skeletal system

• long bones • short bones • flat bones • irregular bones • sesamoid bones

• long + cylindric; • support weight, allow movement • femur, humerus, tibia

• cube shaped • good for stability not movement • carpals (wrist), tarsals (ankles)

• thin, flat, usually curved • protect organs • ribs, skull, sternum, scapula

• oddly shaped, comoplex • dont fit any other category • skull bones, many facial bones, vertebrae

• found in tendons • patella (kneecap)

• dense outer layer of bone • contains 1. osteons (basic unit of compact bone) 2. haversean canal (center canal for blood vessels and nerves ) 3. Lamellae (concentric rings of bones) 4. Lacunae (small spaces housing osteocytes) 5. Canaliculi (tiny channels connecting cells) 6. Volkmans canals (carry vessels horizontally)

• found inside bone • contains trabeculae (mesh like structures) • lighter and porous • contains red bone marrow (blood cell production) • thing of it like a strong honeycomb

• outer covering of the bone • contains nerves, blood vessels • helps with bone growth and repair

• made of thin interconnected plates called trabeculae • no central canals unlike compact bone • contains osteocytes in little spaces called caniculi

• inorganic part: calcium phosphate, calcium carbonate - hardness and strength • organic part: mainly collagen + GAGS + non collagen proteins - flexibility

• come from osteoprogenitor cells • build bone by secreting collagen + bone matrix

• mature bone cells trapped in lacunae • maintain bone tissue • recycle minerals

• formed from monocytes ( a type of WBC) • break down bone (resorption) using acid + enzymes • release calcium into the blood

• fibrous joints • cartilaginous joints • synovial joints

• held together by fibrous connective tissue • no movement or very little • suture: immovable, skull • gomphosis: immovable, teeth in sockets • syndesmosis: slightly moveable, distal tibia fibula • no joint cavities

• bones held by cartilage • synchondrosis: hyaline cartilage, almost no movement (first rib - sternum) • symphysis: fibrocartilage, slightly movable (pubic symphysis, intervertebral discs) • limited movement

• most common joint type • have a joint cavity with synovial fluid (reduces friction, allows smooth movement) • pivot, hinge, saddle, gliding, condyloid, ball and socket

• rotation • neck

• flex/extend • knee, elbow

• back and fourth + side to side • thumb

• sliding • carpals

• flex, extend, side to side • Oval surface fits into a shallow cavity • knuckes

• most movement • hip, shoulder