Connective Tissue 2023-1.ppsx

ConnectiveTissues CHAPTER 5 Connective Tissue • • • • • • Bone Blood Cartilage Fat Ligament Tendon OBJECTIVES:  List & describe the components of connective tissues  Differentiate between areolar, adipose & reticular connective tissues  Differentiate between dense regular, dense irregular &...

ConnectiveTissues CHAPTER 5 Connective Tissue • • • • • • Bone Blood Cartilage Fat Ligament Tendon OBJECTIVES:  List & describe the components of connective tissues  Differentiate between areolar, adipose & reticular connective tissues  Differentiate between dense regular, dense irregular & elastic connective tissues  Differentiate between hyaline cartilage, elastic cartilage & fibrocartilage  Describe the structure, functions & locations in the body of the 4 types of membranes Connective Tissue Diverse forms give rise to wide range of functions: • Forms structural & metabolic connections between other tissues • Provides frame supporting the body • Forms protective sheath around organs • Helps insulate the body & acts as a reservoir for energy • Plays role in healing & in control of invading microbes Connective Tissue Composition • Cells • Extracellular fibers • Ground substance Extracellullar Matrix Ground substance – amorphous, homogeneous material (ex) = Glycosaminoglycans (GAGs)  Orientation of fiber formation  Medium for nutrient/waste exchange  Shock-absorbing cushion  Obstacle for invading microbes Fibers • Collagenous (white fibers) tensile strength • Reticular – support network • Elastic (yellow fibers) - stretch & contract Cells Fixed – production & maintenance of extracellular matrix • Fibroblast – secrete collagen & ground substance  Chondroblasts - > cartilage  Osteoblasts -> bone • Adipocyte –> adipose tissue (fat) • Reticular cells – involved in production of reticular fibers & in the immune response (found in lymph nodes, spleen, bone marrow) Cells Transient (Wandering) • Leukocytes (WBCs) – move into tissues via diapedesis in response to infection  Phagocytize microbes  Produce antibodies • Mast Cells – release granules containing histamine & heparin -> initiate an inflammatory response • Macrophages – phagocytosis & lysosomal digestion of microbes & cellular debris Types of Connective Tissue Connective Tissue Proper • Loose Connective Tissue Areolar – most common; fibroblasts, hyaluronic acid; support & cushion; moderately elastic but tears easily Adipose – adipocytes; energy source, shock absorber, thermal insulator; highly vascularized Reticular – fibroblasts, reticular fibers (stroma); framework for certain organs Connective Tissue Proper • Dense Fibrous Connective Tissue (DFCT)  Dense Regular – tightly packed, parallel collagen fibers; tensile strength in one direction; white; avascular & slow to heal  Tendons, ligaments, fascia  Dense Irregular – thicker collagen fiber bundles arranged randomly for strength in many directions  Dermis, joint & organ capsules  Elastic – parallel elastic fibers or interwoven w/ fibroblasts & collagen  Ligaments, IV discs, vessel walls, stomach, bronchi, bladder, heart Types of Connective Tissue Specialized • Cartilage – chondrocytes, GAGs (hyaluronic acid, chondroitin sulfate), chondronectin, fluid; gets nutrients from perichondrium  Hyaline – most common; most rigid; articular cartilage, trachea, costochondral junctions  Elastic – most flexible; epiglottis, pinnae  Fibrocartilage – no perichondrium; w/ hyaline cartilage & DCT; IV discs, pelvis, knee joint • Bone (osseous connective tissue) – osteoblasts, osteoclasts, collagen & calcium salts; well vascularized; supports & protects; calcium reserve • Blood – cells, proteins, plasma Membranes • Thin, protective layers that line body cavities, separate organs and cover surfaces • Composed of epithelial sheet bound to underlying layer of connective tissue proper • 4 common types: Mucous Serous Cutaneous Synovial Mucous Membranes • Line organs having connections to the outside environment (digestive, respiratory, reproductive, urinary tracts) • Either stratified squamous or simple columnar epithelial layer covering layer of loose connective tissue = lamina propria • Submucosa = connective tissue layer under lp that connects mucosa to the underlying structures • Secretes mucus (water, electrolytes & mucin)  Decreases friction  Traps pathogens & foreign particles • Some also have absorprtive properties Serous Membranes • Line body cavity walls (parietal layer) and cover outer surfaces of organs (visceral layer) • Composed of a continuous sheet doubled to form 2 layers with a potential space between them • Simple squamous epithelium bound to underlying layer of loose connective tissue • Produces thin, watery fluid = transudate (no mucin) that serves to reduce friction between organs & between organs & body cavity wall Other Membranes • Cutaneous = integument = skin  Epithelium = epidermis - attached to = dermis • Synovial - lines joint cavities  Composed entirely of loose connective tissue & adipose covered by a layer of collagen fibers & fibroblasts  No epithelial layer  Produces synovial fluid