Human Skeleton & Articular System Flashcards
What are bones? Describe its properties
- composed primarily of calcium
- resists compression and tension forces
- bound by joints (through ligaments)
- muscles attach to bone (through tendons) to produce movement
- around 300 bones at birth; about 206 in adulthood
What are the five types of bones? where are they found
- Long - found in arms & legs
- Short - found in wrists & ankles
- Flat - bones of the skull
- Irregular - bones of the vertebrae
- Sesamoid - wrapped with tendons (ex. patella)
What are the three types of fractures? Describe each
- Simple fractures
~ no separation of bone into parts but breaks or cracks (hairline or greenstick) - Compound fractures
~ bone breaks into two pieces that separate
~ major blow
~ open/closed - Comminuted
~ broken bones have been shattered into many pieces
What are the main functions of the skeletal system
- structural support: structural support for soft tissue like muscles and internal organs
- protection: protective cage for delicate parts of the body
- growth centre for cells: red bloods cells & platelets are made in bones
- reservoir of minerals: a reservoir that the body can call upon to regulate levels of calcium & phosphorus
- movement: muscles attach to bones by tendons; muscles contract and move bones to facilitate movement
Axial vs. Appendicular Skeleton
Axial:
~ 80 bones (26 vertebral column, 1 hyoid, 22 skull, 6 auditory, 24 ribs, 1 sternum)
Appendicular:
~ 126 bones (62 lower extremity, 64 upper extremity)
What are epiphyseal plates and lines?
epiphyseal plates (growth plates):
~ occur at various locations at the epiphysis of long bones
~ allow for lengthwise growth
~ new cartilage is continuously formed and older cartilage become ossified
epiphyseal lines:
~ occur when epiphyseal plates have fused or come together
~ lengthwise growth not possible
What are the effects of aging on the skeleton?
- remodelling declines from fourth decade onward (bone healing)
- process of bone remodeling reverses - bone density decreases
- affects overall calcium levels in the body
What is osteoporosis? how do you prevent it?
what is it?
~ low bone mass and deterioration of the bone tissue
~ leads to bone fragility, susceptibility to bone fractures
prevention:
~ balanced diet rich in calcium, vitamin D
~ healthy lifestyle; no smoking/alcohol
~ weight-bearing exercises
~ bone density testing and medication when appropriate
Why do we have joints
- are the points at which bones connect
- play a critical role in movement
- point of great stress and can be a common source of injury
- the articular system refers to the joints & surrounding tissue
What are the three types of joints? Describe each.
- Fibrous Joint
~ bound tightly by connective tissue that allow no movement
~ interlocking bones of the skull (suture)
~ after birth, all suture joints become immobile - Cartilaginous Joint
~ the body of one bone connects to the body of another bone by means of cartilage
~ slight movement is possible - Synovial Joint
~ joints that allow the most movement
What are the different types of Synovial joints?
- ball-and-socket joint
- gliding joint
- hinge joint
- pivot joint
- saddle joint
- ellipsoid joint
What’s a ball-and-socket joint?
the ball of one bone fits into the “socket” of another, allowing movement around three axis
What’s a gliding joint?
connects flat or slightly curved bone surfaces that glide against one another
What’s a hinge joint?
a convex portion of one bone fits into the concave portion of another - movement on one plane
ex. knee is modified hinge; elbow is true hinge
What’s a pivot joint?
a rounded point of one bone fits into a groove of another
What’s a saddle joint?
allows movement in two planes (not rotation like the ball-and-socket)
What’s an ellipsoid joint?
this type of joint also allows movement in two planes
What are ligaments?
- tough bands of white, fibrous tissue
- attach bone to bone
- Avascular - no blood supply
- allow some stretch (limited)
what is cartilage?
- connective tissue found at the ends of bones
- “avascular” - no blood supply
- torn cartilage is common among athletes in sports such as basketball and football
What is osteoarthritis?
- heavy use of joints can lead to erosion of the surface of bones
- common concern for athletes and physically active individuals
- larger weight-bearing joints
What are dislocations?
- caused by collisions or fails
- occur when a bone is displaced from its joint
What are separations?
- occur when a ligament is torn and bones are separated from each other
- classified in grades depending on the severity
What are sprains?
- occur to ligaments
- ligaments can overstretch and tear
- falling, twisting, or getting hit directly on a joint can force a joint out of its normal position and cause damage
