What is the diaphysis?
The shaft of a long bone composed primarily of compact bone
What are the epiphyses?
The proximal and distal ends of a long bone composed mainly of spongy bone
What is the metaphysis?
The region between the diaphysis and epiphysis containing the growth plate or epiphyseal line
What is the epiphyseal plate?
Hyaline cartilage responsible for longitudinal bone growth
What is the epiphyseal line?
The remnant of the epiphyseal plate after growth stops
What type of bone tissue resists compression?
Compact (cortical) bone
What type of bone tissue aligns along stress lines?
Spongy (trabecular) bone
What are trabeculae?
Lattice-like struts of spongy bone aligned with mechanical stress
What do osteoblasts do?
Build bone by secreting osteoid
What do osteocytes do?
Maintain bone matrix and sense mechanical stress in the lacunae. Found in compact and spongy bone; connected by canaliculi
What do osteoclasts do?
Break down bone via resorption
Where are osteocytes located?
In lacunae within the bone matrix
Which bone cell is responsible for bone resorption?
Osteoclasts
What is osteoid?
Unmineralized organic bone matrix
What provides bone tensile strength?
Collagen fibers
What is the inorganic component of bone?
Hydroxyapatite (calcium phosphate)
What is red bone marrow?
Hematopoietic tissue that produces blood cells
What is yellow bone marrow?
Fat storage tissue found in the medullary cavity
What is the periosteum?
Tough connective tissue covering bone; site of growth and repair
What is the endosteum?
Inner lining of the medullary cavity containing osteoprogenitor cells
What hormone increases blood calcium via bone resorption?
Parathyroid hormone (PTH)
What vitamin increases intestinal calcium absorption?
Vitamin D (calcitriol)
How does exercise affect bone?
Increases bone density through remodeling
What causes rickets?
Vitamin D deficiency leading to poor mineralization and bowed legs
