scholarly journals Elastic recoil action amplifies jaw closing speed in an aquatic feeding salamander

2020 ◽  
Vol 287 (1927) ◽  
pp. 20200428 ◽  
Author(s):  
Mateo Rull ◽  
Jacob Solomon ◽  
Nicolai Konow
Keyword(s):  
Food Processing ◽  
Adductor Muscle ◽  
Ambystoma Mexicanum ◽  
Aquatic Animal ◽  
Elastic Recoil ◽  
Joint Rotation ◽  
Muscle Shortening ◽  
Fluid Environment ◽  
Prey Escape ◽  
Aquatic Food

Tendon springs often influence locomotion by amplifying the speed and power of limb joint rotation. However, less is known about elastic recoil action in feeding systems, particularly for small aquatic animals. Here, we ask if elastic recoil amplifies the speed of gape closing during aquatic food processing in the Axolotl ( Ambystoma mexicanum ). We measure activation of the adductor mandibulae externus via electromyography and strain of the jaw adductor muscle–tendon unit (MTU), and gape kinematics via fluoromicrometry. The muscle is pre-activated coincident with gape opening, which causes MTU stretch. Activation lasts significantly shorter for fish than cricket processing, and muscle shortening during MTU lengthening yields significantly greater elastic strain for cricket processing. The speed of MTU shortening, which dictates the speed of gape closing is 2.5–4.4 times greater than the speed of the initial shortening of the muscle fascicles for fish and cricket gape cycles, respectively. These data demonstrate a clear role for elastic recoil, which may be unexpected for a MTU in a feeding system of a small, aquatic animal. Amplification of jaw-closing speed resulting from elastic recoil likely confers ecological advantages in reducing prey escape risks during food processing in a dense and viscous fluid environment.

Limitation of airway smooth muscle shortening by cartilage stiffness and lung elastic recoil in rabbits

1993 ◽  
Vol 75 (2) ◽  
pp. 738-744 ◽  
Author(s):  
R. H. Moreno ◽  
C. Lisboa ◽  
J. C. Hogg ◽  
P. D. Pare
Keyword(s):  
Smooth Muscle ◽  
Effective Dose ◽  
Airway Smooth Muscle ◽  
Maximal Response ◽  
Positive End Expiratory Pressure ◽  
Elastic Recoil ◽  
Pulmonary Resistance ◽  
Muscle Shortening

Airway smooth muscle can contract to 20% of its starting length when stimulated maximally and allowed to contract isotonically in vitro. In vivo airway smooth muscle contraction of this degree would result in widespread airway closure. We hypothesized that elastic loads related to cartilage stiffness and lung parenchyma-airway interdependence limit in vivo airway smooth muscle shortening. We measured pulmonary resistance in anesthetized tracheostomized New Zealand White rabbits before and after intravenous treatment with papain in a concentration that produced generalized cartilage softening. Papain treatment caused a significant increase in pulmonary resistance that was completely reversed by application of 4 cmH2O positive end-expiratory pressure and that was partially reversed by vagotomy. Papain pretreatment also resulted in a substantial alteration in the pulmonary resistance-dose relationship to intravenously administered acetylcholine. In addition, maximal resistance after the highest concentration of acetylcholine was greater in papain-treated animals than in the control animals, but the position of the dose-response relationship was not shifted (i.e., there was no change in the effective dose causing 50% maximal response). Application of 4 cmH2O positive end-expiratory pressure in untreated animals resulted in a marked decrease in the bronchoconstriction produced by an effective dose of acetylcholine causing 50% of maximal response, whereas application of 4 cmH2O negative end-expiratory pressure resulted in a marked enhancement of the bronchoconstrictor response to the same intravenous dose of acetylcholine. We conclude that cartilage elasticity and lung recoil are important determinants of the ability of airway smooth muscle to shorten and produce airway narrowing in vivo.

scholarly journals Mandibular musculature constrains brain–endocast disparity between sarcopterygians

2020 ◽  
Vol 7 (9) ◽  
pp. 200933
Author(s):  
T. J. Challands ◽  
Jason D. Pardo ◽  
Alice M. Clement
Keyword(s):  
Muscle Mass ◽  
Trigeminal Nerve ◽  
Adductor Muscle ◽  
Ambystoma Mexicanum ◽  
Brain Morphology ◽  
Micro Ct ◽  
Latimeria Chalumnae ◽  
Dermal Bones ◽  
The Brain ◽  
Ct And Mri

The transition from water to land by the earliest tetrapods in the Devonian Period is seen as one of the greatest steps in evolution. However, little is understood concerning changes in brain morphology over this transition. Here, we determine the brain–braincase relationship in fishes and basal lissamphibians as a proxy to elucidate the changes that occurred over the fish–tetrapod transition. We investigate six basal extant sarcopterygians spanning coelacanths to salamanders ( Latimeria chalumnae, Neoceratodus, Protopterus aethiopicus, P. dolloi, Cynops, Ambystoma mexicanum ) using micro-CT and MRI and quantify the brain–braincase relationship in these extant taxa. Our results show that regions of lowest brain–endocast disparity are associated with regions of bony reinforcement directly adjacent to masticatory musculature for the mandible except in Neoceratodus and Latimeria . In Latimeria this deviation from the trend can be accounted for by the possession of an intracranial joint and basicranial muscles, whereas in Neoceratodus difference is attributed to dermal bones contributing to the overall neurocranial reinforcement. Besides Neoceratodus and Latimeria, regions of low brain–endocast disparity occur where there is less reinforcement away from high mandibular muscle mass, where the trigeminal nerve complex exits the braincase and where endolymphatic sacs occupy space between the brain and braincase wall. Despite basal tetrapods possessing reduced adductor muscle mass and a different biting mechanism to piscine sarcopterygians, regions of the neurocranium lacking osteological reinforcement in the basal tetrapods Lethiscus and Brachydectes broadly correspond to regions of high brain–endocast disparity seen in extant taxa.

Airway smooth muscle shortening in excised canine lung lobes

1993 ◽  
Vol 74 (4) ◽  
pp. 1613-1621 ◽  
Author(s):  
M. Okazawa ◽  
T. R. Bai ◽  
B. R. Wiggs ◽  
P. D. Pare
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Cross Sections ◽  
Muscle Length ◽  
Elastic Recoil ◽  
Pulmonary Resistance ◽  
Airway Narrowing ◽  
Arterial Perfusion ◽  
Muscle Shortening ◽  
Lung Lobes

To estimate the importance of lung parenchymal airway interdependence in attenuating airway narrowing, airway smooth muscle shortening in response to nebulized carbachol was measured in excised canine lung lobes and compared with the calculated load applied by lung elastic recoil. Pulmonary resistance of matched right and left upper lobes of five dogs was measured in a pressure-compensated volume plethysmograph by forced oscillation (6 Hz) before and after administration of an aerosol of carbachol (250 mg/ml) or saline. Matched lobes were studied at transpulmonary pressures (PL) of 5, 7, 10, 12, and 15 cmH2O. The lungs were then fixed at that PL by pulmonary arterial perfusion with formaldehyde, and cross sections of multiple airways from each lobe (n = 275) were examined by use of morphometric techniques to measure luminal area and smooth muscle length. By use of the saline lobe as a control, percentage of muscle shortening and decrease in airway lumen area caused by carbachol could be calculated. Passive and active smooth muscle stresses in each airway were calculated from PL and the calculated change in peribronchial pressure for a given change in airway diameter. The increase in pulmonary resistance and average smooth muscle shortening after administration of carbachol was greater in lobes held at lower PL. There was marked variation in narrowing between airways within a lobe: smooth muscle shortening ranged between 0 and 65% but averaged < 45% at all levels of PL.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Lipids, pots and food processing at Hočevarica, Ljubljansko barje, Slovenia

2014 ◽  
Vol 41 ◽  
pp. 181-194 ◽  
Author(s):  
Nives Ogrinc ◽  
Mihael Budja ◽  
Doris Potočnik ◽  
Andreja Žibrat Gašparič ◽  
Dimitrij Mlekuž
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Food Processing ◽  
Isotope Ratio ◽  
Isotope Ratio Mass Spectrometry ◽  
Gas Chromatography Mass Spectrometry ◽  
Aquatic Food ◽  
Ruminant Meat ◽  
Ljubljansko Barje ◽  
High Temperature Gas

 The paper presents the results of lipid analyses of pottery samples from Ho≠evarica (Ljub- ljansko barje, Slovenia). Total lipid extracts were subjected to high temperature gas chromatography (HT-GC), gas chromatography-mass spectrometry (GC-MS) and gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The results show that some vessels were used for prepar- ing ruminant meat and vegetable, but also the remains of aquatic food were identified. The processing of non-ruminant meat was detected in a few samples. A high number of pottery samples yielded the presence of beeswax lipids. The charred residual on pottery was AMS 14C dated.

The Ultrastructure of Myocardial Cells in Normal and Cardiac Lethal Mutant Mexican Axolotls, (Ambystoma Mexicanum)

1970 ◽  
Vol 28 ◽  
pp. 62-63
Author(s):  
Larry F. Lemanski ◽  
Eldridge M. Bertke ◽  
J. T. Justus
Keyword(s):  
Fine Structure ◽  
Heart Development ◽  
Osmium Tetroxide ◽  
Picric Acid ◽  
Ambystoma Mexicanum ◽  
Recessive Mutation ◽  
Acid Mixture ◽  
Myocardial Cells ◽  
Lethal Mutant ◽  
Mexican Axolotl

A recessive mutation has been recently described in the Mexican Axolotl, Ambystoma mexicanum; in which the heart forms structurally, but does not contract (Humphrey, 1968. Anat. Rec. 160:475). In this study, the fine structure of myocardial cells from normal (+/+; +/c) and cardiac lethal mutant (c/c) embryos at Harrison's stage 40 was compared. The hearts were fixed in a 0.1 M phosphate buffered formaldehyde-glutaraldehyde-picric acid-styphnic acid mixture and were post fixed in 0.1 M s-collidine buffered 1% osmium tetroxide. A detailed study of heart development in normal and mutant embryos from stages 25-46 will be described elsewhere.

Arrangement of Mitochondria in Spermatozoa of the Mexican Axolotl, Ambystoma Mexicanum

1973 ◽  
Vol 31 ◽  
pp. 626-627
Author(s):  
Ezzatollah Keyhani ◽  
Larry F. Lemanski ◽  
Sharon L. Lemanski
Keyword(s):  
Plasma Membrane ◽  
Sperm Motility ◽  
Substrate Oxidation ◽  
Ambystoma Mexicanum ◽  
Axial Filament ◽  
Mexican Axolotl ◽  
Middle Piece

Energy for sperm motility is provided by both glycolytic and respiratory pathways. Mitochondria are involved in the latter pathway and conserve energy of substrate oxidation by coupling to phosphorylation. During spermatogenesis, the mitochondria undergo extensive transformation which in many species leads to the formation of a nebemkem. The nebemkem subsequently forms into a helix around the axial filament complex in the middle piece of spermatozoa.Immature spermatozoa of axolotls contain numerous small spherical mitochondria which are randomly distributed throughout the cytoplasm (Fig. 1). As maturation progresses, the mitochondria appear to migrate to the middle piece region where they become tightly packed to form a crystalline-like sheath. The cytoplasm in this region is no longer abundant (Fig. 2) and the plasma membrane is now closely apposed to the outside of the mitochondrial layer.

The structure of the gills of the axolotl, Ambystoma mexicanum

1987 ◽  
Vol 45 ◽  
pp. 824-825
Author(s):  
Mohinder S. Jarial
Keyword(s):  
Leydig Cells ◽  
Secretory Granules ◽  
Light And Electron Microscopy ◽  
Cell Types ◽  
Ambystoma Mexicanum ◽  
Basal Cells ◽  
Granular Cells ◽  
Gill Filaments ◽  
Mitotic Figures ◽  
Apical Membranes

The axolotl is a strictly aquatic salamander in which the larval external gills are retained throughout life. The external gills of the adult axolotl have been studied by light and electron microscopy for ultrastructural evidence of ionic transport. The thin epidermis of the gill filaments and gill stems is composed of 3 cell types: granular cells, the basal cells and a sparce population of intervening Leydig cells. The gill epidermis is devoid of muscles, and no mitotic figures were observed in any of its cells.The granular cells cover the gill surface as a continuous layer (Fig. 1, G) and contain secretory granules of different forms, located apically (Figs.1, 2, SG). Some granules are found intimately associated with the apical membrane while others fuse with it and release their contents onto the external surface (Fig. 3). The apical membranes of the granular cells exhibit microvilli which are covered by a PAS+ fuzzy coat, termed “glycocalyx” (Fig. 2, MV).

Muscle shortening in the normal esophagus during swallowing

2001 ◽  
Vol 120 (5) ◽  
pp. A633-A633 ◽  
Author(s):  
A KORIMILLI ◽  
A HORATAGIS ◽  
S PULLELA ◽  
C CHUNG ◽  
F NOWROUZZADEH ◽  
...  
Keyword(s):  
Normal Esophagus ◽  
Muscle Shortening

First clinical experience with the Multi-LOC multiple stent delivery system for focal stenting in long femoro-popliteal lesions

VASA ◽  
2017 ◽  
Vol 46 (6) ◽  
pp. 452-461 ◽  
Author(s):  
Klaus Amendt ◽  
Ulrich Beschorner ◽  
Matthias Waliszewski ◽  
Martin Sigl ◽  
Ralf Langhoff ◽  
...  
Keyword(s):  
Observational Study ◽  
Clinical Experience ◽  
Delivery System ◽  
Target Lesion ◽  
Lesion Length ◽  
Elastic Recoil ◽  
Delivery Device ◽  
Clinical Assessments ◽  
Balloon Catheters ◽  
Considerable Length

Abstract. Background: The purpose of this observational study is to report the six-month clinical outcomes with a new multiple stent delivery system in patients with femoro-popliteal lesions. Patients and methods: The LOCOMOTIVE study is an observational multicentre study with a primary endpoint target lesion revascularization (TLR) rate at six months. Femoro-popliteal lesions were prepared with uncoated and/or paclitaxel-coated peripheral balloon catheters. When flow limiting dissections, elastic recoil or recoil due to calcification required stenting, up to six short stents per delivery device, each 13 mm in length, were implanted. Sonographic follow-ups and clinical assessments were scheduled at six months. Results: For this first analysis, a total of 75 patients 72.9 ± 9.2 years of age were enrolled. The majority of the 176 individually treated lesions were in the superficial femoral artery (76.2 %, 134/176) whereas the rate of TASC C/D amounted to 51.1 % (90/176). The total lesion length was 14.5 ± 9.0 cm with reference vessel diameters of 5.6 ± 0.7 mm. Overall 47 ± 18 % of lesion lengths could be saved from stenting. At six months, the patency was 90.7 % (68/75) and all-cause TLR rates were 5.3 % (4/75) in the overall cohort. Conclusions: The first clinical experience at six months suggests that the MSDS strategy was safe and effective to treat femoro-popliteal lesions of considerable length (14.5 ± 9.0 cm). Almost half of the lesion length could be saved from stenting while patency was high and TLR rates were acceptably low.

Sign in / Sign up

Export Citation Format

Share Document