Cells, Tissues and Organs
David Sturgeon in Introduction to Anatomy and Physiology for Healthcare Students, 2018
Dense connective tissue has a much greater concentration of fibres and tends to provide structural and mechanical support. One of the most important connective tissue fibres is collagen and although it is found in loose connective tissue, there is a much greater abundance in dense connective tissue. For example, in ligaments and tendons, collagen fibres are thick, long and tightly packed together in order to provide the tensile strength necessary to connect and move bones. In cartilage and bone, however, collagen fibres are coated in calcium and phosphate salts in order to provide solidity and strength (see Chapter 4). Dense connective tissue also makes up the lower layers of the skin (dermis) where it is arranged in sheets. Finally, bone, cartilage and blood are all examples of specialised connective tissue (see Chapters 4 and 5). Blood is classified as connective tissue since it contains proteins mixed with water (plasma) and can form a gel. In Chapter 1, we saw that blood consists of a cellular component (red blood cells, white blood cells, etc.) and a non-cellular matrix (plasma). The liquid plasma allows blood to transport a wide variety of substances around the body dissolved in solution or attached to cells. In this sense, therefore, it is supremely connective. The only difference with other connective tissue is that it does not contain the fibre elements.
Breast
Joseph Kovi, Hung Dinh Duong in Frozen Section In Surgical Pathology: An Atlas, 2019
A married woman, age 33, noted a tumor in her left breast. Examination revealed a hard, indurated area measuring approximately 3 by 3 cm in the upper outer quadrant of the breast. The lump was fixed to the surrounding breast tissue. Mammogram demonstrated diffuse, stippled calcification in the lesion. No axillary lymphadenopathy was noted. An incisional biopsy was submitted for study. The excised tissue measured 12 by 10 by 8 mm and was firm in consistency. The cut surface appeared to be gray-white and was studded with tiny brown granules. Microscopically, extreme proliferation of the alveolar epithelium was noted. The epithelial cells in the form of cords and strands appeared to infiltrate the dense connective tissue. The glandular proliferation was, however, distinctly patchy in character. The excessive growth of the alveolar epithelium resulted in the formation of what appeared to be giant, irregular distorted lobules. Higher magnification revealed that the infiltrating cords and strands were in fact compressed and flattened alveoli lined by a double layer of cells, an inner layer of epithelial cells, and an outer layer of myoepithelial cells (Figures 42 to 44).
The spleen
Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie in Bailey & Love's Short Practice of Surgery, 2018
The splenic parenchyma consists of white and red pulp that is surrounded by serosa and a collagenous capsule with smooth muscle fibres. These penetrate the parenchyma as trabeculae of dense connective tissue fibres rich in collagen and elastic tissue. These, with the reticular framework, support the cells of the spleen and surround the vessels in the splenic pulp. The white pulp comprises a central trabecular artery surrounded by nodules with germinal centres and periarterial lymphatic sheaths that provide a framework filled with lymphocytes and macrophages. Arteries from the central artery and the peripheral ‘penicillar’ arteries pass into the marginal zone that lies at the edge of the white pulp. Plasma-rich blood that has passed through the central lymphatic nodules is filtered as it passes through the sinuses within the marginal zone, and particles are phagocytosed.
Intra-articular drug delivery systems for osteoarthritis therapy: shifting from sustained release to enhancing penetration into cartilage
Published in Drug Delivery, 2022
Huirong Huang, Zijian Lou, Shimin Zheng, Jianing Wu, Qing Yao, Ruijie Chen, Longfa Kou, Daosen Chen
The articular capsule is a cystic structure composed of fibrous connective tissue that closes the articular cavity. It is divided into inner and outer layers, whereby the outer layer is collagen fibril dense connective tissue, which is continuous with the periosteum for maintenance of the joint stability. On the other hand, the inner layer, which is also called synovium, is loose and has a smooth surface. It protrudes to the joint cavity to form synovial folds or villi and has lymphatic vessels inside it. There are two types of synovial cells covering the synovial. One is the macrophage-like cell, which contains more lysosomes and has phagocytosis ability and the other is the fibroblast, which contains rougher endoplasmic reticulum and secretes hyaluronic acid as well as mucopolysaccharide, which lubricates the joints.
Effect of High Fructose Corn Sirup on Pancreatic Ductal Adenocarcinoma Induced by Dimethyl Benzantracene (DMBA) in Rats
Published in Nutrition and Cancer, 2021
Gulsah Ozcan-Sınır, Sevda Inan, Senem Suna, Canan Ece Tamer, Mustafa Barış Akgül, Deniz Bagdas, Gursel Sonmez, Turkkan Evrensel, Ekrem Kaya, Emre Sarandol, Halit Ziya Dündar, Omer Faruk Tarım, Ilker Ercan, Deniz Sıgırlı, Bige Incedayı, Omer Utku Copur
On histopathological examination of DMBA treated HFCS, sucrose, and the chow groups, necrotic, hemorrhagic, and hyperemic areas with surrounding dense connective tissue (desmoplastic structure) and inflammatory cells were seen (Figure 2). DMBA-induced crystal structures were observed into the dense connective tissue. The tubular complexes were seen around the normal pancreatic tissue. Most pancreatic ducts had lost the single layer structure and transformed to multilayered epithelium. Ductal epithelial cells were observed to be different in terms of cytoplasmic and nuclear size. The ducts had irregular and narrow lumen. The nuclei of tumoral cells showed dark basophilic staining and vesicular structure. Necrotic neoplastic epithelial cells were observed in the lumen of the ducts (Figure 2). Some of the ducts were seen cystic. The lumen of cystic ducts was full of neutrophilic leukocytes and secretory materials (Figure 2). Unlike other animals, in one animal from DMBA treated chow group demonstrated widespread hemorrhagic and necrotic areas in the tumor tissue. The oval and round shaped tumor cells with vesicular nuclei, varying in cytoplasm and nucleus sizes were observed (Figure 3). Sarcomatous changes in the tumoral area were noticed. Between the tumor cells, tumor type giant cells were observed. The same tumor cells were seen in the serosal layer of stomach, intestine, omentum, peritoneum, mesenterial lymph nodes, and spleen (Figure 3). HFCS, sucrose, and chow groups without DMBA showed no microscopic lesions in pancreas parenchyma.
Effect of the relative position of electrode and stellate ganglion during thermal radiofrequency ablation: a simulation study
Published in International Journal of Hyperthermia, 2021
Ramiro M. Irastorza, Maite Bovaira, Carles García-Vitoria, Víctor Muñoz, Enrique Berjano
Table 1 shows the physical characteristics considered for the tissues (obtained from the IT’IS Foundation database [23]) and RF electrode (taken from Pérez et al. [24]). Although no specific data are available on SG, the sensory ganglia are known to comprise the soma of sensory neurons, most of which appear pale and foamy after H&E staining due to the presence of myelinated nerve fibers. We considered that the SG could have homogeneous properties equivalent to brain tissue (specifically white matter) due to the presence of myelin. Since the ganglia are surrounded by a dense connective tissue capsule, we considered a 1 mm thickness connective tissue layer surrounding the SG. The properties for vertebrae were considered to be the mean values between the cortical and trabecular bone.
Related Knowledge Centers
- Bone
- Elastic Fiber
- Tendon
- Type I Collagen
- Connective Tissue
- Extracellular Matrix
- Fibroblast
- Ligament
- Skeletal Muscle
- Joint