Biochemical Basis of Cervical Maturation
Gabor Huszar in The Physiology and Biochemistry of the Uterus in Pregnancy and Labor, 2020
Fibrous connective tissue is characterized by the presence of an abundant extracellular matrix which surrounds individual cells. The major macromolecular component of this matrix is collagen. In fibrous connective tissue, the collagen fibers appear either as rigid rods arranged in bundles and dispersed in the space between cells or as smaller fibers arranged in a fine network. A second component, glycosaminoglycans and protein-bound glycosaminoglycans, or proteoglycans is a heterogeneous group of macro-molecules which are dispersed in the space between collagen bundles, tightly bound to collagen fibers, or primarily associated with cell surfaces. A third component, elastin, a highly cross-linked collagen-like protein, is found primarily in the fibrous connective tissue of large blood vessels. Structural glycoproteins form an important fourth component. The most extensively characterized of these proteins, fibronectin, is composed of multiple subunits, each of which has specific sites which preferentially bind to col-lagens, to the glycosaminoglycans hyaluronic acid and heparan sulfate, and to cell membranes. Thus, it may be very important in organizing the components of the extracellular matrix.
The circulatory system
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella in Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
The walls of the blood vessels may contain varying amounts of fibrous tissue, elastic tissue, and smooth muscle. All blood vessels are lined with a single layer of endothelial cells, as found forming the endothelium of the heart. The fibrous connective tissue provides structural support and stiffens the vessel. The elastic connective tissue allows vessels to expand and hold more blood. It also causes the vessels to recoil and exert pressure on the blood within the vessels, which pushes this blood forward. Most blood vessels contain smooth muscle that is arranged in either circular or spiral layers. Therefore, contraction of vascular smooth muscle, or vasoconstriction, narrows the diameter of the vessel and decreases the flow of blood through it. Relaxation of vascular smooth muscle, or vasodilation, widens the diameter of the vessel and increases the flow of blood through it. The smooth muscle of the vessel is innervated by the autonomic nervous system and is, therefore, physiologically regulated. Furthermore, this is where endogenous vasoactive substances and pharmacological agents exert their effects. The endothelium has several important physiological functions including contributing to the regulation of blood pressure, blood vessel growth and the exchange of materials between the blood and the interstitial fluid of the tissues (see Table 6.1).
Sample Preparation for Liquid Scintillation Counting
Graham Lappin, Simon Temple in Radiotracers in Drug Development, 2006
There are four basic types of tissue: epithelium, connective tissue, muscle tissue, and nervous tissue. The epithelium is usually the layer of cells that resides closer to the outside world. The outermost layer of skin is composed of dead scaly or platelike epithelial cells. Other examples are the mucous membranes lining the inside of mouths and body cavities. Internally, epithelial cells line the insides of the lungs, the gastrointestinal tract, the reproductive and urinary tracts, and make up the exocrine and endocrine glands. The primary functions of epithelial cells include secretion, absorption and protection. Loose connective tissue holds organs and epi-thelia in place and contains a variety of proteinaceous fibers, including collagen and elastin. Ligaments and tendons are a form of fibrous connective tissue. In most vertebrates, cartilage is found primarily in joints, where it provides cushioning. Muscle cells contain contractile filaments that move past each other, changing size as they do so. The most obvious examples of nervous tissue are the cells forming the brain, spinal cord and peripheral nervous system. The nervous system consists chiefly of two types of cells, neurons and Glia.
Anatomic variations of the human falx cerebelli and its association with occipital venous sinuses
Published in British Journal of Neurosurgery, 2021
Safiye Çavdar, Bilgehan Solmaz, Özgül Taniş, Orhan Ulas Guler, Hakkı Dalçık, Evren Aydoğmuş, Leyla Altunkaya, Erdoğan Kara, Hızır Aslıyüksek
Falx cerebelli, is composed of fibroelastic, dense irregular connective tissue. The connective tissue consisted of cells predominantly of fibroblast which produced the ground substance and collagen fibers. Additionally, the connective tissue contained sensory nerve endings and blood vessels. The arterioles were composed of 1–2 layers of smooth muscle cells in the tunica media and the venules were composed of a single layer of endothelium with many erythrocytes in their lumens (Figure 10a). Furthermore, a large number of lymphatic vessels appeared to be undulated with a single layer of endothelium and a subendothelial layer (Figure 10b). Extravagated lymphocytes surrounding the lymphatic vessels were observed (Figure 10b). Near the vessels, a peripheral nerve characteristically formed a round bundle of nerve processes surrounded by connective tissue sheath perineurium was detected (Figure 10a).
Intra-articular injection PLGA blends sustained-release microspheres loaded with meloxicam: preparation, optimization, evaluation in vitro and in vivo
Published in Drug Delivery, 2022
Zheng Sun, Xuejing Gu, Teng Hao, Jiali Liu, Rongrong Gao, Yanli Li, Bin Yu, Hui Xu
The histopathological examination results of rats were shown in Figure 10. According to the histopathological scoring results shown in Table 7, the score of model group was higher than that of blank control group. The articular cavity of normal rats (A1–A4) maintained a steady state, the surface of the articular cartilage was smooth and flat, and the chondrocytes were evenly distributed and arranged neatly. Occasionally, chondrocyte hypertrophy was observed, and no obvious cell clustering was observed. In the Model group (B1–B4), there were different degrees of defects in the left articular cavity, soft tissue edema tissue in the articular cavity, focal necrosis and hemorrhage, infiltration of inflammatory cells, formation of foam cells and multinucleated giant cells, and proliferation of synovial blood vessels. In addition, the articular cartilage of rats became thinner and distributed disorderly. A large number of hypertrophic chondrocytes were seen in the bottom of the cartilage, and some articular cartilage was hardened. The proliferation of bone marrow cells in the bone marrow cavity was active, showing obvious symptoms of arthritis. As shown in Figure 10(C1–C4), Histological score of OA decreased significantly after MLX-MS intervention (p < .05), rat bone tissue cell regeneration, partial recovery of bone hyperplasia; there was no obvious tissue necrosis and hemorrhage in the joint cavity. The edema of the surrounding soft tissue disappeared. The fibrous tissue proliferated. There was no obvious inflammatory cell infiltration.
High-intensity focused ultrasound (HIFU) for the treatment of uterine fibroids: does HIFU significantly increase the risk of pelvic adhesions?
Published in International Journal of Hyperthermia, 2020
Xiaofang Liu, Xiaojing Dong, Yan Mu, Guohua Huang, Jia He, Lina Hu
Pelvic adhesions are a common surgical complication. It refers to the connection of separated organs by fibrous tissue. Adhesions can be induced by mechanical injury, thermal injury, radiation, pelvic inflammatory disease, and endometriosis. Pelvic adhesions may cause chronic pelvic pain, infertility, and lead to reoperations. For women with prior open abdominopelvic surgery, the presence of adhesions could lead to added morbidity with an increased risk of bowel injury if further surgery is required. Moreover, the cost of management for pelvic adhesions is a heavy burden both on patients and society. According to the studies, in the United States of America, the annual cost of treatment for abdominal adhesions was over $2 billion. In the United Kingdom, the cost of hospitalization due to adhesions after surgeries was £2.42 million [1,2].