what are the mechanical functions of the skeletal system?
- movement
- support
- protection
What are the metabolic functions of the skeletal system/
- RBC
- WBC
- platelet production (produced by bone marrow)
- storage of calcium and phosphorous
What does the skeletal system include?
bones, joints, cartilage and ligaments associated with joint structures
what are axial bones for?
protection
What are appendicular bones?
limbs
When are bones strongest?
resisting compression(shortening)
when are bones weakest?
resisting shear movements
Cartilage has ___ nerve or blood supply
no
Long bones
movement
ex: arm/leg, femur, 1st metacarpal
short bones
transfer forces
ex: wrist/ankle, calcaneus
flat bones
protection
ex: skull, ribs, sternum
irregular bones
support, protection, leverage
ex: vertebral column (no regular shape)
Sesamoid bones
increase leverage, reduce stress
ex: patella (supported by tendons and ligaments)
Bone Development Flat
start from origin and grown out
Bone Development Long
develop as embryo from center of shaft out (cartilage is at ends of long bones ossify soon after birth)
Define joint
any place where 2 bones meet or join in the body
Function of joint
- join bones together controlling motion
- transfer forces between bones
Synovial joints
- highly mobile
- joint cavity that encloses space between joints
- most joints of the appendicular skeleton
immovable joints
fibrous
ex: skull sutures (fused together)
slightly movable joints
cartilaginous
ex: pubic symphysis, pelvic gurtal cartalige joint with coxis fused by cartilage
Types of synovial joints
-gliding, hinge, ball and socket, pivot, saddle, elliposidal
Gliding joints
- non axial (only non axial joint)
- movements such as gliding and twisting
- intercapal and intertarsal joints
- short bones of wrist/ankle
- no flexion/extension
Hinge joints
uniaxial (one degree of freedom)
- flexion and extension
- elbow and ankle
Ball and socket joint
triaxial (3 degrees of freedom) only 3
- flexion, extension, abduction, adduction, interal/external rotation
- shoulder/hip
Pivot
uniaxial (1 degree of freedom)
- rotation about a longitudinal axis
- base of radis and ulna
Saddle
biaxial (2 degrees of freedom)
- flexion, extension, abduction, adduction
- thumb
Elliposidal
biaxial(2 degrees of freedom)
- oval ball and socket
- phalangeal joints, fingers
Factors that affect flexibility and mobility
- how tight or lose a muscle is
- elasticity of ligamentous tissue
Osteoarthritis
lost fluid between joints, cartilage on cartilage, how cartilage is breaking down
Cartalige has _____ blood supply to it so it ____ get nutrients from blood supply, it gets it from ______
- zero
- doesn’t
- synovial fluid
Skeletal muscles
-attach to bones, voluntary control (somatic nervous system), striated or striped
Smooth muscles
visceral, organs/vessel walls, smooth in appearance, automatic nervous system
Cardiac muscles
-looks like skeletal muscle, involuntary control
Skeletal muscle mechanical functions
- movement (provide force and toque to move joints)
- support (posture maintance, stiffness at the joints)
- protection (physical barrier, absorb shock)
Other skeletal muscle functions
- pressure altercation (venous return)
- Heat production