THE SKELETAL SYSTEM

Focus on the Pectoral Girdle

Appendicular Skeleton

126 bones

Includes

bones of the limbs (arms and legs)

Pectoral girdle (shoulder)

Pelvic girdle (hip)

Allows free movement of upper limb

few ligaments = loose attachment = large range of motion

Downside; Easily dislocated

Consists of two bones

1. clavicle (collarbone)

2. scapula (shoulder blade)

Pectoral Girdle (the shoulder)

The Clavicle (“little key”; collarbone)

Acts as a brace to hold the arm

away from the thoracic cage

Helps prevent shoulder dislocation

Structures to know:

Sternoclavicular joint – where the

clavicle meets the sternum

Acromioclavicular joint – where the

clavicle meets the scapula

Right Pectoral Girdle - Anterior

clavicle

scapula

Acromioclavicular joint

Sternoclavicular joint

Right Pectoral Girdle -Posterior

The Scapula (“little shovel”)

Anatomy:

Flattened body

Spine (posterior surface)

Supraspinous fossa – shallow depression above the spine

Infraspinous fossa – shallow depression below the spine

Subscapular fossa (anterior surface)

The Scapula (“little shovel”)

Anatomy continued:

Acromion process = enlarged end of the spine

articulates with the clavicle to form the acromioclavicular joint

Coracoid process = “beak” like process

Points over the top of the shoulder and anchors arm muscles

Suprascapular notch = nerve passageway (suprascapular nerve)

Glenoid fossa (cavity) = shallow socket that receives the

head of the arm

In greek “glene” (socket)

Right Scapula – posterior aspect

Medial border

Lateral border

spine

Suprascapular notch

Coracoid process

acromion Superior border

Glenoid Fossa Supraspinous fossa

Infraspinous fossa

Right Scapula – anterior aspect

Medial border Lateral border

Glenoid Cavity

Suprascapular notch

Coracoid process

acromion

Superior angle

subscapular fossa

Inferior Angle

Appendicular Sketches

I. Scapula

Anterior view

Posterior view

Lateral View

LABEL ALL STRUCTURES LISTED IN NOTES

Spine, acromion, coracoid process, infraspinous/supraspinous

fossa, subscapular fossa, glenoid fossa, suprascapular notch

Rotator Cuff Muscles

Anatomy in Clay…

Build a 3D model of a right scapula

Use the models at the front of the room and on the skeletons as reference

Your scapula model should have the following: Show your teacher when you are finished

Spine, supraspinous and infraspinous fossa

Acromion

Coracoid process

Medial, lateral, superior and inferior borders

Suprascapular notch

Glenoid cavity

THE UPPER LIMB

Bones of the Upper limbs

30 separate bones in each

upper limb

Arm, forearm, hand

The Humerus (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

Anatomical neck – slight constriction just inferior to the head

Surgical neck – most frequently fractured part of the humerus

The Humerus (arm)

head

Greater tubercle

Lesser tubercle

Intertubercular Sulcus

Anatomical

Neck Surgical

Neck

The Humerus (arm)

Features of the Diaphysis:

Deltoid tuberosity – attachment of deltoid (shoulder) muscle

Radial groove – where the radial nerve rests

The Humerus (arm)

head

Greater tubercle

Lesser tubercle

Intertubercular Sulcus

Anatomical

Neck Surgical

Neck

Deltoid tuberosity Deltoid tuberosity

Radial Groove

Greater tubercle

The Humerus (arm)

Distal features:

Epicondyles (protrusions): medial and lateral

Olecranon fossa: posterior pocket; “funny bone”

Coronoid fossa: anterior pocket

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

Capitulum: (lateral) articulates with head of the radius

The Humerus (arm)

head

Greater tubercle

Lesser tubercle

Intertubercular Sulcus

Anatomical

Neck Surgical

Neck

Deltoid tuberosity Deltoid tuberosity

Radial Groove

trochlea capitulum

Coronoid fossa

Olecranon fossa

Medial

Epicondyle Lateral Epicondyle

Radial fossa

Greater tubercle

Lateral ridge

Medial ridge

Appendicular Sketches

I. Scapula

II. Humerus

Anterior view

Posterior view

LABEL ALL STRUCTURES LISTED IN NOTES

Head, neck, greater/lesser tubercles, deltoid tuberosity, radial

groove, olecranon fossa, coronoid fossa, medial/lateral

epicondyles, trochlea, capitulum

The forearm

Consists of two bones

1. Radius = lateral bone when in anatomical position

2. Ulna = medial bone when in anatomical position

Radioulnar joints = site 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

Appendicular Sketches

I. Scapula (3: anterior, posterior, lateral)

II. Humerus (2: anterior and posterior)

III. Radius and Ulna (1; anterior)

Anterior view

LABEL ALL STRUCTURES LISTED IN NOTES

The Hand

Wrist (carpals) = 8 short bones

Scaphoid, capitate, trapezium, trapezoid, lunate, pisiform, hamate, triquetrum

Palm (metacarpals) = 5 long bones

Numbered 1(thumb) to 5 (pinky)

Fingers (phalanges)= long bones

Each finger has 3 phalanges

Thumb has 2 phalanges

Phalanges

Metacarpals

Carpals

Ulna Radius

trapezium

trapezoid

scaphoid

capitate

hamate

pisiform

triquetrum

lunate

distal

middle

proximal

Appendicular Sketches

I. Scapula (3: anterior, posterior and lateral)

II. Humerus (2: anterior and posterior)

III. Radius and Ulna (1; anterior)

IV. Hand (1; anterior)

Anterior view

LABEL ALL STRUCTURES LISTED IN NOTES

Grab a chromebook and research the origin of the names of

the 8 carpal bones – add this information to your sketch book

Sketches

1. Scapula (3; anterior, posterior and lateral)

Label: acromion, coracoid process, spine, infraspinous, supraspinous and subscapular fossa, medial lateral and superior borders, glenoid cavity, suprascapular notch

2. Humerus (2: anterior AND posterior)

Label: head, surgical neck, anatomical neck, greater and lesser tubercles, intertubercular sulcus, radial groove, deltoid tuberosity, capitulum, trochlea, medial and lateral epicondyles, olecranon and coronoid fossa

3. Radius and Ulna (1: anterior)

Label:

Hand (1: anterior)

Label: