Unit 1 - Anatomy - Skeletal System Flashcards
How many bones does the body have? What percent of body weight do bones account for?
Humans start with 300 bones which later fuse, leaving us with 206 bones. Bones account for 14% of total body weight.
What are the longest and smallest bones?
The longest is the femur, in the thigh, the shortest is the stirrup, in the ear.
What is the difference between male and female skeletal structures?
Males have longer arm and leg bones, females have wider pelvises to support the birthing process.
What are bones mostly made of?
Bones are mainly made of calcium, causing them to be hard and durable.
What can cause the weakening of bones? Who is this a concern with?
Lack of calcium. This is a concern with children if the calcification process is still incomplete. Concern with the elderly as they suffer from loss of calcium.
5 major functions of the skeletal system?
Structural Support - rigid supporting framework. Protection - skull for brain, ribs for heart and lungs. Movement - lever system on which attached muscles work. Growth Centre for Cells - rbc, platelets, and most wbc. Mineral Reservoir - calcium and phosphorous storehouse.`
Axial vs Appendicular
Axial - 80 bones, mainly comprised of vertebral column, rib cage, most of skull.
Appendicular - 126 bones, mainly comprised of limbs and their girdles.
2 functions of axial skeleton?
- support and protect organs in anterior and posterior cavities.
- Creates surface for attachment of muscles.
5 main parts of the axial skeleton?
- Skull (Cranium, face, Auditory Ossicles)
- Hyoid Bone
- Vertebral Column
- Sternum
- Ribs
10 main parts of the appendicular skeleton? 6 major regions?
- Pectoral Girdle *
- Arms (and Forearms)*
- Wrists
- Hands *
- Fingers
- Hips /Pelvis *
- Legs (and Thighs) *
- Ankles
- Feet (and Ankles) *
- Toes
1 function of appendicular skeleton?
Movement
What girdles do the arms and legs go in, respectively? What cavities do the humerus and femur go in, respectively?
Arms - Pectoral Girdles (shoulder blades and clavicle)
Legs - Pelvic Girdle ( hip bones and sacrum)
Humerus - Glenoid Cavity
Femur - Acetabulum Cavity
What does cartilage do?
Allows smooth movement of bones.
What does periosteum do?
Layer of connective tissue covering the bone that allows bone to connect to bone or muscles.
What does the medullary cavity do?
Contains red and yellow bone marrow used to create rbc, platelets, and most wbc.
What does compact bone do?
Is responsible for bone’s structural integrity.
What is the diaphysis?
The shaft of the bone
What is the epiphysis?
Very end of the long bone
What is cancellous bone?
Small, cavity-like spaces in the bone that contain bone marrow and distribute force well
What is the cortex?
Dense, smooth exterior of bone.
What are trabeculae?
Bony fibres running throughout the cancellous tissue
What are epiphyseal plates?
Black spaces between the diaphysis and epiphysis on x-rays, occur at various locations at the epiphyses of long bones, make growth possible.
What are epiphyseal lines?
Appears as a solid epiphysis (no black spaces) on an x-ray when epiphyseal plates fuse, inhibit growth.
Define Landmark
Ridge, bump, groove, depression, or prominence on the surface of a bone.
Function of landmarks?
Leads to location of other body structures, allows for passage of blood vessels and nerves; joints between bones; and attachment of ligaments, muscles, and tendons.
5 types of bones?
- Long bones - arms and legs
- Flat bones - flat and thin (parietal bone)
- Irregular bone - can’t otherwise be categorized, oddlooking (sphenoid)
- Sesamoid - small, flate bones wrapped with tendons, move over bony surfaces (patella)
- Short bones - common in wrists (carpals)
Who are the most likely targets for bone fractures? Why?
The old and the young. The old because of loss of calcium, the young because calcification is still incomplete.
3 types of fractures
- Simple, 2. Compound, 3. Comminuted
Difference between simple, compound and comminuted fractures?
Simple - no separation of bone, only crack or break. Compound - bone is separated into different pieces
Comminuted - when the broken ends of the bone are shattered
When does a stress fracture occur and give an example
A stress fracture occurs when the muscles in a limb are to exhausted to absorb shock and transfer the shock to the bone, causing the development of tiny cracks. Ex. long distance running.
What is osteoporosis?
A degenerative condition involving low bone mass as well as deterioration of bone tissue. Causes bone fragility, susceptibility to bone fractures especially in hips, spine and wrist.
What else is deterioration of bone tissue know as?
Porous bone.
Regarding osteoporosis, what happens to older women?
After menopause they can lose 20% bone mass in 5-7 years, making them more susceptible.
Defense for osteoporosis?
Build strong bones during childhood and adolescence, balanced diet rich in calcium and vitamin D, weight bearing exercises, no smoking and alcohol, bone density testing and medication when appropriate.
