H87 A laboratory manual (or comparative vert 3 DATE DUE I must therefore ask the indulgence of the expert in vertebrate anatomy for the. The purpose of this book, now in its third edition, is to introduce the morphology of vertebrates in a context that emphasizes a comparison of structire and of the. Hyman's Comparative Vertebrate Anatomy, , pages, Marvalee H. Wake, The Dissection of Vertebrates A Laboratory Manual, Gerardo De Iuliis.
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Hyman, Libbie H. Comparative Vertebrate Anatomy. Chicago: The University of Chicago Press, p. $ Greta Oppe · Search for more papers by this . Comparative Vertebrate Anatomy - Ebook download as PDF File .pdf), Text File ( .txt) or read book online. Author: Henrietta Hyman. INVERTEBRATE ZOOLOGY: An In- troduction to. Animal. Morphology and. Bionomics. . Hyman, L. H. A Laboratory Manual for Comparative. Vertebrate.
Lateralthe sides, right and left.
OIA_Pectorals.pdf - Summarized by Jericho Falcon Salviejo...
Anterior, cephalic, or cranialthe head end of the animal superior in human anatomy. Posterior or caudalthe tail end of the animal inferior in human anatomy. Medianthe middle. Adverbs made by substituting d for the terminal letter of these words mean "in the direction of," as craniad, toward the head; caudad, toward the tail; etc. Other descriptive terms are: Centralthe part of a system nearest the middle of the animal. Peripheralthe part nearest the surface.
Proximalnear the main mass of the body, as the thigh. Distalaway from the main mass of the body, as the toes. Superficialon or near the surface. Deepsome distance below the surface. The median plane is a vertical longitudinal plane passing from head to tail through the center of the body from dorsal to ventral surfaces.
I t divides the body into two nearly identical halves, right and left. The sagittal plane or section is any vertical longitudinal plane through the bodythat is, the median plane or any plane parallel to it. Sagittal planes other than the median plane are sometimes designated as parasagittal to avoid misunderstanding. The horizontal or frontal plane or section is any horizontal longitudinal section through the bodythat is, all planes at right angles to the median plane and parallel to the dorsal and ventral surfaces.
The transverse or cross plane or section cuts vertically across the body at right angles to the sagittal and horizontal planes. The longitudinal or anteroposterior axis is a line in the median sagittal plane extending from head to tail; a sagittal or dorsoventral axis is any line in the median sagittal plane extending from dorsal to ventral surfaces; a transverse or mediolateral axis is any line in the transverse plane running from side to side.
Since all vertebrates are bilaterally symmetrical, the other types of symmetry will not be considered here.
Bilateral symmetry. The parts of a bilaterally symmetrical animal are arranged symmetrically with reference to three axesthe longitudinal, transverse, and sagittal axes; the two ends of the sagittal axis in any given cross-section are unlike.
There is but one plane of symmetry in such an animalthat plane which passes through the longitudinal and Sagittal axesnamely, the median sagittal plane. I t divides the animal into approximately identical right and left halves, which are mirror images of each other. The digestive tract is the only system which does not exhibit a symmetrical relation to the median plane in the adult, although it, too, is bilaterally symmetrical in early embryonic stages.
The body of segmented animals is composed of a longitudinal series of divisions in each of which all or most of the body systems are represented, either by entire paired organs or parts or by a portion of the median unpaired structures. Each such division of the body is termed a metamere, segment, or somite.
The anterior and posterior boundaries of each segment may or may not be marked externally by a constriction of the body wall. In the former case the animal is said to exhibit both external and internal segmentation; in the latter case internal metamerism alone is present. An ideal segmented animal would consist of a series of identical segments; but no such animal exists, since the head and terminal segments must necessarily differ, if only slightly, from the other segments.
However, the more primitive ringed worms, such as Nereis, closely approach the ideal. The segmentation of the animal body into nearly like segments is spoken of as homonomous. The majority of segmented animals have heteronomotis segni'entation, in which the various segments differ from each other to a greater or less extent.
In the evolution of segmented animals there has been a continuous progression from the homonomous to the extreme heteronomous condition. Homonomous segmentation is a primitive and generalized state in which the various segments are more or less independent and capable of performing all necessary functions.
As heteronomy progresses, the segments become unlike, and different body regions specialize in the performance of different functions.
Each segment is then no longer capable of carrying on all functions but becomes dependent upon the other segments, with a resulting unification and harmony of performance lacking in homonomously segmented forms.
The heteronomous condition is derived from the homonomous through a number of different processes, such aloss of segments, fusion of adjacent segments, enlargement or reduction of segments, loss of organs or parts from some segments with their retention in others, structural changes among the repeated organs or parts so that those of different segments become unlike, etc. The segmented groups of animals are the annelids, the arthropods, and the chordates.
Whereas relationship between annelids and arthropods is generally acknowledged, most zoologists are now of the opinion that the chordates stem from a quite different line of evolution and hence that segmentation has arisen in them independently of the metamerism of the annelid-arthropod line. Segmentation in chordates concerns primarily the musculature; that of the endoskeleton and nervous system seems to be secondary to that of the muscles.
Among vertebrates there is a rapid loss of segmentation, which can be followed to some extent during embryology.
Comparative vertebrate anatomy hyman pdf
Embryonic stages are much more obviously segmented and more homonomous than adults, and heteronomy progresses during the development of a given vertebrate. Adult vertebrates are thus internally and heteronomously segmented animals.
This differentiation of the head consists chiefly of the localization within the head of the main part of the nervous systemi. Since the brain and the sense organs control, to a very large degree, the activities and responses of the rest of the body, the head thus becomes the dominant part of the organism. This centralization or localization of nervous structures and functions in the head with accompanying dominance of the head is called cephalization.
Cephalization is more and more marked the higher one ascends in the animal kingdom, and is particularly prominent as a structural and functional feature of the vertebrates.
In segmented animals the advance in cephalization is correlated with the progression of the heteronomous condition. Heteronomy, in fact, appears first in the head region and gradually progresses posteriorly.
The anterior end thus retains the least, and the posterior end the most, resemblance to the original homonomous condition. This results in an illusion of a retreat of certain systems toward the posterior regions of the body, whereas the situation in reality arises from the fact that these systems have disappeared from the anterior segments and are retained in the posterior segments.
In the case of certain vertebrate organs, as the heart, a real posterior descent occurs during the evolution of the vertebrates.
In the vertebrates, as in other heteronomously segmented animals, the head is produced through the fusion of a certain number of the most anterior segments with a loss of some segments or of parts of segments and the disappearance from these head segments of nearly all systems except the nervous system.
As cephalization progresses, the head appropriates more and more of the adjacent segments, incorporating them into its structure, so that in general it may be said that the higher the degree of cephalization the greater is the number of segments composing the head.
In advanced cephalization, such as is possessed by vertebrates, it is very difficultindeed, almost impossibleto decipher the number and boundaries of the segments which originally went into the composition of the head; in fact, the problem of the segmentation of the vertebrate head has not been completely solved, although it has received the attention of the foremost vertebrate anatomists.
The vertebrates are, then, animals characterized by the possession of bilateral symmetry, internal and markedly heteronomous segmentation, and a high degree of cephalization.
Homology is intrinsic similarity injiicative of a common evolutionary origin.
Homologous structures may seem unlike superficially but can be proved to be equivalent by any or all of the following criteria: similarity of anatomical construction, similar topographical relations to the animal body, similar course of embryonic development, and similarity or identity of specific physiological function or mechanism. A familiar example of homology is the wing of the bird, the flipper of the seal, and the foreleg of the cat; investigation shows that they have a similar arrangement of bones and muscles, have the same positional relation to the body, develop in the same way from a similar primordium, and work physiologically by the same mechanism.
The necessity of including specific physiological function or mechanism as a criterion will become apparent when one considers such structures as the endocrine glands. Although these have a similar anatomical histological structure throughout the vertebrates, they frequently difl'er in position and in the details of their embryonic origin in various vertebrates; but their specific function, which is the ultimate test of their homology, remains the same throughout.
Analogy is similarity of general function or of superficial appearance not associated with similarity of intrinsic anatomical construction or of embryonic origin and development. Thus fish and snakes are covered with scales for protective purposes similar general function , but inyestigation of the two types of scales shows that they are histologically dissimilar and differ in their mode of embryonic origin. Analogous structures also differ in precise functional mechanism; thus an insect leg and a cat leg serve the same broad general function, that of walking, but the mechanism of walking is quite different in the two cases.
When analogous structures present striking similarity of appearance, this is termed convergence or parallelism. Such correspondences are usually associated with living in a common environment, i.
On the other hand, animals closely related by descent may differ greatly in general apjiearance after long sojourn in different environments, as seals and cats. This phenomenon is termed divergence. These characteristics are: 1. The wall of the pharynx of the embryo or adult is pierced by openings, the gill slits, originally probably a food-catching device. A notochord is present in embryo or adult. The notochord is a rod lying dorsal to the intestine, extending from anterior to posterior end, and serving as a skeletal support.
In vertebrates the notochord is partially or wholly replaced by the skull and vertebral column. The central nervous system is hollow in the tunicates in the embryo only , containing a single continuous cavity, and is situated entirely on the dorsal side of the body.
In the invertebrates the central nervous system is always solid and lies mainly ventral in the body. Theoretically, therefore, it would be im' It is customary to include a third group, the Hemichordata also called Enteropneusta and Branchiotremata , with the vertebrates as a subphylum of the Chordata.
The intervertebral disc in mammals is composed of three parts: a jelly-like center called the nucleus pulposus, the cartilaginous annulus fibrosus and anterior and posterior endplates that attach the discs to vertebrae. In order to understand the origin of the disc, we have investigated the intervertebral region of chickens. Surprisingly, our comparison of mouse and chicken discs revealed that chicken discs lack nuclei pulposi.
In addition, the notochord, which in mice forms nuclei pulposi, was found to persist as a rod-like structure and express Shh throughout chicken embryogenesis. Our fate mapping data indicates that cells originating from the rostral half of each somite are responsible for forming the avian disc while cells in the caudal region of each somite form vertebrae. A histological analysis of mammalian and non-mammalian organisms suggests that nuclei pulposi are only present in mammals.
In humans, the intervertebral discs IVD often deteriorate and are believed to cause most cases of lower back pain. Current treatments for the deterioration of the discs include anti-inflammatory pain management and disc arthroplasty artificial disc replacement Mirza and Deyo, Though implants help to restore mobility, they are subject to failure through wearing Hanley et al.
The mammalian IVD functions to resist compressive loads placed on the vertebral column while also providing it with structural support and flexibility. In mammals, the disc is composed of two distinct parts, the nucleus pulposus and annulus fibrosus. The central nucleus pulposus is a hydrogel-like structure made primarily of proteoglycans. The annulus fibrosus surrounds the nucleus pulposus and contains layers of collagen I fiber bundles arranged in alternating directions and a less organized layer of collagen II fibers Humzah and Soames, ; Smith et al.
The breakdown of proteoglycans in the nucleus pulposus and tears in the annulus fibrosus can lead to disc deterioration. In mice, the embryonic notochord is present from E7. Previous work from our laboratory has demonstrated that the embryonic mouse notochord forms all cell types in the nucleus pulposus Choi et al.
The nucleus pulposus persists throughout adult life in both mice and in humans. Given the established role of the notochord as a signaling center during embryonic formation of the vertebral column, it is possible that notochord derived cells in the nucleus pulposus continue to regulate disc morphology into adulthood Hunter et al. These cells may serve as a stem cell population to replace damaged cells in the discs or they may secrete proteins that have the potential to induce cell division in damaged nuclei pulposi.
The molecular pathways responsible for the formation of the intervertebral discs has been postulated to be similar in all mammals, an assumption based on observations that the IVD structures in organisms such as humans, canines, rabbits, and pigs are similar Walmsley, ; Butler, ; Alini et al. In the mouse system it has been demonstrated that cells from the notochord contribute to the nucleus pulposus and that the notochord disappears during later embryonic development Walmsley, ; Choi et al.
The cellular origin of the annulus fibrosus is less clear. It has been proposed that the annulus fibrosus is derived from the sclerotome, the ventral portion of each of the somites Bagnall and Sanders, ; Goldstein and Kalcheim, ; Huang et al.
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At embryonic day 12 in the mouse, sclerotome cells migrate toward the midline and condense around the notochord Christ and Wilting, At embryonic day 12 in the mouse, sclerotome cells migrate toward the midline and condense around the notochord Christ and Wilting, Volume 27 , Issue 1. Current treatments for the deterioration of the discs include anti-inflammatory pain management and disc arthroplasty artificial disc replacement Mirza and Deyo, Epiceratodus, Protopterus, Lepidosiren.
The notochord was also present in the middle of all vertebrae during embryogenesis Figure 1. Since the brain and the sense organs control, to a very large degree, the activities and responses of the rest of the body, the head thus becomes the dominant part of the organism. The Comparative Anatomy of. From HH19 through birth the notochord was observed to persist throughout the ventral midline of chicken embryos Figure 1. Currently the literature provides conflicting reports as to which half-sclerotome gives rise to the disc based on studies of the fate of half-somites in chickens.