Studies on the epidermis of Tamnocephala II. Epidermal sensory receptors of Temnocephala novae-zealandiae

1977 ◽  
Vol 25 (2) ◽  
pp. 187 ◽  
Author(s):  
JB Williams
Keyword(s):  
The Body ◽  
Sensory Receptors ◽  
Epidermal Surface ◽  
Striated Rootlet ◽  
Fibre Pattern

Uniciliate receptors occur on the body, tentacles and attachment disc of T. novae-zealandiae, often grouped in tufts or clusters. The free ends of the associated nerve processes project above the epidermal surface. Elongated microvilli are associated with the ciliary tufts. The receptive cilium has the typical 9+2 fibre pattern and a striated rootlet.

Sensory Receptors and Epidermal Structures of a Meiofaunal Turbellarian (Proseriata, Monocelididae, Minoninae)

1995 ◽  
Vol 43 (1) ◽  
pp. 69 ◽  
Author(s):  
K Rohde ◽  
NA Watson
Keyword(s):  
Basal Body ◽  
High Energy ◽  
The Body ◽  
Lateral Part ◽  
Basal Bodies ◽  
Sensory Receptors ◽  
Ecological Requirements ◽  
Morphological Studies ◽  
Epidermal Surface ◽  
Eastern Australia

The senogram (set of sensory receptors) of a proseriate turbellarian from the meiofauna of a high-energy beach in south-eastern Australia is described, based on serial ultrathin sections. It comprises a pair of rhabdomeric eyes that lack a pigment cup, a statocyst located ventro-anteriorly to the brain and consisting of one lithocyte with a single ovoid statolith in the electron-lucent cytoplasm, several parietal and accessory cells and nerve fibres penetrating the statocyst capsule, and at least eight (and possibly eleven) types of epidermal receptors: A, an anterior and antero-lateral receptor with basal bodies and strongly branched processes (modified cilia); B, an 'insunk' collar receptor in all parts of the body surface, with eight microvilli surrounding the single cilium; C, a ciliary bundle arising from basal bodies at the base of a deep pit, in anterior third of body; D, a bundle of dendrites, reaching the surface, in anterior third of body, possibly a protonephridial pore; E, a multiciliate receptor with long branched ciliary rootlets, in anterior and antero-lateral part of body; F, as for E but with a single rootlet; G, as for F but with a vertical and an oblique rootlet arising from the basal body (F and G are possibly modifications of E); H, a receptor with a single cilium and short rootlet, somewhat raised above the epidermal surface; I, a pharyngeal receptor with a short cilium; J, a pharyngeal receptor with a long cilium; K, an anterior receptor with a bulbous cilium. A single cilium or up to three cilia surrounded by a cytoplasmic tube may constitute a further receptor type. Most epidermal perikarya are 'insunk', and epidermal cilia have large anteriorly directed, very thin vertical rootlets and short 'spurs' at the basal body. Bundles of rootlets of epidermal cilia converge towards their tips, some tips located close to the epidermal surface; it is suggested that they may be directly stimulated by mechanical stimuli. The variety of receptors indicates that the animal must respond to a complex array of stimuli. It is stressed that morphological studies of sensory receptors are the basis for an understanding of their function and of the ecological requirements of a species.

scholarly journals Ultrastructural observations on the oncomiracidium epidermis and adult tegument of Discocotyle sagittata, a monogenean gill parasite of salmonids

2021 ◽  
Vol 120 (3) ◽  
pp. 899-910
Author(s):  
Mohamed Mohamed El-Naggar ◽  
Richard C Tinsley ◽  
Jo Cable
Keyword(s):  
Surface Layer ◽  
Cell Layer ◽  
Ciliated Cell ◽  
The Body ◽  
Life Stages ◽  
Sensory Receptors ◽  
Ciliated Cells ◽  
Membrane Turnover ◽  
Free Swimming ◽  
Gill Parasite

AbstractDuring their different life stages, parasites undergo remarkable morphological, physiological, and behavioral “metamorphoses” to meet the needs of their changing habitats. This is even true for ectoparasites, such as the monogeneans, which typically have a free-swimming larval stage (oncomiracidium) that seeks out and attaches to the external surfaces of fish where they mature. Before any obvious changes occur, there are ultrastructural differences in the oncomiracidium’s outer surface that prepare it for a parasitic existence. The present findings suggest a distinct variation in timing of the switch from oncomiracidia epidermis to the syncytial structure of the adult tegument and so, to date, there are three such categories within the Monogenea: (1) Nuclei of both ciliated cells and interciliary cytoplasm are shed from the surface layer and the epidermis becomes a syncytial layer during the later stages of embryogenesis; (2) nuclei of both ciliated cells and interciliary syncytium remain distinct and the switch occurs later after the oncomiracidia hatch (as in the present study); and (3) the nuclei remain distinct in the ciliated epidermis but those of the interciliary epidermis are lost during embryonic development. Here we describe how the epidermis of the oncomiracidium of Discocotyle sagittata is differentiated into two regions, a ciliated cell layer and an interciliary, syncytial cytoplasm, both of which are nucleated. The interciliary syncytium extends in-between and underneath the ciliated cells and sometimes covers part of their apical surfaces, possibly the start of their shedding process. The presence of membranous whorls and pyknotic nuclei over the surface are indicative of membrane turnover suggesting that the switch in epidermis morphology is already initiated at this stage. The body tegument and associated putative sensory receptors of subadult and adult D. sagittata are similar to those in other monogeneans.

THE ETHOLOGY OF THE SYNAPTID HOLOTHURIAN, OPHEODESOMA SPECTABILIS

1966 ◽  
Vol 44 (3) ◽  
pp. 457-482 ◽  
Author(s):  
Michael Berrill
Keyword(s):  
Body Wall ◽  
The Body ◽  
Tactile Sensitivity ◽  
Sensory Receptors ◽  
Rhythmic Contraction ◽  
Anterior Portion ◽  
Nervous Control ◽  
Strong Light ◽  
Activity Peak ◽  
Early Evening

Opheodesoma spectabilis commonly occurs in aggregations in the alga Sargassum echinocarpus, a source of shade from which it scrapes adhering detritus, and which allows the dense populations necessary for efficient spawning. The animal is photonegative and moves away from a strong light source. Ocelli provide information on the direction and intensity of sunlight. Statocysts, aided by tactile sensitivity, maintain dorsoventral equilibrium."They may also inhibit unwarranted rapid locomotion. The animal shows no gravity orientation. All sensory receptors are most concentrated in the region of the tentacle crown, and their interaction in controlling the animal's reactions implies considerable central integration of stimuli. The three primary muscular activities are the rhythmic contraction and extension of the tentacles, used in feeding and for slow locomotion; peristalsis of the body wall, involved in rapid locomotion; and the contraction, bending, and reextension of the anterior portion of the body. These activities may vary in rate and amplitude and occur independently or in any combinations. Their initiation and coordination are under central nervous control. Opheodesoma spectabilis has a diurnal rhythm of behavior, reaching an activity peak during the early evening hours and apparently directly dependent on changes in light intensity. Spawning occurs during the summer months.

Outbreaks of hyperkeratotic dermatitis of athymic nude mice in northern Italy

1997 ◽  
Vol 31 (3) ◽  
pp. 206-211 ◽  
Author(s):  
E. Scanziani ◽  
A. Gobbi ◽  
L. Crippa ◽  
A. M. Giusti ◽  
R. Giavazzi ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Histological Examination ◽  
Nude Mice ◽  
Northern Italy ◽  
The Body ◽  
Inflammatory Infiltration ◽  
Athymic Nude Mice ◽  
Coryneform Bacterium ◽  
Coryneform Bacteria ◽  
Epidermal Surface

Hyperkeratotic dermatitis of athymic nude mice is an infectious disease caused by a coryneform bacterium. During the spring of 1995, outbreaks of hyperkeratotic dermatitis were observed in several nude mice facilities in northern Italy. In this report we describe the clinical, histopathological and microbiological features of the disease in two different animal facilities. Affected animals showed a typical 'scaly' appearance with small white flakes of material adherent to the skin. In one of the outbreaks (facility 2) the lesions were less severe and involved only limited areas of the body. The infection spread very quickly and the morbidity reached more than 80% in a few days, while the mortality was about 1%. The lesions resolved spontaneously within 7-10 days. Histological examination of affected skin revealed orthokeratotic hyperkeratosis, acanthosis and dermal inflammatory infiltration which were more severe in mice from facility 1. In Gram-stained sections groups of rods consistent with coryneform bacteria were detectable in the keratin layers covering the epidermal surface. A coryneform bacterium, biochemically typed as Corynebacterium bovis, was isolated from 11 out of 11 mice from facility 1 and from 8 out of 11 mice from facility 2.

scholarly journals Abnormal Epidermal Keratinization in the repeated epilation mutant mouse

1982 ◽  
Vol 92 (2) ◽  
pp. 387-397 ◽  
Author(s):  
KA Holbrook ◽  
BA Dale ◽  
KS Brown
Keyword(s):  
Cell Structure ◽  
Genetic Defect ◽  
Terminal Differentiation ◽  
Gross Anatomy ◽  
The Body ◽  
Epidermal Differentiation ◽  
Tissue Architecture ◽  
Defective Structure ◽  
Epidermal Surface ◽  
Granular Layers

Repeated epilation (Er) is a radiation-induced, autosomal, incomplete dominant mutation in mice which is expressed in heterozygotes but is lethal in the homozygous condition. Many effects of the mutation occur in skin: the epidermis in Er/Er mice is adhesive (oral and nasal orifices fuse, limbs adhere to the body wall), hyperplastic, and fails to undergo terminal differentiation. Skin from fetal +/+, Er/+ and Er/Er mice at ages pre- and postkeratinization examined by light, scanning, and transmission electron microscopy showed marked abnormalities in tissue architecture, differentiation, and cell structure; light and dark basal epidermal cells were separated by wide intercellular spaces, joined by few desmosomes, and contained phagolysomes. The numbers of spinous, granular, and superficial layers were highly variable within any given region and among various regions of the body. In some areas, 2-8 layers of granular cells, containing large or diminutive keratohyalin granules, extended to the epidermal surface; in others, the granular layers were covered by several layers of partially keratinized or nonkeratinized cells. In rare instances, a single or small group of cornified cells was present among the granular layers but was not associated with the epidermal surface. Both the granular and nonkeratinized/partially keratinized upper epidermal layers Er/Er skin gave positive immunofluorescence with antiserum to the histidine-rich, basic protein, filaggrin. Proteins in epidermal extracts from +/+, Er/+ and Er/Er mice were separated and identified by radio- and immunolabeling techniques. The Er/Er extract was missing a 26.5- kdalton protein and had an altered ratio of bands in the keratin region. The 26.5-kdalton band was histidine-rich and cross-reacted with the antiserum to rat filaggrin. Several high molecular weight bands present in both Er/Er and +/+ extracts also reacted with the antiserum. These are presumed to be the precursors of filaggrin and to account for the immunofluorescence om Er/Er epidermis even though the product protein is absent. The morphologic and biochemical data indicated that the genetic defect has a general and profound influence on epidermal differentiation, including alteration of two proteins (filaggrin and keratin) important in normal terminal differentiation, tissue architecture, and cytology. Identification of epidermal abnormalities at early stages of development (prekeratinization) and defective structure of other tissues and gross anatomy suggest that the mutation is responsible for a defect in same regulatory step important in many processes of differentiation and development.

scholarly journals Sensory structures of lungs and airways

2011 ◽  
Vol 10 (3) ◽  
pp. 100-104 ◽  
Author(s):  
L. V. Filippova ◽  
A. D. Nozdrachev
Keyword(s):  
Respiratory Function ◽  
The Body ◽  
Sensory Receptors ◽  
Neuroepithelial Bodies ◽  
Stretch Receptors ◽  
C Fiber ◽  
Respiratory Centre ◽  
Sensory Structures ◽  
Existing Data ◽  
Lungs And Airways

The оptimum realization to respiratory function depends on varied sensory feedbacks from ensemble of the sources of the body. Pulmonary sensory receptors are the initiating sites for lung reflexes. The information arriving from lungs and airways information is one of the most important feedbacks that provide the adaptation of the respiratory centre for producing of the pattern optimal in terms of work and force of breathing. In article the review of currently existing data about morphology and functional characteristics of sensitive pulmonary structures is presented: slowly adapting stretch receptors, rapidly adapting receptors, C-fiber receptors and neuroepithelial bodies.

scholarly journals Epidermis as a Platform for Bacterial Transmission

2021 ◽  
Vol 12 ◽  
Author(s):  
Fernando Baquero ◽  
Claudia Saralegui ◽  
Daniel Marcos-Mencía ◽  
Luna Ballestero ◽  
Sergio Vañó-Galván ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Three Dimensional ◽  
Physical Structure ◽  
The Body ◽  
Normal Density ◽  
Epidermal Surface ◽  
Bacterial Transmission ◽  
Important Host ◽  
Living Organisms ◽  
Interacting Surfaces

The epidermis constitutes a continuous external layer covering the body, offering protection against bacteria, the most abundant living organisms that come into contact with this barrier. The epidermis is heavily colonized by commensal bacterial organisms that help protect against pathogenic bacteria. The highly regulated and dynamic interaction between the epidermis and commensals involves the host’s production of nutritional factors promoting bacterial growth together to chemical and immunological bacterial inhibitors. Signal trafficking ensures the system’s homeostasis; conditions that favor colonization by pathogens frequently foster commensal growth, thereby increasing the bacterial population size and inducing the skin’s antibacterial response, eliminating the pathogens and re-establishing the normal density of commensals. The microecological conditions of the epidermis favors Gram-positive organisms and are unsuitable for long-term Gram-negative colonization. However, the epidermis acts as the most important host-to-host transmission platform for bacteria, including those that colonize human mucous membranes. Bacteria are frequently shared by relatives, partners, and coworkers. The epidermal bacterial transmission platform of healthcare workers and visitors can contaminate hospitalized patients, eventually contributing to cross-infections. Epidermal transmission occurs mostly via the hands and particularly through fingers. The three-dimensional physical structure of the epidermis, particularly the fingertips, which have frictional ridges, multiplies the possibilities for bacterial adhesion and release. Research into the biology of bacterial transmission via the hands is still in its infancy; however, tribology, the science of interacting surfaces in relative motion, including friction, wear and lubrication, will certainly be an important part of it. Experiments on finger-to-finger transmission of microorganisms have shown significant interindividual differences in the ability to transmit microorganisms, presumably due to genetics, age, sex, and the gland density, which determines the physical, chemical, adhesive, nutritional, and immunological status of the epidermal surface. These studies are needed to optimize interventions and strategies for preventing the hand transmission of microorganisms.

Touch and the Mouthfeel of Wine

Neuroenology ◽  
2016 ◽  
pp. 98-105
Author(s):  
Gordon M. Shepherd
Keyword(s):  
The Body ◽  
Sensory Receptors ◽  
The Future ◽  
Sensory Qualities ◽  
Mouth Feel

In a wine tasting, as soon as the wine touches our lips and mouth our brain creates the illusion that all the ensuing wine sensations are due to “taste” in the mouth. The wine touching the mouth gives rise to the sensations of “mouth feel”, due to a variety of sensory receptors in the tongue and cheeks. One of the most important is “astringency”, due to tannins which bind proteins and precipitate them, contributing to the “body” of the wine. Instruments are being developed that measure precipitation quantitatively, perhaps giving a glimpse of the future when many sensory qualities can also be measured instrumentally.

Sensory and other superficial structures in living marine Crustacea

1985 ◽  
Vol 76 (2-3) ◽  
pp. 123-136 ◽  
Author(s):  
M. S. Laverack ◽  
Y. Barrientos
Keyword(s):  
Outer Surface ◽  
Chemical Sensors ◽  
Gland Cell ◽  
The Body ◽  
Sensory Receptors ◽  
Environmental Signals ◽  
Different Types ◽  
Cell Opening ◽  
Decapod Larvae

ABSTRACTLiving Crustacea possess many types of sensory receptors that detect environmental signals. These structures allow the speculation that similar organs existed in fossil arthropods and were involved in similar ways in the fossil forms when they were extant.Posture, for example, is difficult to reconstruct in fossils without the understanding that internal proprioceptors monitoring position and movement are crucial in determining the placement of limbs, and the position of the abdomen and other jointed portions of the body. These receptors are associated also with autotomy reflexes through soft cuticle detectors that respond to strain not associated with joints.Many receptors are placed on the outer surface of the animal, the eyes being the most obvious. The eyes receive no attention in this paper, but descriptions are given of a number of different types of setae, serving both mechanical and chemical sensors. The possession of a pore at the apex (or sub-apex) of a seta or setule probably indicates a chemoreceptor function, but its absence does not necessarily indicate a lack of such sensitivity. A range of forms is illustrated.The dorsal organ is a recently discovered structure in decapod larvae. It is composed of a central single gland cell opening via an aperture in the midline just behind the rostrum. It is bounded by four depressions each containing a central ‘nipple’. These prove to be sensors, with ciliated endings (bifid) that end in a highly modified cuticle at the depression nipple. The function is unknown, but it is proposed that it represents an unusual chemoreceptor.

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