Loose CT (or areolar tissue) is the most widespread CT of the body. Furthermore, it provides protection against infection, gives passage to nerve and blood vessels through other tissues and fixes organs together. The cytoplasm is composed of thin, pale-staining and flattened processes extending into the matrix. All of these characteristics give LCT a delicate and flexible consistency that is not very resistant to stress. Introduction to the musculoskeletal system. The extent of invasion of the lamina propria is a feature used to determine the stage and prognosis of several carcinoma types. Connective (supporting) tissue is a voluminous, strong, yet elastic type of tissue with significant roles in the human body. They are a loose array of random fibers that has a wide variety of cell type. There is a well-developed network of collagen reticular fibers surrounding the fat cells, elastic fibers are almost absent. In addition to the ECM, connective tissue also has a cellular component. They are stained by eosin, although not readily, so they cannot be easily distinguished from collagen fibers. Supportive connective tissue—bone and cartilage—provide structure and strength to the body and protect soft tissues. Lying free within the stroma close to the pupil margin is the sphincter pupillae muscle, a circumferential ring of smooth muscle fibres about 1 mm in width. Over time, remodelling takes place to maximise collagen strength and reduce the numbers of capillary vessels. A connective tissue has two elements and these are the cell and the matrix. II. Areolar Connective Tissue Areolar connective tissue A variety of connective tissue consisting of a gel-like matrix combining strands of protein fibers (collagen and elastin) and so cells as fibroblasts, mast cells, macrophages, and fat cells. Loose connective tissue (structure and Location) (3) Fibers loosely intertwined between cells consists of Areolar tissue Adipose tissue Reticular tissue. It forms a supporting frame, called the stroma, and the outer covering of the organs, called the dermis. The most abundant fibers of connective tissues are: Collagen. In association with ground substance, the loose network of elastin fibers and collagen fibers, both of which branch freely, provides moderate amounts of elasticity and strength in tissues and organs. There are three major categories of dense connective tissue: regular, irregular, and elastic. II- Connective tissue proper 1- Loose areolar CT. Usually, only the nuclei are visible after hematoxylin and eosin (H&E) staining, which appear condensed, elongated and disclike. Dense Connective Tissue: Dense connective tissue produces tendon and ligaments by forming strong, rope-like structures. Loose connective tissue is found around every blood vessel, helping to keep the vessel in place. Loose connective tissue is rich in blood and lymph because of the numerous vessels that run through it. It provides mechanical strength, together with physical and metabolic support to all the other types of tissues. T issue-resident macrophages (histiocytes) are derived from monocytes that mature after migrating into connective tissue. Part 4 in an 8 part lecture on Histology in a flipped Human Anatomy course taught by Wendy Riggs. Blood. General connective tissue is either loose, or dense, depending on the arrangement of the fibres. So you may try to carefully prop up the lumber on the foundation. Loose connective tissue is the most abundant type. Movement. Whereas, dense connective tissue is less abundant, and it consists of many fibres in the matrix. The areolar tissue is found beneath the dermis layer and is also underneath the epithelial tissue of all the body systems that have external openings. There are seven types of connective tissues found in the body of people. loose arrangement of fibres (elastin, collagen, reticular), cells (fibroblasts, macrophages, lymphocytes) loose areola connective function. Hyaluronan protects the synovium from being locked and pinched in between the cartilage. Loose connective tissue holds organs in place and attaches epithelial tissue to other underlying tissues. Ground substance occupies the greatest proportion in LCT, being responsible for the flexible consistency of this tissue type. Adrian Rad BSc (Hons) Connective tissue includes several types of fibrous tissue that vary only in their density and cellularity, as well as the more … The cytoplasmic processes of different myofibroblasts can contact each other. These vasoactive mediators are important in mounting an immune response, but they can also cause the typical symptoms of allergic reactions. At the end of the process, they are replaced by stronger type I collagen fibers. 1.7). The ultrastructure of these cells reveals the presence of vimentin filaments in the portion between the contained lipid and surrounding cytoplasm. Once straightened, they resist further stretching. It is technically composed of roughly only 80% fat. Kenhub. The cells sit in a matrix made up of glycoproteins, fibrous proteins and glycosoaminoglycans , which have been secreted by the fibroblasts, and the … Carcinoma is a type of cancer originating from the epithelium. During periods of wound repair or active growth, fibroblasts become activated and produce ECM. It generally connects and support various tissues and organs and helps them to resist strain and displacement. The word "recticulum" means (net or network). ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. URL: https://www.sciencedirect.com/science/article/pii/B9780444536327010029, URL: https://www.sciencedirect.com/science/article/pii/B9780702044304000014, URL: https://www.sciencedirect.com/science/article/pii/B9780323341264000323, URL: https://www.sciencedirect.com/science/article/pii/B978141603779810017X, URL: https://www.sciencedirect.com/science/article/pii/B9780702068645000128, URL: https://www.sciencedirect.com/science/article/pii/B9780128001097000200, URL: https://www.sciencedirect.com/science/article/pii/B9780702055546000010, URL: https://www.sciencedirect.com/science/article/pii/B9780128041826000137, Carla Stecco MD, ... Raffaele De Caro MD, in, Functional Atlas of the Human Fascial System, Pain Procedures in Clinical Practice (Third Edition), Connective and other mesenchymal tissues with their stains, Bancroft's Theory and Practice of Histological Techniques (Eighth Edition), Anne Hoffmann, Elizabeth Berry-Kravis, in, Neuronal and Synaptic Dysfunction in Autism Spectrum Disorder and Intellectual Disability, John V. Forrester MB ChB MD FRCS(Ed) FRCP(Glasg) (Hon) FRCOphth(Hon) FMedSci FRSE FARVO, ... Eric Pearlman BSc PhD, in, Genetics of Bone Biology and Skeletal Disease (Second Edition), Journal of Oral and Maxillofacial Surgery, Journal of Plastic, Reconstructive & Aesthetic Surgery. It is the initial site where antigens, bacteria and other agents that have breached an epithelial surface can be destroyed. Each monomer consists of three polypeptide chains, called alpha chains, bound into a helical protein. Definition. They mature upon entering connective tissue and develop their characteristic granules. Loose (areolar connective tissue) is the most abundant form of collagenous connective tissue. Many of the macrophages are heavily pigmented, and a subgroup may form large ovoid ‘clump cells’ (of Koganei), which tend to accumulate near the iris root and sphincter pupillae muscle (Fig. It consists of proteoglycans, which are composed of complex carbohydrates called glycosaminoglycan molecules (GAGs) and glycoproteins. The loose connective tissue underlying the epithelium in the gastrointestinal tract is a good example of this heterogeneity (Fig. It provides structural integrity, serves as a matrix for intercellular communication, and is involved in biochemical and bioelectric signaling. GAGs attract many water molecules due to their highly negatively charged nature, giving the ground substance a gel like consistency. 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