Massey Documents by Type

Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294

Browse

Subject: search.filters.subject.Anatomy

Search Results

Now showing 1 - 10 of 14
  • Thumbnail Image
    Item
    Predicting horse limb responses to surface variations with a 3D musculoskeletal model : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Biomechanics at Massey University, Palmerston North, New Zealand
    (Massey University, 2020) Bardin, Aliénor
    Thoroughbred racehorses are often affected by musculoskeletal injuries, leading to involuntary rest periods, early retirement or death. A number of studies have focused on identifying risk factors. A major focus of research has been track surface properties because it should be possible to modify these so that the risk of musculoskeletal injury is minimised. Among all the track surface properties studied to date, consistency of the surface is reported to be one of the main injury risk factors. The aim of this study was to develop a preliminary 3D musculoskeletal model of the whole equine forelimb based on data published in the literature and derived from anatomical measurements; and to determine the effects of the perturbations by the ground surface on the limb response with the musculoskeletal model developed and to assess whether the response occurs acutely in the perturbed stance phase or in the next stance phase. To answer these questions, gait data were collected from ridden Thoroughbreds passing through a perturbation area, where the surface hardness was changed by adding wood or foam under the baseline sand surface. The horses changed their joint flexion/extension patterns in response to changes in hardness. In response to the hard perturbation, the proximal limb spring was more compliant, evidenced by increased shoulder flexion. The elbow and carpal joints were more flexed in the intervening swing phase. In response to the soft perturbation, more coffin joint flexion was observed during both the perturbed and the following stance phase. The preliminary musculoskeletal model of the equine forelimb developed in this thesis allow the observation and study of the forelimb reaction to hardness perturbation through the joint excursions and tendon and ligament strains.
  • Thumbnail Image
    Item
    The effect of incubation temperature on early malformation, regionalisation and meristic characters of the vertebral column in farmed Chinook salmon (Oncorhynchus tshawytscha) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Science at Massey University, Manawatū, Palmerston North, New Zealand
    (Massey University, 2018) De Clercq, Adelbert
    Skeletal deformities are a recurrent problem in farmed Chinook salmon which limit production and have animal welfare impacts. Skeletal deformities of a variety of types are recognised especially when the external phenotype of the animal is affected. These types are well described in juvenile and adult stages of the production cycle. Which skeletal malformations affect early life stages in salmonids is less well known. Temperature is commonly manipulated in fish farming husbandry. High rearing temperatures are related to higher growth rates and in Atlantic salmon, elevated temperature has been inferred as a potential risk factor for skeletal deformities. In this thesis, malformations of the vertebral column in post-hatch to first feed life stages (500-900 degreedays) were studied in farmed Chinook salmon (Oncorhynchus tshawytscha) in New Zealand. Fish were reared at a constant 4°C, 8°C and 12°C, from fertilisation to juvenile stages. The effects of rearing fish at these temperatures on malformations of the vertebral column were studied in specimens whole-mount stained for cartilage and mineralised bone, and in histological sections. The external phenotype of post-hatch stages could be linked to internal skeletal malformations such as notochord malformations, chordacentra fusions and malformations of the associated elements. In all temperature groups, externally normal specimens could have internal malformations, predominantly fused chordacentra. Conversely, externally malformed fish usually displayed internal malformations. Specimens raised at 8°C had fewest malformations, followed by specimens of the 12°C group. Specimens raised at 4°C had the highest number of malformations. This study indicates that 8°C is the best incubation temperature of those tested. In addition, the effects of rearing temperature on morphological variation of skeletal elements such as vertebrae, vestigial ribs and vestigial elements in the caudal fin were studied. Six vertebral column regions were identified. The defining characters of each of these regions remained independent of the rearing temperature. Still, the postcranial, transitional and ural regions showed temperature sensitive meristic variation of the vertebrae, vestigial ribs, arches, epurals and uroneurals. Meristic variation can foreshadow skeletal malformations that emerge late in life and thus be significant for the early diagnosis of vertebral deformities.
  • Thumbnail Image
    Item
    An investigation into the structure and function of the ileocaecal junction of the sheep : a thesis presented in fulfilment of the requirements for the degree of Master of Science by thesis only at Massey University
    (Massey University, 1992) Murphy, Peter Grant
    The sheep ileocaecal junction has been shown to have sphincter-like properties, fulfilling the criteria for a gastrointestinal sphincter identified by Fisher and Cohen (1973). However the short zone of elevated pressure within the lleocaecal Junction (ICJ) could be due to venous engorgement rather than tonic muscular activity, as the tip of the ileum examined histologically reveals an irregular musculature interspersed with a vascular loose connective tissue. A similarity is suggested to the human ileocaecal sphincter as described by Quigley, Borody, Phillips, Weinbeck, Tucker and Haddad (1984). This short (less than 5mm) zone of elevated pressure in the sheep would appear to work in conjunction with a valvular action as described by Kuman and Phillips (1987) for the human ICJ, preventing retrograde digesta flow from the caecum to the ileum. EMG recordings of the ileocaecal region in the conscious sheep showed approximately 70-80% of the MMC phase 3 activity that reaches the distal ileum progresses as far as the ICJ. This appears to be the main motility pattern present in this region in the conscious sheep, and very little coordination was observed between patterns of caecal and ileal activity. Feeding was found to decrease the amount of MMC activity in the distal ileum by lengthening the interval between successive MMC phase 3 patterns of motility. This effect of feeding on MMC activity appears not to be due to the levels of circulating gastrin, and could be due to either a reflex inhibition such as an intestino-intestinal reflex mediated by noradrenaline as has been described for cats, or humoral mechanisms involving another. agent such as cholecystekinin, VIP or Substance P. Both the latter substances were shown to be present in nervous tissue within the ileum, though their role remains unclear.
  • Thumbnail Image
    Item
    Structure and optics of the anterior segment of the cetacean eye : a thesis presented in fulfilment of the requirements for the degree of Master of Philosophy at Massey University
    (Massey University, 1999) Mellor, Lynda
    The anterior segment of the mammalian eye is concerned with the function and maintenance of its optical components, the most important of these being the maintenance of transparency and stable intraocular pressure. The structures of the eye change throughout life. Continuous growth occurs in the lens, and a number of other changes associated with aging also occur, many of which reduce visual capacity. Many of these manifest in humans because of their long life span but have very little relevance in terms of survival. However, other long lived animals such as some birds, reptiles and whales, could be severely compromised by complete or partial blindness associated with aging. The aims of this study were to evaluate the importance of vision as a sense in whales by observation of the structure and optics of the anterior segment, and compare the findings with other species whose visual functions are well known. Pathological changes were recorded where appropriate. The findings in this thesis are based on a three year survey of eyes from 45 whales in which i) differences between species in the size of the globe, lens, and cornea are described ii) the unique histological structure of the uveal tract is demonstrated and defined iii) evidence of emmetropia in both air and water from NMR images of two eyes is given iv) lens shape and capsular features which indicate that there could be a capacity for accommodation, are described, and v) lens pathology (four cataracts and one case of phacolysis) is described in five animals. The largest whales (baleen and sperm) had the largest eyes, but this was mainly due to the thickness of sclera. Internal dimensions showed little variation with respect to body size, suggesting that there is an upper limit on internal size which is dependant on the focal length of the lens, a structure which enlarges only slightly with age. Corneal and lens sizes were especially large in the baleen whales, and particularly small in the sperm whale. The uveal tract was found to be very vascular when compared to other species, and particularly well innervated with specialised nerve endings which are thought to be unique to cetaceans. Although the findings are not conclusive, evidence from this study suggests that the whales' unique uveal vasculature and aqueous drainage methods may be instrumental in modifying the dioptric strength of the eye. The abundance of specialised pressure-receptors in the ciliary body indirectly supports a proposed mechanism for this, whereby the engorged ciliary body raises intraocular pressure causing increased corneal curvature, and releases tension on the zonule to allow 'rounding up' of the lens. Optically, the study showed that eyes from two long-finned pilot whales were emmetropic by virtue of a cornea with only a very small amount of optical power in both air and water, and a very powerful lens (about 72D in water). Emmetropia was thus not affected unduly by transition from air to water as it is in most mammals, where the cornea is optically very significant in air but neutral in water. Lenses in both animals showed an unusual 'bump' on the central posterior : surface, and the increased radius of curvature in this area was responsible for the very high dioptric strength of the lenses. The prevalence of lens pathology, particularly cataracts in young animals, was high. but in all cases the cause was unknown.
  • Thumbnail Image
    Item
    A preliminary musculoskeletal model of the German Shepherd lumbosacral spine : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Animal Science at Massey University, Manawatū, New Zealand
    (Massey University, 2017) Reed, Sophie Anna
    German shepherd dogs (GSD) are commonly utilised in police and military forces, where they undertake physically demanding working roles. These duties, combined with the typical GSD musculoskeletal conformation, consequently result in a high incidence of degenerative lumbo-sacral stenosis in this breed. This debilitating condition compromises the welfare of the animal and often results in premature loss from service. A preliminary mathematical musculoskeletal model was developed in the AnyBody Modelling System software platform from computed tomography imagery and muscle dissection. Positions of hard and soft tissue elements were recorded from the specimen to construct this patient-specific model. Inverse dynamics simulations were run with incremental alterations of two muscle input parameters: muscle fibre length and sarcomere length. The effect of these parameters was found to be extremely sensitive on the model output values, with minor input variations resulting in major output variations. Histology data was obtained from muscle excised in the dissection, and indicated variability in muscle sarcomere length up to 0.681 μm within the muscle and an average of 0.389 μm between GSD muscles. The sensitivity analysis indicated a 0.1 μm variation in sarcomere length exceeded the set threshold of ± 2.5 % from the measured sarcomere length output value of strength for the muscle sacrocaudalis dorsalis medialis. Muscle length sensitivity indicated a 1 mm input variation remained within the strength output threshold, while a 2 mm variation exceeded the threshold. This research resulted in the development of a preliminary and functional biomechanical model of the GSD lumbo-sacral spine capable of simulation studies. The results of the inverse dynamics sensitivity analysis identified the critical effect of variation of muscle fibre length and sarcomere length as muscle input parameters, and emphasised the requirement of precise muscle measurement, specific to each individual muscle.
  • Thumbnail Image
    Item
    The casemoth, Liothula omnivoa (Psychidae : lepidoptera) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Zoology at Massey University
    (Massey University, 1967) Ooi, Thean Chooi
    Liothula omnivora, one of the two known casemoths endemic to New Zealand, belongs to the Lepidopteran family Psychidae. It is distributed throughout the country, and can be found on a large number of host plants (see later). The other N.Z. casemoth, Orophora concolor, has been found on Wild Irishman and cassinias in the river beds of the South Island (Miller, 1955). L. omnivora was first described by Fereday in 1878, but Meyrick (1890) transferred it to the genus Oiketicus (Guilding, 1827) mis-spelling it Oeceticus. Dr. Allan Watson (1967, pers. comm.) of the British Museum (Natural History) considers that this species should belong in the genus Liothula and the writer has adopted Watson's view in calling it L. omnivora. The type of L. omnivora is in the Canterbury Museum, Christchurch (Entomologische Beihefte 4, Horn and Kahle, 1937). Descriptions of the external morphology of the adult male and female have been made by Fereday (1878), Meyrick (1890) and Hudson (1928). Fereday and Hudson also described the larva, the pupa has been described by Hudson and Quail (1901), and the appearance of the egg briefly noted by Hudson.
  • Thumbnail Image
    Item
    Cannon bones : some dimensions, heritabilities and relationships to carcass quality in Romney wether lambs : a thesis presented in partial fulfillment of the requirements for the degree of M. Agr. Sc.
    (Massey University, 1957) Hughes, Alan Herbert
    In the past and to a certain extent at the present time sheep breeders have paid considerable attention to the dimensions of the cannon bones of their animals in the belief that this bone serves as a good indicator of the quality of the conformation and constitution of their animals. Scientific workers interested in meat and carcass quality have also attached considerable importance to the cannon bone as an index of carcass composition and hence of carcass quality. The origin of the sheep breeders beliefs is no doubt due to years of farmer observation supported to some extent by the findings of the scientific workers, who of necessity, using relatively small numbers of animals, have established relationships between the dimensions of the cannon bone and other characters of' economic importance. The existence at Massey Agricultural College of complete records, concerning cannon bone dimensions and carcass quality, collected from a relatively large number of animals, prompted this present study which was intended to yield more accurate results than those previously reported. At the same time this study was designed to yield estimates of the heritability of cannon bone dimensions and their relationship to carcass quality thus providing a basis on which breeders might decide whether or not they could continue to place the present amount of emphasis on the cannon bone in their selection practices .
  • Thumbnail Image
    Item
    Ultrastructural studies on horse ligaments : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biophysics at Massey University
    (Massey University, 1993) Davankar, Sachin Padmakar
    This thesis has been devoted to studying one of the largest structural units present in most connective tissues - the collagen fibriL Diameter distributions of collagen fibrils from horse ligaments have been investigated as a function of age. A fairly complete age-related study of collagen fibril diameter distribution was targeted during this work. The ligaments (lateral collateral ligament, medial collateral ligament, radioscaphoid ligament, lateral pisoformometacarpal ligament and scaphocapitate ligament) were sampled from horses of ages one year, two-and-half year, five year, six year and eleven year. Electron microscopy methods were employed and corresponding electron micrographs were obtained from transverse sections. These were used to calculate a mean diameter and mass-average diameter of the collagen fibrils. Individual histograms were plotted showing the frequency and mass distribution of the fibrils versus the diameter at each of the ages studied. The data obtained have been related to the mechanical properties of the ligaments and their mode of growth. The diameter distributions obtained clearly reflect the mechanical needs of the ligaments during various stages of maturation. Results from a previous study of these ligaments at one particular age (four years) have been compared and found to be compatible with the results obtained during the course of this study. The effect of training on collagen fibril diameter distribution of horse ligaments has also been discussed.
  • Thumbnail Image
    Item
    Some aspects of the vagal innervation of the canine esophagus : an anatomical study : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science at Massey University
    (Massey University, 1974) Watson, Alastair Gordon
    The anatomical disposition of the branches from the vagus nerves to the entire canine esophagus were investigated and the effects of various nerve transections on esophageal function were observed radiographically. Twenty one adult mongrel dogs were carefully dissected; fourteen were dissected as fresh specimens and seven were formalin embalmed and dissected later. Ten of these dogs hed previously undergone various surgical nerve transections: bilateral pharyngoesophageal neurectomy, bilateral cranial thoracic vagotomy, transection of recurrent laryngeal nerves at their origins, double bilateral cranial thoracic vagotomy, and caudal thoracic vagotomies. The surgical approaches for transection of these esophageal nerves have been investigated and the various techniques are described. Esophageal function before and after nerve transection was studied radiographically, especially by cineradiography; all radiographs were made on conscious dogs, trained to stand in a normal position freely eating barium impregnated meal from a bowl placed immediately in front of their forepaws. Radiographic observations on esophageal motility were made on fifteen additional apparently normal dogs. Contrary to standard texts, it was found in the present study that each parent recurrent laryngeal nerve was always divided into two trunks: the recurrent laryngeal nerve proper which coursed directly to and terminated in the ipsilateral intrinsic laryngeal muscles (excluding cricothyroideus), and a more dorsally lying pararecurrent laryngeal nerve which coursed parallel to the recurrent proper but freely supplied many branches to the esophagus and trachea. These esophageal branches were especially numerous on the left side, as the left pararecurrent nerve richly supplied the cranial thoracic esophagus as well as the cervical portion. However, the right pararecurrent nerve supplied the cervical esophagus only. Each pararecurrent nerve then terminated in the anastomotic ramus from the internal branch of the ipsilateral cranial laryngeal nerve. From the experimental studies it was concluded that the recurrent laryngeal nerves were functionally involved with the cranial thoracic esophagus, since this region was completely paralysed following bilateral recurrent laryngeal neureetomy. Some dysfunction was also seen in the cervical esophagus after this operation. The cervical esophagus was primarily innervated and functionally controlled by the pair of pharyngoesophageal nerves which arose solely from the pharyngeal branch of each vagus nerve. Caudal to the origins of the recurrent nerves, the thoracic and abdominal vagi supplied and controlled the caudal thoracic and abdominal portions of the esophagus. The vagus nerves innervate and are involved in the normal function of the gastroesophageal junction, since bilateral cranial thoracic vagotomy considerably altered the activity of this region. However, double caudal thoracic vagotomy appeared only slightly to affect the function of the gastroesophageal junction. In addition, the course and the histological structure of the canine esophagus has been observed and described. During this study, radiographic observations were repeatedly made, on apparently normal dogs, that put in question the validity of the currently held concepts of esophageal physiology. Propulsive esophageal contraction waves did not necessarily directly follow each oropharyngeal deglutition sequence. Swallowed boluses were frequently delayed in the cranial cervical, thoracic inlet, and cranial thoracic regions of the esophagus, Twenty two of the twenty five apparently normal dogs examined, exhibited significant reflux of material from the stomach into the caudal thoracic esophagus. More detailed radiographic studies of the normal canine esophagus under truly physiological conditions are required.
  • Thumbnail Image
    Item
    A radiographical study of the feline urinary system : a dissertation presented in partial fulfilment of the requirements for the Master of Philosophy in the Faculty of Veterinary Science at Massey University, New Zealand
    (Massey University, 1978) Kurosawa, Tsutomu
    Although radiographical techniques to examine the urinary system are well established in dogs and humans, these techniques have not been widely accepted or applied to examine the feline urinary system. Considerable confusion and controversy exist regarding anatomical features and radiographical interpretation of the feline urinary system. Much of the currently available information on the feline urinary system has been assumed from comparative studies in other species, particularly the dog. This study comprises a comprehensive literature review of the anatomy and radiography in the feline urinary tract and includes results of a limited radiographical study of the urinary tract in 27 clinically normal cats. The cats studied were prepared for radiography and restrained with various anaesthetic agents and techniques. Radio-graphical examinations of the urinary system involved standard radiography, and the use of an image intensifier connected with a television monitor and 70 mm spot films. The kidney was studied using plain radiography, intravenous and intramuscular excretory urography, renal arteriography and renal venography. With these techniques the kidney location, size, outline, radiographical density and blood supply were observed. Changes in kidney position in various postures relative to the lumbar vertebrae were also studied. The ureteral course, size and blood supply were studied following excretory urography and in some cats the presence of vesico-ureteral reflux enabled retrograde ureterography. The location, shape, size and radiographical density of the urinary bladder were studied by plain radiographyt excretory radiography, and retrograde cystography including positive, negative and double contrast techniques. The urethral course, shape, size and sex differences were studied by retrograde and micturating urethrography. Following the radiographical studies, all cats were euthanized and their urinary system were macroscopically examined at postmortem. Selective findings of this study are as follows. The internal structures of the kidney, namely the cortex, medulla, renal columns, pelvic diverticuli, pelvis and renal vessels were visualized. using contrast radiography. The internal venous drainage of the kidney was demonstrated by selective renal venography. As previously described in the literature, the kidney location varied in individual cats posture respiratory phase and the geometrical relationship between the x-ray tube and the animal. However the angle of the longitudinal axis, the length and width of the kidney and the ratio between the length of the kidney and lumbar vertebrae were relatively consistent. The proximal ureters had a characteristic step-wise course. Vesicoureteral reflux was observed in 36% of cats studied during micturating cysto-urethrography but no evidence of this reflux was found in cats sedated with xylazine. Although the urinary bladder expanded proportionally during filling, it assumed an hour-glass-shape during micturition. The male urethra narrowed at the levels of the prostate and bulbourethral glands. The female urethra formed a bulbous enlargement immediately proximal to its narrow external orifice. The total length of the urethra was 111.3 mm in the male and 64.2 mm in the female.