Block 4 Anatomy

Parts of Clavicle

Pectoral girdle: lighter/less dense bones where upper limb attaches to axial skeleton (sternum, skull, vertebral column)

Clavicle

Sternal (medial end), Acromial (Lateral) end; articulation with scapula

Clavicle

Posterior view: Conoid tubercle near acromial end; Trapezoid line; Impression for costoclavicular ligament

Scapula

Anterior view: Lateral/medial borders; superior/inferior spine.
Subscapular fossa for subscapularis
Acromion articulates with acromial end of clavicle;
Acromial clavicular joint

Scapula

Posterior view: Spine (Upper spine is supraspinous fossa: contains supraspinatus; lower is infraspinous fossa: contains infraspinatus and teres minor

Origin of Muscle

Constricted to bone it is attached to (attachment point)

Origin of Muscle

More proximal and less movable

Insertion of muscle

allows for contraction as muscle is pulled closer to point of origin

Insertion of Muscle

More distal from body and movable end

Head of Humerus

Greater tubercle and lesser tubercle

Humerus

Deltoid tuberosity serves as site of insertion for deltoid muscle.

Inferior end of humerus

Contains condyles (inferior to medial/lateral epicondyles)

Capitulum

Proximal end of radius has fovea (indentation) for articulation (flexion and extension)

Trochlea

In hinged joint (shape of facet)

Trochlea

C-shaped proximal end of ulna rotates around this

Radial and coronoid fossa

Superior to trochlea and capitulum

Olecranon fossa

Posterior side of humerus: Articulates with olecranon process of head of ulna

Surgical neck

Injury to axillary nerve

Middle of Shaft fracture

May cause injury to radial nerve = Wrist drop

Distal end of humerus (Fracture)

injury to median nerve

Medial epicondyles

Injury to ulnar nerve

Dislocation of shoulder joint

Head of humerus dislocated from glenoid cavity

Traumatic separation of proximal epiphysis pre-pubescent 

results in premature closure of epiphyseal plates

Acromioclavicular joint

Where acromion and clavicle meet

Glenohumeral joint

Glenoid cavity of scapula and head of humerus

Glenohumeral joint

Primary shoulder joint

Scapulothoracic joint

Articulation between scapula and thorax (rib cage), allowing scapula to slide and move across the back of the chest

Sternoclavicular joint

Only join that connects arm to skeleton; collarbone meets breastbone

Glenoid labrum

Fibrocartilage that surrounds the shoulder socket (glenoid fossa) to deepen it; stablizing it

Trapezius

Origin: Descending point: occipital bone

Spinous Process of C1-C7T

Trapezius

Origin: Transverse part: Aponeurosis at T1-T4

Spinous Processes

Trapezius

Origin: Spinous process of T5-12

Trapezius

Innervation: Accessory nerve (CN XI), Cervical Plexus (C3-C4)

Trapezius

Function: Draws scapula medially, medially downward
Draws scapula obliquely upward

Trapezius

Function: Rotates glenoid cavity superiorly; tilts head to same side and rotates it to the opposite

Latissimus Dorsi

Origin: Vertebral Part: Spinous process of T7-T12 vertebra; Thoracolumbar fascia

Latissimus Dorsi

Origin: Scapular (inferior) part

Latissimus Dorsi

Origin: Costal part: 9th to 12th ribs

Latissimus Dorsi

Origin: iliac part: crest

Latissimus Dorsi

Innervation: Thoracodorsal N. (C6-C8)

Latissimus Dorsi

Function: Internal rotation, adduction, extension, respiration

Latissimus Dorsi

Function: Cough muscle

Teres Major

Origin: Scapula (inferior angle)

Teres Major

Innervation: Lower Subscapular n. (C5-C7)

Teres Major

Function: Internal rotation, adduction, extension

Levator scapulae

Origin: Transverse process of C1-C4

Levator scapulae

Innervation: Dorsal Scapular n. (C4-C5)Levator scapulae

Levator scapulae

Action: Draws scapula medially upward while moving inferior angle medially; inclines neck to same side

Rhomboid minor

Origin: Spinous process of C6, C7

Rhomboid minor

innervation: Dorsal Scapular n.

Rhomboid minor

Function: Steadies scapula, draws scapula medially upward

Rhomboid major

Origin: Spinous process of T1-T4

Rhomboid major

Innervation: Dorsal Scapular n.

Rhomboid major

Function: Steadies scapula, draws scapula medially upward

Supraspinatus

Function: Abductor of Arm

Supraspinatus

Origin: Supraspinous fossa

Supraspinatus

Innervation: Suprascapular n. (C4-C6)

Infraspinatus

Function: Lateral rotator of the arm

Infraspinatus

Innervation: Suprascapular n. (C5-C6)

Infraspinatus

Origin: Infraspinatus fossa

Subscapularis

Function: Arm adduction and medial rotation

Subscapularis

Origin: Subscapular fossa

Subscapularis

Innervation: Upper and lower subscapular N. (C5-C7)

Teres minor

Function: Lateral Rotator

Teres minor

Innervation: Axillary (circumflux) n. (C5-C6)

Teres minor

Origin: Lateral border

Rotator cuff muscles

Supra/Infra- Spinatus, Subscapularis, Teres Minor

Which of the following is not a rotator cuff muscle?

Teres Major

Deltoid

Function: Most important abductor of arm up to 90 degrees

Deltoid

Innervation: Axillary nerve (C5-C6)

Deltoid

Anterior part: Flexes the arm and medial rotation of arm

Deltoid

Middle part: Abducts the arm

Deltoid

Posterior part: Extends (retroversion) and lateral rotation

Pectoralis Major

Origin: Clavicular part (clavicle)

Pectoralis Major

Origin: Sternocostal part: Sternum and costal cartilages 1-6

Pectoralis Major

Origin: Abdominal part: Rectus sheath (anterior layer)

Pectoralis Major

Innervation: Medial and lateral pectoral n. (C5-T1)

Pectoralis Major

Function: Entire muscle: adduction, internal rotation

Pectoralis Major

Function: Clavicular and sternocostal parts: Assist in rotation when shoulder is fixed, flexion

Coracobrachialis

Origin: Scapula (coracoid process)

Coracobrachialis

Innervation: Musculocutaneous n. (C6-C7)

Coracobrachialis

Function: Flexion, Adduction, Internal rotation

Subclavius

Origin: 1st rib

Subclavius

Innervation: n. to Subclavius (C5-C6)

Subclavius

Function: Steadies clavicle in sternoclavicular joint

Pectoralis MINOR

Origin: 3rd to 5th ribs

Pectoralis MINOR

Innervation: Lateral pectoral n. (C5-T1

Pectoralis MINOR

Function: Draws scapula downward, causing inferior angle to move posteromedial

Pectoralis MINOR

Function: Rotate glenoid inferiorly; assists in respiration

Serratus anterior

Origin: 1st to 9th ribs

Serratus anterior

Innervation: Long thoracic n. (C5-C7)

Serratus anterior

Function: Superior part: lowers raised arm

Serratus anterior

Function: Entire muscle: draws scapula laterally forward; elevates ribs when shoulder is fixed

Serratus anterior

Function: Inferior part: Rotates scapula laterally

Winged Scapula

Paralysis; lifting beyond 90 degrees is not possible

Winged Scapula

Loss of innervation of rhomboid major/minor, serratus anterior