Blood flow
Peter R Hoskins, Kevin Martin, Abigail Thrush in Diagnostic Ultrasound, 2019
The structure of the arterial wall can change due to disease and these changes may be observed using ultrasound. Artery walls consist of a three-layer structure. The inner layer, the intima, is a thin layer of endothelium overlying an elastic membrane. The middle layer, the media, consists of smooth muscle and elastic tissue. The outer layer, the adventitia, is predominantly composed of connective tissue with collagen and elastic tissue. The intima-media layer can be visualised with ultrasound in the carotid arteries and is normally of the order of 0.5–0.9 mm thick, when measured using ultrasound. Arterial disease will lead to changes in the vessel wall thickness that may eventually lead to a reduction of flow or act as a source of emboli. Vein walls have a similar structure to arteries but with a thinner media layer. Blood vessels not only act as a conduit to transport the blood around the body but are complex structures that respond to nervous and chemical stimulation to regulate the flow of blood.
The Fascial System in Walking
David Lesondak, Angeli Maun Akey in Fascia, Function, and Medical Applications, 2020
If the Achilles tendon and its associated muscles use SSC mechanics, it is safe to assume that other plantar flexor tendons will do the same to reduce the metabolic expense of concentric or eccentric contractions. Allowing the elastic tissue to strain rather than lengthening the muscle fibers optimizes the force–length relationship of the muscle fibers, which further produces more efficiency within the soft tissue system.9 However, the use of SSC requires adequate movement at each joint to allow momentum to strain the elastic tissues. Joint range of motion aids stiffening of the soft tissues acting to decelerate momentum and, if inadequate range of motion is available, other tissues will have to compensate. In the example of the windlass mechanism described above, if reduced ankle motion or toe extension is present, the foot will lose some aspects of the windlass mechanism, inhibiting the foot’s return to a rigid lever and place extra stress on the plantar and calf tissues. However, the implications of decreased foot stiffness might not be limited to the foot and leg.
Disc Structure and Function
Peter Ghosh in The Biology of the Intervertebral Disc, 2019
Annular fibers do not consist of collagen alone, but like the fibers in tendon, consist of a mixture of components; as a result they are presumed, like other connective tissues, to function as composite materials.39 Although the presence of elastic fibers has been controversial in the past, it has now been clearly established by light82 and electron microscopy.67,83,84 Elastic fibers consist of two components — the rubber-like protein elastin and the elastic fiber microfibrils which are composed of glycoprotein.85 During the early stages of development, microfibrils form the bulk of the fibers so that they have an obviously fibrous appearance in the electron microscope,85 which can be clearly seen in micrographs of human fetal annulus.84 During development the proportion of elastin increases85 and so elastic fibers appear more amorphous in micrographs of adult human annulus.67 It has been proposed that the function of elastic fibers is to confer resilience on the annular fibers, i.e., to make them less susceptible to suddenly applied forces;86 this proposal will be discussed in more detail in Section III.B. Furthermore, Johnson et al.82 have shown that elastic fibers only occur in those regions of the annulus close to its attachments with the vertebrae and end-plates.
Identification of Pulmonary Nodules by Sweeping the Surface of the Lung with an Electrical Bioimpedance Probe: A Feasibility Study
Published in Journal of Investigative Surgery, 2019
Rasool Baghbani, Mohammad Hassan Moradi, Mohammad Behgam Shadmehr
Lung tissue includes a wide network of air, blood vessels, and an elastic tissue containing alveoli. As a result, the electrical features of the lung tissue are utilized in one of the two strategies depending on the purpose for which it is applied. If the goal is to examine the microscopic details orFIGURE 2cellular properties of the lung tissue, then the electrical properties of different components of the lung tissue, such as alveoli, bronchi, arterial, and venous walls must be taken into account separately. If on the other hand, the purpose of the application is to identify the type of tissue by the impedance measured via the bioimpedance probe (which is in contact with a large surface of the tissue), the value obtained for the electrical impedance only includes the area through which the current passes. In this case, the value for electrical impedance will be the result of all those areas of the lung that are subjected to the passage of the current.
Improvement in linear depressed atrophic scar using 755-nm picosecond alexandrite laser vs. ablative fractional carbon dioxide laser
Published in Journal of Cosmetic and Laser Therapy, 2022
Da Woon Lee, Hyeongrae Ryu, Hwan Jun Choi, Eun Soo Park
Brauer et al. reported the effectiveness of 755-nm picosecond laser against depressed acne scar in a collagen remodeling experiment (11). Fractional non-ablative picosecond laser can induce the regeneration of collagen and soft tissue based on laser-induced optical breakdown (LiOB), and thus the mechanism of subcision was similar to that of a laser, improving depressed scars. Melanocytes in the epidermal region absorb the laser energy concentrated by the micro lens array, resulting in the generation and emission of free electrons, which re-absorb the laser light to regenerate further free electrons. Ionized plasma formation occurs, as a result, which triggers an explosive reaction in the surrounding tissues and the creation of microscopic intradermal cavity lesions in the epidermis and dermis. The contracted collagen fibers are released into the cavity to induce additional collagen synthesis and regeneration of elastic tissue and mucin (12).
Identifying and Localizing of the In-depth Pulmonary Nodules Using Electrical Bio-Impedance
Published in Journal of Investigative Surgery, 2019
Rasool Baghbani, Mohammad Hassan Moradi, Mohammad Behgam Shadmehr
The lung tissue involves a wide network of air, blood pathways and elastic tissue containing alveoli. As a result, the electrical properties of the lung tissue are considered in one of two strategies, depending on the application for which it is intended. If the goal is to examine the microscopic details or cellular properties of the lung tissue, then, the electrical properties of different components of the lung tissue, such as alveoli, bronchus, arterial, and vein walls are taken into account separately.30 In another application that the purpose of which is to interpret the type of tissue from the impedance measured by the bio-impedance sensor (which is in contact with a larger surface of the tissue), the value obtained for the electrical impedance only includes the area in which the current passes through. In this case, the electrical properties obtained from the measured electrical impedance will be apparent.