasting. this study characterizes the fatty acid profiles of six reptile species subjected to sublethal periods of fasting lasting 0, 56, 112, and 168 days. analyses of fatty acid methyl esters (fames) conducted on the total body lipids of rattlesnakes (crota ... | 2008 | 18657629 |
| ventilation and acid-base balance during graded activity in lizards. | arterial pco2, hydrogen ion ([h+]a), and lactate ([l]a) concentrations, rates of metabolic co2 production (vco2) and o2 consumption (vo2), and effective alveolar ventilation (veff) were determined in the lizards varanus exanthematicus and iguana iguana at rest and during steady-state treadmill exercise at 35 degrees c. in varanus, vco2 increased ninefold and vo2 sixfold without detectable rise in [l]a at running speeds below 1.0 to 1.5 km x h-1. in this range, veff increased 12-fold resulting in ... | 1981 | 6779642 |
| the role of the sarcoplasmic reticulum in the generation of high heart rates and blood pressures in reptiles. | the functional significance of the sarcoplasmic reticulum (sr) in the generation of high heart rates and blood pressures was investigated in four species of reptile; the turtle, trachemys scripta; the python, python regius, the tegu lizard, tupinanvis merianae, and the varanid lizard, varanus exanthematicus. force-frequency trials and imposed pauses were performed on ventricular and atrial tissue from each species with and without the sr inhibitor ryanodine, and in the absence and presence of ad ... | 2006 | 16651560 |
| unidirectional pulmonary airflow patterns in the savannah monitor lizard. | the unidirectional airflow patterns in the lungs of birds have long been considered a unique and specialized trait associated with the oxygen demands of flying, their endothermic metabolism and unusual pulmonary architecture. however, the discovery of similar flow patterns in the lungs of crocodilians indicates that this character is probably ancestral for all archosaurs--the group that includes extant birds and crocodilians as well as their extinct relatives, such as pterosaurs and dinosaurs. u ... | 2014 | 24336209 |
| cells of origin of pathways descending to the spinal cord in some quadrupedal reptiles. | the cells of origin of pathways descending to the spinal cord have been determined in several quadrupedal reptiles, viz., the turtle pseudemys scripta elegans and testudo hermanni and the lizards tupinambis nigropunctatus and varanus exanthematicus, following a technique introduced by kuypers and maisky ('75). this technique was very effective in producing retrograde transport of hrp to a great many neurons in the hypothalamus and in the brain stem. projections from the hypothalamus (the nucleus ... | 1980 | 7419757 |
| [giant mitochondria in the a cells of the pancreas of a lizard: varanus niloticus]. | pancreatic a cells of the lizard varanus niloticus are characterized by the presence of two types of mitochondria: (a) normal, small mitochondria (about 0.4 x 1 micron), and (b) giant mitochondria, measuring up to 9 micron in length and 1 micron in diameter. giant mitochondria show various shapes. their matrix is filled with tubules, filaments, and dense granules. transverse sections of tubules are polygonal in shape and about 20 nm in diameter. they are grouped in bundles. the filaments, about ... | 1985 | 3837128 |
| spontaneous otoacoustic emissions in monitor lizards. | monitors (all of which belong to the genus varanus) make up a very uniform family of often large lizards. they have a large auditory papilla that is not highly specialized, but is divided into two unequal sub-papillae. all hair cells are covered by a tectorial membrane. spontaneous otoacoustic emissions (soae) were examined in cape monitor lizards (varanus exanthematicus) and found between 1.08 and 2.91 khz (at 32 degrees c) and with levels between -2.8 and 25.8 db spl. the frequency of soae was ... | 2004 | 14987751 |
| effect of temperature on chemosensitive locus coeruleus neurons of savannah monitor lizards, varanus exanthematicus. | savannah monitor lizards (varanus exanthematicus) are unusual among ectothermic vertebrates in maintaining arterial ph nearly constant during changes in body temperature in contrast to the typical α-stat regulating strategy of most other ectotherms. given the importance of ph in the control of ventilation, we examined the co2/h+sensitivity of neurons from the locus coeruleus (lc) region of monitor lizard brainstems. whole-cell patch-clamp electrophysiology was used to record membrane voltage in ... | 2016 | 27401762 |
| highly species-specific centromeric repetitive dna sequences in lizards: molecular cytogenetic characterization of a novel family of satellite dna sequences isolated from the water monitor lizard (varanus salvator macromaculatus, platynota). | two novel repetitive dna sequences, vsarep1 and vsarep2, were isolated from the water monitor lizard (varanus salvator macromaculatus, platynota) and characterized using molecular cytogenetics. the respective lengths and guanine-cytosine (gc) contents of the sequences were 190 bp and 57.5% for vsarep1 and 185 bp and 59.7% for vsarep2, and both elements were tandemly arrayed as satellite dna in the genome. vsarep1 and vsarep2 were each located at the c-positive heterochromatin in the pericentrome ... | 2013 | 24129994 |
| experimental exposure of juvenile savannah monitors (varanus exanthematicus) to an environmentally relevant mixture of three contaminants: effects and accumulation in tissues. | using varanids as indicators of pollution in african continental wetlands was previously proposed. the present study aimed at understanding experimentally how monitors absorb and accumulate pollutants and how they are affected. the relevance of non-destructive sampling was also evaluated. savannah monitors (varanus exanthematicus) were orally exposed during 6 months to a mixture of lead, 4,4'-dichlorodiphenyltrichloroethane (4,4'-ddt) and chlorpyrifos-ethyl (cpf) or to the vehicle only. proporti ... | 2013 | 23054794 |
| the cellular force-frequency response in ventricular myocytes from the varanid lizard, varanus exanthematicus. | to investigate the cellular mechanisms underlying the negative force-frequency relationship (ffr) in the ventricle of the varanid lizard, varanus exanthematicus, we measured sarcomere and cell shortening, intracellular ca(2+) ([ca(2+)](i)), action potentials (aps), and k(+) currents in isolated ventricular myocytes. experiments were conducted between 0.2 and 1.0 hz, which spans the physiological range of in vivo heart rates at 20-22 degrees c for this species. as stimulation frequency increased, ... | 2010 | 20053961 |
| ca2+ cycling in cardiomyocytes from a high-performance reptile, the varanid lizard (varanus exanthematicus). | the varanid lizard possesses one of the largest aerobic capacities among reptiles with maximum rates of oxygen consumption that are twice that of other lizards of comparable sizes at the same temperature. to support this aerobic capacity, the varanid heart possesses morphological adaptations that allow the generation of high heart rates and blood pressures. specializations in excitation-contraction coupling may also contribute to the varanids superior cardiovascular performance. therefore, we in ... | 2009 | 19812356 |
| editorial focus: cardiac function of the lizard king: focus on "ca2+ cycling in cardiomyocytes from a high-performance reptile, the varanid lizard (varanus exanthematicus)". | | 2009 | 19793951 |
| chronic electrical stimulation drives mitochondrial biogenesis in skeletal muscle of a lizard, varanus exanthematicus. | we investigated the capacity for phenotypic plasticity of skeletal muscle from varanus exanthematicus, the savannah monitor lizard. iliofibularis muscle from one leg of each lizard was electrically stimulated for 8 weeks. both stimulated and contralateral control muscles were collected and processed for electron microscopy. we used stereological analysis of muscle cross-sections to quantify the volume densities of contractile elements, sarcoplasmic reticulum, mitochondria and intracellular lipid ... | 2007 | 17872989 |
| metabolic and blood gas dependence on digestive state in the savannah monitor lizard varanus exanthematicus: an assessment of the alkaline tide. | a large alkaline tide (up to 20 mmol l(-1) increase in bicarbonate concentration [hco3-] with an accompanied increase in blood ph) has previously been reported for some carnivorous reptiles within 24 h after ingesting a large meal. this phenomenon has been attributed to the secretion of large amounts of h+ ions into the stomach, which is required for digestion of large prey items. to test the generality of this phenomenon in carnivorous reptiles, this study quantified the metabolic and acid-base ... | 2006 | 16513931 |
| why savannah monitor lizards hyperventilate during activity: a comparison of model predictions and experimental data. | the functional and structural factors that limit maximal oxygen uptake (vo2 max) in lizards are not completely understood. using an integrative model describing the interactive nature of the individual oxygen transport conductances, we performed an analysis of the oxygen transport system in the highly aerobic lizard varanus exanthematicus with specific reference to the sensitivity of vo2 max to potential limitations in the ventilatory system. our analysis predicts that dlo2 must increase more th ... | 2004 | 15556107 |
| elevated intra-abdominal pressure limits venous return during exercise in varanus exanthematicus. | the effects of treadmill exercise on components of the cardiovascular (venous return, heart rate, arterial blood pressure) and respiratory systems (minute ventilation, tidal volume, breathing frequency, oxygen consumption, carbon dioxide production) and intra-abdominal pressure were investigated in the savannah monitor lizard, varanus exanthematicus b., at 35 degrees c. compared with resting conditions, treadmill exercise significantly increased lung ventilation, gular pumping, intra-abdominal p ... | 2004 | 15498957 |
| hysteresis of heart rate and heat exchange of fasting and postprandial savannah monitor lizards (varanus exanthematicus). | reptiles are ectothermic, but regulate body temperatures (t(b)) by behavioural and physiological means. body temperature has profound effects on virtually all physiological functions. it is well known that heating occurs faster than cooling, which seems to correlate with changes in cutaneous perfusion. increased cutaneous perfusion, and hence elevated cardiac output, during heating is reflected in an increased heart rate (f(h)), and f(h), at a given t(b), is normally higher during heating compar ... | 2004 | 15123175 |
| an experimental test of the thermoregulatory hypothesis for the evolution of endothermy. | the thermoregulatory hypothesis proposes that endothermy in mammals and birds evolved as a thermoregulatory mechanism per se and that natural selection operated directly to increase body temperature and thermal stability through increments in resting metabolic rate. we experimentally tested this hypothesis by measuring the thermoregulatory consequences of increased metabolic rate in resting lizards (varanus exanthematicus). a large metabolic increment was induced by feeding the animals and conse ... | 2000 | 11108603 |
| patterns of cardiovascular and ventilatory response to elevated metabolic states in the lizard varanus exanthematicus. | the principal function of the cardiopulmonary system is the precise matching of o(2) and co(2) transport to the metabolic requirements of different tissues. in some ecothermic vertebrates (amphibians and reptiles), vdot (o2) increases dramatically following feeding. factorial increments in vdot (o2) range from 1.7 to 44 times above resting rates, and in some cases vdot (o2) approaches or even exceeds values measured during physical activity. there is virtually no information on the cardiopulmona ... | 2000 | 10903158 |
| pentastomiasis in bosc's monitor lizards (varanus exanthematicus) caused by an undescribed sambonia species. | two wild-caught bosc's monitor lizards (varanus exanthematicus) developed clinical signs of pentasomiasis approximately 3 yr after arrival in the united kingdom. one died of chronic parasitic pneumonia associated with adult pentastomids of an undescribed sambonia species. eggs and immature pentastomids were also seen in histologic sections of the lungs and liver. the other animal was treated for pneumonia and for nodular inflammation of the larynx that restricted the diameter of the glottis. fra ... | 2000 | 10884132 |
| distribution of nadph-diaphorase positive somata in the brainstem of the monitor lizard varanus exanthematicus. | the distribution and size of presumptive cholinergic somata in the brainstem of the savanna monitor lizard varanus exanthematicus were determined using the enzyme histochemical marker nadph-diaphorase. numerous neurons were labelled in the lizard brainstem with this technique. a three dimensional computer reconstruction of this population revealed that it shows marked similarity to the laterodorsal tegmental/pedunculopontine tegmental cholinergic cell column, an nadph-diaphorase positive populat ... | 1992 | 1300484 |
| strike-induced chemosensory searching occurs in lizards. | strike-induced chemosensory searching (sics), previously known only in snakes, is experimentally demonstrated in a lizard,varanus exanthematicus. tongue-flicking rate was significantly greater after striking the prey than following three control conditions. the occurrence of sics in a varanid lizard suggests that sics may serve to help relocate dropped or escaped prey not only in snakes, but in other squamates that use the tongue as a chemosensory sampling device during foraging. this in turn su ... | 1989 | 24272014 |
| primary projections and efferent cells of the viiith cranial nerve in the monitor lizard, varanus exanthematicus. | in order to describe the central relations of both the afferent and efferent components of the viiith cranial nerve in one reptile, the methods of anterograde and retrograde axonal transport and anterograde degeneration were used to study the vestibular and cochlear projections and the efferent system of this nerve in varanus exanthematicus. on the basis of cresyl violet and klüver-barrera staining, five vestibular nuclei, four cochlear nuclei, and two clusters of small cells which could not be ... | 1988 | 2466058 |
| the motor complex and primary projections of the trigeminal nerve in the monitor lizard, varanus exanthematicus. | the sensory projections and the motor complex of the trigeminal nerve of the reptile varanus exanthematicus were studied with the methods of anterograde degeneration and anterograde and retrograde axonal transport. the primary afferent fibers diverge in the brainstem into a short ascending and a long descending tract. the former distributes its fibers to the principal sensory trigeminal nucleus, where nerves v1, v2, and v3 are represented along a lateromedial axis. the fibers of the descending t ... | 1986 | 3794009 |
| collateralization of descending pathways from the brainstem to the spinal cord in a lizard, varanus exanthematicus. | with the multiple fluorescent retrograde tracer technique, the collateralization in the spinal cord of descending supraspinal pathways was studied in a lizard, varanus exanthematicus. fast blue (fb) gels were implanted unilaterally in the spinal gray matter of the cervical enlargement and nuclear yellow (ny) gels were implanted ipsilaterally in two series of experiments in all spinal funiculi of the lumbar enlargement or in midthoracic spinal segments, respectively. all brainstem nuclei known to ... | 1986 | 3021824 |
| distribution of some peptides (substance p, [leu]enkephalin, [met]enkephalin) in the brain stem and spinal cord of a lizard, varanus exanthematicus. | the distribution of substance p-like and [leu]- and [met]enkephalin-immunoreactive cell bodies, fibers and terminal structures in the brain stem and spinal cord of a lizard, varanus exanthematicus, was studied with the indirect immunofluorescence technique, using antibodies to these peptides. substance p-like immunoreactive cell bodies were found in the hypothalamus, in a periventricular cell group in the rostral mesencephalon, in the interpeduncular nucleus, in and ventral to the descending nuc ... | 1986 | 2429232 |
| strain gauge measurement of mesokinetic movement in the lizard varanus exanthematicus. | single-element strain gauges were placed across the mesokinetic joint of the skull of the savanna monitor lizard, varanus exanthematicus bosc, in order to document the extent and timing of mesokinetic movement. in addition, rosette strain gauges were placed on various points of the palato-maxillary segment. strain recordings and simultaneous cineradiographic films or videotapes were taken during normal feeding activities, including the strike, prey manipulation, ingestion and pharyngeal compress ... | 1985 | 4009109 |
| distribution of serotonin in the brain stem and spinal cord of the lizard varanus exanthematicus: an immunohistochemical study. | the distribution of serotonin-containing nerve cell bodies, fibers and terminals in the lizard varanus exanthematicus was studied with the indirect immunofluorescence technique, using antibodies to serotonin. most of the serotonin-containing cell bodies were found in the midline, in both of the raphe nuclei, i.e. the nuclei raphes superior and inferior. a considerable number of more laterally shifted serotonergic neurons was found particularly at three levels of the brain stem, viz. in the cauda ... | 1985 | 3883229 |
| ascending and descending axon collaterals efferent from the brainstem reticular formation. a retrograde fluorescent tracer study in the lizard, varanus exanthematicus. | the existence of divergent axon collaterals of neurons in the reticular formation has been studied with fluorescent tracers in a lizard. it appeared that ascending and descending projections arise in at least partially overlapping fields. however, only few reticular or raphe neurons were found with both ascending and descending projections. | 1984 | 6518371 |
| distribution of catecholamines in the brain stem and spinal cord of the lizard varanus exanthematicus: an immunohistochemical study based on the use of antibodies to tyrosine hydroxylase. | antibodies to tyrosine hydroxylase were used to study the distribution of nerve cells, fibers and terminals, containing catecholamines, in the lizard varanus exanthematicus, by means of the indirect immunofluorescence technique. tyrosine hydroxylase-containing cell bodies occurred in the hypothalamus, the ventral and dorsal tegmentum mesencephali, the substantia nigra, the isthmic reticular formation, in and ventrolaterally to the locus coeruleus, in the nucleus tractus solitarii and in a latera ... | 1984 | 6151148 |
| the motor nuclei and primary projections of the ixth, xth, xith and xiith cranial nerves in the monitor lizard, varanus exanthematicus. | the motor nuclei and sensory connections of the ixth, xth, xith, and xiith cranial nerves of the reptile varanus exanthematicus were studied with the methods of anterograde degeneration and anterograde and retrograde axonal transport. the motor nuclei of nerve ix are located ventrally in the rhombencephalon and are constituted medially by the large-celled glossopharyngeal part of the nucleus ambiguus and laterally by the small-celled nucleus salivatorius inferior. the motor nuclei of nerve x con ... | 1984 | 6747035 |
| alterations of endocrine pancreas b cells in a sahelian reptile (varanus exanthematicus) during starvation. | during the long starvation period (november to june) of the lizard (varanus exanthematicus), pancreatic b cells undergo profound modification. the degeneration of beta granules observed in electron microscopy appears correlated with the diminution of the immunoreactive insulin-like content of the pancreas. the analogy between the phenomena observed here and those reported in animals treated with alloxan is discussed. | 1984 | 6379200 |
| the mechanism of intracardiac shunting in the lizard varanus exanthematicus. | intracardiac shunting was studied in unanaesthetized and unrestrained specimens of varanus exanthematicus by simultaneous injection of radioactively labelled microspheres (15 micron) into the right and left atria. lung ventilation was monitored by intratracheal pneumotachography. it was found that intracardiac shunting was not significantly affected by the spontaneously occurring periods of ventilation and apnoea: the right-to-left shunt averaged 29 and 31%, respectively, and the left-to-right s ... | 1983 | 6619725 |
| somatostatin-like immunoreactivity in pancreatic extracts of a sahelian lizard (varanus exanthematicus) during starvation. | in the varanus exanthematicus, the pancreatic complex comprises the true pancreas as well as an intrasplenic islet comparable to a brockmann's body. somatostatin content and concentration were estimated by radioimmunoassay in acetic acid extracts of both organs. relatively large amounts of somatostatin (sli) are present in the pancreas (2.17 +/- 0.07 micrograms) without any difference in distribution between the cranial (cp) and mediocaudal (mcp) regions. the intrasplenic islet contains as much ... | 1983 | 6136368 |
| brainstem afferents to the thalamus in a lizard, varanus exanthematicus. | hrp was injected into various thalamic nuclei in order to investigate the brainstem projections to the thalamus in the lizard varanus exanthematicus. nucleus dorsomedialis receives afferents from the septal area, nucleus entopeduncularis anterior, nucleus periventricularis hypothalami, area triangularis, nucleus raphes superior, nucleus reticularis inferior, and locus coeruleus. nucleus dorsolateralis receives afferents from septal area, nucleus dorsomedialis, nucleus entopeduncularis anterior, ... | 1982 | 7130476 |
| the motor nuclei and primary projections of the facial nerve in the monitor lizard varanus exanthematicus. | the location of the motor nuclei and the projection of the primary afferent fibers of the facial nerve of the reptile varanus exanthematicus were studied by means of the hrp method and the anterograde degeneration technique. the motor nuclei are located ventrolaterally in the rhombencephalon and are constituted by a medial cell group consisting of large, polygonal cells and a lateral cell group consisting of medium-sized, spindle-shaped, and multipolar cells. from hrp applications to the various ... | 1982 | 7096643 |
| funicular trajectories of descending brain stem pathways in a lizard (varanus exanthematicus). | | 1982 | 7156400 |
| prey transport kinematics in tupinambis teguixin and varanus exanthematicus: conservation of feeding behavior in 'chemosensory-tongued' lizards. | although lizards have been predicted to show extensive intraoral prey-processing behaviors, quantitative analyses of the types of prey-processing behavior they demonstrate and of their kinematics have been limited. the more basal lizard lineages (iguanians) have undergone some study, but the prey-processing repertoires of crown taxa have not been thoroughly examined and quantitative comparisons of behaviors within or among species have not been made. in this study, the prey transport behavior of ... | 2000 | 10648221 |
| spinothalamic projections in a lizard, varanus exanthematicus: an hrp study. | in the present study hrp injections have been placed in various thalamic areas in order to investigate spinothalamic projections in the lizard varanus exanthematicus. it appeared that the spinal cord projects to three different thalamic areas: nucleus dorsomedialis, nucleus ventrolateralis, and an area that includes both the nucleus dorsolateralis and nucleus intermediodorsalis. spinal neurons projecting to nucleus dorsomedialis are localized bilaterally at the medial side of the dorsal horn. fo ... | 1981 | 7229142 |
| acid-base regulation during heating and cooling in the lizard, varanus exanthematicus. | current concepts of acid-base balance in ectothermic animals require that arterial ph vary inversely with body temperature in order to maintain a constant oh-/h+ and constant net charge on proteins. the present study evaluates acid-base regulation in varanus exanthematicus under various regimes of heating and cooling between 15 and 38 degrees c. arterial blood was sampled during heating and cooling at various rates, using restrained and unrestrained animals with and without face masks. arterial ... | 1981 | 7263360 |
| heart rate and respiration in reptiles: contrasts between a sit-and-wait predator and an intensive forager. | the current study investigated respiration and heart rate in two species of reptiles with distinct behavioral strategies: (1) the sudan plated lizard (gerrhosaurus major), a sit-and-wait predator; and (2) the savanna monitor (varanus exanthematicus), an intensive forager. it was hypothesized that (a) the plated lizard would not express respiratory sinus arrhythmia, and (b) the monitor, a reptile with behavioral and physiological characteristics similar to mammals, might express respiratory sinus ... | 2003 | 12812808 |
| phacoemulsification in an adult savannah monitor lizard. | an adult male savannah monitor lizard (varanus exanthematicus) was presented for bilateral lens opacities that had progressed rapidly over the previous 2 months. a diagnosis of bilateral mature cataracts was made and phacoemulsification cataract extraction was performed. surgery restored vision and normal activity to the patient. | 2002 | 12236873 |
| [annual lipid cycle of the grassland varanian lizard]. | the circannual chronobiology of varanus exanthematicus exanthematicus bosc, lacertilian reptile of senegal, is characterized by a period of rest from january to june (dry season) and a period of activity from july to december (wet season). the study of the lipids metabolism shows a two month deplacement period: as a matter of fact from november to april the lipogenesis prevails, while from may to october it is the lipolysis. these two phases correspond to the periodicity of the development of th ... | 1976 | 135636 |
| [annual protidic cycle and electrophoregrams of the savanna varan]. | the circannual chronobiology of varanus exanthematicus exanthematicus bose, lacertilian reptile of senegal, is characterized by a period of rest from january to june during the dry season and a period of activity from july to december during the wet season. the study of proteidemia and of the ratio of weight and height shows that the hydratation of corporal compartments is average from november to april and undergoes through changes from may to october. the electrophoresis of proteins shows the ... | 1976 | 137068 |
| [the annual glucido-lipid cycle in a varanid of senegal]. | lipid and carbohydrate storage depots on one hand, blood lipids and glucose on the other hand, were measured every month in varanus exanthematicus exanthematicus, the annual cycle of which is correlated to the characteristic succession of one dry and one wet season in the sahel area. the large cyclic variations of these figures are discussed as a function of the animal behaviour and what is known about its endocrine cycle. | 1975 | 129242 |
| the functional anatomy of the shoulder of the savannah monitor lizard (varanus exanthematicus). | the excursions of the scapulocoracoid and forelimb and the activity of 18 shoulder muscles were studied by simultaneous cineradiography and electromyography in savannah monitor lizards (varanus exanthematicus) walking on a treadmill at speeds of 0.7-1.1 km/hour. during the propulsive phase, the humerus moves anteroposteriorly 40-55° and rotates a total of 30-40°. simultaneously, the coracoid translates posteriorly along the tongue-and-groove coracosternal joint by a distance equivalent to about ... | 1983 | 30068057 |
| the axial anatomy of monitor lizards (varanidae). | because the musculoskeletal anatomy of the trunk is the framework for the behaviors of locomotion, ventilation, and body support in lepidosaurs, comparative study of trunk anatomy in this group is critical for unraveling the selective pressures leading to extant diversity in axial form and function among vertebrates. this work uses gross dissection and computed tomography to describe the muscular and skeletal anatomy of the trunk of varanid lizards (varanidae, anguimorpha). gross muscle dissecti ... | 2018 | 30079494 |
| locomotor rib kinematics in two species of lizards and a new hypothesis for the evolution of aspiration breathing in amniotes. | most lizards walk and run with a sprawling gait in which the limbs are partly advanced by lateral undulation of the axial skeleton. ribs and vertebrae are integral to this locomotor mode, but 3d motion of the axial skeleton has not been reported for lizard locomotion. here, we use xromm to quantify the relative motions of the vertebrae and ribs during slow treadmill locomotion in three savannah monitor lizards (varanus exanthematicus) and three argentine black and white tegus (salvator merianae) ... | 2020 | 32398656 |
| testing the propulsive role of m. peroneus longus during quadrupedal walking in varanus exanthematicus. | some varanid lizards show a prominent and highly distinctive lateral calcaneal process. it has been posited that this structure serves as a lateral "heel" to increase the moment arm for m. peroneus longus, allowing it to function as a powerful propulsive muscle. however, to confirm that m. peroneus longus serves this function requires electromyographic data showing activity during tarsal plantarflexion in the late part of the stance phase. muscle activity patterns of m. peroneus longus, m. tibia ... | 2020 | 32297482 |
| computational fluid dynamics reveals a unique net unidirectional pattern of pulmonary airflow in the savannah monitor lizard (varanus exanthematicus). | this report models pulmonary airflow in the savannah monitor (varanus exanthematicus) using computational fluid dynamics simulations, which are based on computed tomography data. simulations were validated by visualizing the flow of aerosolized lipids in excised lungs with good but not perfect agreement. the lung of this lizard has numerous successive bronchi branching off a long intrapulmonary bronchus, which are interconnected by intercameral perforations. unidirectional flow has been document ... | 2020 | 31650692 |
| the roles of joint tissues and jaw muscles in palatal biomechanics of the savannah monitor (varanus exanthematicus) and their significance for cranial kinesis. | numerous vertebrates exhibit cranial kinesis, or movement between bones of the skull and mandible other than at the jaw joint. many kinetic species possess a particular suite of features to accomplish this movement, including flexible cranial joints and protractor musculature. whereas the musculoskeletal anatomy of these kinetic systems is well understood, how these joints are biomechanically loaded, how different soft tissues affect joint loading and kinetic capacity, and how the protractor mus ... | 2019 | 31481636 |
| breathing with floating ribs: xromm analysis of lung ventilation in savannah monitor lizards. | the structures and functions of the vertebrate lung and trunk are linked through the act of ventilation, but the connections between these structures and functions are poorly understood. we used x-ray reconstruction of moving morphology (xromm) to measure rib kinematics during lung ventilation in three savannah monitor lizards (varanus exanthematicus). all of the dorsal ribs, including the floating ribs, contributed to ventilation; the magnitude and kinematic pattern showed no detectable cranial ... | 2018 | 30257921 |
| squamate reptiles from kanapoi: faunal evidence for hominin paleoenvironments. | the squamate fossil record from kanapoi reveals generic to higher-order similarities with modern east african herpetofaunas. the record is derived from surface collection and screen washing, and consists primarily of isolated vertebrae with a few maxillary and mandibular elements. the most abundant remains are vertebrae of large-bodied python that are morphologically similar to extant python sebae, and vertebrae of varanus cf. (varanus niloticus + varanus exanthematicus). additional cranial and ... | 2020 | 29910043 |
| ultrastructure of the exocrine pancreas in a sahelian reptile (varanus exanthematicus) during starvation. | during the sahelian dry season (november to june) the lizard varanus exanthematicus fasts, and during these 8 months its pancreatic acinar cells lack zymogen granules and show an inactive golgi body and damaged mitochondria. the main peculiarity can be observed in the granular endoplasmic reticulum (ger): each acinar cell posesses a great number of ger vesicles (mean diameter 0.15 μm) and a large spheroid ger resulting from either the nesting of some cisternae or the rolling up of a single ciste ... | 1983 | 30075613 |
| the mechanism of forearm rotation in varanus exanthematicus. | in the sprawling gait of varanus exanthematicus, the bicondylar distal humerus requires both the radius and ulna to rotate in the same direction. the joints between the radius and radiale and between the ulna and ulnare and pisiform accomodate these specific rotations. a ligament system between radius, ulna, radiale, and ulnare causes the radius and ulna to approximate one another during external rotation of the forearm. this approximation is conveyed distally resulting in a narrowing of the han ... | 1983 | 30068061 |
| an electromyographic study of the function of the jaw adducting muscles in varanus exanthematicus (varanidae). | the function of major features of the skull of varanus exanthematicus during feeding was examined using cineradiography and electromyography. during the initial stages of feeding, varanus grabs and orients a prey item in the mouth with no mastication, tearing of the prey, or killing bite. ingestion is through a highly stereotyped movement, inertial feeding. the tongue plays no role in food transport. once the prey is in the pharyngeal region, the hyoid apparatus squeezes the prey into the esopha ... | 1982 | 30081616 |
| estimation of shunting, systemic and pulmonary output of the heart, and regional blood flow distribution in unanaesthetized lizards (varanus exanthematicus) by injection of radioactively labelled microspheres. | circulatory parameters in a lizard (varanus exanthematicus) were determined using the microsphere method. microspheres (ms) (slightly larger than the erythrocytes and labelled with different gamma-emitting isotopes) were injected into a pulmonary vein or the left atrium for determination of the left-to-right (l-r) shunt and the regional distribution of the ventricular systemic output. injections were also made into the sinus venosus for determination of the right-to-left (r-l) shunt. the relativ ... | 1977 | 599322 |