12 Appendicular: add on: attach extremities to the axial skeleton Upper extremity atttached to body via pectoral girdle Lower extremities to body: pelvic girdle345 • Pectoral girdle • = clavical + scapula • 2 bones that make it up: clavical (collar bone), scapula • How you attach the upper extremity to the axial skeleton • Scapula and clavicle join eachother at: • Need range of motion here, not weight baring joint • Give up security and support for ROM6 • Appendicular skeleton: girdles and appendiges • Pectoral attachment bone-wise = only ONE (sternum)7 • Clavicle: shaped like a gental S • Extends laterally from menubrium and then hooks to scapula • Bows anteriorly first, and then posteriorly • Sternal end: thin and tapered • Acromial end: round and fat • Clavical acts as a strut: keep the shoulders away from the midline • The S curve (sigmoude shape) is not great…if the clavicle is going to absorb force, it typically absorbs force laterally first, then medially • Tend to snap where the convex becomes concave…most fragile there • Easy bone to break b/c of its shape and weakness89 • Scupula is a flat, thin, triangular shaped bone. • Has sides and angles. • Main portion of bone = body • Sides = borders • Medial border is facing the spinous processes of the vertebral column • Lateral border = traverses armpit region (axillary region) • Superior angle, inferior angle, lateral angle • Lateral angle – imaginary spot where superior and lateral would come together • Anteriorly, the body looks plain. IN real life the subscapularious muscle lies againsts it • Subscupular fossa = named for the muscle there. • Facing forward (up against the back of rib rage) • Posterior portion • There is a BIG ridge posteriarly. Runs as an angle past the body. Sticks out and terminates. Acromion/Acromiel process = The lateral, flat, flared endingSupraspinious fossa = above the spine Infraspinious: below the spine 2 important muscles lying here • Named after the fossa they sit in • Body = thick and flat • There is a fossa facing laterally = gleniod fossa • Flat, circular piece of bone • Will articulate with the head of the humerus • At the glenohumeral joint • Beak of bird = the corociod process. Comes out anteriorly here where the body meets with the gleniod process • Corociod means “birds beak” • Sticks out anteriorly and articulate with NO bone at all • Point of attachemt for muscles • Articulates with NOTHING bony • Sternal end laterally and ends in the acromial end • Only ONE joint at the pectoral girdle: acromioclavicular joint • Holds the scapula to the cavicle • Sternoclavicialar joint: holds the bones to the rest of the body 910111213 • Common pattern to upper and lower extremities: proximal to distal • Proximal: one bone, distal to that – 2 bones, then many bones….same in the upper and lower extremities • One bone, 2 bones, many bones • Humeris: arm • Articulates with pectoral girdle • Figure 8.4A and 8.4AC • Forearm: elbow to wrist (raduis and ulna) • Wrist (carpal bones) • Hands (phelanges)14 • Gleniod fossa = socket (glenohumeral joint): joint = ball and socket joint. Head of humeris = ball. Socket “shoulder”= glenoid fossa . Not a very deep ball and socket fit. Everything is made for range of motion. Not terribly stable • Easy to dislocate the shoulder • Just below head of humerus: complex…. • Bony features just distal to the humeris head • Anatomical neck: the circle enscribed by the head of the humeris • Would look like cartilege on a kid…their epiphysial plate • When it ossifies, you’ve got the true anatomic neck • Greater and Lesser tubrecle: trubricles are bumpy> greater = more lateral and superior. More anteriorly and inferiorly = lesser tubricle • Both points of attachment for muscles for movement • Intertubercular groove: Groove between the greater and lesser tub.• Surgical neck: right where the tapering starts. Often where this bone BREAKS • Deltiod tuberacity: half way down the shaft. Roughened bump. Tuberacity = a roughened bump too…a tubricle is too (above) • Point of insertion of deltiod muscle (tendon) • All function parts of the deltiod insert here • Distal part: condyler modifications to form articulations at the elbow 1415 • Between the lateral and medial epicondyles, 2 little divets: medial to the epicondyles: 2 fossa that accept portions of the radius and the ulna • Fossa usually named for the thing that touches them/they accept • Radial fossa: accepts a part of the head of the radius • Coroniod fossa: accept a process on the ulna, the coronoid process • Both need places to “tuck away” when we flex the elbow16 Olecronon fossa: distal end, big, deep fossa • Posterior side of the humeris • Accepts a portion of the ulna • When you flex the elbow, it’s the bony knobby part. Goes “away” and tucks in when you extend1718 • 2 different condyler portions: the radius and the ulna • elbow joint = humeris, radius, ulna • Hinge joint • Condyler portions are modified to accept the radius and the ulna • Trochlae: region on the humeris that articulates with the ulna • Trochlae looks like a spool of thread without the thread • Accepts the modifications of the ulna • Capitulum: rounded knob (lateral portion of the articular portion) • Head of the radius articulates with the capitulum • Capitulum: you put a “cap” on your “head” • Medial and lateral epicondyles: above or beyond the condyles • Epicondyles: points of attachemnt for ligaments of other muscles • Help to make the whole synovial capsule around this joint1920 • Ulna has electronon process (big pointy elbow bone) • Look at lateral view for the rest • 8.5C2122 • Radius: on the thumb side • Articulates with ulna at a little notch • Inscribe a radius with your thumb when you pronate and supinate • Radial arch with the thumb made • Flip the hand from palm-up to palm-down • Features of the raduis: • Has a radial head (button shaped) • Articulate with the ulna at the ulnar notch. • Neck of the radius underneath the head • Radial tuberoscity: produces bump. Point of attachment for a muscle • Membrane between raduis and ulna: interossious ligament • Distally, the radius