Skeletal System Flashcards
functions of the skeletal system
support
protection
movement
blood cell production
storage
skeletal system is divided into 2 divisions namely
axial skeleton - skull, ribs, vertebra
appendicular skeleton - pelvis, extremeties
o Arms, legs, fingers, toes
o Covered with dense connective tissues
long bone
o Generally cube-shape
o Mostly sponge bone
o E.g. carpals of wrist
short bone
o Thin and flattened
o Thin layers of compact bone around a layer of spongy bone
o Parietal bone of skull
flat bones
o Do not fit into other bone classification categories
o Vertebra
irregular bones
o produce bone matrix and become osteocytes
osteoblasts
o connect to one another through cell extensions and surround themselves w/ bone matrix
osteocytes
formation of new bone by osteoblasts
occurs by appositional growth on the surface
ossification
occurs within connective tissue membranes
Intramembranous ossification
occurs within cartilage
Endochondral ossification
composed of the skull, vertebral column, and thoracic cage
axial skeleton
composed of pectoral and pelvic girdle; upper and lower limbs
appendicular skeleton
has 22 bones
joined by sutures
only the mandible is attached by a freely movable joint
skull
o 8 bones
o Protect brain and form attachment points for the meninges on the interior and the muscles that move the head on the exterior
cranial bones
o 14 bones
o House the openings to the airways and digestive system
o Protect the sensory organs
o Provide attachments for facial muscles
facial bones
o Protects the spinal cord
o Supports the head and neck
o Permits movement
o Provides attachment points for back muscles, ribs, pelvis
o 26 bones
vertebral column
o 7 bones
o Neck region
cervical vertebrae
o 12 bones
o Posterior to chest cavity
o Serve as attachment for ribs
thoracic vertebrae
o 5 bones form the lower back
lumbar vertebrae
5 fused vertebrae; forms the posterior wall of pelvis; blood vessels pass thru the openings
sacrum
aka tailbone; 4 fused vertebrae
coccyx
o Ribs and sternum form the framework for the thorax
o Sternum made of 3 parts = fuse by age 25
o 24 ribs (12 pairs)
thoracic cage
o Shoulder girdle which attach the upper limbs to the axial skeleton
pectoral girdle
o Hip bones
o Composed of 3 pair of fused bones
o Protects several organs
o Reproductive organs
o Urinary bladder
o Parts of the large intestine
pelvic girdle
function of joints
- Hold bones together
- Allow for mobility
immovable joints
Synarthroses
slightly movable joints
amphiartrosis
freely movable joints
diarthroses
o generally movable
o Bones united by fibrous tissue
fibrous joints
o immovable or slightly moveable
o Bones connected by cartilage
cartilaginous joints
o freely movable
o Articulating bones are separated by joint cavity
o Synovial fluid is found in the joint cavity
synovial joints
