Chapter 5 (2)

• Connective tissues are where cells occupy less space than the matrix. They support, connect, and protect organs.
• Cells called fibroblasts are responsible for producing connective tissues. There are 4 types of connective tissues: Loose connective tissue, Dense connective tissue, cartilage(avascular meaning no blood), and other tissues.
• There are three types of loose connective tissues: Areolar(Loosely organized fibers that bind cells and fibers together but also allow movement and have an abundance of blood vessels), Adipose(fat tissue that stores nutrients, insulates, gives heat, and protects organs.), and Reticular(looks like dense webbing but allows for structure and flow of substances)
• There are two types of fat in adipose tissue; brown fat and white fat. Brown is in children and helps provide heat while white is the one in adults.
• Reticular tissue forms supportive stroma (framework) for lymphatic organs and is found in lymph nodes, spleen, thymus, and bone marrow.
• There are 2 types of dense connective tissue: Regular and irregular. Regular dense connective tissue makes up the tendon(muscle to bone) and ligaments(bone to bone) while irregular makes up the dermis.
• There are 3 types of cartilage: Hyaline(the most abundant cartilage in the body and provides support even as it is pliable), Elastic(provides support while still able to stretch), and Fibrocartilage (provides strong support and handles heavy pressure)
• Chondroblasts are cartilage cells that produce the matrix that will trap them. Chondrocytes are cartilage cells that are trapped in lacunae (cavities). The perichondrium is the sheath of dense irregular connective tissue that surrounds elastic and most hyaline cartilage.
• Cartilage is avascular and heals slowly.
• Hyaline cartilage has a clear, glassy appearance because of collagen fibers. Elastic cartilage contains an abundance of elastic fibers and is covered with perichondrium. Fibrocartilage contains large, coarse bundles of collagen fibers and resists compression and absorbs shock.
• There are two types of other tissues: Bone(needed for support and has hard tissue of collagen fibers and calcium surrounding osteocytes) and blood(has red blood cells, white blood cells, platelets, and plasma)
• Bone is obviously calcified and there are two types of bone: Spongey bone(delicate and porous in appearance) and compact bone(tough, hard, and dense with no visible spaces)
• Osteon is the central canal and its surrounding lamellae. Osteocytes are mature bone cells within lacunae. Canaliculi are delicate canals radiating from each lacuna to its neighbors, allowing osteocytes to contact each other. And Periosteum are tough fibrous connective tissue that cover the whole bone.
• Blood is the only liquid connective tissue in the body. Like ever. It transports cells and dissolved matter from place to place. Plasma is blood’s ground substance and Erythrocytes(red blood cells), Leukocytes(white blood cells), and Platelets(cell fragments involved in blood clotting) are its cellular components.
• Erythrocytes are red blood cells (RBCs) that transport O2 and CO2. Leukocytes are white blood cells (WBCs) that defend against infection and disease. Platelets are cell fragments involved in clotting.