BIOL 2457 1st Edition Lecture 16Outline of Last Lecture The skeletal system: appendicular Outline of Current LectureSKELETAL SYSTEM: appendicular Appendicular The primary functions is movement It includes bones of the upper and lower limbs Girdles attach the limbs to the axial skeletonSkeleton of upper limb Each upper limb has 32 bones Two separate regionsThe pectoral (shoulder) girdle (2 bones)ClavicleScapulaThe free part (30 bones)HumerusRadius and ulnaCarpalsMetacarpalsPhalangesUpper Limb The pectoral girdle consists of two bones, the scapula and the clavicle The free part has 30 bones 1 humerus (arm) 1 ulna (forearm) 1 radius (forearm) 8 carpals (wrist) 19 metacarpal and phalanges (hand)Pectoral Girdle – clavicle The clavicle is “S” shaped The medial end articulates with the manubrium of the sternum forming the sternoclavicular joint The lateral end articulates with the acromion forming the acromioclavicular joint The clavicle is convex in shape anteriorly near the sternal junction The clavicle is concave anteriorly on its lateral edge near the acromionPectoral Girdle – Scapula Also called the shoulder blade Triangular in shape Most notable features Spine - a large process on the posterior of the scapula that ends laterally as the acromion Acromion - the flattened lateral portion of the spine of the scapulaCoracoid process - a protruding projection on the anterior surface justinferior to the lateral aspect of the clavicleGlenoid cavity - shallow concavity that articulates with the head of thehumerusSkeleton of an arm- humerus Longest and largest bone of the free part of the upper limb The proximal ball-shaped end articulates with the glenoid cavity of thescapula The distal end articulates at the elbow with the radius and ulnaSkeleton of the forearm – ulna The longer of the two forearm bones Located medial to the radius Olecranon - the large, prominent proximal end, the “tip of the elbow” Coronoid process - the anterior “lip” of the proximal ulna Trochlear notch - the deep fossa that receives the trochlea of the humerus during elbow flexion Styloid process - the thin cylindrical projection on the posterior side of the ulna’s headSkeleton of forearm- radius Lies lateral to the ulna (thumb side of the forearm) The head (disc-shaped) and neck are at the proximal end The head articulates with the capitulum of the humerus and the radial notch of the ulna Radial tuberosity - medial and inferior to neck, attachment site for biceps brachii muscle Styloid process - large distal projection on lateral side of radiusSkeleton of hand The carpus (wrist) consists of 8 small bones (carpals) Two rows of carpal bones Proximal row - scaphoid, lunate, triquetrum, pisiform Distal row - trapezium, trapezoid, capitate, hamate Scaphoid - most commonly fractured Carpal tunnel - space between carpal bones and flexor retinaculumMetacarpals and Phalanges Five metacarpals - numbered I-V, lateral to medial 14 phalanges - two in the thumb (pollex) and three in each of the other fingers Each phalanx has a base, shaft, and head Joints - carpometacarpal, metacarpophalangeal,
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