4th Lecture Connective Tissue Part 1 PDF

Connective Tissue C.T Part 1 CLS 272 Descriptive Histology 4th Lecture Objectives  By the end of this lecture, the student should be able to: 1. Enumerate the general characteristics of C.T. 2. Understand the functions of C.T. 3. Classify C.T. proper (C.T.P.) 4. Describe the s...

Connective Tissue C.T Part 1 CLS 272 Descriptive Histology 4th Lecture Objectives  By the end of this lecture, the student should be able to: 1. Enumerate the general characteristics of C.T. 2. Understand the functions of C.T. 3. Classify C.T. proper (C.T.P.) 4. Describe the structure (components) and distribution of different types of C.T.P. Connective tissue The term connective tissues is applied to tissues which provide  General structure,  Mechanical strength,  Space filling (sculpting body shape)  Physical and metabolic support for more specialized tissues. General characteristics of connective tissue  Connective tissue is the most abundant and widely distributed tissue in the body  Provides support, binds together, and protects tissues and organs of the body.  Connective tissues tend to be very vascular (have a rich blood supply).  Tensile strength to resist pulling , stretching and tearing  Elasticity to facilitate return to original shape after mechanical distortion  Volume Functions of Connective Tissue Most connective tissue is serving several vital functions including:  Transport of nutrients and metabolites,  Immunological defense,  Mechanical support. After injury, connective tissue is instrumental in tissue repair, specifically in scar formation. Additional functions found in specialized sites include  Reserve energy storage (as fat),  Heat generation (brown fat),  Hemopoiesis (blood cell formation). Connective tissue components Connective tissue consists of three main components:  Cells,  Protein fibers, Extra Cellular Matrix  Ground substance. ECM  Together the fibers and ground substance make up the extracellular matrix.  Whereas the other tissue types (epithelium, muscle, and nervous tissue) are largely made up of cells, the extracellular matrix is the major component of most connective tissue  Component of Connective Tissue Cells Extra Cellular Matrix Fixed Wondering Fibres Ground Substance Fibroblasts Macrophage Collagen Adipocytes Mast Cell Elastic GAG/MGP Proteoglycan Persistent Plasma Cell Reticular Mesenchymal Cell Pigment Cell Eosinophil Neutrophil Extra Cellular Matrix (ECM) Extra Cellular Matrix composed of different combinations of protein fibers (collagen, elastic, and reticular fibers) and ground substance which is a complex of anionic, hydrophilic, macromolecules include the following Glycosaminoglycans (or GAGs), Proteoglycans, and Multiadhesive glycoproteins. Embryonic Mesenchyme. Cells matrix Ground substance  Colorless and transparent/semi solid gel.  Fills the space between cells and fibers of the CT  It primarily consists of protein and carbohydrate molecules and variable amounts of water.  Also present in the ground substance are adhesion proteins such as fibronectin,laminin and thrombospondin  Proper Connective tissue Supporting Connective with special Connective Tissue Tissue properties Cartilage Loose Adipose tissue Bone Dense - Regular & Irregular Elastic tissue Hematopoietic Mucous tissue Connective tissue proper  Connective tissue proper includes those types of connective tissues that exhibit a variable mixture of both connective tissue cell types and extracellular protein fibers suspended within a viscous ground substance.  It generally has higher protein fiber content  These connective tissue types differ with respect to their numbers and types of cells and the relative properties and proportions of their fibers and ground substance.  Its main function is to bind cells and tissues into organ and organ system. A) Loose connective tissue (low in Fiber and high in ground substance Call also Areolar CT  Structure  composed of a jumble of fibers and cells.  Gel-like matrix  The cells (dark spots within the tissue) are called fibroblasts (fibro= fiber, blast= to make or create).  These are the cells responsible for secreting the fibers.  The larger fibers (typically pink) are called collagen fibers.  The small black fibers are elastic fibers.  Collectively, the fibers and the rest of the substance surrounding the cells would be referred to as the matrix. Areolar CT  Functions Wrap and cushions organs Hold tissue fluid  Location subcutaneous layer and mucous membranes (Lamina propria), and around blood vessels, nerves and organs Loose Connective tissue consists of 1. Fibers  Collagen  Elastin  Reticular 2. Cells  Fibroblasts  Plasma Cells  Adipocytes  Mast Cells, and  Macrophages Loose Connective Tissue Adipose Tissue Adipose Tissue is a loose fibrous connective tissue that is packed with many fat cells (called "adipocytes").  Locations of adipose tissue include: Subcutaneous layer deep to skin; Around the heart; Around the kidneys; Yellow marrow of the long bones Padding around the joints Inside the eye-socket, posterior to the eyeball. The Functions of adipose tissue  Adipose tissue acts as an insulating layer, helping to reduce heat loss through the skin.  It also has a protective function, providing mechanical protection ("padding") and support around some of the major organs, e.g. kidneys.  Adipose tissue is also a means of energy storage. Food that is excess to requirements is converted into fat and stored within adipose tissue in the body. nuclei of adipocytes Adipocytes in growing stage B) Dense Connective Tissue Dense Connective Tissue:  Dense regular connective tissue Tendons and ligaments  Dense irregular connective tissue Dermis of skin, submucosa of digestive tract Ligaments and Tendon  Tendon is a connective tissue that connects muscle to bone. The tendon’s job is to enable movement. They are resistant to tearing but not very stretchy.  Ligaments are connective tissues connecting one bone to another bone. Ligaments are composed of a lot of strong collagen fibres. In addition, ligaments look like cords and come in various forms in the body. Difference Between Tendon And Ligament Tendon Ligament Connects the skeletal muscles to the bones. Connects bones to bones Tough and inelastic structure Highly elastic and flexible Connect the ends of the muscles to the bones Connects the end of the bones at joints There is usually one tendon per muscle. Each joint contains many ligaments Proteoglycan content is low Proteoglycan content is high The colour of the tendon is white The ligament is yellow in colour Fibroblasts lie in a continuous row Fibroblasts in ligament are scattered The fibres are compact, and Present They are not arranged in similar bundles but compactly packed They are classified into three types: Articular ligaments, No such classification or types Remnant ligaments, and Peritoneal ligaments. Blood supply is poor Blood supply is just as poor Dense regular Connective Tissue Dense Irregular Connective Tissue Extra References Histology Connective Tissues of the Body Connective Tissue – Histology | Lecturio