Section 11

• contain no blood vessels or nerves
• surrounded by the perichondrium (dense irregular connective tissue)

hyaline, elastic, and fibrocartilage

support, protection, movement, mineral storage, blood cell formation

dense outer layer

• cancellous
• honeycomb of trabeculae with red bone marrow

• longer than wide
• humerus

• thin flattened, and a bit curved
• sternum

flat, long, short, and irregular

outside of

one end of a long bone (head)

over joint surfaces acts as friction reducer and shock absorber

marrow cavity

how bones "growth"

vascularized

periosteum and endosteum

double layered protective membrane

• part of periosteum membrane
• where osteoblast and osteoclast are
• create bone
• out layer

• delicate membrane covering internal surfaces of bone
• the remodel bones
• innerlayer

• in infants-medullary cavity anf all areas of spongy bone
• in adults- flat bones, vertabrae, sternum, pelvis, and the head of femur and humerus

red marraow

mature bone cells

small cavities that contain osteocytes

interconnect lacunae to each other and the central canal

the structural single unit of compact bone

tubes composed mainly of collagen

central channel containing blood vessels and nerves

channels lying at right angles to the central canal

boneforming cells

large cells that resorb or break down bone matrix from fused monocytes

distinctive extra cellular matrix that iniciates bone formation

mineral slats

the process of bone tissue formation (fully mineralized) hard

blood vessels

bone develops from a fibrous membrane (flat cranial bones)

bone forms by replacing hyaline cartilage (long bones)

• (to make flat bones)
• 1. develop ossification center
• 2. calcification; formation of bone spicules
• 3. formation of woven bone (trabeculae)
• 4. development of periosteum and compact bone collar

• begins in the second month
• process of making long bones
• uses hyaline cartilage as a model to form the new one

the conversion of perichondrium to vascularized periosteum

• 1.develop and growth of cartilage bone
• 2. formation of bone collar and deterioration of medullary cartilage
• 3. development of the primary ossification center
• 4. development of medullary cavity
• 5. development of the secondary ossification center
• 6. formation of articular cartilage and epiphyseal plate

middle of bone where bone marrow is

hyaline cartilage on epiphyseal side of plate

where chondrocytes will pull the head away from shaft

older cells enlarge, the matrix becomes calcified, cartilage cells die and the matrix begins to deteriorate

new bone formation occurs

membrane

phospholipids

• osteoblast and osteoclasts deposit and resorb bone at the periosteal and endosteal surfces
• with help from lysosomes

hormones

• hormones that controls calcium in blood
• mechanical and gravitational forces acting on the skeleton

• transmission of nerve impulses
• muscle contraction
• blood coagulation
• secretion by glands and nerve cells
• cell division

• raising Ca triggers the release of calcitonin (hormone)
• calcitonin stimulates calcium salts deposit in bone
• falling Ca signal the release of PTH
• PTH signals osteoclasts to degrade bone matrix for release Ca into the blood

stress

• group of diseases in which bi=one reabsorption outspaces bone deposit (taking out of Ca is faster than it can be put back in)
• happens most in postmenopausal women

• bones are inadequately mineralized causing softened weakened bones
• cause by insufficient Ca or Vitamin D