Connective Tissue Components 3 major components of connective tissue: Extracellular fibers, Ground substance, Cells _______________ ________ = Extracellular fibers + Ground substance Matrix surrounds and separates the cells, providing important structural and nutritional support to them, allowing them to be farther apart than epithelial cells. 1. Ground substance Liquid, solid, or gel 2. Extracellular fibers Collagenous, Reticular, Elastic 3. Cells Fixed cells Fibroblasts, Adipocytes (fat cells), Reticular cells Wandering cells Mast cells, Leukocytes (white blood cells), Macrophages (fixed and wandering)

Connective Tissue Components: Ground Substance Composed of glycoproteins called __________________ (GAGs) hyaluronic acid Help to orient fiber formation in connective tissue. Is medium through which cells exchange nutrients and waste with the __________ ___________. Acts as shock absorbing cushion and helps to protect the delicate cells that it surrounds.

Fibers of Connective Tissue Collagenous: Most common fiber found in the body Strong, thick bands organized into bundles, composed of ____________ (structural protein). Resist ___________ forces, so they are found in tendons and ligaments that are continuously being pulled and stretched. wavy appearance when not stretched

Fibers of Connective Tissue Reticular: Composed of collagen Thin, delicate, ____________ into complicated networks. Form support around highly ____________ organs endocrine glands, lymph nodes, spleen, bone marrow, liver Elastic: Composed primarily of protein ________. Are branched and form networks Can stretch and contract. Found in tissues that stretch: vocal cords, lungs, skin, blood vessel walls.

Major Cell Types of Connective Tissue Fixed Cells: Remain in the connective tissue Produce and maintain the __________ Fibroblast: secrete fibers and ground substance of the matrix Can reproduce and are metabolically active. Name is based on _________. oChondroblast (cartilage), osteoblast (bone), etc. As the cells mature and the matrix is formed, cells become less active and suffix is changed to –_______. oChondrocyte, osteocyte, fibrocyte oCan revert back to blast if more matrix is needed.

Major Cell Types of Connective Tissue Fixed cells continued. Adipose cells/Adipocytes: Found throughout connective tissue Resemble fibroblasts early on, but as they age they become filled with lipid and swell. __________ gets pushed to the side Adipocytes clustered together form _________ tissue. found all over, but is prominent under the skin and in the abdomen Reticular Cells: Flat, star-shaped cells that form net-like connections with other cells Manufacture reticular fibers. Found in tissues of the immune system: lymph nodes, spleen, bone marrow

Major Cell Types of Connective Tissue Wandering Cells: Move in and out of connective tissue as needed. Help _______ and _________ the tissue Leukoctyes: (white blood cells) Found in blood, move into connective tissue during periods of infection/inflammation. Squeeze through the simple squamous epithelium of blood vessels (diapedesis) Important in immune function- engulf and digest invaders or produce antibodies against them Mast cells Carry histamine and heparin granules which initiate inflammatory response when released into tissue Usually found near blood vessels

Major Cell Types of Connective Tissue Wandering cells continued.. Macrophages: ___________ scavengers that may be either fixed or transient in connective tissue. Engulf microbes, dead cells and debris that are digested by the macrophage’s lysosomes drawn to sites of infection where they engulf invaders

Types of Connective Tissue Connective Tissue Proper: Loose Connective Tissue- supports structures that it surrounds Areolar, Adipose, Reticular Dense Connective Tissue- highly fibrous (collagen); little vascularization, ground substance, or cells; reinforces and binds structures Dense regular, Dense irregular, Elastic Specialized Connective Tissue: Cartilage Hyaline, Elastic, Fibrocartilage Bone Compact, Cancellous Blood

Loose Connective Tissue: Areolar Most common type of connective tissue Surrounds every organ Acts to support and cushion organs and other delicate structures. Predominant cell is ____________. Has “_______” spaces that are filled with fluid and viscous ground substance Filling of open spaces during trauma is called __________

Commonly known as ________ Found beneath skin, in bone marrow, in abdomen Energy storage, insulator, shock absorber Highly vascularized areolar tissue in which adipocytes predominate Cells __________/__________ based on amount of lipid being stored in them. May be classified as: White: Found throughout body Adipocytes change from resembling fibroblasts to filling with lipid Brown: Found in _________ and ____________ animals Site of heat production, temperature regulation Loose Connective Tissue: Adipose

Loose Connective Tissue: Reticular Framework for spleen, liver, lymph nodes, bone marrow Called _________ Contains only one type of fiber: ___________ Many fibroblasts

Dense Connective Tissue: Regular Makes up tendons and ligaments, fascia Tightly packed,__________ collagen fibers Little vascularization, slow to heal Little ground substance Fibroblasts line the collagen bundles Resists strong pulling forces in _____ direction.

Dense Connective Tissue: Irregular Found in dermis, organ capsules Forms tough capsule of joints. Collagen fibers in thicker bundles than those in dense regular connective tissue. Sheets of collagen in ___________ directions. Single sheet that can withstand pulling force from _______ different directions.

Dense Connective Tissue: Elastic Found in areas of the body that require ___________: Stomach, artery walls, bladder Beneath transitional epithelium in urinary tract High concentration of elastic fibers (more than collagen) that are extremely flexible.

Specialized Connective Tissue: Cartilage More rigid than dense connective tissue, more flexible than bone. Prevents bones from rubbing against each other. Does not contain nerves or blood vessels. Receives nutrition from ________________. Chondrocytes live in pockets called _______ 3 types of cartilage: Hyaline cartilage, Elastic Cartilage, Fibrocartilage

Specialized Connective Tissue: Types of Cartilage Hyaline Cartilage Most common type of cartilage found in body. Found as ____________ cartilage at end of long bones and joints and connects ribs to the sternum. Most rigid type of cartilage. Closely packed collagen fibers that make it tough but more flexible than bone. Elastic Cartilage Similar to hyaline cartilage but contains _________ fibers Give it flexibility, ability to bend Found in pinnae, epiglottis

Specialized Connective Tissue: Types of Cartilage Fibrocartilage Found between vertebrae, in pelvis, and in knee joint Able to handle compression, absorbs ______ Thick bundles of collagen, but few chondrocytes

Specialized Connective Tissue: Bone Also called osseous connective tissue Hardest and most rigid type of connective tissue Structure Matrix – collagen fibers and calcium salts ____________- tiny channels through matrix that allows osteocytes to communicate _________- chambers where osteocytes reside Blood Supply- __________ canals (channels in bone that carry blood supply and nerves) Cells- Osteoclasts and osteoblasts Remodel bone as needed

Specialized Connective Tissue: Blood Most atypical type of connective tissue. Carries nutrients and gases through the body Matrix: _______ (plasma) Fibers: few and only visible in a _____ Cells: Erythrocytes (______ blood cells) Leukocytes (________ blood cells) Thrombocytes (________)