supporting CT

supporting CT

includes cartilage and bone

cartilage and types of it

provides shock absorption and protection, matrix is a firm gel that contains polysaccharide derivatives called chondroitin sulfates, cells in matrix are chondrocytes found in lacunae, avascular, has chondroblasts that secrete protein fibers and ground substance of matrix

the perichondrium surrounds cartilage that has outer, fibrous layer (support and protection) and inner, cellular layer (growth and maintenance

types are hyaline, elastic, fibrocartilage

hyaline

most common, matrix contains closely packed collagen fibers

locations - between tips of ribs and bones of sternum, covers bone surfaces at synovial joints, supports larynx, trachea, bronchi, forms part of nasal septum

functions - provides stiff but somewhat flexible support, reduces friction between bony surfaces

elastic

matrix contains elastic fibers

locations - auricle of external ear, epiglottis, auditory canal, cuneiform cartilages of larynx

functions - provides support but tolerates distortion without damage and returns to original shape

fibrocartilage

matrix abundant of densely interwoven collagen fibers

locations - pads within knee join, between pubic bones of pelvis, intervertebral discs

functions - resists compression, prevents bone to bone contact, limits movement

cartilage grows by which two mechanisms

interstitial growth - enlarges cartilage from within

appositional growth - add to outer surface of cartilage

BONE!!

also known as osseous tissue, matrix is calcified (mixture of calcium salts), and contains collagen fibers

periosteum membrane surrounds a bone and contains osteoblasts (function in bone growth and repair), they secrete organic components of matrix then become trapped in lacunae, then mature into osteocytes, central canal contains blood vessels, surrounded by rings of matrix called concentric lamellae.

canaliculi (small channels in lamellae) provide passageways for diffusion of nutrients and wastes