The Dimensions and Sensitivities of Semicircular Canals

1970 ◽  
Vol 53 (2) ◽  
pp. 501-514
Author(s):  
J. H. TEN KATE ◽  
H. H. VAN BARNEVELD ◽  
J. W. KUIPER
Keyword(s):  
Growth Rate ◽  
Body Mass ◽  
Semicircular Canal ◽  
Semicircular Canals ◽  
The Body ◽  
Horizontal Semicircular Canal ◽  
Order Of Magnitude ◽  
Allometric Functions ◽  
Special Growth ◽  
Narrow Duct

1. The dimensions of the semicircular canals of pike can be expressed as allometric functions of the body length L. 2. The equal sensitivity of pike of different sizes to rotatory stimulation can be explained as a quadratic bending of the cupula. 3. In the pike the sensitivity is of the same order of magnitude for the vertical and horizontal semicircular canals. 4. In the pike the growth rate of the volumes of duct and ampulla is the same for the horizontal semicircular canal and for the posterior semicircular canal. 5. The special growth rate of the dimensions of the horizontal semicircular canal of the ray can be explained by a quadratic bending of the cupula. 6. For equally large cupulae the sensitivity of the horizontal semicircular canal is of the same order of magnitude for twenty-three mammals, fourteen birds and one reptile as it is for the pike. 7. Within the limits of error the ‘growth rate’ of the diameter of the narrow duct is the same in mammals as in the pike. 8. At the same body mass the absolute value of the diameter of the narrow duct is smaller in mammals than in the pike by a factor of 1.69. 9. For a body mass of 1 kg the value of the enclosed area of the horizontal semicircular canal is 6 times smaller in mammals than in pike. 10. The model of the overcritically damped oscillator for the semicircular canal remains valid during growth if a quadratic bending of the cupula is assumed.

The functional allometry of semicircular canals, fins, and body dimensions in the juvenile centrarchid fish, Lepomis gibbosus (L.)

Development ◽  
1973 ◽  
Vol 29 (3) ◽  
pp. 721-743
Author(s):  
Howard C. Howland ◽  
Joseph Masci
Keyword(s):  
Body Mass ◽  
Semicircular Canal ◽  
Semicircular Canals ◽  
Lepomis Gibbosus ◽  
Swimming Velocity ◽  
Body Dimensions ◽  
Moments Of Inertia ◽  
Significant Difference ◽  
Vertical Semicircular Canal ◽  
Vertical Semicircular Canals

1. The ontogenetic allometry of radii of curvature and the tube radii of the semicircular canals of approximately 85 juvenile (2–20 g) centrarchids of the species Lepomis gibbosus (L.) was investigated. The radii of curvature of the semicircular canals have different allometries; these arefor the anterior vertical, posterior vertical and horizontal canals respectively. The differences in growth exponents between the anterior and posterior vertical semicircular canals and between the anterior vertical and horizontal semicircular canals were statistically significant (P < 0·02 and P < 0·05 respectively). 2. Body mass and standard length were almost equally good predictors of the radii of curvature of the anterior vertical semicircular canals, but body mass was the better predictor of the radii of curvature of the posterior vertical and horizontal semicircular canals, as judged by the magnitude of the mean squares about the logarithmic regressions of radii on length and mass. 3. By measuring and estimating the area moments of the fins of the fish, the moments of inertia about various axes and the allometry of the characteristic swimming velocity of the fish, we attempted to account for the magnitude and direction of the differences in allometric growth exponents of the radii of curvature of the semicircular canals. Unexplained by our best estimate of growth exponents was the very high value observed for the posterior vertical semicircular canals. 4. No significant correlation could be found between the residuals of the major dimensions of the posterior vertical semicircular canals and those of body width or depth once the influence of body mass was removed. This finding suggests the rejection of the hypothesis that the allometry of this semicircular canal is simply correlated with overall body expansion in its plane. 5. The discrepancies between our predictions and observations of growth exponents could be explained by a gradual increase of the spring constant of the semicircular canals on the order ofthough they may also be due to other factors neglected in our model, e.g. the allometry of the added mass of the fish. 6. No evidence suggested that the shape of the semicircular canals was altered over the size range of the fish we studied. However, among the fins of the fish and the major body dimensions, only the width and the depth of the fish exhibited growth constants that did not differ significantly from each other. 7. We computed the effective toroidal radii of the non-toroidal-shaped vertical semicircular canals and found that the equivalent toroidal radius of the anterior vertical semicircular canal was consistently greater than that of the posterior vertical semicircular canal. This difference is explicable on the basis of the different moments of inertia of the animal about axes through the center of gravity and parallel to the axes of the semicircular canals. 8. We computed the allometry of the ratios R̄/r2 for all three semicircular canals and found in accordance with the prediction of Jones & Spells that they did not differ significantly from zero. 9. The allometry of the outer tube radii of the several semicircular canals was determined, and, while there was no significant difference in the growth exponents of the tube radii, it was noted that the tube radius of the horizontal semicircular canal was consistently and significantly smaller than that of the vertical semicircular canal. We suggested that this difference might be due to the broader range of frequencies that the fish experienced about its yaw axis. 10. Taken as a whole the data and calculations of this paper generally support the theory that the dimensions of the semicircular canals and the ontogenetic changes in them attune the semicircular canals to the angular frequency spectra that the fish experience about their axes.

scholarly journals Biomechanical Analysis of Angular Motion in Association with Bilateral Semicircular Canal Function

2019 ◽  
Author(s):  
Shuang Shen ◽  
Fei Zhao ◽  
Zhaoyue Chen ◽  
Qingyin Zheng ◽  
Shen Yu ◽  
...  
Keyword(s):  
Theoretical Approach ◽  
Semicircular Canal ◽  
Amplitude Ratio ◽  
Semicircular Canals ◽  
Vestibular Dysfunction ◽  
Angular Motion ◽  
Biomechanical Analysis ◽  
Fe Model ◽  
Healthy Human ◽  
Horizontal Semicircular Canal

AbstractThe aim of this study was to develop a finite element (FE) model of bilateral human semicircular canals (SCCs) in order to simulate and analyze the complex fluid-structural interaction between the endolymph and cupulae by calculating the degree of cupular expansion and the cupular deflection. The results showed that cupular deflection responses were consistent with Ewald’s II law, whereas each pair of bilateral cupulae simultaneously expanded or compressed to the same degree. In addition, both the degree of cupular expansion and cupular deflection can be expressed as the solution of forced oscillation during head sinusoidal rotation, and the amplitude of cupular expansion was approximately two times greater than that of cupular deflection. Regarding the amplitude-frequency and phase-frequency characteristics, the amplitude ratios among the horizontal semicircular canal (HC) cupular expansion, the anterior semicircular canal (AC) cupular expansion, and the posterior semicircular canal (PC) cupular expansion was constant at 1:0.82:1.62, and the phase differences among them were constant at 0 or 180 degrees at the frequencies of 0.5 to 6 Hz. However, both the amplitude ratio and the phase differencies of the cupular deflection incresed nonlinearly with the increase of frequency and tended to be constant at the frequency band between 2 and 6 Hz. The results indicate that the responses of cupular expansion might only be related to the mass and rigidity of three cupulae and the endolymph, but the responses of cupular deflection are related to the mass, rigidity, or damping of them, and these physical properties would be affected by vestibular dysfunction. Therefore, both the degree of cupular expansion and cupular deflection should be considered important mechanical variables for induced neural signals. Such a numerical model can be further built to provide a useful theoretical approach for exploring the biomechanical nature underlying vestibular dysfunction.Statement of significanceBy taking the advantage of the torsional pendulum model and the FE model, a healthy human vestibular SCCs was developed to investigate the angular motion in association with SCC function. As a result, the responses of cupular expansion and deflection during head horizontal sinusoidal rotation were analyzed for the first time, showing quantitative correlation to the eye movement due to the vestibular ocular reflex (VOR) pathway. These responses play important roles in the cupular mechano-electrical transduction process. The significant outcome derived from this study provides a useful theoretical approach for further exploring the biomechanical nature underlying vestibular dysfunction.

The interplay between resource supply and demand determines the influence of predation on prey body size

2016 ◽  
Vol 73 (4) ◽  
pp. 709-715 ◽  
Author(s):  
John P. DeLong ◽  
Matthew Walsh
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Body Mass ◽  
Supply And Demand ◽  
Interspecific Variation ◽  
The Body ◽  
Growth Responses ◽  
Resource Demand ◽  
Growth Constants ◽  
Sd Model

Predation has been shown to either increase or decrease the body mass of fish, as well as cause variable changes in growth rate. The mechanisms underlying these contrasting responses are not well understood. Here we compared intraspecific body size and growth responses to predation against a backdrop of 2006 estimates of asymptotic mass and growth constants (i.e., von Bertalanffy parameters) across species. We show that intraspecific responses can be quite large relative to interspecific variation and confirm that the magnitude and direction of body size responses is variable. We then employed the supply–demand (SD) model of body mass evolution to explore how predator-induced changes in resource demand or supply could alter body mass. The SD model predicts that any combination of increasing or decreasing body mass and increasing or decreasing growth rate is possible when predation risk is increased, which is consistent with the literature. Finally, we use three case studies to illustrate how the interplay of resource supply and resource demand determines the actual body mass and growth rate response to predation.

Use of Vestibular Rehabilitation in the Treatment of Benign Paroxysmal Positional Vertigo

2020 ◽  
Vol 5 (4) ◽  
pp. 917-939
Author(s):  
Richard A. Clendaniel
Keyword(s):  
Semicircular Canal ◽  
Benign Paroxysmal Positional Vertigo ◽  
Semicircular Canals ◽  
Signs And Symptoms ◽  
Positional Nystagmus ◽  
Test Procedures ◽  
Horizontal Semicircular Canal ◽  
Treatment Techniques ◽  
Positional Vertigo ◽  
Paroxysmal Positional Vertigo

Purpose The purposes of this article are (a) to describe the different test procedures for benign paroxysmal positional vertigo (BPPV) and (b) to provide guidance for the treatment of the various forms of BPPV and to discuss the efficacy of the different interventions. Conclusions While BPPV primarily occurs in the posterior semicircular canal, it is also seen in the anterior and horizontal semicircular canals. There are distinctive patterns of nystagmus that help identify the affected semicircular canal and to differentiate between cupulolithiasis and canalithiasis forms of BPPV. There is reasonable evidence to support the different treatments for both posterior and horizontal semicircular canal BPPV. Anterior semicircular canal BPPV is rare, and as a consequence, there is little evidence to support the various treatment techniques. Finally, while BPPV is generally easy to identify, there are central causes of positional nystagmus with and without vertigo, which can complicate the diagnosis of BPPV. The signs and symptoms of BPPV are contrasted with those of the central causes of positional nystagmus.

scholarly journals Labyrinthine Reactions and Their Relation to the Clinical Tests

1937 ◽  
Vol 30 (7) ◽  
pp. 905-916 ◽  
Author(s):  
W. J. McNally
Keyword(s):  
Semicircular Canal ◽  
Semicircular Canals ◽  
Careful Analysis ◽  
The Body ◽  
Tilt Test ◽  
Head Turning ◽  
Second Mode ◽  
Protective Reaction ◽  
The Individual ◽  
Vertical Semicircular Canals

The rapid tilt test has shown that the vertical semicircular canals are in close connexion with the whole postural body musculature. Nystagmus reactions are only a small part of semicircular canal sphere of control. Further knowledge of the reaction-pattern of the body musculature resulting from the stimulation of each semicircular canal will help in diagnosing a lesion, not only of the individual semicircular canals, but also—even more important—of its intracranial connexions. The few reaction patterns already known, but not recognized as such, namely post-pointing, falling, and head turning, are true compensatory reactions, more easily understood if so considered and grouped with the protective reactions to the tilt tests. Recognition of the two modes of utricular action is essential to a correct analysis of tilt test reactions. The slow tilt described by Grahe and others, is an excellent test for “first mode” utricular action, but not for “second mode” action or for vertical semicircular canals. The quick tilt is primarily a test of vertical semicircular canal action, but normally the reaction is complicated by reactions from “second mode” utricular stimulation. If this fact is not taken into account the analysis of a reaction to a quick tilt may be misleading. When performing a quick tilt test, in addition to watching for the absence of the protective reaction (due to loss of one or both labyrinths), the investigator should try to note whether there is a tendency for the patient to be more easily thrown in the direction of the tilt—owing to a lesion of the vertical canals, the utricles being intact (“second mode” utricular action)—or whether there is a tendency for the patient to over-compensate (owing to a lesion of the utricles, the vertical canals being intact). If, in addition to the usual equilibrial tests, the quick tilt test is used in this way and a careful analysis is made of the reactions of patients with labyrinthine or intracranial lesions, diagnosis of lesions of individual labyrinthine end-organs or of their intracranial connexions may become a routine procedure in the clinic just as it is now possible in the laboratory.

A theoretical and comparative study of the functional dependence of the semicircular canal upon its physical dimensions

1963 ◽  
Vol 157 (968) ◽  
pp. 403-419 ◽  
Keyword(s):  
Theoretical Prediction ◽  
Body Mass ◽  
Semicircular Canal ◽  
Functional Dependence ◽  
Semicircular Canals ◽  
Radius Of Curvature ◽  
Body Dimensions ◽  
Internal Radius ◽  
Range Of Variation ◽  
Made In

It has long been known that, in contrast to the range of variation of body dimensions, the semicircular canals of different animals are approximately similar in size. In the present study, measurements of the internal radius ( r ) and radius of curvature ( R ) of the endolymphatic canal were made in 87 species, comprising 46 mammals, 17 birds, 17 fishes and 7 reptiles, using specimens, and photographic records of specimens, already available. Using the principles of dynamical similarity, theoretical arguments are adduced which predict that if Steinhausen’s (1933) interpretation of semicircular canal function is correct there should be very slow increases, systematic but discreet, of r and R with body mass ( m ). The results of the measurements largely confirmed the theoretical prediction, the actual relations obtained for all species together being: log 10 100 r 2 = 0·0945 (±0·0549) log 10 m +0·2519 and log 10 100 R = 0·0761 (±0·0402) log 10 m + 2·3797 (where r and R are measured in mm and m in kg), similar relations being obtained for each class examined. It is shown that the observed changes in r and R can to a large extent account respectively for the changes in canal sensitivity and the time constant of cupular return which the theory suggests should be called for by changes in animal shape and body mass.

Responses of pigeon horizontal semicircular canal afferent fibers. I. Step, trapezoid, and low-frequency sinusoid mechanical and rotational stimulation

1989 ◽  
Vol 62 (5) ◽  
pp. 1090-1101 ◽  
Author(s):  
J. D. Dickman ◽  
M. J. Correia
Keyword(s):  
Mechanical Stimulation ◽  
Semicircular Canal ◽  
Action Potentials ◽  
Transfer Functions ◽  
Semicircular Canals ◽  
Primary Afferent ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Best Fit ◽  
Rotational Stimulation

1. The horizontal semicircular canals of anesthetized (barbiturate/ketamine) pigeons were stimulated by rotational and by mechanical stimulation. 2. The mechanical stimulation consisted of making a small (less than 1 mm) fistula in the lateral part of the bony horizontal semicircular canal and, after inserting a probe coupled to a piezoelectric micropusher through the fistula, providing controlled indentation of the exposed membranous horizontal semicircular duct. 3. Extracellular action potentials from single horizontal semicircular canal primary afferent (HCA) fibers were recorded during sinusoidal rotational and during step, ramp, and sinusoidal mechanical stimulation. 4. The mean spontaneous discharge rate of 160 horizontal canal afferents was 86 +/- 4 (SE) spikes/s. This rate was not significantly different from that reported previously for pigeon HCA fibers recorded with the horizontal canal intact (i.e., no fistula introduced). 5. Sinusoidal mechanical indentation of the horizontal semicircular duct produced clearly entrained action potentials on 36 HCA fibers for a range of peak displacements from +/- 0.5 to +/- 30 microns. Action potentials were never modulated on afferents (n greater than 100) identified as innervating the anterior and posterior semicircular canals or the otolith organs during mechanical stimulation of the horizontal semicircular canal, even for displacements as large as 30 microns. 6. Intensity functions relating peak firing frequency (spikes per second) and peak probe displacement (micrometers) for 1.0-Hz sinusoidal mechanical stimulation were linear over the range 1.0-5.0 microns. The most sensitive units (6/36, 17%) showed response saturation as the stimulus magnitude was extended to 7 microns and beyond. 7. In 15 of 36 units, both mechanical and rotational sinusoidal stimulation (1.0 Hz) were applied to the same unit. The duct indentation magnitudes were 1.0, 2.5, 5.0, and 7.0 microns and the rotational velocities were 5, 10, and 20 deg/s. The constant of proportionality found to equate the peak response produced by rotational to that elicited by mechanical stimulation was 7.0 deg.sec-1/1.0 microns. 8. Bode plots and best-fit transfer functions of the frequency response (0.05-10.0 Hz) of 14 HCAs exposed to both mechanical and rotational stimulation were nearly identical. 9. Parameters for best-fit transfer functions, responses to step, and trapezoidal duct displacements were in excellent agreement with previous rotational studies carried out using the pigeon. 10. Although the mechanisms by which focal identation of the horizontal membranous duct produce responses have not yet been determined, primary afferent responses using this method of stimulation are directly comparable with rotatory stimulation.(ABSTRACT TRUNCATED AT 400 WORDS)

Site of Cortical Utricular Representation with Special Reference to the Somatosensory Barrel Field in the Gerbil

1998 ◽  
Vol 107 (5) ◽  
pp. 411-415 ◽  
Author(s):  
Muneyuki Ito ◽  
Akiko Seto-Ohshima
Keyword(s):  
Temporal Bone ◽  
Semicircular Canal ◽  
Semicircular Canals ◽  
Histochemical Staining ◽  
Horizontal Semicircular Canal ◽  
Barrel Field ◽  
Fine Grain ◽  
Hollow Space ◽  
Utricular Nerve ◽  
Made In

In mammals, the osseous semicircular canals of the vestibular labyrinths are usually embedded in the pyramis of the temporal bone. Thus, the osseous semicircular canals are a cavity system that can only be visualized by injection molding. Exceptionally, the walls of the osseous semicircular canals of the Mongolian gerbil are not embedded, but exposed in the hollow space in the temporal bone. Under urethane anesthesia, a window was made in the periotic capsule of the gerbil to reach this hollow space (semicircular canal triangle), and a pair of wire electrodes were inserted through an opening made in the horizontal semicircular canal toward the utricular nerve endings. Repetitive electric stimuli at 80 Hz were applied, and the direction of eye movements was noted. Subsequently, the stimulation frequency was reduced to 0.3 Hz, and evoked potentials were recorded from the neocortex. Positive surface potentials and negative deep potentials were recorded in the somatosensory area and, more specifically, in the vibrissa “barrel field,” as judged by later histochemical staining of the cortical specimens. This unique anatomic feature of the gerbil labyrinth offers an opportunity whereby the vestibular organ can be reached without any heavy surgical insult, and the presence of fine-grain vibrissa barrels in this species (seven rows instead of five rows in most rodents) will help elucidate functional interactions between vestibular and somatosensory sensations.

Role of semicircular canals in positional alcohol nystagmus

1965 ◽  
Vol 208 (6) ◽  
pp. 1065-1070 ◽  
Author(s):  
K. E. Money ◽  
W. H. Johnson ◽  
B. M. A. Corlett
Keyword(s):  
Semicircular Canal ◽  
Semicircular Canals ◽  
The Other ◽  
Positional Nystagmus ◽  
Horizontal Semicircular Canal ◽  
Horizontal Canal ◽  
Unilateral Labyrinthectomy

Following unilateral labyrinthectomy or inactivation of one horizontal semicircular canal in cats, a horizontal positional nystagmus was observed when the cat, after ingesting alcohol, was held with the head up or with the head down. This nystagmus was toward the operated ear in the head-up position and away from the operated ear in the head-down position. It disappeared following inactivation of the horizontal canal of the other ear. In cats with both horizontal canals discretely inactivated, there was no horizontal alcohol nystagmus in any position, but the vertical and rotary components of positional alcohol nystagmus were still present. It was concluded that positional alcohol nystagmus is initiated by the action of gravity on receptors of the semicircular canals. No conclusion could be drawn concerning the site or mechanism of the action of alcohol.

scholarly journals Automatic Measurement of Inner Ear in Different Mammals1

2020 ◽  
Author(s):  
Yi Du ◽  
Han-dai Qin ◽  
Chen Liu ◽  
Da Liu ◽  
Shuo-long Yuan ◽  
...  
Keyword(s):  
Inner Ear ◽  
Semicircular Canal ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Automatic Measurement ◽  
The Body ◽  
Human Data ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Mini Pigs

AbstractObjectiveThe aim of this research is to develop an accurate and automatic measuring method based on the aid of centerline to construct three dimensional models of inner ear in different mammals and to assess the morphological variations.MethodsThree adult healthy mice, three adult guinea pigs, three adult mini pigs and one left temporal bone of human were included in this research. All 18 animal specimens and the human sample were scanned with the use of Micro-CT. After being segmented, three-dimensional models of the inner ear in different mammals were reconstructed using Mimics. A novel method with the use of centerline was established to estimate the properties of 3D models and to calculate the length, volume and angle parameters automatically.ResultsMorphological models of inner ears in different mammals have been built, which describe detailed shape of cochlear, vestibule, semicircular canals and common crus. Mean value of lengths and volumes of the cochlear, lateral semicircular canal, superior semicircular canal and posterior semicircular canal, tended to increase with the body size of the mammals, showed the proximity to the human data in mini pig. The angles between the semicircular canal planes showed differences between mammals. The mean values of semicircular canals of mice and mini pigs closely resembled to human data in numerical assessment.ConclusionThe automatic measurement of the inner ear based on centerline builds an effective way to assess lengths, volumes and angles of three-dimensional structures. This study provides a theoretical basis for mechanical analysis of inner ear in different mammals and proves the similarity between mini pig and human.

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