Skeleton basics + APPENDICULAR Flashcards
Bones of appendicular skeleton
Upper and lower limb bones, supporting elements (girdles) connecting limbs to trunk (pectoral and pelvic girdle)
Upper limbs
Pectoral girdle, arm, forearm, hand
Clavicle and scapula. Position shoulder to provide base for movement.
Pectoral Girdle
Parts:
Glenoid fossa (articulates with head of humerus)
Acromion (most superior structure, articulates with clavicle)
Coracoid process (site of muscle attachment - such as pectoralis minor or short head of biceps brachii).
Scapula
Sternoclavicular joint
synovial joint (gliding joint), articular disc (shock absorber).
Acromioclavicular joint
Joint between acromion and clavicle. Strong ligamentous support
Head - articulates with glenoid fossa of scapula
Capitulum (lateral) - articulates with head of radius
Trochlea (medial) - articulates with ulna (trochlear notch)
Olecranon fossa (posterior) - articulates with ulna
Humerus
Shoulder joint
Synovial joint - ball and socket, designed for mobility not stability
Axillary recess
All movements (flex, extend, abduct, adduct, rotate, circumduct)
Glenohumeral Joint
Hinge articulation with humerus at elbow. closer to the midline of body. More robust proximally and less robust distally.
Ulna
Head in pivot articulation with humerus. Further from midline of body than the ulna.
Radius
Made up of the humeroulnar and humeroradial joints.
Synovial Joint
Hinge joint - flex/extend only
Reinforced by collateral ligaments
Cubital Joint (elbow joint)
Allows muscles to take radius and flip it over the ulnar.
Pivot joint. Pronation/supination
Radius rotates about the ulna at distal aspects (proximal aspect remains fixed in location but rotates in place. Annular ligament supports).
Radioulnar joint
Hand
Carpal bones
Metacarpals
Phalanges
(digits 2-5 are proximal, middle, distal and digit 1 is proximal and distal).
Carpal Bones
8 bones
Necessary to dissipate forces, allow for change in tendon direction and mechanical advantage, and protect vessels and nerves.
Synovial joint (modified condyloid joint)
Radius articulating with scaphoid and lunate
Ulnar side has fibrocartilage pad - no direct bony articulation
Movements: flex/extension, ulnar/radial deviation, circumduction.
Radiocarpal Joint
Parts of lower limb
Pelvic girdle, thigh, leg, foot
Formed from the sacrum and 2 os coxae (hip bones): ilium, ischium, pubis
Acetabulum - socket of the hip joint
Basin formed by anterior union at pubic symphysis, and posterior union at sacrum
Sacrum: 5 FUSED VERTEBRAE
Pelvis
Narrow and tall
Outlet and inlet is narrower
Sacrum larger and more curved
Iliac fossa deeper
Pubic angel acute (<70 degrees)
Male Pelvis
Wide and short
Outlet and inlet wider
Sacrum shorter and less curved
Iliac fossa shallower
Pubic angle obtuse (>80 degrees)
Female Pelvis
Longest and largest bone in the body
Head - articulates with acetabulum of pelvis
Greater trochanter (for muscle attachment for muscles around the hip)
Patellar surface
Medial and lateral condyles - articulates with tibia.
Femur
Synovial joint (ball and socket joint) - all movements
Strong ligamentous support - greater stability, compromise mobility
Ligament of head of femur - minor blood supply to head
Acetabular labrum - functions to deepen the acetabulum and hold head of femur tight to “socket”
Acetabulofemoral joint (hip joint)
Made of Lateral and medial condyles
Medial malleolus (of ankle)
Closer to midline of body
Tibia
Made of Head and lateral malleolus
Further from midline of body
Fibula
Interosseous membrane with very little movement
syndesmosis joint
Reinforced with ligaments
Tibiofibular joint
Tibiofemoral joint
Synovial joint: modified hinge joint (flex/extend, rotate)
Anterior cruciate ligament (ACL)
prevents anterior tibial translation
Posterior cruciate ligament
prevents posterior tibial translation
Menisci
Fibrocartilage
Deepen the tibia plateau for femoral condyles
Protect and cushion the joint surface and bone ends
Foot
Tarsal bones
metatarsal
phalanges (digits 2-5 are proximal, intermediate distal, and digit 1 is proximal and distal).
Tarsal Bones
7 bones. Act as shock absorbers, provide muscle attachment, and protect vessels and nerves.
Three arches distribute weight, provide balance and support.
