Skeletal system - general knowledge Flashcards
How many bones are in the human body?
approximately 206
Functional divisions of the skeletal system?
- axial: bones of head neck and trunk
- appendicular: bones of extremities/limbs
What is included in the axial skeleton?
- Skull
- hyoid bone
- vertebrae
- ribs
- sternum
- sacrum
What is included in the appendicular skeleton?
- pectoral girdle
- upper extremities
- lower extremities
- pelvic girdle
Skeleton is composed of….
cartilage and bones
What is cartilage and what is its function?
avascular connective tissue that offers flexibility to the skeleton
How does cartilage obtain nutrients?
by diffusion because it is avascular
What is articular cartilage?
cartilage that covers articulating surfaces of bones that participate in synovial joints, providing a smooth, low friction surface for movement
What is bone tissue?
living, hard, connective tissue that makes up most of the skeleton
Functions of bones?
- support
- protection
- mechanical movement
- storage of salts
- continuous supply of blood cells
What is periosteum?
fibrous connective tissue that covers bones, except when cartilage is present, and provides attachment surface for tendons and ligaments
What is perichondrium?
fibrous connective tissue that covers cartilage
Types of bone?
compact and spongy
Describe compact bone
thin layer of bone that surrounds spongy bone
-found in greater amounts near the shafts of weight-bearing bones
Describe spongy bone
- central compartment of bones
- composed of large and numerous spaces
- contains trabeculae
- sometimes replaced or combined with medullary cavities
What are medullary cavities?
yellow (fatty) or red (blood cell and platelet forming) bone marrow
Bones are classified by what shapes?
- long
- short
- flat
- irregular
- sesamoid
Define long bones
tubular and long such as humerus and femur
Define short bones
cuboidal and only found in ankle and wrist
Define flat bones
flat and usually serve protective function such as the bones of the skull
Define irregular bones
are not long, short or flat such as bones of the face
Define sesamoid bones
develop in the tendons and protect them from wear and change the angle of tendons as the pass to attachments
What is the significance of bone markings?
they appear wherever tendons, ligaments or fascia are attached, wherever arteries lie adjacent to or enter bones or in relation to passage of a tendon