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)

forms the shoulder Consists of two bones

1. clavicle (collarbone)- long bone1. Latin word “clavicula” = little key

2. 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

Pectoral Girdle

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

The Scapula

Aka Shoulder blade (little shovel) Anatomy:

Flattened body Spine (posterior)

Supraspinous fossa – Superior to (above) the spine Origin of the supraspinatus muscle (rotator cuff)

(posterior) Infraspinous fossa – Inferior to (below) the spine

Origin of the supraspinatus muscle (rotator cuff) (posterior)

Additional Fossae: Subscapular fossa- anterior

Origin of the subscapularis muscle (rotator cuff) (anterior)

The Scapula

Acromion process = enlarged end of the spine of the scapula Articulates with the clavicle to form the acromioclavicular

joint Comes from the Greek word “Akron”(peak) and

“Omos”(shoulder) Coracoid process = “beak”-like process

Points over the top of the shoulder and anchors arm muscles Suprascapular notch = nerve passageway

Forms a foramen (ossification of transverse ligament) that provides passage way for the suprascapular nerve.

Glenoid fossa(cavity) = shallow socket that receives the head of the arm Comes from the greek work “glene” (socket)

The Scapula

Borders: Lateral (axillary) border Medial (vertebral) border Superior border

The Scapula- posterior aspect

Medial border

Lateral border

spine

Suprascapular notch

Coracoid process

acromion

The Scapula- anterior aspect

Medial border

Lateral border

Glenoid Cavity

Suprascapular notch

Coracoid process

acromion

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 Proximal features:

Head – fits into glenoid cavity of scapula Greater and lesser tubercles – two bony projections lateral

to the head Separated by the intertubercular sulcus Attachment of tendons

Anatomical neck – slight constriction just inferior to the head Surgical neck – most frequently fractured part of the humerus

Features of the diaphysis:

Features of the diaphysis (shaft): Deltoid tuberosity: attachment for the

deltoid(shoulder) muscle Radial groove- marks the course of the

radial nerve

The arm

Distal features: Lateral and medial epicondyles: External and internal condyles: Olecranon fossa: groove that receives the

olecranon process of the ulna upon extension of the arm.

Coronoid fossa: groove that receives the coronoid process of the ulna upon flexion of the arm.

Trochlea (medial) articulates with trochlear notch of the ulna.

Capitulum (lateral) articulates with head of the radius

The right arm (humerus)head

Greater tubercleLesser tubercle

Intertubercular Sulcus

Anatomical

Neck

SurgicalNeck

The right arm (humerus)head

Greater tubercleLesser tubercle

Intertubercular Sulcus

Anatomical

Neck

SurgicalNeck

Deltoid tuberosity

Deltoid tuberosity

Radial Groove

trochleacapitulum

Coronoid fossa

Olecranon fossaMedial Epicondyle Lateral

Epicondyle

Radial fossa

Greater tubercle

The forearm

Consists of two bones1. Radius = lateral bone when in anatomical position2. 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

Radius

Ulna

Interosseous membrane

Trochlear Notch

Olecranon Process

Coronoid Process

Proximal Radioulnar joint

Distal Radioulnar joint

Styloid Process (ulna)Styloid Process (radius)

Radial tuberosity

neck

head

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

Proximal phalange Medial phalange Distal phalange

Phalanges

Metacarpals

Carpals

UlnaRadius

trapezium

trapezoid

scaphoid

capitate

hamate

pisiform

triquetrum

lunate

Can you identify the following??1.

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