Skeletal System Part 1 Flashcards
How many bones are in the body?
206 bones
What are the 2 divisions of the skeleton?
Axial Skeleton & Appendicular Skeleton
Axial Skeleton
Longitudinal axis of the body.
Protects internal organs.
Appendicular Skeleton
The bones of the limbs and girdles that are attached to bones.
Facilitate movement.
Joints
The place at which two bones meet to produce movement.
Cartilage
Strong flexible connective tissue that protect bones and joints.
Ligaments
Strong bands or straps of fibrous, collagen, tissue that provide support to bones and link bones to bones in and around joints.
What are the functions of bones?
Support, Protection, Movement, Storage, & Blood Cell Formation
Support (function)
Form the internal framework that supports the body and cradles the soft organs.
Protection (function)
Protects the soft body organs.
Ex: Skull protects the brain
Movement (function)
Skeletal muscles use bones as levers to walk, swim, throw a ball, and breathe.
Storage (function)
Fat is stored in the internal cavity of the bone (also known as marrow)
Blood Cell Formation (function)
Hematopoiesis occurs in the marrow cavities of certain bones.
What are the two types of bone tissue?
Compact & Spongy
Compact (bone tissue type)
Dense & appears smooth.
Riddled with passageways that carry nerves and blood vessels.
Mature bones cells are found in lacunae (tiny cavities).
Spongy (bone tissue type)
Composed of smaller needlelike pieces of bone & lots of open space.
Provides balance to the dense & heavy compact bone by making bones lighter so that muscles can move them more easily.
Haversian Canals
Carry blood vessels & nerves
Lacunae
Tiny cavities.
Arranged in concentric circles calles lamellae.
Canaliculi
Tiny canals that radiate outward from the central canals to all lacunae.
What are the four classifications of bones?
Long, Short, Flat, & Irregular
Long (bone)
Longer than they are wide.
Mostly compact tissue.
All bones of the limbs except patella, wrist, & ankle bones.
Yellow & Red Marrow.
Short (bone)
Generally cube-shaped.
Spongy bone tissue.
Bones of the wrist & ankle.
Flat (bone)
Thin, flattened, & curved.
Two thin layers of compact bone sandwiching a layer of spongy bone.
Skull, ribs, & sternum.
Irregular (bone)
Bones that do not fit in any of the categories above.
Vertebrae & facial bone.
