Focus on the Pectoral Girdle The Skeletal System Focus on the Pectoral Girdle

General anatomical terms to know Process Ramus Trochanter Tuberosity Tubercle Crest Line Spine Head Neck Condyle Trochlea Facet Fossa Sulcus Foramen Canal of meatus Fissure Sinus

Appendicular Skeleton 126 bones Includes bones of the limbs (appendages) Supporting bones of the pectoral and pelvic girdles (connect limbs to axial skeleton)

Pectoral Girdle forms the shoulder Consists of two bones clavicle (collarbone) scapula (shoulder blade) Allows free movement of upper limb Sternoclavicular joint – where the clavicle meets the sternum Acromioclavicular joint – where the clavicle meets the scapula Loose attachment allows scapula to move freely Shoulder joint is poorly reinforced by ligaments Easily dislocated

Right Pectoral Girdle - Anterior

Right Pectoral Girdle -Posterior

The Clavicle Aka Collarbone Slender, doubly curved bone Acts as a brace to hold the arm away from the thoracic cage Helps prevent shoulder dislocation Structures to know: Acromioclavicular joint and sternoclavicular joint

The Clavicle – Superior view Posterior Medial (sternal) end Lateral (acromial) end Anterior

The Clavicle – Inferior view Anterior Medial (sternal) end Lateral (acromial) end Posterior

The Clavicle

The Scapula Aka Shoulder blade Anatomy: Flattened body Spine Supraspinous fossa – above the spine Infraspinous fossa – below the spine Acromion process = enlarged end of the spine of the scapula Connects with the clavicle to form the acromioclavicular joint Coracoid process = beaklike process Points over the top of the shoulder and anchors arm muscles Suprascapular notch = nerve passageway Glenoid cavity = shallow socket that receives the head of the arm

Scapula – posterior aspect Coracoid process Suprascapular notch acromion spine Medial border Lateral border

Scapula – anterior aspect acromion Suprascapular notch Coracoid process Glenoid Cavity Lateral border Medial border

Scapula

The Upper LImb

Bones of the Upper limbs 30 separate bones in each upper limb Arm, foreharm, hand

The arm The humerus – single typical long bone of the upper arm Articulates proximally with scapula and clavicle and distally with radius and ulna Structures to know: Head – fits into glenoid cavity of scapula Greater and lesser tubercles – two bony projections lateral to the head Separated by the intertubercular sulcus Anatomical neck – slight constriction just inferior to the head Surgical neck – most frequently fractured part of the humerus

The right arm (humerus) Greater tubercle head Lesser tubercle Anatomical Neck Surgical Neck Intertubercular Sulcus

The arm More structures to know: Deltoid tuberosity – attachment of deltoid muscle Radial groove – marks the course of the radial nerve Trochlea (medial) articulates with ulna Capitulum (lateral) articulates with radius

The right arm (humerus) Greater tubercle Greater tubercle head Lesser tubercle Anatomical Neck Surgical Neck Intertubercular Sulcus Radial Groove Deltoid tuberosity Deltoid tuberosity Coronoid fossa Olecranon fossa Radial fossa Medial Epicondyle Lateral Epicondyle capitulum trochlea

The forearm Consists of two bones Radius = lateral bone when in anatomical position Ulna = medial bone when in anatomical position Radioulnar joints = sight of articulation of radius and ulna Two bones are connected along their entire length by interosseous membrane Structures to know: radial tuberosity, styloid process, coronoid process, olecranon process, trochlear notch

Trochlear Notch Olecranon Process head Coronoid Process neck Radial tuberosity Proximal Radioulnar joint Radius Ulna Interosseous membrane Styloid Process (ulna) Styloid Process (radius) Distal Radioulnar joint

The Hand Wrist (carpals) = 8 short bones Palm (metacarpals) = 5 long bones Fingers (phalanges)= long bones Thumb has 2 phalanges Each finger has 3 phalanges

Phalanges Metacarpals trapezium hamate pisiform Carpals trapezoid triquetrum scaphoid lunate capitate Ulna Radius