MSK anatomy Flashcards
What is the arm?
Everything between the shoulder and elbow joints
What is the forearm?
Everything between the elbow and wrist joints
What is the hand?
Everything distal to the wrist
What is the movement of the humerus?
Can be rotated medially and laterally around a vertical axis
What is an origin?
An attachment site that doesn’t move during contraction
What is an insertion?
An attachment site that moves during contraction
What are the movements for every 3 degrees of abduction of the arm?
2 degrees of abduction in shoulder and 1 degrees of rotation of scapula
What are the borders of the scapula?
Medial
Inferolateral
Superior
What is the origin of the trapezius?
Medial 1/3 of superior nuchal line of occipital bone, spine of all thoracic vertebra
What is the insertion of the trapezius?
Lateral 1/3 of clavicle, Acromion process, Medial end of spine of scapula
What is the innervation of the trapezius?
Accessory nerve; CN XI
What is the action of the trapezius?
Upper fibres elevate scapula, Middle fibres retract scapula, Lower fibres depress scapula
What is the origin of latissimus dorsi?
Posterior part of iliac crest, lumbar fascia, spines of lower 6 T vertebrae, lower 3 ribs
What is the insertion of latissimus dorsi?
Tendon wraps around lower border of teres major, inserts onto floor of bicipital groove of humerus
What is the innervation of latissimus dorsi?
Thoracodorsal nerve (branch of posterior cord of brachial plexus)
What is the action of latissimus dorsi?
Adducts arm and shoulder (Rings a bell ;))))
What is the origin of the levator scapulae?
Transverse processes of upper four cervical vertibrae
What is the insertion of levator scapulae?
Medial border of scapula opposite supraspinous fossa
What is the innervation of lavator scapulae?
Dorsal scapula nerve (C5)
What is the action of levator scapulae?
Elevates scapula
What is the origin of rhomboid major?
T2-5 spines
What is the origin of rhomboid minor?
lower part of ligamentum nuchae and spines of C7 and T1
What is the insertion of rhomboid minor?
Medial border of scaupula opposite root of spine
What is the insertion of rhomboid major?
Medial border of scapula opposite infraspinous fossa
What is the innervation of rhomboid major and minor?
Dorsal scapula nerve
What is the action of rhomboid major and minor?
Retracts and rotates scapula
What is the attachment of the deltoid?
Anterior; lateral 1/3 of medial border of clavical
Middle; lateral border of acromion process
Posterior; lower border of spine of scapula
What is the insertion of deltoid?
Fibres converge and insert onto deltoid tuberosity on middle of lateral surface of shaft of humerus
What is the innervation of the deltoid?
Axillary nerve (C5 and C6)
What is the action of the deltoid?
Abducts arm past 15 degrees. Anterior fibres flex arm at shoulder. Middle fibres abduct arm. Posterior fibres extend arm at shoulder
What is the attachment of teres major?
Lower 1/3 of posterior surface of lateral border of scapula
What is the insertion of teres major?
Medial lip of bicipital groove of humerus
What is the innervation of teres major?
Subscapular nerve (C6-C7)
What is the action of teres major?
Adducts and medially rotates arm
What are the muscles of the rotator cuff?
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
What is the origin of supraspinatus?
Supraspinous fossa of scapula
What is the attachment of supraspinatus?
Superior greater tubercle
What is the innervation of supraspinatus?
Suprascapular nerve
What is the action of supraspinatus?
Abducts arm up to 15 degrees
What is the origin of infraspinatus?
Infraspinous fossa of scapula
What is the attachment of infraspinatus?
Posterior greater tubercle
What is the innervation of infraspinatus?
Suprascapular nerve
What is the action of infraspinatus?
Laterally rotates arm
What is the origin of teres minor?
Upper 2/3 of posterior surface of lateral border of scapula
What is the attachment of teres minor?
Inferior greater tubercle
What is the innervation of teres minor?
Axillary nerve
What is the action of teres minor?
Laterally rotates arm
What is the origin of subscapularis?
Subscapular fossa on anterior surface of scapula
What is the attachment of subscapularis?
Lesser tubercle
What is the innervation of subscapularis?
Axillary nerve
What is the action of subscapularis?
Medially rotates arm
What is often damaged during posterior dislocation of the shoulder?
Axillary nerve and posterior circumflex humoral artery
What is the clinical result of damage to the axillary nerve?
Paralysis of deltoid
Sensory loss in skin over insertion of deltoid muscle
What is frozen shoulder?
The tendon of supraspinous passes through tight gap between humerus and acromion. There is an inflamed tendon and pain whislt the swollen part goes through the gap. Patient can typically lift arm a short distance without pain, then becomes very painful. Once swollen area has passed through gap further raising arm is pain free.
What is axillary nerve palsy?
The axillary nerve can be damaged with posterior shoulder dislocation and fracture of the neck of humerus. Paralysis of deltoid in sensory loss in skin over deltoid insertion.
What is radial nerve palsy?
The radial nerve is damaged by direct pressure of humerus fracture. Numbness from triceps down to fingers, problems extending to wrist/fingers. Inability to control muscles from triceps down to the fingers
What is the action of serratus anterior?
Protraction of scapula
What is the origin of the long thoracic nerve?
Roots of brachial plexus; C5-7
What is contained within the axilla?
Fat Lymph nodes Axillary artery Axillary vein Brachial plexus
What is the role of the axillary sheath?
Encloses axillary artery and three cords of brachial plexus
How many lymph nodes can be found in the pectoral region?
3-5
How many lymph nodes can be found in the subscapular region?
6-7
How many lymph nodes can be found in the humeral region?
4-6
How many lymph nodes can be found in the central region?
3-4 large nodes
What are the splits of the brachial plexus named?
Roots Trunks Divisions Cords Branches
What spinal nerves form the brachial plexus?
C5-T1
What are the trunks of the brachial plexus?
Superior; C5 and C6
Middle; C7
Inferior; C8 and T1
What are the cords of the brachial plexus?
Lateral
Posterior
Medial
What are the major branches of the brachial plexus?
Musculocutaneous Axillary Median Radial Ulnar
What are the roots of the musculocutaneous nerve?
C5,6,7
What are the roots of the axillary nerve?
C5 and C6
What are the roots of the median nerve?
C6-T1 (and sometimes C5)
What are the roots of the radial nerve?
C5-T1
What are the roots of the ulnar nerve?
C8 and T1
What is the motor function of the musculocutaneous nerve?
Innervates brachialis, biceps brachii and coracobrachialis muscles. Flex upper arm at shoulder and elbow, biceps brachii also supinates forearm
What is the sensory function of the musculocutaneous nerve?
Gives off the lateral cutaneous branch of forearm, this innervates the lateral 1/2 of anterior forearm and small lateral portion of posterior forearm
What is the motor function of the musculocutaneous nerve?
Innervates teres minor, subscapularis, and deltoid
What is the sensory function of the axillary nerve?
Gives of superior cutaneous nerve of arm, which innervates inferior region of deltoid
What is the motor function of the median nerve?
Innervates most of flexor muscles in forearm, the thenar muscles and 2 lateral lumbricals associated with index/ middle fingers
What is the sensory function of the median nerve?
Gives of palmar cultaneous branch. Innervates lateral part of palm. Gives off digital cutaneous branch. Innervates later 3.5 fingers on anterior hand surface.
What is the sensory function of the radial nerve?
Innervates the posterior aspect of the arm and forearm, and posterolateral aspect of the hand. There are 4 branches; Lower lateral cutaneous nerve of arm Posterior cutaneous nerve of arm Posterior cutaneous nerve of forearm Superficial branch
What is the motor function of the radial nerve?
Innervates triceps brachii and muscles in posterior compartment of the forearm. Runs in spiral groove directly against humerus
What is the motor function of the ulnar nerve?
Innervates muscles of hand, flexor carpi ulnaris, medial 1/2 of flexor digitorum profundus
What is the sensory function of the ulnar nerve?
Innervates anterior and posterior surfaces of medial 1.5 fingers and associated palm area
What are the branches of the axillary artery?
Highest thoracic artery Thoracoacrominal artery Lateral thoracic artery Subscapular artery Anterior circumflex humeral artery Posterior circumflex humeral artery
What is the innervation of the shoulder joint?
Axillary, suprascapular, and lateral pectoral nerves
What is the arterial supply of the shoulder joint?
Circumflex arteries of the humerus
What are the origins of the triceps?
Long head- posterior aspect of upper 1/3 of humerus
Lateral head- origin of humerus, insertion onto olecranon process of una
Medial head- arises in medial side below spinal groove
How many heads does the biceps have?
2 Heads
What are the muscles of the anterior arm?
Biceps
Brachialis
Coracobrachialis
What is the origin of the biceps brachii?
Long head; from supraglenoid tubercle of the scapula
Short head; from coracoid process of scapula
What is the insertion of the biceps brachii?
Inserts distally onto radial tuberosity and fascia of forearm via bicipital aponeurosis
What is the action of the biceps brachii?
Supination of forearm
Flexes arm at elbow
What is the origin of the brachialis?
Medial and lateral surfaces of humeral shaft
What is the insertion of the brachialis?
Ulna tuberosity
What is the action of the brachialis?
Main flexor of arm at elbow
What is the origin of the coracobrachialis?
Coracoid process of scapula
What is the insertion of the coracobrachialis?
Medial side of humeral shaft at level of deltoid tubercle
What is the action of coracobrachialis?
Flexes the arm at the shoulder. Weak adduction
What is the insertion of the triceps?
Distally heads converge to 1 tendon, insert onto olecranon of the ulna
What is the innervation of the triceps?
Radial nerve
What is the action of the triceps?
Extends arm at elbow
What is the arterial supply to the posterior compartment of the arm?
Profunda brachii artery
What are the contents of the anteCubital fossa?
Radial nerve
Biceps tendon
Brachial artery
Median nerve
What is Erb’s palsy?
Upper 1 or 2 roots of brachial plexus damaged. External rotators of shoulder are paralysed, extensors of wrist are paralysed.
