Upper Limb Anatomy Flashcards
What is the axilla?
Pyramidal space below the shoulder joint. Provides passageway for vessels and nerves going to and from the upper limb.
What forms anterior wall of axilla?
Pectoralis major and Pectoralis minor muscles.
What forms posterior wall of axilla?
Teres major muscle
Medial wall of axilla?
Thoracic wall and serratus anterior muscle.
Lateral wall of axilla?
Intertubercular groove of the humerus.
What is the axillary artery a continuation of?
subclavian.
Where does the axillary artery begin?
Lateral border of 1st rib.
What does the axillary artery become after it leaves axilla?
Brachial artery. (changes name at lower margin of teres major muscle)
What are the nerve roots of the brachial plexus?
C5, C6, C7, C8 and T1.
What is Erb’s point?
Landmark of brachial plexus on upper trunk. Erb’s palsy.
- Upper trunk of plexus?
2. Lower trunk of plexus?
- C5, C6
2. C8 , T1 (Klumpke’s palsy)
What are the 3 cords of the brachial plexus?
Lateral (C5 and C6)
Posterior (C7)
Medial (C8 and T1)
What are the branches of lateral cord?
Lateral pectoral.
Lateral root of median nerve.
Musculocutaneous nerve.
What are the branches of medial cord?
Medial pectoral. Ulnar nerve. Root of median nerve. Medial cutaneous nerve of arm. Medial cutaneous nerve of forearm.
What are the branches of posterior cord?
Thoracodorsal nerve.
Radial nerve.
Axillary nerve.
Subscapular nerve.
What are the major arterial branches of the upper limb?
Brachial artery.
Ulnar artery.
Radial artery.
What are the main superficial veins of the upper limb?
Cephalic vein
Basilic vein.
Median cubital vein.
Where does the dorsal venous arch lie?
Dorsum of the hand. Dorsal venous plexus.
Where does the 1. Cephalic vein arise and 2. Basiclic vein arise?
- Lateral end of dorsal venous arch.
2. Medial end of dorsal venous arch.
What does the median cubital vein do?
Large communicating vein, shunts blood from cephalic to basilic vein.
What are the dermatomes in the upper limb?
C5-T1. C6 - thumb C7 - index and middle C8 - ring and pinky T1 - arm after pinky leading up.
What is the Glenohumeral joint?
A ball (head of humureus) and socket (glenoid cavity) joint between the scapula and the humerus. It is the major joint connecting the upper limb to the trunk. Rim of cartilage surrounding socket is glenoid labrum.
- What makes up the clavicle?
2. What is the weakest point of clavicle?
- Sternal and acromial ends. Medial and Lateral convexity.
2. Junction between medial 2/3 and lateral 1/3
What makes up the scapula?
Acromion Coracoid process Glenoid cavity Spine of scapula Supraspinous and infraspinous fossa Subscapular fossa Medial and lateral border Inferior and superior angle Supra- and infraglenoid tubercle.
What type of joints are the Acromioclavicular and sternoclavicular?
Synovial plane.
What muscles are responsible for elevation of scapula?
Upper trapezius
Levator scapulae
What muscles are responsible for depression of scapula?
Lower trapezius
pectoralis minor
Muscles causing protraction (forward) of scapula?
Serratus anterior
Pectoralis major
Muscles causing retraction (backward) of scapula?
Trapezius (middle)
Rhomboids
Muscle causing Lateral (upward) rotation: Elevating glenoid cavity?
Upper and middle trapezius
Serratus anterior
Muslces causing medial (downward) rotation: Depressing Gelnoid cavity?
Gravity
Levator scapulae
Rhomboids
Pectoralis minor
Function of glenoid labrum?
Depens glenoid cavity and increases surface of shoulder joints.
What does the caracoacromial ligament do?
Strengthens superior aspect of joint capsule.
What does the coraco-acromial arch do?
Prevents superior displacement of the humeral head.
Which part of the shoulder joint is the weakest?
Inferior part as not protected by muscles and ligaments.
What are Bursae?
Fluid filled interior that provide cushioning around joints.
What is the role of subracromial bursa?
Reduce friction. Supports deltoid and supraspinatus muscles.
What is the most important role of rotator cuff muscles?
Supply mobility and stability of the joint.
What are the deep veins in the upper limb?
Brachial veins
Ulnar veins
Radial veins
Where do all lymphatic vessels from the upper limb drain into?
Axillary nodes.
What does the glenohumeral ligament do?
Strengthens the anterior aspect of the joint capsule.
What does the suprascapular bursa do?
Communicates with joint cavity. Reduces wear and tear on the suprascapularis tendon.
What does the deltoid do?
Anterior fibres - flex and medially rotate at the shoulder joint.
Middle fibres - abduct at the shoulder joint.
Posterior fibres - extend at the shoulder joint.
What does the pectoralis major do?
Flexes and medially rotates the humerus at the glenohumeral joint.
What does the serratus anterior do?
Protraction of scapulae, stabilises during limb movements.
What does the trapezius do?
Superior fibres - elevates scapula.
Middle fibres - retract scapula
Inferior fibres - pull scapula inferiorly.
(accessory nerve)
What does the teres major do?
Adduction of shoulder joint.
What does the latissimus dorsi do?
Extension and internal/medial rotation of shoulder joint.
What is the biceps brachii?
Where does it arise?
What does the muscle act on?
Most anterior muscle of the anterior arm.
Arises from the scapula by two heads.
Act on both shoulder, elbow and radio-ulnar joints.
What are the 2 heads of the bicep brachii and where do they arise?
Short - arises from coracoid process.
Long - arises from supraglenoid tubercle.
To which bony process of the radius is the tendon of biceps attached to distally?
Radial tuberosity.
What is the action of the biceps on the shoulder and elbow joint?
Flexes both joints.
What is the action of biceps on superior radio-ulnar joint?
Powerful supinator.
What is the nerve supply to the bicep brachii?
Musculacutaneous nerve - Lateral cord of brachail plexus.
Which cervical segments innervate the biceps brachii?
5th, 6th and 7th
What is the coracobrachialis and where does it arise?
Slender, rounded muscles arising from tip of coracoid process and is inserted into medial margin of humerus.
What is the action of coracobrachialis on the shoulder?
Adduction and flexion
What never supplies the coracobrachialis?
Musculocutaneous nerve
What is the brachialis and where does it arise?
Strong muscle arises from front of distal half of the shaft of humerus. Inserted into coronoid process of ulna.
What is the main action of the brachialis on the elbow?
Flexion
Which nerve supplies the brachialis?
Musculocutaneous nerve.
Where does the musculocutaneous nerve arise and descend.
Arises from lateral cord of brachial plexus. Main nerve of anterior compartment of arm. Perforates coraco-brachalis and descends between biceps and brachilalis. It continues as lateral cutaneous nerve of forearm.
Brachial artery: Where does it begin, end, and come from?
Direct continuation of the axillary artery.
Begins at lower border of teres major muscle and ends in cubital fossa close to neck of radius where it divides into radial and ulnar arteries.
Median nerve: Where does it arise, descend and end?
Arises in the axilla by two roots - on from medial and one from lateral. Descends along the lateral side of axillary artery and upper part of brachial artery. Enters the cubital fossa.
Ulnar nerve: Where does it arise, descend and end?
Arises from medial cord of brachial plexus. Descends along the medial side of brachial artery and then enters posterior compartment of arm through medial intermuscular septum. Runs along medial head of tricep and back of medial epicondyle.
What is the cubital fossa?
What are its borders?
A triangular depression in front of the elbow.
Base - line between 2 epicondlyes
Medial border - Prontor teres muscle
Lateral border - Brachioradialis muscle
Where does the triceps arise and cover?
Occupies the entire posterior compartment of the arm. Arises long head from scapula and 2 shorter heads from humerus.
What is the nerve supply of the triceps and ancouneus?
Radial nerve
What is the main action of the of the triceps and anconeus on the elbow joint?
Extension
What bone is the olecranon and coronoid process a part of?
Ulna
What does the radial nerve innervate?
All the extensor muscles of the elbow and wrist joint.
Where does the radial nerve run?
Enters anterior to triceps and runs with profunda femoris artery, main branch of brachial, and curves around midshaft region of humerus in radial groove. (radial artey and nerve)
What is segmental value of radial nerve?
C5,6,7,8 T1
What is characteristic of a radial nerve injury?
Wrist drop
What type of joint is the elbow? What movement does this allow?
Synovial hinge - allows flexion and extension.
What muscles flex the elbow?
Brachialis
Bicep Brachii
Brachioradialis
What muscles extend the elbow?
Triceps brachi
Anioreus.
What are the ligaments of the elbow?
Medial (ulnar) collateral
Lateral (radial) collateral
What ligament forms a collar and hold head of radius?
Annular
What type of joint are the radio-ulnar joints?
Proximal (top) and Distal (bottom) = pivot synovial.
What muscles are involved in supination of the radio-ulnar joint?
Biceps Brachi - Most powerful
Seperator muscles
What muscles are involved in the pronation of the radio-ulnar joint?
Pronator teres - most powerful
Pronator quadratus.
What are the 4 muscles of the superficial group in the forearm?
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris - flex wrist, median nerve.
What is the action of the pronator teres?
What is the innervation of the muscle?
Pronation of forearm and Flexion of wrist
Median nerve.
What is the action of the Flexor Carpi Ulnaris?
Innervation?
Flexion and adduction of wrist.
Ulnar nerve
What is the action of the Flexor Carpi Radialis?
Innervation?
Flexion and abduction of the wrist.
Median nerve
On what joint does the brachioradialis act?
What is its action?
Which nerve innervates it?
Elbow
Flexion at the elbow
Radial nerve.
To which fingers is the Flexor Digitorum Superficialis 4 tendons attached to?
What nerve innervates it?
Index
Long
Ring
Little
Median nerve.
What do these FDS tendons do?
Flex wrist, metacarpophalangeal and interphalangeal joints.
What are the 3 deep muscles of the anterior forearm?
Flexor digitorum profundus (FDP) (ulna) Flexor pollicis longus (radius) Pronator quadratus (distal parts of bones)
What is the action of the FDP on wrist and joints of the fingers?
Flexes wrist and distal interphalageal joints of digits 2,3,4,5.
What is the innervation of the FDP?
Ulnar nerve to median part.
Median nerve to lateral part.
What is the innervation of the Flexor pollicis longus?
Long flexor of the thumb.
Anterior interassueus nerve.
What is the action and innervation of the pronator quadratus?
Pronates forearm
Anterior interossues nerve.
Median nerve is main nerve of anterior compartment - what muscles does the median nerve not supply in the forearm?
Brachioradialis
Median half of FDP.
What is the relationship of the brachial artery to the median nerve in the cubital fossa?
Medial to brachial artery.
Enters below - in carpal tunnel.