Geographical variation in limb muscle mass of the Andrew’s toad (Bufo andrewsi)

2017 ◽  
Vol 67 (1) ◽  
pp. 17-28 ◽  
Author(s):  
Sheng Nan Yang ◽  
Xiao Fu Huang ◽  
Mao Jun Zhong ◽  
Wen Bo Liao
Keyword(s):  
Geographical Variation ◽  
Biceps Femoris ◽  
Relative Mass ◽  
Flexor Carpi Radialis ◽  
Hindlimb Muscles ◽  
Model Animal ◽  
Limb Muscles ◽  
Forelimb Muscles ◽  
Bufo Andrewsi ◽  
Extensor Carpi Radialis

Muscles are vital for the process of movement, mating and escape of predators in amphibians. During evolution, the morphological and genetic characteristics as well as the size of muscles in species will change to adapt different environments. Theory predicts that low male-male competition in high-altitude/latitude selects for small limb muscles. Here, we used the Andrew’s toad (Bufo andrewsi) as a model animal to test this prediction by analyzing geographical variation in the mass of limb muscles across nine populations from the Hengduan Mountains in China. Inconsistent with the prediction, we found that latitude and altitude did not affect the relative mass of total combined limb muscles and mass of combined hindlimb muscles among populations. Meanwhile, the relative mass of combined forelimb muscles, the two forelimb muscles (flexor carpi radialis and extensor carpi radialis) and the four hindlimb muscles (e.g. biceps femoris, semimebranous, semitendinosus and peroneus) was lowest in middle latitude and largest in low latitude whereas gracilis minor was largest in high latitudes. However, we did not find any correlations between the two forelimb muscles and the four hindlimb muscles and altitude. Our findings suggest that combined forelimb muscles, flexor carpi radialis, extensor carpi radialis, biceps femoris, semimebranous, semitendinosus and peroneus are largest in low latitudes due to pressures of mate competition.

No sexual dimorphism in limb muscles of a frog not engaging in amplexus

2013 ◽  
Vol 63 (4) ◽  
pp. 397-405
Author(s):  
Lixia Zhang ◽  
Yunyun Zhao ◽  
Jie Yang ◽  
Xin Lu ◽  
Xiaohong Chen
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Scramble Competition ◽  
Sexual Differences ◽  
Limb Muscle ◽  
Form And Function ◽  
Hindlimb Muscles ◽  
Limb Muscles ◽  
Forelimb Muscles ◽  
And Function

Sexual dimorphism in limb muscles is widespread among anurans, with males having stronger limbs than females. This phenomenon has been interpreted in the context of intrasexual selection: 1) the robust forelimb muscles in males are associated with amplexus, in which the male tries to grasp the female tightly, and also with rejection of rivals’ attempts at taking over, and 2) massive hindlimb muscles favor the ability to kick away rivals during scramble competition. However, in a few species, fertilization occurs without any form of amplexus and in these species the limb muscle dimorphism is expected to be absent. We tested this prediction inFeirana taihangnicus: a species without amplexus. As expected, we detected non-significant sexual differences in the mass of both forelimb and hindlimb muscles after accounting for body size and age. Our findings represent an interesting example of coevolution of form and function.

Effects of surface grade on proximal hindlimb muscle strain and activation during rat locomotion

2002 ◽  
Vol 93 (5) ◽  
pp. 1731-1743 ◽  
Author(s):  
Gary B. Gillis ◽  
Andrew A. Biewener
Keyword(s):  
Muscle Activity ◽  
Vastus Lateralis ◽  
Biceps Femoris ◽  
Muscle Strain ◽  
Activation Patterns ◽  
Rat Muscle ◽  
High Speeds ◽  
Hindlimb Muscle ◽  
Limb Muscles

Sonomicrometry and electromyography were used to determine how surface grade influences strain and activation patterns in the biceps femoris and vastus lateralis of the rat. Muscle activity is generally present during much of stance and is most intense on an incline, intermediate on the level, and lowest on a decline, where the biceps remains inactive except at high speeds. Biceps fascicles shorten during stance, with strains ranging from 0.07–0.30 depending on individual, gait, and grade. Shortening strains vary significantly among grades ( P = 0.05) and average 0.21, 0.16, and 0.14 for incline, level, and decline walking, respectively; similar trends are present during trotting and galloping. Vastus fascicles are stretched while active over the first half of stance on all grades, and then typically shorten over the second half of stance. Late-stance shortening is highest during galloping, averaging 0.14, 0.10, and 0.02 in the leading limb on incline, level, and decline surfaces, respectively. Our results suggest that modulation of strain and activation in these proximal limb muscles is important for accommodating different surface grades.

Histology of allometric growth in hindlimb muscles of pigs

1982 ◽  
Vol 98 (3) ◽  
pp. 629-632
Author(s):  
H. J. Swatland
Keyword(s):  
Cross Sections ◽  
Muscle Length ◽  
Biceps Femoris ◽  
Longitudinal Growth ◽  
Muscle Fibres ◽  
Allometric Growth ◽  
Cross Sectional ◽  
Relative Growth ◽  
Limb Bones ◽  
Hindlimb Muscles

SUMMARYHindlimbs of pigs were dissected at 4-week intervals from 9 to 29 weeks after birth. Allometric growth ratios of the gluteal muscles, biceps femoris and semitendinosus were calculated relative to gastrocnemius. Relative growth in weight of the proximal limb muscles was greater than that of the distal muscle, gastrocnemius. The greater relative growth of proximal muscles was not due to greater relative growth of muscle fibre diameters, nor to greater relative growth of muscle cross-sectional areas. In biceps femoris and gluteal muscles, growth in the area of musole cross sections did not keep pace with the radial growth of muscle fibres. The relative longitudinal growth of proximal limb bones exceeded that of distal bones, and the relative longitudinal growth of biceps femoris and semitendinosus exceeded that of any of the limb bones. New sarcomeres were added to muscle length at a faster rate in biceps femoris and semitendinosus than in the peroneus longus located distally in the limb.

MORPHOMETRIC AND BIOMECHANICAL COMPARISON OF TENDONS USED FOR INTERPOSITION ARTHROPLASTY IN CARPOMETACARPAL ARTHRITIS OF THE THUMB

Hand Surgery ◽  
2011 ◽  
Vol 16 (01) ◽  
pp. 43-47 ◽  
Author(s):  
Jens Dargel ◽  
Dietmar Pennig ◽  
Hans Philipp Springorum ◽  
Jürgen Koebke ◽  
Peer Eysel ◽  
...  
Keyword(s):  
Compressive Loading ◽  
Carpometacarpal Joint ◽  
Interposition Arthroplasty ◽  
Flexor Carpi Radialis ◽  
Abductor Pollicis Longus ◽  
Interpositional Arthroplasty ◽  
The Mean ◽  
Biomechanical Comparison ◽  
Extensor Carpi Radialis

Purpose: To identify the wrist tendon most effectively maintaining the trapezial space in interpositional arthroplasty in osteoarthritis of the carpometacarpal joint of the thumb. Methods: The morphometrics of the os trapezium and the tendons of the flexor carpi radialis, extensor carpi radialis longus, and abductor pollicis longus were determined. The stiffness and compressive loading characteristics of the rolled-up tendons were compared to the os trapezium. Results: No significant morphometric differences between the three tendons were found. The mass and volume of the trapezium was significantly larger when compared to the tendon balls. No significant differences in the compressive loading resistance were found between the tendons, but the mean stiffness was 85% lower when compared to the os trapezium. Conclusions: Neither tendon material approached the volume nor the stiffness provided by the os trapezium. Any tendon is considered to insufficiently maintain the trapezial space following trapeziectomy.

scholarly journals Intra-limb modulations of posterior root-muscle reflexes evoked from the lower-limb muscles during isometric voluntary contractions

2021 ◽  
Author(s):  
Akira Saito ◽  
Kento Nakagawa ◽  
Yohei Masugi ◽  
Kimitaka Nakazawa
Keyword(s):  
Lower Limb ◽  
Motor Evoked Potential ◽  
Biceps Femoris ◽  
Knee Extension ◽  
Spinal Reflex ◽  
Posterior Root ◽  
Lower Limb Muscles ◽  
Limb Muscles ◽  
Voluntary Contractions ◽  
Muscle Reflexes

AbstractAlthough voluntary muscle contraction modulates spinal reflex excitability of contracted muscles and other muscles located at other segments within a limb (i.e., intra-limb modulation), to what extent corticospinal pathways are involved in intra-limb modulation of spinal reflex circuits remains unknown. The purpose of the present study was to identify differences in the involvement of corticospinal pathways in intra-limb modulation of spinal reflex circuits among lower-limb muscles during voluntary contractions. Ten young males performed isometric plantar-flexion, dorsi-flexion, knee extension, and knee flexion at 10% of each maximal torque. Electromyographic activity was recorded from soleus, tibialis anterior, vastus lateralis, and biceps femoris muscles. Motor evoked potentials and posterior root-muscle reflexes during rest and isometric contractions were elicited from the lower-limb muscles using transcranial magnetic stimulation and transcutaneous spinal cord stimulation, respectively. Motor evoked potential and posterior root-muscle reflex amplitudes of soleus during knee extension were significantly increased compared to rest. The motor evoked potential amplitude of biceps femoris during dorsi-flexion was significantly increased, whereas the posterior root-muscle reflex amplitude of biceps femoris during dorsi-flexion was significantly decreased compared to rest. These results suggest that corticospinal and spinal reflex excitabilities of soleus are facilitated during knee extension, whereas intra-limb modulation of biceps femoris during dorsi-flexion appeared to be inverse between corticospinal and spinal reflex circuits.

The Evaluations of the Muscle Activity During “Momi” by Using the Different Immersed Bamboo in Water to Making Kyo-Uchiwa (Japanese Paper Fan)

2013 ◽  
Author(s):  
Porakoch Sirisuwan ◽  
Chieko Narita ◽  
Tetsushi Koshino ◽  
Hisanori Yuminaga
Keyword(s):  
Muscle Activity ◽  
Latissimus Dorsi ◽  
Biceps Brachii ◽  
Gluteus Medius ◽  
Triceps Brachii ◽  
Flexor Carpi Radialis ◽  
Japanese Paper ◽  
Bending Process ◽  
The Difference ◽  
Extensor Carpi Radialis

The aim of study is to evaluate whether altering the bamboo moisture by immersed bamboo in water on 4-hour and 3 -day that would affect the muscle activity during separated bamboo by bending process. Moreover, thirteen muscles which bilateral side of Pectoralis major, Biceps brachii, Triceps brachii, Latissimus dorsi, Gluteus medius and only right side of Rectus abdominis, Extensor carpi radialis longus and Flexor carpi radialis were recorded. As a result, the bilateral side of Biceps brachii, right side of Extensor carpi radialis longus and Flexor carpi radialis, left side of Triceps brachii showed the difference quite clearly. When the craftsman was bending the bamboo he was necessary more effortful by these muscles activity on the 4-hour immersed bamboo in water than the 3-day. The scanning electron microscopy (SEM) photographs showed the fracture characteristic of 2 subjects that the adhesive of bamboo fiber decreased when increased moisture.

scholarly journals Anticipatory and Reactive Response to Falls: Muscle Synergy Activation of Forearm Muscles

Hand Surgery ◽  
2015 ◽  
Vol 20 (03) ◽  
pp. 343-351
Author(s):  
Greg Couzens ◽  
Graham Kerr
Keyword(s):  
Elbow Flexion ◽  
Muscle Synergy ◽  
Shoulder Abduction ◽  
Anticipatory Response ◽  
Surface Electromyogram ◽  
Flexor Carpi Radialis ◽  
Abductor Pollicis Longus ◽  
Forearm Muscles ◽  
Flexor Carpi Ulnaris ◽  
Extensor Carpi Radialis

We investigated the surface electromyogram response of six forearm muscles to falls onto the outstretched hand. The extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris, abductor pollicis longus, flexor carpi radialis and flexor carpi ulnaris muscles were sampled from eight volunteers who underwent ten self-initiated falls. All muscles initiated prior to impact. Co-contraction is the most obvious surface electromyogram feature. The predominant response is in the radial deviators. The surface electromyogram timing we recorded would appear to be a complex anticipatory response to falling modified by the effect on the forearm muscles following impact. The mitigation of the force of impact is probably more importantly through shoulder abduction and extension and elbow flexion rather than action of the forearm muscles.

scholarly journals Do toads have a jump on how far they hop? Pre-landing activity timing and intensity in forelimb muscles of hopping Bufo marinus

2010 ◽  
Vol 6 (4) ◽  
pp. 486-489 ◽  
Author(s):  
Gary B. Gillis ◽  
Trupti Akella ◽  
Rashmi Gunaratne
Keyword(s):  
Muscle Activity ◽  
Positive Relationship ◽  
Bufo Marinus ◽  
Muscle Recruitment ◽  
Significant Positive Relationship ◽  
Limb Muscles ◽  
Forelimb Muscles ◽  
Anticipatory Muscle Activity

During jumping or falling in humans and various other mammals, limb muscles are activated before landing, and the intensity and timing of this pre-landing activity are scaled to the expected impact. In this study, we test whether similarly tuned anticipatory muscle activity is present in hopping cane toads. Toads use their forelimbs for landing, and we analysed pre-landing electromyographic (EMG) timing and intensity in relation to hop distance for the m. coracoradialis and m. anconeus , which act antagonistically at the elbow, and are presumably important in stabilizing the forelimb during landing. In most cases, a significant, positive relationship between hop distance and pre-landing EMG intensity was found. Moreover, pre-landing activation timing of m. anconeus was tightly linked to when the forelimbs touched down at landing. Thus, like mammals, toads appear to gauge the timing and magnitude of their impending impact and activate elbow muscles accordingly. To our knowledge these data represent the first demonstration of tuned pre-landing muscle recruitment in anurans and raise questions about how important the visual, vestibular and/or proprioceptive systems are in mediating this response.

Geographic variation in skin structure in male Andrew’s toad (Bufo andrewsi)

2020 ◽  
Vol 70 (2) ◽  
pp. 159-174
Author(s):  
Can Wang ◽  
Long Jin ◽  
Zhi Ping Mi ◽  
Wen Bo Liao
Keyword(s):  
Water Absorption ◽  
Local Adaptation ◽  
Water Loss ◽  
Geographical Variation ◽  
Single Species ◽  
Complex Environments ◽  
Skin Structure ◽  
Different Populations ◽  
Bufo Andrewsi ◽  
Loose Layer

Abstract Variation in organ structure likely provides important clues on local adaptation and reflects the pressure target of natural selection. As one of the important organs, the skin plays a key role in adapting to complex environments by reducing water loss or increasing water absorption. Nevertheless, variation in the skin structure across different populations in a single species of anurans remains enigmatic. Here, we studied geographical variation in the skin structure of male Andrew’s toads (Bufo andrewsi) across ten populations using histological methods. We quantified thickness of the skin, the epidermis, the loose layer, the compact layer, and of the epidermis, area of granular glands (GGs) and of ordinary mucous glands (OMGs), width of the calcified layer, and number of capillary vessels. We found that the thickness of the skin, dermis and loose layer in dorsal skin increased with latitude whereas the area of granular glands decreased with altitude. Moreover, the width of the calcified layer in ventral skin decreased with latitude among populations. Our findings suggest that geographical variation in skin structure in male B. andrewsi is likely to reduce water loss or make water absorption occur faster in complex high-latitude environments, improving local adaptation.

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