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
The solid, outer layer surrounding each bone
Cortical bone/compact bone
Structural unit of compact bone, includes lamella, lacunae, canaliculus, central canal, osteocytes
Osteon
Rings of bon matrix
Lamella
Spaces vetween lamella
Lacunae
Center of osteon and contains blood vessels
Central canal
tiny canals and transport nutrients and remove waste
Canaliculus
Shaft
Compact bone tissue (on outside)
Diaphysis
End
Spongy bond tissue
Epiphysis
It covers the epiphysis and reduces friction
Articular cartilage
Site of growth
Between diaphysis and epiphysis
Epiphyseal plate
When bone stops growing in length, an epiphyseal plate becomes ossified
Epiphyseal line
Center of diaphysis
Red or yellow marrow
Madullary cavity
Site of blood cell formation
Red marrow
Adipose tissue
Yellow marrow
Membrane around bone’s outer surface
Periosteum
Membrane that lines the medullary cavity and smaller cavities (spongy and compact bone)
Endosteum
It is the process of bone formation that occurs in the utero
Ossification
What are the types of ossification?
Intramembranous ossification
Endochondral ossification
Bone formation within embryonic connective tissue membranes
Intramembranous ossification
Osteoblasts build bone
Intramembranous ossification
Locations in the membrane where intramembranous ossification starts
Centers of ossification
Cartilage models are replaced by bone
Endochondral ossification
Bones of base of the skull
Endochondral ossification
Endochondral ossification
- Cartilage model formation
- Bone collar formation
- Primary ossification center
- Secondary ossification center
- Adult bone
Formation of new bone on surface of ilder or cartilage
Appositional growth
Epiphyseal plate is replaced by an epiphyseal line
Appositional growth
Removal of exiting bone
Osteoclasts
Deposition of new bone
Osteoblasts
Responsible for changes in bone shape, bone repair, adjustment of bone to stress, and calcium ion regulation
Bone remodeling
Major site for calcium
Bone
Calcium homeostasis is maintained by the following
Parathyroid hormone PTH
Calcitriol
Calcitonin