Session 8 Part 3 Flashcards
Why is quadrangular space clinically important
Route via which the axillary nerve and posterior circumflex humeral artery and vein enter the posterior compartment of the arm
Quadrangular space is bounded by
Teres minor
Teres major
Long head of triceps brachii
Surgical neck of humerus
What is triangular space
Passageway through which circumflex scapular vessels enter the infraspinous fossa
Triangular space bounded by
Teres minor and major, triceps brachii
What are visible at the base of the triangular interval
Radial nerve and profunda brachii artery as they wind around humerus in spiral groove
Bursae in shoulder joint
Subacromial (under acromion)
Subscapular (between tendon of subscapularis and neck of scapula)
Subacromial bursa role
Separates Supraspinatus tendon from
coraco-Acromial ligament
coracoid process
Deep surface of deltoid muscle
Cushion- reduces friction
Subscapular bursa role
Protects tendon of subscapularis as it passes inferior to the root of coracoid process and over neck of scapula
What is the subacromial space
Space between coracoid process, coraco-acromial ligament and acromion (coraco-acromial arch)
And head of humerus
Contents of subacromial space
Subacromial bursa
Supraspinatous tendon
Joint capsule
Long head of biceps
Risk during abduction
Potential for impingement of soft tissues in subacromial space
Where does tendon of long head of biceps brachii lie within
Cavity of shoulder joint, acquires a tubular sleeve of synovial as it enters
Abduction of shoulder first 90 degrees
90 degrees at glenohumoral joint
0-15 by Supraspinatous (subscapular nerve)
15-90 by deltoid (axillary nerve)
Abduction of shoulder above 90
Scapulothoracic joint through rotation of scapula
Trapezius upper fibres
Serratus anterior
Adduction of shoulder
Pectoralis major
Latissimus dorsi
Teres major
Flexion of shoulder
Anterior fibres of deltoid (axillary nerve) Pec major (medial and lateral pectoral nerves) Coracobrachialis (musculocutaneous nerve) Biceps brachii (musculocutaneous nerve)
Extension of shoulder
Posterior fibres of deltoid (axillary nerve) Latissimus dorsi (thoracodorsal nerve) Teres major (lower subscapular nerve)
Internal rotation of shoulder
Subscapularis (upper and lower subscapular nerves) Teres major (lower subscapular nerve) Pec major (medial and lateral pectoral nerves) Latissimus dorsi (thoracodorsal nerve)
External rotation of shoulder
Infraspinatous (suprascapular nerve) Teres minor (axillary nerve)
Rotator cuff is an important
Dynamic stabiliser
Muscles of rotator cuff mnemonic
SITS
Supraspinatus (suprascapular nerve C5,C6)
Infraspinatus (suprascapular nerve C5,C6)
Teres minor (axillary nerve, C5, C6)
Subscapularis (Upper and lower subscapular nerves C5,6)
Static stabilisers of glenohumoral joint
Congruency of humeral head and glenoid cavity Glenoid labrum Joint capsule Glenohumoral ligaments anteriorly Extra-capsular ligaments Negative intra-articular pressure
Dynamic stabilisers of glenohumoral joint
Rotator cuff muscles Extrinsic muscles that cross shoulder joint biceps brachii long head triceps brachii short head deltoid pec major Coracobrachialis
Right subclavian artery arises from the
Brachiocephalic trunk