Observations on the anatomy of mammary glands in two species of conilurine rodent (Muridae: Hydromyinae) and in an opossum (Marsupialia: Didelphidae).

1993 ◽  
Vol 16 (1) ◽  
pp. 9
Author(s):  
M. Griffiths ◽  
N.G. Simms
Keyword(s):  
Connective Tissue ◽  
Body Wall ◽  
Striated Muscle ◽  
Mammary Glands ◽  
Monodelphis Domestica ◽  
The Body ◽  
Rodent Species ◽  
Voluntary Muscle ◽  
The Subject

The pups of Pseudomys nanus and P. australis are attached to their mothers' teats for extended periods of time, analogous to the situation encountered in pouchless marsupials. The structures in the mammary glands involved in facilitating prolonged attachment are different in the two rodent species and both kinds are different from those in marsupial glands including those of Monodelphis domestica, the subject of the present study. In P. nanus, the teats are anchored to postero-ventrally directed, tubular diverticula of the body wall. In P. australis there are no diverticula. However, support for the mammary glands and teats is afforded by the body wall, in the form of two well-developed fan-shaped muscles dorsal to the mammary glands in conjunction with a broad lamina of connective tissue, smooth and striated muscle situated between the skin of the belly and the mammary glands. In M. domestica, the teats are anchored to swathes of striated voluntary muscle, derived from the ilio-marsupialis muscles which pass ventrally through the secretory parenchyma to be inserted onto the bases of the teats. Since this musculature has not been observed in the mammary glands of any eutherians so far studied, nor in those of Monotremata, it is put that it is a character unique to the Marsupialia.

scholarly journals Sperm Transfer Through the Vector Tissue in Piscicola Respirans (Clitellata, Hirudinea, Piscicolidae)

2009 ◽  
Vol 54-55 (1-4) ◽  
pp. 5-12 ◽  
Author(s):  
Piotr ŚwiĄtek ◽  
Anna Świder ◽  
Aleksander Bielecki
Keyword(s):  
High Pressure ◽  
Connective Tissue ◽  
Body Wall ◽  
The Body ◽  
Sperm Transfer ◽  
Ultrastructural Observation ◽  
Granular Cells ◽  
Main Mass ◽  
Tissue Cells ◽  
Cytoplasmic Processes

Sperm Transfer Through the Vector Tissue in Piscicola Respirans (Clitellata, Hirudinea, Piscicolidae) In fish leeches (Piscicolidae) indirect (hypodermic) insemination has evolved, thus the spermatophores are released in the specialised region of the body wall known as a copulatory area or a copulatory region. The way in which the spermatozoa reach the ovaries is not fully understood. In piscicolids beneath the copulatory area there is a specialized connective tissue (vector tissue), which is thought to guide the spermatozoa toward the ovaries. To date the structure of the vector tissue has not been observed in copulating specimens, which have spermatophores implanted in their coplulatory area. Here we present the first ultrastructural observation of massive sperm transfer from the spermatophore throughout the vector tissue to the ovaries. Our results show that the sperm transfer is both massive and rapid. The migrating spermatozoa form huge aggregations which push aside the vector tissue cells, in such a way that between these cells voluminous gaps are formed. Unexpectedly to our previous suggestions, the ultrastructural pictures show that the long cytoplasmic processes of granular cells, which constitute the main mass of the vector tissue, are not engaged in sperm transport. We suggest that the sperm is pumped with a high pressure from the spermatophore into the vector tissue, and as a result the vector tissue cells are pushed aside and spermatozoa can freely pass between them.

scholarly journals A contribution to the comparative biochemistry of muscular and electrical tissues

1937 ◽  
Vol 122 (827) ◽  
pp. 197-219 ◽  
Keyword(s):  
Body Wall ◽  
Smooth Muscles ◽  
The Body ◽  
Muscular Tissue ◽  
Comparative Biochemistry ◽  
Jaw Muscles ◽  
Recent Advances ◽  
Preliminary Communication ◽  
The Subject ◽  
Significant Bearing

Recent advances in the biochemistry of muscle have made it clear that the disappearance of glycogen and the resynthesis of phosphocreatine during anaerobic contraction are connected by a complex cyclical system of reactions in which a leading part is played by adenylic compounds (see for example Ostern, Baranowski and Reis 1935; Needham and van Heyningen 1935; Lehmann 1935). The subject has recently been summarized by Parnas (1936); full details and references will be found in his review. The present paper reports the results of some comparative work on the presence of similar systems in some hitherto unexamined tissues. These were, first, the electrical organs of the ray Torpedo , which, although extensively modified in the course of their development, arise from pre-muscular tissue in the embryo and may therefore be regarded in some measure as muscular in origin. We also used the striated jaw muscles of a typical echinoid and the smooth muscles of the body wall of a holothurian. In addition we determined the type of phosphagen present in representatives of two other groups of Echinodermata, the Ophiuroidea and the Crinoidea, which have not hitherto been examined. The results on echinoderm muscle have a significant bearing upon the phylogenetic aspects of our knowledge of the distribution of the phosphagens. A preliminary communication has already appeared (Baldwin and Needham 1936).

scholarly journals Pulmonary Mechanics and the Work of Breathing in the Semi-Aquatic Turtle, Pseudemys Scripta

1986 ◽  
Vol 125 (1) ◽  
pp. 137-155 ◽  
Author(s):  
Timothy Z. Vitalis ◽  
William K. Milsom
Keyword(s):  
Body Wall ◽  
Striated Muscle ◽  
Work Of Breathing ◽  
Body Cavity ◽  
The Body ◽  
Mechanical Work ◽  
Pulmonary Mechanics ◽  
Pump Frequency ◽  
Elastic Forces ◽  
Pseudemys Scripta

Measurements of pulmonary mechanics on anaesthetized specimens of the aquatic turtle Pseudemys scripta (Schoepff) indicate that the static pulmonary mechanics of the total respiratory system are determined primarily by the mechanics of the body wall rather than those of the lungs. This is also true under the dynamic conditions of pump ventilation at low pump frequencies. As pump frequency increases, the work required to inflate the multicameral lungs of the turtle begins to contribute an increasing portion to the total mechanical work required to produce each breath as measured from pressure volume loops. The rise in the work performed on the lungs results from an increase in the non-elastic, flow-resistive forces which must be overcome during ventilation. The primary bronchus to each lung is the most likely site of flow resistance. There is also a small elastic component to the work required to ventilate the lungs associated with movement of the intrapulmonary septa and the striated muscle surrounding the lungs. The contribution of the work required to distend the body cavity as a percentage of the total mechanical work required to generate each breath remains relatively unchanged with increasing ventilation frequency, indicating that the majority of the forces to be overcome in the body wall are elastic in nature. For a constant rate of minute pump ventilation, as frequency increases, the work done per minute to overcome elastic forces decreases, while that done to overcome non-elastic forces begins to rise. These opposing trends produce an optimum combination of pump volume and frequency at which the rate of mechanical work is minimum.

Surgical Anatomy of the Retroperitoneal Spaces–Part I: Embryogenesis and Anatomy

2009 ◽  
Vol 75 (11) ◽  
pp. 1091-1097 ◽  
Author(s):  
Petros Mirilas ◽  
John E. Skandalakis
Keyword(s):  
Connective Tissue ◽  
Abdominal Wall ◽  
Body Wall ◽  
Surgical Anatomy ◽  
The Body ◽  
Retroperitoneal Space ◽  
Variable Degree ◽  
Loose Connective Tissue ◽  
Posterior Abdominal Wall ◽  
Renal Fascia

Embryologically, the retroperitoneal (extraperitoneal) connective tissue includes three strata, which respectively form the internal fascia lining of the body wall, the renal fascia, and the covering of the gastrointestinal viscera. All organs, vessels, and nerves, that lie on the posterior abdominal wall, along with their tissues and surrounding connective and fascial planes, are collectively referred to as the retroperitoneum. The retroperitoneal space is the area of the posterior abdominal wall that is located between the parietal peritoneum and the fascia. Within the greater retroperitoneal space, there are also several small spaces, or subcompartments. Loose connective tissue and fat surround the anatomic entities, and, to a variable degree, occupy the subcompartments. The multilaminar thoracolumbar (lumbodorsal) fascia begins at the occipital area and terminates at the sacrum.

scholarly journals THE PLATING OF TUMOR COMPONENTS ON THE SUBCUTANEOUS EXPANSES OF YOUNG MICE

1962 ◽  
Vol 115 (6) ◽  
pp. 1211-1230 ◽  
Author(s):  
James S. Henderson ◽  
Peyton Rous
Keyword(s):  
Connective Tissue ◽  
Body Wall ◽  
Mammary Tumors ◽  
The Body ◽  
Subcutaneous Connective Tissue ◽  
Factor Type ◽  
Milk Factor ◽  
Forcible Injection ◽  
Young Mice

A procedure analogous to the plating of bacteria is described whereby some complex tumors have been taken apart and their components separately propagated. It was the outcome of finding that the forcible injection of Locke's solution followed by air can be used to split the subcutaneous connective tissue of sucklings and weanlings horizontally over the entire expanse of their backs or bellies, without inducing any complicating inflammation. Tumor fragments suspended in Locke's were widely scattered on the surfaces thus exposed. Most of them remained where they had lodged on the body wall, and rapidly becoming fixed in place, formed growths protected by the overlying cutaneous layer—which, throughout many weeks, remained unattached either to the wall or to them. The procedure is more searching in its disclosure of tumor constituents than those currently employed, and it has the advantage that it preserves the neoplastic components that it reveals. It has been used thus far only to rescue for experimental purposes transplantable, benign, epidermal papillomas from the hidden carcinomas deriving from their cells, and to set free and maintain the neoplastic components of complex mammary tumors of milk factor type. Success was obtained with such of the latter as were chosen for separate propagation, though successive platings were sometimes required for their isolation. Incidentally the procedure revealed two components in the mammary growths which could not have been discerned by previous methods of search. Each formed tumors peculiar to itself.

Neural control of muscle relaxation in echinoderms

2001 ◽  
Vol 204 (5) ◽  
pp. 875-885 ◽  
Author(s):  
M.R. Elphick ◽  
R. Melarange
Keyword(s):  
Smooth Muscle ◽  
Connective Tissue ◽  
Body Wall ◽  
Muscle Relaxation ◽  
The Body ◽  
Body Wall Muscle ◽  
Asterias Rubens ◽  
Cardiac Stomach ◽  
Stichopus Japonicus ◽  
Neuronal Signalling

Smooth muscle relaxation in vertebrates is regulated by a variety of neuronal signalling molecules, including neuropeptides and nitric oxide (NO). The physiology of muscle relaxation in echinoderms is of particular interest because these animals are evolutionarily more closely related to the vertebrates than to the majority of invertebrate phyla. However, whilst in vertebrates there is a clear structural and functional distinction between visceral smooth muscle and skeletal striated muscle, this does not apply to echinoderms, in which the majority of muscles, whether associated with the body wall skeleton and its appendages or with visceral organs, are made up of non-striated fibres. The mechanisms by which the nervous system controls muscle relaxation in echinoderms were, until recently, unknown. Using the cardiac stomach of the starfish Asterias rubens as a model, it has been established that the NO-cGMP signalling pathway mediates relaxation. NO also causes relaxation of sea urchin tube feet, and NO may therefore function as a ‘universal’ muscle relaxant in echinoderms. The first neuropeptides to be identified in echinoderms were two related peptides isolated from Asterias rubens known as SALMFamide-1 (S1) and SALMFamide-2 (S2). Both S1 and S2 cause relaxation of the starfish cardiac stomach, but with S2 being approximately ten times more potent than S1. SALMFamide neuropeptides have also been isolated from sea cucumbers, in which they cause relaxation of both gut and body wall muscle. Therefore, like NO, SALMFamides may also function as ‘universal’ muscle relaxants in echinoderms. The mechanisms by which SALMFamides cause relaxation of echinoderm muscle are not known, but several candidate signal transduction pathways are discussed here. The SALMFamides do not, however, appear to act by promoting release of NO, and muscle relaxation in echinoderms is therefore probably regulated by at least two neuronal signalling systems acting in parallel. Recently, other neuropeptides that influence muscle tone have been isolated from the sea cucumber Stichopus japonicus using body wall muscle as a bioassay, but at present SALMFamide peptides are the only ones that have been found to have a direct relaxing action on echinoderm muscle. One of the Stichopus japonicus peptides (holothurin 1), however, causes a reduction in the magnitude of electrically evoked muscle contraction in Stichopus japonicus and also causes ‘softening’ of the body wall dermis, a ‘mutable connective tissue’. It seems most likely that this effect of holothurin 1 on body wall dermis is mediated by constituent muscle cells, and the concept of ‘mutable connective tissue’ in echinoderms may therefore need to be re-evaluated to incorporate the involvement of muscle, as proposed recently for the spine ligament in sea urchins.

The Infrastructure of the Tegument of Moniliformis dubius(Acanthocephala)

1965 ◽  
Vol s3-106 (74) ◽  
pp. 137-146
Author(s):  
W. L. NICHOLAS ◽  
E. H. MERCER
Keyword(s):  
Electron Microscope ◽  
Connective Tissue ◽  
Basement Membrane ◽  
Body Wall ◽  
The Body ◽  
Fibrous Connective Tissue ◽  
Vacuole Formation ◽  
Cytoplasmic Organelles

The ultrastructure of the body wall of Moniliformis dubius has been studied in the light and electron microscope. It consists of an apparently syncytial tegument, overlaid by a tenuous cuticle in the form of a finely fibrous extracellular fringe and is backed by a basement membrane and fibrous connective tissue. The tegument contains a framework of fibres, which, distally, is connected to a dense fibrous meshwork separated from the cuticle by two membranes. Within the syncytial tegument are found the usual cytoplasmic organelles: mitochondria (often degenerate in structure), Golgi clusters, small amounts of other smooth membranes, and numerous dense particles (glycogen and perhaps ribosomes). Many mitochondria contain dense particles. Evidence of vacuole formation at the surface of the tegument suggests that pinocytosis plays a part in assimilation.

scholarly journals Three-Component Model of the Spinal Nerve Branching Pattern, based on the View of the Lateral Somitic Frontier and Experimental Validation

2020 ◽  
Author(s):  
Shunsaku Homma ◽  
Takako Shimada ◽  
Ikuo Wada ◽  
Katsuji Kumaki ◽  
Noboru Sato ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Body Wall ◽  
Intercostal Nerve ◽  
Spinal Nerve ◽  
The Body ◽  
Branching Pattern ◽  
Lateral Plate ◽  
Embryonic Mouse ◽  
Human Gross Anatomy ◽  
Thoracic Spinal

ABSTRACTOne of the decisive questions about human gross anatomy is unmatching the adult branching pattern of the spinal nerve to the embryonic lineages of the peripheral target muscles. The two principal branches in the adult anatomy, the dorsal and ventral rami of the spinal nerve, innervate the intrinsic back muscles (epaxial muscles), as well as the body wall and appendicular muscles (hypaxial muscles), respectively. However, progenitors from the dorsomedial myotome develop into the back and proximal body wall muscles (primaxial muscles) within the sclerotome-derived connective tissue environment. In contrast, those from the ventrolateral myotome develop into the distal body wall and appendicular muscles (abaxial muscles) within the lateral plate-derived connective tissue environment. Thus, the ventral rami innervate muscles that belong to two different embryonic compartments. Because strict correspondence between an embryonic compartment and its cognate innervation is a way to secure the development of functional neuronal circuits, this mismatch indicates that we may need to reconcile our current understanding of the branching pattern of the spinal nerve with regard to embryonic compartments. Accordingly, we first built a model for the branching pattern of the spinal nerve, based on the primaxial-abaxial distinction, and then validated it using mouse embryos.In our model, we hypothesized the following: 1) a single spinal nerve consists of three nerve components: primaxial compartment-responsible branches, a homologous branch to the canonical intercostal nerve bound for innervation to the abaxial compartment in the ventral body wall, and a novel class of nerves that travel along the lateral cutaneous branch to the appendicles; 2) the three nerve components are discrete only during early embryonic periods but are later modified into the elaborate adult morphology; and 3) each of the three components has its own unique morphology regarding trajectory and innervation targets. Notably, the primaxial compartment-responsible branches from the ventral rami have the same features as the dorsal rami. Under the above assumptions, our model comprehensively describes the logic for innervation patterns when facing the intricate anatomy of the spinal nerve in the human body.In transparent whole-mount specimens of embryonic mouse thoraces, the single thoracic spinal nerve in early developmental periods trifurcated into superficial, deep, and lateral cutaneous branches; however, it later resembled the adult branching pattern by contracting the superficial branch. The superficial branches remained segmental while the other two branches were free from axial restriction. Injection of a tracer into the superficial branches of the intercostal nerve labeled Lhx3-positive motoneurons in the medial portion of the medial motor column (MMCm). However, the injection into the deep branches resulted in retrograde labeling of motoneurons that expressed Oct6 in the lateral portion of the medial motor column (MMCl). Collectively, these observations on the embryonic intercostal nerve support our model that the spinal nerve consists of three distinctive components.We believe that our model provides a framework to conceptualize the innervation pattern of the spinal nerve based on the distinction of embryonic mesoderm compartments. Because such information about the spinal nerves is essential, we further anticipate that our model will provide new insights into a broad range of research fields, from basic to clinical sciences.

scholarly journals The morphology of autotomy structures in the sea cucumber Eupentacta quinquesemita before and during evisceration

2001 ◽  
Vol 204 (5) ◽  
pp. 849-863 ◽  
Author(s):  
M. Byrne
Keyword(s):  
Connective Tissue ◽  
Muscle Contraction ◽  
Sea Cucumber ◽  
Body Wall ◽  
The Body ◽  
Whole Body ◽  
Retractor Muscle ◽  
Coelomic Fluid ◽  
Ground Substance ◽  
Tissue Change

Evisceration in the dendrochirotid sea cucumber Eupentacta quinquesemita is a whole-body response involving a predictable series of events including muscle contraction and failure of three autotomy structures: (i) the introvert, the dexterous anterior extensible portion of the body wall, (ii) the tendon linking the pharyngeal retractor muscle to the longitudinal body wall muscle and (iii) the intestine-cloacal junction. The autotomy structures are histologically complex, consisting of muscle, nervous and connective tissue. Autotomy resulted from complete loss in the tensility of the connective tissue ground substance. Separation of the autotomy structures was facilitated by muscle contraction. The cell and tissue changes involved with autotomy were documented by microscopic examination of autotomising tissue. Change in the autotomy structures appears to initiate from the peritoneal side with delamination of the peritoneum followed by a wave of disruption as the connective tissue is infiltrated by coelomic fluid. Evisceration and autotomy in E. quinquesemita are neurally controlled, so particular attention was paid to the fate of neuronal elements. Neurosecretory-like processes containing large dense vesicles and axons were present in the connective tissue layers of the autotomy structures in association with extracellular matrix, muscles and neurons. These neuronal elements remained largely intact during autotomy and did not appear to be a source of factors that effect connective tissue change. They may, however, be involved in muscle activity. Holothuroid autotomy structures are completely or partially bathed in coelomic fluid, so there is potential for hormonal or neurosecretory activity using the coelomic fluid as a conduit. Connective tissue change during evisceration appears to be effected or mediated by an evisceration factor present in coelomic fluid that has a direct transmitter-like or neurosecretory-like mode of operation. The final outcome, expulsion of the viscera, is likely to result from a suite of factors that interact in a manner yet to be determined.

scholarly journals The Contractile Mechanism in Obliquely Striated Body Wall Muscle of the Earthworm, Lumbricus Terrestris

1971 ◽  
Vol 8 (2) ◽  
pp. 413-425 ◽  
Author(s):  
M. F. KNAPP ◽  
P. J. MILL
Keyword(s):  
Body Wall ◽  
Striated Muscle ◽  
Lumbricus Terrestris ◽  
The Body ◽  
Band Width ◽  
Physiological Data ◽  
Muscle Fibres ◽  
Contraction Mechanism ◽  
Cross Links

Obliquely striated muscle fibres from the longitudinal and circular layers of the body wall of the earthworm were prepared in extended and contracted states for study in the electron microscope. Contracted fibres differ from extended ones in the following respects: (i) the I-bands are narrower, (ii) the A-bands are wider, and (iii) there are more rows of thick myofilaments in each A-band. The arrangement of the thick and thin myofilaments in interdigitating arrays and the occurrence of cross-links between the 2 types of myofilament indicate a classical sliding-filament mechanism of contraction as in cross-striated muscle, resulting in a reduction in the I-band width. The increase in the A-band width could be due to a moving apart of the myofilaments during contraction to preserve constant volume of the lattice. The third change, the increase in the number of rows of thick myofilaments in the A-band, can be explained only by a shearing of these filaments past one another in such a way as to increase the amount of their overlap. The role of the sliding-filament and shearing contraction mechanisms in bringing about the changes observed in earthworm muscle fibres is considered and the possible correlation of these mechanisms with certain physiological data is discussed. The function of the sarcoplasmic reticulum in the transmission of impulses to the interior of the fibre and/or in the control of the contraction mechanism is also discussed.

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