skeletal system and bones Flashcards
How does the skeletal system support the body?
structural framework for the body, attachment point for tendons of muscles
How does the skeletal system protect the body?
encloses visceral organs
How does the skeletal system provide movement in the body?
skeletal muscles attach to bone, contraction pulls on bone to produce movement
How does the skeletal system maintain mineral homeostasis in the body?
store minerals (NaCl, Ca2+), can release into blood on demand
How does the skeletal system store triglycerides in the body?
yellow bone marrow stores triglycerides
How does the skeletal system produce blood cells?
red bone marrow within bones produces red blood cells (RBCs)
Define axial skeleton
bones of head, neck and trunk
Define appendicular skeleton
- bones of limbs (incl. pectoral and pelvic girdle)
- bones are vascular and innervated
What are bones made of?
- Form of connective tissue
- extracellular matrix surrounding widely separated cells
What are the percentage components of what bones are made of?
45% organic components
55% chrystalised mineral salts
- strong and resilient: minerals resist compression, collagen resists tension
What are compact bones?
- Dense bone, forms outer shell of all bone, surrounds spongy bone
- Hollow pillars of bone matric containing nerves and blood vessels
What are spongy bones?
- looks poorly organised, BUT trabeculae aligned to assist with weight bearing
- lines of compressive stress + lines of tensile stress
- filled with red or yellow bone marrow (also medullary cavity)
classification of long bones
- longer than they are wide
- bear a lot of weight
classification of short bones
- similar width and length (cube shaped)
- stability and support with little movement
- sesamoid bones: a special type that forms in a tendon
classification of flat bones
- thin, flattened, usually a bit curved
- protect vital organs, provide surfaces for large muscle attachment
classification of irregular bones
do not fit into other categories, complicated shapes
Define diaphysis in long bones
forms the long axis of the bone
Define epiphysis in long bones
proximal and distal ends
Define articular cartilage in long bones
Hyaline (glassy appearance) cartilage covering the joint surface
Define metaphysis in long bones
regions between epiphysis and diaphysis
Define periosteum in long bones
Outer fibrous covering, double-layered membrane - entire surface except joints
Define marrow (medullary) cavity in long bones
Hollow space within diaphysis; contains yellow (fat) marrow + blood vessels
Define endosteum in long bones
Thin membrane, lines medullary cavity, internal bone surfaces, trabeculae, lines canals of compact bones
Which part of the bone has a rich blood supply?
Bone tissue + periosteum