BIO 230 Chapter 3 Connective Tissues
Supportive connective tissue BONE
- made of osteons Osteons consist of ~central canal ~osteocytes ~Lacunae ~Canaliculi ~Matrix of Lamellae
Connective Tissue Proper -Loose -Areolar
-"Packing materials" of the body -more ground substance, fewer fibers LOCATION -deep dermis -everywhere FUNCTION -fill spaces between organs, provides cushioning -support epithelia -anchor blood vessels and nerves -stores lipids
Fibrocytes
-active fibroblasts -differentiate from fibroblasts -have the ablity to turn back into fibroblasts -second most aboundent fixed cell
Classification of Connective Tissue
-connective tissue proper -fluid connective tissue -supporting connective tissue
Adipocytes
-contain a single lipid droplet -aka fat or adipose cells
Fluid Connective Tissue Blood
-distinct cell types in a fluid matrix with dissolved proteins -plasma~watery matrix ~red blood cells ~white blood celss ~proteins ~platelets
Fixed Macrophages (connective tissue proper)
-engulf damaged cells, dead cells and pathogens -upon stimulation release chemicals that attract wandering cells -aka resident or resting macrophages
Functions of Connective Tissue
-establish structural framework for the body -transport fluid and dissolved materials -protect delicate organs -support, surround and interconnect with other tissue types -store energy; usually lipids -defend the body from invasion by microorganisms
Connective Tissue Proper Wandering Cells
-free macrophages -mast cells -lymphocytes -neutrophils -eosinophils
Reside in Mast Cells
-histamine and heparin -these chemicals are released after injury or infection and stimulate local inflammation
Free Macrophages (wandering cells)
-large phagocytic cells atht wander rapidly through the connective tissues -aka wandering macrophages or elicited macrophages
Fibroblasts
-manufactures and secretes protien subunits -secrete hyaluronan (makes ground substane viscous) -most abundent fixed cell -the only cell that is always present
Connective Tissue Proper Fixed Cells
-mesenchymal (stem) cells -fibroblasts -fibrocytes -fixed macrophages -adipocytes -melanoctyes
Lymphocytes
-migrate throughout the body -mulitple whenever tissue damage occurs -may develope into plasma cells
Connective Tissue Proper Dense Irregular
-more fibers(mostly collagen); less ground substance -resist distortion -resists tension from many directions LOCATION -deep dermis of skin -capsules of visceral organs
Neutrophils and Eosinophils
-phagocytic blood cells that are smaller then monocytes -small number migrate through connective tissue -attracted to an area when stimulated by macrophages and mast cells chemical release
Plasma Cells
-produce antibodies
Mast Cells
-small, mobile connective tissue cells often found near blood vessels
Components of Connective Tissue
-specialized cells -extracellular protein fibers -ground substance
Melanocytes
-synthesize and store the brown pigment melanin
Connective Tissue Fluid Lymph
-white blood cells -dissolved proteins -lymph fluid
Appositional Growth
1) Cells in cellular layer of perichondrium differentiate into condroblasts 2)Immature chloroplasts secrete new matrix 3) As Matrix englarges, more chondroblasts are incorporated. Cells are replaced by stem cells in perichondrium
Interstitial Growth
1)Chondocyte undergoes division within a lacuna surrounded by cartilage matrix 2) Daughter cells secrete additional matrix as they move apart expanding cartilage from within
Supporting Connective Tissue
CARTILAGE -Gel matrix made of chondroitin sulfate -cells reside in lacunae BONE -solid matrix made of calcium phosphate -Cells reside in lacunae
Elastic Cartilage Tissue
LOCATION -Auricle of ear -Epiglottis -Auditory Tube FUNCTION flexible support MATRIX gel
Hyaline Cartilage Tissue
LOCATION -between ribs and sternum -within joints of elbows and knee -Tracheal cartilage rings FUNCTION -flexible support -reduces friction MATRIX gel
Connective Tissue Proper- Loose- Adipose
LOCATION -deep to skin -buttocks -breasts FUNCTIONS -provides padding cushions and shock -insulates -stores energy
Fibrous Cartilage Tissue
LOCATION -pads within knee joins -pads between spinal vertebrae -Pubic symphysis FUNCTION -resists compression -absorbs shock MATRIX gel
Matrix
Mix of extracellular fibers and ground substance that surrounds cells in connective tissues
Antibodies
Specialized proteins that aid in destroying disease
Connective Tissue Proper Dense- Regular
Tough, Strong, and durable -more fibers(mostly collagen); less ground surface -resist tension -interconnect bones tendons skeletal muscle to bone ligaments bone to bone
Monocytes
free macrophages in the blood
Wandering Cells
help defend and repair damaged tissues
Mesenchymal cells
stem cells that respond to local injury or infection