compact bone
responsible for bone’s characteristic strength
spongy bone
lattice structure known as trabeculae on the inside
filled with bone marrow internally
red marrow
hematopoietic stem cells
yellow marrow
inactive, mostly fat
portions of the long bones
- epiphysis- spongy cores, internal edge holds the cartilaginous epiphyseal plate for longitudinal growth
- metaphysis- bone marrow
- diaphysis- shaft
- periosteum fibrous sheath w bone-forming cells surrounds bone for attachment
tendons
connective tissue, muscle to bone
ligaments
connective tissue, hold bones together at joints
what does the bone matrix consist of?
organic ~> collagen, glycoproteins, peptides
inorganic ~> hydroxyapatite crystals made of calcium, phosphate, and hydroxide ions and also minerals
osteons
- structural units of bone
- lamellae surrounding central channel
- Haversian and Volkmann’s canals that house nerves and blood vessels and lymph vessels
lacunae
-small spaces between lamellar rings that house osteocytes
- interconnected by canaliculi, nutrient and waste exchange
osteoblasts
build bone
osteoclast
polynucleated resident macrophages that resorb bone
parathyroid hormone
- peptide hormone
- promotes resorption of bone to accommodate for low blood calcium
- activates Vitamin D to do the same
Vitamin D
- promotes bone resorption but in the process of doing this, bone overcompensates and builds newer stronger bone
calcitonin
- peptide hormone
- released by the parafollicular cells of thyroid in response to high blood Ca2+ and promotes bone formation
cartilage
- elastic network of chondrin made by chondrocytes
- avascular
- precursor to bone
cartilage to bone pipeline…
- endochondral ossification
- long bones
mesenchymal tissue to bone pipeline…
- intramembranous ossification
- indifferentiated embryonic connective tissue into bone
- bones of skull
immovable joints
bones fused together to form sutures or similar fibrous joints
movable joints
ligaments
synovial capsule
articular cartilage
