Upper Extremity Lecture Questions Flashcards
What are the major areas of transition in the upper extremity?
-The axilla
-Cubital fossa
-Carpal tunnel
What is the main communication between the upper arm and the neck?
the axilla
What is the main communication between the arm and forearm?
the cubital fossa
What is the main communication between the forearm and hand?
the carpal tunnel
What percent of the head of the humerus articulates with the glenoid cavity? Why?
only about 30%, because the shoulder has to be really mobile in order to move the hand and arm through space
How many degrees of shoulder abduction comes from the glenohumeral joint? Where does the rest of shoulder abduction come from?
Glenohumeral joint accounts for 120 degrees and the rest of the 60 degrees of abduction comes from the scapula
What is thoracic inlet syndrome?
when structures in thoracic inlet are compressed
What structures form the thoracic inlet?
-Lateral margin of rib I
-The posterior surface of the clavicle
-The superior margin of scapula
-The medial surface of the coracoid process
What are the major vessels and nerves that pass through the thoracic inlet?
-Nerves to upper limb
-Axillary vein
-Axillary artery
What muscles make up the posterior thoracic wall?
-Trapezius
-Levator scapulae
-Rhomboid major & minor
-Latissimus dorsi
-Serratus anterior
Which muscles make up the anterior thoracic wall?
-Pectoralis major & minor
What plexus innervates the upper limb?
The brachial plexus
What are the major nerves of the upper limb?
-Musculocutaneous nerve
-Median nerve
-Radial nerve
-Ulnar nerve
-Axillary nerve
What bones make up the pectoral girdle?
-Proximal humerus
-Scapula
-Clavicle
What joints are in the pectoral girdle?
-Glenohumeral
-Acromioclavicular
-Sternoclavicular
What is unique about the clavicle?
It is the only bony attachment between the trunk and upper limb
What is the function of the coracoacromial ligament?
It prevents the head of the humerus from being dislocated superiorly
What structure provides the major stability in the shoulder? Why?
The glenoid labrum provides the most stability in the shoulder because it increases the depth of the glenoid cavity by about 50%
What is the largest bursa in the body? What is a common occurence in this bursa?
The subacromial bursa, which sits right on top of the tendon of the supraspinatus. Inflammation is common here, because it is right in between the supraspinatus and the deltoid, so there isn’t much space for it to move.
What are the main stabilizers of the shoulder?
-Glenoid labrum
-Supraspinatus, upper part of the capsule, and coracohumeral ligament
-Rotator cuff tendons & fibrous capsule
-Long head of biceps and coracoacromial arch
What movement does the surpaspinatus, upper part of the capsule, and the coracohumeral ligament limit?
Prevents downward displacement
What movement does the rotator cuff tendons and fibrous capsule limit?
They act as a guardian of the joint, so movement in all directions
What movement does the long head of biceps tendon and coracoacromial arch limit?
Prevents upward dislocation of the humerus
What are the 2 main disorders of the rotator cuff?
-Impingement
-Tendinopathy
What muscle in the rotator cuff is the most commonly affected? Why?
The supraspinatus is typically the most affected because it has poor blood supply and it passes between the acromion and the acromioclavicular joint, so it has very limited space
What forms the anterior wall of the axilla?
Formed by the lateral part of the pec major, pec minor, and subclavius muscles
What forms the posterior wall of the axilla?
Formed by the subscapularis, latissimus dorsi, posterior scapular muscles
What forms the lateral wall of the axilla?
Formed by the humerus
What forms the medial wall of the axilla?
Upper thoracic wall and the serratus anterior muscle
What muscles are in the superficial anterior compartment of the forearm?
-Flexor carpi ulnaris
-Palmaris longus
-Flexor carpi radialis
-Pronator teres
What muscles are in the intermediate anterior compartment of the forearm?
-Flexor digitorum superficialis
What muscles are in the deep anterior compartment of the forearm?
-Flexor digitorum profundus
-Flexor pollicis longus
-Pronator quadratus
What nerve innervates all the muscles in the posterior compartment of the forearm?
The radial nerve
What nerve innervates the anterior compartment of the forearm? Are there any exceptions?
-The median nerve.
-It innervates everything except for the flexor carpi ulnaris and the medial half of the flexor digitorum profundus which is innervated by the ulnar nerve
What muscles are in the superficial posterior compartment of the forearm?
-Brachioradialis
-Extensor carpi radialis longus
-Extensor carpi radialis brevis
-Extensor digitorum
-Extensor digiti minimi
-Extensor carpi ulnaris
-Anconeus
What muscles are in the deep posterior compartment of the forearm?
-Supinator
-Abductor pollicis longus
-Extensor pollicis brevis
-Extensor pollicis longus
-Extensor indicis
Where do most of the muscles in the deep posterior compartment originate from? Which muscle does not originate there?
-The posterior surface of the radius and ulna, and the interosseous membrane
-The supinator does not originate here
Where do the muscles in the superficial anterior compartment of the arm originate from?
-The medial epicondyle of the humerus
What are the major arteries of the forearm?
-Radial artery
-Ulnar artery
-Common interosseous artery
What does the ulnar nerve give rise to?
-Muscular branches
-Palmar branch
-Dorsal branch
Where do the muscles in the superficial posterior compartment of the forearm originate from?
-The supraepicondylar ridge and lateral epicondyle of the humerus
What are the three fossa of the distal humerus?
-Radial fossa which is superior to the capitulum
-Coronoid fossa which is superior to the trochlea
-Olecranon fossa which is superior to the trochlea on the posterior surface
What is the etiology of a biceps tendon rupture? What functional consequences are there?
-It happens from a sudden contraction of the biceps associated with resisted elbow flexion and supination
-There is very little functional consequences since the brachialis performs the majority of elbow flexion
What puts people at higher risk of rupturing their biceps tendon?
-Age: older people are more likely
-Smoking: nicotine use affects health of tendons
-Corticosteroids: linked to increase muscle and tendon weakness
-Gender: more common in males
What are the main arteries in the upper arm?
-Brachial artery located in the anterior compartment
-Profunda brachii located in the posterior compartment
What are the main veins in the upper arm?
-Paired brachial veins which pass along the medial & lateral side of the brachial artery
-Basilic vein which passes inferiorly to pec minor and on the medial/ulnar side of the arm
-Cephalic vein which passes superiorly to the pec minor and on the lateral/radial side of the arm
What is the purpose of the fat pads in the synovial membrane of the elbow?
-They fill the space so that the joint is not loose
What are the main ligaments at the elbow that help form the joint capsule?
-Radial collateral ligament
-Ulnar collateral ligament
-Annular ligament of radius
What structures form the cubital fossa?
-Line between lateral and medial condyles
-Brachioradialis
-Prontator teres
What passes through the cubital fossa?
-Brachial artery
-Median nerve
-Biceps brachii tendon
What is the ceiling of the cubital fossa? What is its function?
-Bicipital aponeurosis
-It protects the brachial artery
