Lecture 8 Flashcards
(31 cards)
Chondroblasts
Cartialge forming cells
Chondocytes
Cartilage- maintenance cells
ECM of cartilage
Collagen (mostly type 2)
Amourphous ground substance (proteoglycans)
Perichondrium
outer fibrous layer surrounding mass of cartilage (contains fibroblasts)
Inner chondrogenic layer
Gives rise to chondoblasts, which become chondrocytes
Chondrocytes are involved in
thep roduction of colalgen and proteoglycans in the matrix
Cartilage characteristics
Covered in perichondrium membrane
Avascular - slow to heal
Formed by chondoblasts, maintained by chondrocytes
Lacunae are pockets where chondroblasts and chondrocytes are found
Hyaline Cartilage
Most common type
Type 2 collagen
Mostly involved in support
Associated with highly movable joints
Appositional growth
Growth that occurs by adding more material to the outside of existing material
Interstitial growth
Growth that occurs by inserting additional material into the existing substance
Articular cartilage covering the ends of long bones does not possess a perichondrium, therefore
Cannot be repaired or replaced if it is damaged
Deteriorates due to aging or pathological processes
Cartilage tends to develop in regions of low
oxygen
Hyaline cartilage can be found in
Ears, nose Moveable joint surfaces Larynx Tracheal Bronchial Articular ends of bones
Elastic cartilage characteristics
Adds elastic fibers to matrix Surrounded by perichondrium membrane Yellow Type 2 collagen Auricle (pinna) of ear epiglottis
Fibrocartilage characteristics
Increased collagen in matrix Less cells, more fibrous than hyaline NOT SURROUNDED BY PERICHONDRIUM Type 1 collagen Intervertebral disks, pubic pymphysis insertion of some tendons and ligaments
Bone tissue characteristics
Canalicular system (canals)
Highly vascular, found in close proximity to capillaries
Continually reabsorbed, reconstructed and remodeled
Formed by osteoblasts which become osteocytes
medullary cavity
periosteum membrane
Volkmann canals
Extend from exterior of the bone to the bone matrix - perpendicular to surface
Haversion canals
Extend from volkmann canals and run parallel to the long axis of the bone
Canaliculi
Tiny canals that interconnect the lacunae with each other and with the haversion canals
Bones grow by
appositional growth of hyaline cartilage, however bones can only grow interstitially
Periosteum
Serves for attachment of muscles, tendons, ligaments
Does not cover articular surface
Medullary cavity
Most bones contain a cavity filled with red or yellow marrow - red marrow contains hematopoietic tissue. yellow has fat in it
Types of bone
Woven
Compact
Spongy
Compact bone
Lacks cavities
Haversion system (concentric lamellae)
Osteocytes are found between lamellae within lacunae