22. Skeletal System Flashcards
(28 cards)
What are the two major components of the human skeleton?
Cartilage: avascular, soft, flexible connective tissue; Bone: hard, strong, lightweight living connective tissue.
What is the axial skeleton?
Basic framework: skull, vertebral column, rib cage.
What is the appendicular skeleton?
Bones of appendages, pectoral & pelvic girdles (everything not axial).
What are the functions of bone?
Supports soft tissue, protects organs, locomotion, stores minerals, produces blood cells, stores energy as adipose in marrow.
What happens when stress is put on a bone?
Osteoblasts deposit collagen, calcium, phosphate; strengthens bone by making hydroxyapatite.
What is a foramen?
An opening in bone for passage of nerves; e.g., foramen magnum for spinal cord.
What is origin?
Point of attachment of muscle to stationary bone.
What is insertion?
Point of attachment of muscle to bone that moves.
What is flexion?
Bending of a joint.
What is extension?
Straightening of a joint.
What are sutures?
Immovable joints that hold skull bones together.
What are ligaments?
Bone-to-bone connectors that strengthen joints; e.g., ACL connects femur to tibia.
What are tendons?
Dense connective tissue connecting muscle to bone, enabling movement.
What are osteoprogenitor/osteogenic cells?
Mesenchymal stem cells that differentiate into osteoblasts.
What are osteoblasts?
Secrete collagen, form organic bone compounds, differentiate into osteocytes.
What are osteocytes?
Incapable of mitosis; exchange nutrients/waste with blood, regulate bone mass.
What are osteoclasts?
Resorb bone matrix, release minerals into blood; multinucleated, derived from monocytes.
What is a long bone?
Has shaft (diaphysis) and ends (metaphysis & epiphysis).
What is an osteon?
Functional unit of compact bone; includes lamellae and Haversian canals.
What are lamellae?
Concentric rings of compact bone that form Haversian canals.
What are lacunae?
Spaces where osteocytes are trapped; connected by canaliculi.
What is the medullary cavity?
Hollow bone part with yellow (fat) and red (blood cell production) marrow.
What is compact bone?
Organized, dense bone with Haversian canals.
What is spongy/cancellous bone?
Less dense, lattice of trabeculae; spaces filled with red marrow.
