Skeleton bones and joints Flashcards
Axial skeleton
The group of bones that support and protect the internal organs;
Form the central axis of the body.
Appendicular skeleton
the bones that form the upper and lower limbs;
allow movement of the limbs and support and move the axial skeleton.
Bone shape classifications
Long bones, short bones, flat bones, irregular bones.
Long bones
Longer than they are wide;
slightly curved and tend to spiral, which gives them more strength and enables them to withstand stress.
Short bones
About equal in length and width, appearing roughly cube-shaped.
They act as shock absorbers.
Flat bones
Thin and somewhat curved in appearance;
they provide a surface for attachments of muscles and function to protect underlying soft tissues.
Irregular bones
Have complex intricate shapes, and don’t fit into the other categories.
examples; the vertebrae, and the facial bones.
Projections for tendon and ligament attachments
Crest, epicondyle, process, protuberance, spine, trocanter, tubercle, and tuberosity.
Crest
A narrow, prominent ridge.
Epicondyle
A small, nonarticular projection above a condyle.
Process
A general term for any bony prominence.
Protuberance
A protruding projection.
Spine
A sharpe, slender, pointed process.
Trocanter
A very large, rough projection found only on the femur bone.
Tubercle
A small, rounded projection.
Tuberosity
A large, rounded projection that is sometimes rough in texture.
Features that help form joints ( articulating surfaces )
Condyle, facet, head, and trochlea.
Condyle
A rounded articular projection on the extremity of a bone; usually occurs in pairs.
Facet
A small, shallow ( nearly flat ) articulating surface.
Head
A large, usually ball-shaped expansion at the end of a bone.
Trochlea
A spool-like articulating surface that acts like a pully.
Depressions ( for muscles ) and opennings ( for blood vessels and nerves )
Foramen, and fossa.
Foramen
A round or oval aperture ( opening ).
Fossa
A shallow, basin-like depression.
Joints
Fibrous joints, cartilaginous joints, and synovial joints.
The junction or union of two or more bones. Held together by connective-tissue, and may have surrounding structures ( cartilage, ligament, synovial membrane ).
Fibrous joints
Bones held together by fibrous connective tissue;
Sulture joint, gomphosis joint, and syndesmosis joint.
Suture joint
A fibrous joint that is saw-edged, bevelled, or overlapping;
very short fibers; immovable.
example; suture joints of the skull.
Gomphosis joint
A fibrous joint, a ‘peg’ in a socket; immovable.
example; joints connecting the teeth to the upper and lower jaw.
Syndesmosis joint
A fibrous joint that combines slight movability with strength.
example; interosseous membrane between the radius and ulna.
Cartilaginous joints
Bones are connected by cartilage material
Synchondrosis joint, and symphysis joint.
Synchondrosis joint
A cartilaginous joint that provides stability; immovable.
example; joint at first coastal carilage ( of rib ) and sternum.
Symphysis joint
A cartilaginous joint that occurs on the medial line of the body; slightly movable.
example; intervertebral joints of the spinal column, and the pubic symphysis of the pelvis.
Types of synovial joints
Ball-and-socket joint, Ellipsoid or condyloid joint, gliding or plane joint, hinge joint, pivot joint, and saddle joint.
Ball-and-socket joint
Ball-shaped head of one bone fits into cuplike socket of another bone.
multiaxial movement; flexion and extension, abduction and adduction, rotaional movement, circumduction.
Ellipsoid / condyloid joint
Oval-shaped end of one bone fits into oval-shaped cavity of another bone.
biaxial movement; flexion and extension, abduction and adduction.
Gliding / plane joint
Two bones with slightly flattened surfaces glide across each other.
uniaxial movement; limited to side-to-side movement.
Hinge joint
Convex surface of one bone fits into concave surface of another bone.
uniaxial movement; flexsion and extention.
Pivot joint
Rounded end of one bone rotates within ringlike structure formed by another bone and ligament.
uniaxial movement; rotation.
Saddle joint
Two ends of bones shaped somewhat like saddles, with convex and concave surfaces.
uiaxial movement; flexsion and extension, abduction and adduction.
( some experts consider the saddle to have joint to have triaxial movement capability; circumduction).
Uniaxial
A joint or bone that can only move in one plane.
Biaxial
A joint or bone that can move in two planes.
Triaxial / multiaxial
A joint or bone that can move in all three planes.
