Chapter 3 Flashcards
function of the skeletal system
protect bodys organs
provide a supporting framework for movement
bone is
a living tissue complete with blood supply and nerves
human skeleton
divisions: axial
appendicular
how many bones
approx 206 bones
different shapes
classes of bone tissue
axial skeleton
80 bones
supports stabilizes, and protects
skull, sterum, ribs, vertebral column
appendicular skeleton
126 bones
responsible for large portion of movement
pectoral gridle, upper limb, pelvic gridle, lower limb
shape determines
function
short bones
includes bones of the ankle (tarsals) and wrists (carpals)
serve as good shock absorbers
long bones
include femur, humerus, any bone whos length greatly exceeds its diameter
provide levers for movement
flat bones
include bones of the skull, scapula, ribs, sternum, clavicle
largely protect underlying organs
irregular bones
include bones of your face, and vertebre
bones that cannot be placed in other groups
fulfill special functions
sesamoid bones
includes the patella
oval shape, like a pea, and found in tendons
2 classes of bone tissue
compact/cortical: compact, stiff and stress resistant, long bones
spongy/cancellous: flexible, shock absorbers, vertebrae
babies are born with how many bones
300 bones (94 more than adult)
bone composition
calcium carbonate and calcium phosphate
collogen protien
water
calcium carbonate and calcium phosphate
60-70% of bone
stiffness
reistance to pressing/squezzing
collagen protien
flexibility
resist pulling and stretch
when lost, bone becomes brittle (aging)
water
20% of bone
lower water composition makes bones stronger than other tissues
bone develops from
cartilige model
cartilige soldifies into bone through process called ossification
muscle types
skeletal
cardiac
smooth
skeletal muscle
attached to bone
contraction = body movement
motor nerve control/ voluntary
cardiac muscle
heart contraction/beating
very fatigue resistant
has own intrinsic beat
automatic nerve control/involuntary
smooth muscle
blood vessels & organs
slow and uniform contractions
fatigue resistant
automatic nerve control/involuntary
what is a joint
connection between two or more bones
strands of connective tissue (ligaments) ensure stability and hold joint together
classified by the degree of movement
origin
proximal attachment
closer to center of the body
attached to more stationary parts
insertion
distal attachment
away from the center of the body
more mobile structure
three types of joints
fibrous joints
cartilaginous joints
synovial joints
fibrous joints
no movement
absorb shock
ex) skull structures
cartilaginous joints
limited movement
absorb shock
ex) interverbral discs
synovial joints
greatest degree of movement
allow movement most common
ex) hip joint
four points of synovial joints
joint capsule-surrounds and provides support (secretes synovial fluid)
joint cavity-filled with synovial lubrication
hyaline cartilage- dense white connective tissues that protect aticulating bones
ligaments, extrinstic and (intrinstic)-support and articulate
joint movements
uniaxial-movement about one axis
biaxial joints- movement about two perpendicular axes
multiaxial joints- movement about all the perpendicular
types of synovial joints
- hinge joint (uniaxial)
- pivot joint (uniaxal)
- condyloid joint (biaxial)
- saddle-shaped joint (biaxial)
- ball and socket joint (multiaxial)
- plane joint (biaxial)
- hinge joint
has one articulating surface that is convex, and another that is concave
ex) elbow
2.pivot joint
one bone rotates around one axis
ex) neck
- condyloid joint
the joint surfaces are usually oval
one is ovular convex shape, and other reciprocally shaped concave surface
ex) knuckles joint
- saddle joint
the bones set together as in sitting on a horse
ex) thumb joint
- ball and socket joint
a rounded bone is fitted into a cup-like receptable
ex) shoulder and hip joints
- plane joint
the bone surfaces involved are nearly flat
ex) acromioclavicular
