Appendicular Skeleton (Ch 8) Flashcards
Pectoral Girdle
attaches to upper limb
includes: L/R scapula, L/R clavicle
Clavicle
*collarbone
-spans superior throat
-S-shaped
-sternal end: attaches to manubrium of sternum (medial)
-acromial end: attaches to acromial process of scapula (lateral)
Functions: muscle attachment, acts as brace for scapula/arms
–> ligaments are strong- most likely to break, not dislocate
Scapula
-does NOT join to axial skeleton, attached by muscles/ligaments
-loose connection to clavicle
-lots of movement/flexible but not stable
-located on posterior surface of rib cage
Includes:
-scapular spine: on posterior side
-glenoid cavity (fossa) articles with humerus to form shoulder joint
-corocoid process: attachment to bicep muscle
-acromion attaches with acromial end of clavicle
Upper Limb
- 30 bones
- Arm: one bone, humerus
- Forearm: two bones, ulna and radius
- Hand (+wrist): 27 bones, carpals/metacarpals/phalanges
Humerus
- longest bone of upper limb
- head articulates with scapula at glenoid cavity
- distal end articulates with radius/ulna
- greater/lesser tubercles: sites of muscle attachment
- -> deltoid tuberosity: attachment of deltoid
Where do most fractures of humerus occur?
at surgical neck (1) or mid shaft spiral fracture (2)
–> nerves run through an can be damaged, possibly permanent upper limb dysfunction
Ulna
- trochlea of humerus articulates w/trochlear notch of ulna = hinge
- coronoid process of ulna fits into coronoid fossa when forearm BENDS
- olecranon fossa of humerus receives olecranon process of ulna when forearm EXTENDS
- lateral/medial epicondyles on humerus are attachment sties for forearm muscles
Radius
- capitulum of distal humerus articulates w/head of radius
- radial head also articulates w/radial notch of ulna (proximal radioulnar joint) to form pivot joint –> elbow can bend/forearm can twist
- ligaments that anchor the wrist attach to radial/ulnar styloid processes
Supination
palms up
-radius parallel to ulna
Pronation
palms down
-radius crosses over ulna
Wrist fractures
- typically distal radius while catching self during fall –> scaphoid (bad blood supply–> severe fracture = necrosis of bone)
- common in older females
- “dinner fork” presentation
- may lead to nerve damage/dysfunction
Carpals
*8 in wrist, two rows
-gliding movements
-endochondrial bone ossification
hamate-capitate-trapezoid-trapezium
pisiform-triquetrum-lunate-scaphoid
Metacarpals/Phalanges
- 5 digits, numbered I-V (thumb to pinkie)
- each has a metacarpal
- digits II-V have 3 phalanges (proximal, middle, distal)
- -> thumb/pollex only has two (no middle)
Pelvis
“hip bones” + sacrum + coccyx
- includes appendicular and axial skeletal bones
- attaches lower limbs to spine (body weight basses through girdle) and support viscera
- strong attachment to axial skeleton at SI joint (stable)
- less freedom of movement compared to pectoral girdle
Ox Coxae
“hip bones”
- acetabulum: lateral sockets where head of femur articulates (composed of all 3 pelvic bones)
- two os coxae join anteriorly at pubic symphysis