Skeletal System (Laboratory) Flashcards
Secreted by cells in the parathyroid gland- increases blood calcium levels
PTH (Parathyroid hormone)
It is a steroid hormone derived from vitamin D3
Calcitriol
Secreted from C cells in the thyroid gland - decreases blood calcium levels
Calcitonin
Bon matrix
35% organic material
65% inorganic material
Collagen and proteoglycans
Organic material
Calcium phosphate crystals (hydroxyapatite crystals)
Inorganic material
Responsible for the major functional characteristics of bone
Collagen and mineral
Maintain bone matrix
Osteocytes
Housed in lacunae
Osteocytes
Bond destroying cells
Osteoclasts
Massive, multinucleated
Osteoclasts
Releases powerful lysosomal enzymes and acid
Osteoclasts
Digest the protein and mineral components of the underlying extracellular bone matrix
Osteoclasts
Breakdown of bone
Bone reabsorption
As bone is broken down, the ___ goes back into the blood.
Ca2+
What are the classification of bones
Long, short, flat, irregular bones
Cancellous bone
Spongy bone
Consists of trabeculae:
- interconnecting rods or plates of bone
- no blood vessels; obtain nutrients through canaliculi
Spongy bone
Location of spongy bone
Epiphyses of long bones and center of the other bones
Cortical bone
Compact bone