Loose fibrous connective tissue fibroblasts and myofibroblasts begin secreting new ECM, filling the damaged area with fibro-collagenous material. Their nuclei are large with a prominent nucleolus. Composition[ edit ] Schematic representation of the composition of loose connective tissue It is a pliable, mesh-like tissue with a fluid matrix and functions to cushion and protect body organs.
The cytoplasmic processes of different myofibroblasts can contact each other. The ultrastructure of these cells reveals the presence of vimentin filaments in the portion between the contained lipid and surrounding cytoplasm.
Due to its position, LCT is a major site of inflammatory and immune reactions. Because of the abundance of open, fluid-filled space, leukocytes can move about freely in areolar tissue and can easily find and destroy pathogens.
Its fibers run in random directions and are mostly collagenous, but elastic and reticular fibers are also present. More generally, it is found at the same locations throughout the body as areolar connective tissue.
Over time, remodelling takes place to maximise collagen strength and reduce the numbers of capillary vessels. Almost all cells obtain their nutrients from and release their wastes into areolar connective tissue.
Internally, it is located around organs and peritoneal structures. It may likewise be present in the mediastinal extremities. Similar classifications are carried out for gastric and colon cancers, using the lamina propria as a reference point.
Adipose tissue forms a thick layer under the skinaround the kidneys and in the buttocks. Transient macrophages enter connective tissue in response to tissue injury and inflammation. Clinical considerations Fibrosis and scarring Following cellular and tissue damage, an inflammatory reaction ensues that eliminates the damaging agent and clears away the dead tissue.
They actually consist of collagen fibrils, which are composed of type III collagen. The nucleus also appears to be undulated.
LCT is also well-vascularized to facilitate effective immune cell migration. They give rise to fibroblasts and new blood vessels.
They join connective tissues to other tissues. Fibronectin controls the deposition and orientation of collagen fibers in the ECM. Reticular fibers can be made visible by the periodic-acid Schiff reaction or silver staining procedures, giving them a black and threadlike appearance. They also help in linking the ECM to the surface of cells.
It is also found in the mesentery which is surrounding the intestine. This is where potential pathogens that have breached the skin are challenged and hopefully destroyed by the immune system. The cytoplasm is filled with basophilic granules, together with small amounts of rER, mitochondria and Golgi apparatus.
The extent of invasion of the lamina propria is a feature used to determine the stage and prognosis of several carcinoma types. They are lineage specific cells and occupy specific sites, called niches.
The collagen fibrils constituting reticular fibers are narrower, do not bundle into thick fibers, are Loose fibrous connective tissue branched and contain more sugar groups in comparison to the typical type I collagen.
Further repair begins with proliferation and differentiation of mesenchymal cells from the periphery of normal tissue into fibroblasts and myofibroblasts. Each monomer consists of three polypeptide chains, called alpha chains, bound into a helical protein. The cytoplasmic surface is folded and has many finger like projections called pseudopodia.
As a result, these networks are primarily located at sites of wound healing and scar tissue formation, where new ECM is synthesized by fibroblasts. Elastic fibers The flexibility of LCT is also due to elastic fibers, not just due to the high content of ground substance.
They synthesize both types of fibers and the complex carbohydrates of the ground substance. This process can result in normal functioning, but more often than not, the tissue is not completely restored. Fibroblasts are widely dispersed in this tissue; they are irregular branching cells that secrete strong fibrous proteins and proteoglycans as an extracellular matrix.
They are stained by eosin, although not readily, so they cannot be easily distinguished from collagen fibers. Adipocytes are large and usually spherical cells containing a single and large lipid droplet in the centre of the cytoplasm.
The granules appear membrane bound in TEM. A text and atlas: There are three main types:In vertebrates, the most common type of connective tissue is loose connective tissue.
It holds organs in place and attaches epithelial tissue to other underlying tissues. Loose connective tissue is named so because of the "weave" and type of its constituent fibers. Loose connective tissue: Loose connective tissue is composed of loosely-woven collagen and elastic fibers.
The fibers and other components of the connective tissue matrix are secreted by fibroblasts. The fibers and other components of the connective tissue matrix are secreted by fibroblasts. Start studying Loose Connective Tissue Types, Location, and Function.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. Dense connective tissue contains more collagen fibers than does loose connective tissue.
As a consequence, it displays greater resistance to stretching. There are three major categories of dense connective tissue: regular, irregular, and elastic. The proportions and organizations of the fibers result in several types of connective tissues, one being loose connective tissue.
This article will firstly describe some general aspects of connective tissue and then it will zoom into the key components of loose connective tissue. One of the specific types of connective tissue is fibrous connective tissue, or FCT.
This high-strength, slightly stretchy tissue consists mainly of .Download