Elastic blood vessels

Wang C, Cen L, Yin S, Liu Q, Liu W, Cao Y, et al. A small diameter elastic blood vessel wall prepared under pulsatile conditions from polyglycohc acid mesh and smooth muscle cells differentiated from adipose-derived stem cells. Biomaterials February 2010 31(4) 621-30. 

ELRs are a promising model of biocompatible protein-based polymers. The basic structure of ELRs involves a repeating sequence based on the recurring sequences found in the mammalian elastic protein elastin [4]. As far as their properties are concerned, some of their main characteristics are derived from those of the natural protein. Elastin is an extracellular matrix protein that is present in aU vertebrate connective tissue. Its functions include the provision of elasticity and resilience to tissues, such as large elastic blood vessels (aorta), elastic ligaments, lung and skin, which are subjected to repetitive and reversible deformation [5, 6]. 

Blood vessels have elastic walls that expand or contract due to changes in pressure or the passage of corpuscles. How should Equations (14.11) and (14.12) be modified to reflect this behavior ... 

The geometry and structure of a bone consist of a mineralised tissue populated with cells. This bone tissue has two distinct structural forms dense cortical and lattice-like cancellous bone, see Figure 7.2(a). Cortical bone is a nearly transversely isotropic material, made up of osteons, longitudinal cylinders of bone centred around blood vessels. Cancellous bone is an orthotropic material, with a porous architecture formed by individual struts or trabeculae. This high surface area structure represents only 20 per cent of the skeletal mass but has 50 per cent of the metabolic activity. The density of cancellous bone varies significantly, and its mechanical behaviour is influenced by density and architecture. The elastic modulus and strength of both tissue structures are functions of the apparent density. 

Lethias, C., Hartmann, D.J., Masmejean, M., Ravazzola, M., Sabbagh, I., Ville, G., Herbage, D., and Eloy, R. (1987) Ultrastructural immunolocalizadon of elastic fibers in rat blood vessels using the protein A-gold technique./. Histochem. Cytochem. 35, 15-21. 

Fig. 5.2 Immunofluorescent demonstration of smooth muscle actin (FITC, green channel) in the blood vessel wall of the human kidney. Red autofluorescence of erythrocytes, elastic lamellae and kidney tubules was captured with a filter exciting the autofluorescence in red spectrum under a longer exposure than with the filter exciting specific fluorescence in the green spectrum. Nuclei are counterstained with DAPI (blue channel)...

Figure 5.2 Cross section through bLood vessels (a) an artery. Sizes of arteries vary from 25 mm diameter with 2 mm wall thickness in the aorta to 20 pm diameter with a 15 pm wall thickness in the smallest arterioles, (b) a vein. Note there are no elastic lamellae in veins so tension is maintained by elastic fibres which are arranged within the media. Typically, veins are approximately 5 mm in diameter but with a very thin wall, for example 0.5 mm. The vena cava is the largest vein at 30 mm diameter...

Many tissues, such as lung, blood vessels, and skin, require elasticity for proper function this property is fulfilled by the matrix elastic fibers, which are composed of the proteins elastin and fibrillin. 

Microscopically, the skin is a multilayered organ composed of many histological layers. It is generally subdivided into three layers the epidermis, the dermis, and the hypodermis [1]. The uppermost nonviable layer of the epidermis, the stratum corneum, has been demonstrated to constitute the principal barrier to percutaneous penetration [2,3]. The excellent barrier properties of the stratum corneum can be ascribed to its unique structure and composition. The viable epidermis is situated beneath the stratum corneum and responsible for the generation of the stratum corneum. The dermis is directly adjacent to the epidermis and composed of a matrix of connective tissue, which renders the skin its elasticity and resistance to deformation. The blood vessels that are present in the dermis provide the skin with nutrients and oxygen [1]. The hypodermis or subcutaneous fat tissue is the lowermost layer of the skin. It supports the dermis and epidermis and provides thermal isolation and mechanical protection of the body. 

Connective tissues made of collagen and elastic fibers, and blood vessels Smooth muscle fibers arranged in an outer longitudinal layer and an inner circular layer... 

Thin, fibrous layer composed of dense sheath of collagen and elastic fibers contains blood vessels, lymph vessels, and nerves... 

Blood vessels include capillaries, arterioles, arteries, and veins. Each of these structures is composed of three layers the intima, media, and adventitia (Figure 3.12). For example, in elastic arteries the wall consists of an intimal layer containing endothelial cells and connective tissue a media containing smooth muscle cells, collagen, and elastic fibers and an adventitia containing collagen fibers, nerves, and blood vessels. In cross-section,... 

The arterial wall of animals contains three layers the intima, media, and adventitia however, the wall structure of different vessels varies somewhat. The intima extends from the blood vessel lumen to the internal elastic... 

Extracellular matrices (ECM) are the primary structural materials found in connective tissue in vertebrates that serve to maintain tissue shape (skin), aid in locomotion (bone), transmit and absorb mechanical loads (tendon and ligament), prevent premature mechanical failure (tendon, ligament, skin, and blood vessel wall), partition cells and tissues into functional units (fascia), act as scaffolds that define tissue and organ architecture (organ parenchyma), act as storage devices for elastic energy (tendon and blood vessel wall), and as the substrate for cell adhesion, growth, and differentiation of a variety of cell types. 

The lamina propria constitutes a continuous sheet of connective tissue containing collagen, elastic fibres and cellular components in a hydrated ground substance. It also carries blood capillaries and nerve fibres that serve the mucosa. It is through the blood vessels in the lamina propria that drag moieties can gain entry to the systemic circulation. 

Elastin is present in large blood vessels and tendons, and its function is to be elastic. 

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