Skeleton, Postcranial

Sentiel Rommel , John E. ReynoldsIii, in Encyclopedia of Marine Mammals (2nd Edition), 2009

F Lumbar Region

The lumbar vertebrae are body vertebrae that typically practice not behave movable ribs ( Fig. 3). Remember that ribs and transverse processes develop from homologous embryonic structures. Occasionally, a singled-out pleurapophysis may exist found in this region. As noted in a higher place, pleurapophysis are commonly found in manatees; these "lumbar ribs" are conspicuously distinct from thoracic ribs (Fig. 4B). Typically, the lumbar vertebrae are more flexible dorsoventrally than they are laterally and they may have no axial flexibility. Some of the mobility of the lumbar vertebrae may be constrained by the ribs in front of them.

Every bit already noted, the number of lumbar vertebrae is unremarkably closely linked to the number of thoracic vertebrae; an increase in number in ane department typically means a reduction in the other. For case, there are 19 thoraco-lumbar vertebrae in all species of Artiodactyla, whereas there are 20 or 21 in the Carnivora; compare these numbers with those of the selected marine mammals (Fig. 3).

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Immobilization Osteoporosis

William A. Bauman , Christopher P. Cardozo , in Osteoporosis (Fourth Edition), 2013

Bed Rest for Prolapsed Lumbar Intravertebral Disc

Lumbar vertebrae BMD was adamant in a sequent series of 34 patients who were hospitalized for low dorsum pain secondary to protrusion of a lumbar intravertebral disc [211]. The written report cohort consisted of 17 men and 17 women with a mean age of 38 years (range of xviii–60 years) who were consecutively admitted to the hospital with low back pain. BMD of the lumbar spine (L2–iv) was obtained upon admission then at the conclusion of bed remainder, a menstruum which ranged between 11 and 61 days. With bed rest, there was an mean decrease in lumbar spine BMD of 0.9% per week. With re-ambulation, BMD was about completely restored to the lumbar spine. Thus, therapeutic bed residue for a prolapsed intravertebral disc was reported to result in significant vertebral bone loss, which, if recurrent, would be anticipated to result in osteoporosis of the spine.

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Skeletal System

Christopher Jerome , ... Cathy Southward. Carlson , in Comparative Anatomy and Histology (Second Edition), 2018

Gross Anatomy

Rodent and human being lumbar vertebrae differ in several respects, such equally relative vertebral body size ( Fig. five.13). Rodents also usually have more presacral vertebrae besides as more than tail (coccygeal) vertebrae than humans (Tabular array 5.i). The full number of precoccygeal vertebrae rarely varies within a species, just it is non uncommon to observe "sacralization" or fusion of the concluding lumbar vertebra with the sacrum in rodents or to have one extra thoracic vertebra accompanied by i fewer lumbar vertebra in either rodents or humans. In humans the fifth lumbar vertebra may besides be fused with the sacrum.

Figure five.13. Gross anatomy of the lumbar vertebra.

(A) The rodent (mouse) lumbar vertebra has a relatively small vertebral body (centrum) and ventrally directed transverse processes. (B) The human lumbar vertebra has a large vertebral body for axial support. The transverse processes are located dorsally on the neural arch.

Need-to-know

◆

The rodent vertebra has a relatively pocket-size trunk.

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The human vertebra has a large vertebral for axial support.

 Source: ©Elsevier, Inc., world wide web.netterimages.com. (A) Adapted with permission from K.J. Cook. The anatomy of the laboratory mouse, 143 pages. Elsevier. Copyright © 1965.

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Vertebrae, Ribs, Sternum, Pectoral and Pelvic Girdles, and Bones of the Limbs

Robert Lewis Maynard , Noel Downes , in Anatomy and Histology of the Laboratory Rat in Toxicology and Biomedical Inquiry, 2019

Lumbar Vertebrae

The rat has six lumbar vertebrae (human has 5). There are no ribs attached to them, though the remnants of ribs are incorporated into the transverse processes (L3 is typical, see Fig. 4.5). All the usual processes are present, with the dorsal spine forming a flat plate that runs the length of the vertebra in the sagittal aeroplane. We mentioned in the last section the accompaniment and mamillary processes. Much confusion attends these processes, and a multifariousness of names take been applied to them. The following table sets out the terminology.

Figure 4.5. (A) Third lumbar vertebra (anterior attribute). (B) Third lumbar vertebra (lateral aspect).
Standard zoological terminology, afterwards Owen Terminology of human anatomy equally practical to lumbar vertebrae Terminology of homo anatomy as applied to the terminal few thoracic vertebrae that may acquit these processes
Anapophysis Accessory process Inferior tubercle of the transverse procedure
Metapophysis Mamillary process Superior tubercle of the transverse process

The accompaniment procedure is piece of cake to find in the rat, forming a small-scale, sharp spike that projects posteriorly and lies beneath the posterior zygapophysis. The mamillary process is less obvious, but appears as a thickening on the lateral aspect of the inductive zygapophysis.

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Hyoid and Vertebrae

Tim D. White , ... Pieter A. Folkens , in Human Osteology (Third Edition), 2012

6.5.1 Anatomy and Identification

a.

The bodies of lumbar vertebrae are larger than those of cervical or thoracic vertebrae. Lumbar bodies lack costal pits and transverse foramina. The superior outlines of lumbar bodies are ovoid, although Fifty-ane and L-2 may exist somewhat kidney-shaped.

b.

The vertebral foramina of lumbar vertebrae are triangular in outline, and are very small relative to the size of the vertebral bodies.

c.

The spinous processes of lumbar vertebrae are hatchet-shaped, large, blunt, and more horizontally oriented than other vertebral barbed processes (they are orthogonal to the coronal plane).

d.

The transverse processes of lumbar vertebrae are relatively smaller and thinner than thoracic transverse processes and they lack whatever articular surfaces. They are rudimentary or absent on L-1 and increment in size and project inferiorly.

e.

The superior and junior articular facets are not parallel in lumbar vertebrae; instead, the superior articular facets are concave (cupped) and face posteromedially. The inferior articular facets are convex and face anterolaterally.

f.

The mammillary process is a somewhat elongated tubercle that originates from the posterolateral margin of the superior articular process.

g.

The accessory process is a variable, atomic tubercle on the dorsal attribute of the base of operations of the lumbar transverse process.

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The Skull and Vertebral Column

J. Kevin Kealy MVB, MVM, MRCVS, DVR, DECVDI (Hon) , ... John P. Graham MVB, MSc, DVR, MRCVS, DACVR, DECVDI , in Diagnostic Radiology and Ultrasonography of the Dog and Cat (Fifth Edition), 2011

Lumbar Vertebrae

The bodies of the lumbar vertebrae are longer than those of the thoracic. The barbed processes are directed cranially, and the transverse processes are directed cranially, laterally, and somewhat ventrally. Accessory processes are present on the starting time four vertebrae. They overlie the intervertebral foramina and are particularly prominent in cats. The barbed processes increment in elevation from the first to the sixth. The cranioventral aspect of the fourth lumbar vertebra projects more ventrally than exercise the other vertebrae. The ventral margins of the 3rd and 4th lumbar vertebrae are often poorly defined on radiographs, peculiarly in larger dogs. This is because of a diaphragmatic attachment in that area ( Figure five-25, Due east to I).

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Biology and Diseases of Rabbits

Megan H. Nowland DVM, BS, DACLAM , ... Howard G. Blitz DVM, MS, DACLAM , in Laboratory Brute Medicine (Third Edition), 2015

Etiology

Subluxation or compression fractures of lumbar vertebrae are often secondary to struggling during restraint, especially when the hindquarters of the rabbit are not supported ( Bergdall and Dysko, 1994). The seventh lumbar vertebra (L7) or its caudal articular processes are considered the most frequent sites of fractures, with fracture occurring more usually than dislocation (Flatt et al., 1974).

Clinical Signs

Clinical signs include posterior paresis or paralysis, loss of sensation in the hindlimbs, urinary and/or fecal incontinence, and perineal staining.

Pathology

Spinal cord hemorrhage and necrosis can be found.

Diagnosis

Diagnosis is based on clinical signs, history of recent restraint, struggling or other trauma, and palpation or radiographic analysis of the vertebral column.

Differential Diagnoses

Spinal cord trauma.

Handling, Prevention, and Control

Euthanasia of affected animals is usually warranted. Moderate cases (subluxation with spinal edema) may resolve over time. The conclusion to euthanize should be based on severity of clinical signs. Supportive intendance includes regular expression of the urinary bladder and prevention and treatment of decubital ulcers. Corticosteroid and diuretic therapy may be effective for cases of subluxation with spinal edema (Bergdall and Dysko, 1994).

Inquiry Complications

Loss of valuable research animals is the primary complication.

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Selective Breeding

Nihar Ranjan Chattopadhyay , in Induced Fish Convenance, 2017

4.11 Excerpt

The Indian major carp, catla, rohu, and mrigal are the natural inhabitants of the perennial river network of India, Pakistan, and Bangladesh and enjoy a wide distribution. These species are well established in almost all the rivers and reservoirs where they accept been transplanted. Substantial research has been carried out to study the biological aspects and propagation of these carp after the initiation of systematic research on inland fisheries at the first of the 1950s. Based on this information culture technologies were developed resulting in intensive and extensive composite (multispecies) culture; product levels increased from 0.half dozen to 10–15   t/ha/year. At the same fourth dimension three decades of effort to develop improved varieties of carps through cross-convenance (hybridization) did not issue in the production of whatsoever commercially feasible hybrid varieties. Cytogenetic investigations, mainly on karyotypes, take shown that though these major carp have their own distinct morphological features, genetically they announced to be very closely related as indicated by non only their karyotypes but too by their isozyme and Deoxyribonucleic acid profiles. The data available on biochemical genetic studies is not very complete. Notwithstanding, recent efforts in this area and in DNA analyses have resulted in the development of some methodologies for the identification of genetic markers in the case of catla, rohu, and mrigal. These techniques may be effectively used for stock identification and to study genetic variation in the individuals of a particular species or putative landraces. These methods were hitherto non developed and consequently there is no record of previous studies to investigate whether at that place exist dissimilar populations or races within a given species of major carp. With the development of allozyme, RAPD, mtDNA RFLP, and microsatellite techniques, some preliminary investigations were carried out which indicated the existence of genetic variations between the stock of different major seed-producing hatcheries and also between the hatchery and wild populations of catla.

Differences in isozyme markers have been likewise noticed among rohu of different river systems, namely, the rivers Ganga, Gomati, Yamuna, Sutlej, and Brahmaputra. Of the three species of Indian major carp, rohu grows relatively slower in carp culture systems, while catla and mrigal exhibit comparatively amend growth. Considering rohu is a highly prized fish, efforts are being initiated to meliorate the species genetically through choice. There appears to exist regional preference, for a particular species in India. While rohu is preferred in most of the states in the Eastern region, catla is popular in the Southern states, especially in the provinces of Karnataka and Andhra Pradesh. Genetic improvement of catla has been taken up in Karnataka province. The aim of current choice projects is to provide right breeding procedures to the hatchery managers and to develop genetically superior lines that can produce quality seed which tin grow to over a kilogram within 1 year under intensive composite farming system. The slowest growing among the major carp, Labeo calbasu, is an upcoming species and is gaining popularity. Every bit mentioned earlier, this species has proficient resistance against parasite infection and can stand rough handling to a better extent than other major carp species. In almost every bother farming nation in Asia, proper use of the genetic potentials of these species has non been sincerely attempted, probably due to the preoccupation to develop suitable culture technologies with the already-existing resource and the demand to come across the immediate and urgent protein requirement of the masses in their respective nations. At present many of these nations in Asia, after achieving the goal to a notable extent in ascension the average fish production levels through improved culture technologies, have started realizing that quality comeback is necessary to increment further the quantity. These ii aspects cannot be separated. During the coming decades, if aquaculture is to be a viable manufacture, it must be supported by technologies which ensure sustainable higher productions. Conservation and protection of the genetic resources and exploitation of genetic potentials of the species of fish to their optimum levels appears to exist an excellent immediate pathway to achieve the goal.

Virtually nations, especially in Asia, accept already initiated activeness by taking upwards conservation of genetic resource and genetic improvement activities of important species. The major carp culturing nations of Bharat, Bangladesh, Pakistan, People's republic of china, Thailand, Vietnam, etc., have already started working on the chore either independently or in a collaborative manner among themselves or with other avant-garde nations. The International Network for Genetics in Aquaculture (INGA) is coordinating fish genetic inquiry among all the member countries. The to a higher place-mentioned countries are amid the member countries under the INGA network. Republic of india, Philippines, and Vietnam accept collaborated with the Institute of Aquaculture Research (AKVAFORSK), Norway, on selective breeding programs. Recently the International Centre for Living Aquatic Resource Management (ICLARM) launched a bother genetic improvement projection in which the research on genetic improvement of carp is supported through providing funds and also coordinating the research among the INGA member countries of Bangladesh, China, Republic of india, Indonesia, Thailand, and Vietnam. Exchange of carp germplasm among interested countries has also been planned under this program. The coming decade may witness an overall improvement in the aquaculture sector through the systematic and sustainable exploitation of fish genetic resources and the wider utilize of genetically improved varieties in aquaculture systems.

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Sacropelvic Fixation

Khaled Kebaish , Mostafa H. El Dafrawy , in Operative Techniques: Spine Surgery (Third Edition), 2018

Trauma

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Fractures of the lower lumbar vertebra and sacral fractures with spinopelvic dissociation

Indications Pitfalls

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Big loads going through this segment, creating cantilever pullout forces, are the main reasons for construct failure.

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Variable anatomy of the sacrum and pelvis may add challenge to the procedure.

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The sacrum has poor bone quality, mainly cancellous and often osteoporotic.

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Restoration of spinopelvic rest is an important determinant of good clinical event.

Indications Controversies

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Long fusion has been described by some authors every bit four levels extending to L2, whereas others define a long fusion as one that crosses the thoracolumbar junction.

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The long lever arm generated past incorporating more segments into the fusion requires additional fixation points to achieve a rigid construct at the lumbosacral junction.

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High hazard of pseudarthrosis (ix% to 41%), instrumentation failure (3% to 44%), and loss of lumbar lordosis (20% to 49%) is associated with fusion down to the sacrum.

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Terminating a long fusion at L5 might lead to subsequent degeneration of the L5-S1 deejay and might touch on sagittal residuum.

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Degeneration of the sacroiliac (SI) articulation, although so far not clinically meaning, might be a concern in patients with implants violating the sacroiliac articulation (iliac and S2AI screws).

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Naked Mole Rat

Rochelle Buffenstein , ... James Eastward. Artwohl , in The Laboratory Rabbit, Guinea Grunter, Hamster, and Other Rodents, 2012

Model of Bone Elongation

Naked mole rat queens take significantly longer lumbar vertebrae for their torso size compared with all other colony members ( Jarvis et al., 1991; O'Riain et al., 2000). This finding parallels eusocial insects in that the dominant breeder is physically dissimilar. The length of the spine is proportional to the number of pregnancies experienced and suggests that hormones related to pregnancy may have a role in bone growth (Henry et al., 2007). Queens no longer experienced net proceeds in lumbar spine length after eight pregnancies, only did have some transient elongation during pregnancy after the 8th pregnancy (Dengler-Crish and Catania, 2009).

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