skeletal system Flashcards
cartilage
avascular, soft and flexible connective tissue
bone
hard, strong, lightweight living connective tissue
bone function
supports soft tissue, protects internal organs, assists in locomotion, stores minerals, produced blood cells and stores energy in the form of adipose cells in bone marrow
osteoprogenitor/osteogenic
cells part of the mesenchymal stem cell lineage that differentiate into osteoblasts
osteoblasts
- secretes collagen, calcium, and phosphate to build bone
- differentiate into osteocytes and incapable of mitosis
think osteoblast = BUILD
osteocytes
- incapable of mitosis
- exchange nutrients and waste material with blood, help regulate bone mass
osteoclasts
- release calcium into blood
calcitonin
think TONE DOWN calcium levels in the blood
stopping the osteoclasts from resorbing the bone (which would lower calcium level)
inducing osteoblast - taking calcium from blood and building up the bone
PTH and vitamin D
increase blood calcium levels
axial skeleton
skull, vertebral column, rib cage
appendicular skeleton
bones of appendages, pectoral and pelvic girdle
sutures
immovable joints that hold together bones of the skull
ligaments
- bone to bone connectors that strengthen joints
- ACL - femur to tibia
tendons
muscle to bone connection, allows for movement
foramen
- an opening in the bone that allows for the passage of nerves
- forum magnum in the skull allows for the passage of the spinal cord
long bone
- long shaft (diaphysis)
- two ends: each has a metaphysis and epiphysis
epiphyseal plate
- sheet of cartilage found between the metaphysis and epiphysis
- location in which vertical bone growth occurs in the cartilage until being replaced by bone in adulthood
osteon
functional unit of compact bone
- includes lamellae + Haversian canals
compact bone
very organized, dense bone
lamellae
concentric rings of compact bone that form the Haversian canals
lacunae
osteocytes trapped between lamellae reside here and exchange nutrients via small canals (canaliculi)
Volkmann’s canals
connects blood vessels and lymph vessels contained in Haversian canal
Haversian canals
passageway for nerves, blood and lymph vessels
Medullary cavity
- hollow part of bone surrounded by compact bone
- contains yellow bone marrow (fat) and red bone marrow (the site of hemopoiesis or red blood cell development)
spongy/cancellous bone
- less dense consisting of an interconnecting lattice of bony spicules called trabeculae
- spaces filled with bone marrow
joint types
- fibrous
- cartilaginous
- synovial (most common)
fibrous joint
- connects bones via dense connective tissues without allowing any movement
ex: between bones of the skull
cartilaginous joint
- bones are attached together by cartilage and allow for little movement
- includes the spine and ribs
synovial joint
allows for movement and is filled with synovial fluid that acts as a lubricant
