Upper Limb Flashcards
Pectoral girdle:
- consists of the clavicle and scapula
- suspends the humerus and the upper limb away from the axial skeleton to increase range of movement
- can be elevated, depressed, protracted, and retracted
- elevated (shoulders to ears)
- depressed (shoulders down)
- protracted (horizontal movement - butterfly stroke bringing hands together)
- retracted (butterfly stroke hands apart) on the chest wall
sternoclavicular joint:
- where the medial end of the clavicle articulates with the sternum
- this is the ONLY articulation between the axial skeleton and the upper limb
- it contains an articular disk that divides the joint into 2 joint cavities
- at the joint between the articular disk and the sternum the clavicle can be protracted (arch forward bringing clavicles closer) and retracted (bringing scapula medial and clavicle out)
- at the joint between the articular disk and the medial end of the clavicle the clavicle can be elevated and depressed
acromioclavicular joint
-where the lateral end of the clavicle articulates with the acromion process of the scapula
Clavicular fractures:
- most commonly occur at the weakest point between the middle 1/3 and lateral 1/3
- medial 2/3 of the clavicle may be elevated by the sternocleidomastoid muscle
- lateral 1/3 may be depressed by weight of limb or aDDucted by the pectoralis major
- ventral rami of C8-T1 in the medial cord of the brachial plexus may be lacerated as a result of the fracture
Shoulder trauma to the acromioclavicular joint:
-may cause subluxation (displacement) of the acromion process at the joint
coracoclavicular ligament
- extends from the acromion to coracoid
- prevents dislocation at the acromioclavicular joint
glenohumeral joint:
- ball in socket joint that articulates the head of the humerus with the glenoid fossa of the scapula
- permits flexion and extension
- abduction and adduction
- medial and lateral rotation
Association between humerus and scapula movement
- when the humerus aBducts, the scapula laterally rotates along the chest wall
- when the humerus aDDucts, the scapula medially rotates along the chest wall
- aBduction: for every 2 degrees of abduction of the arm at the glenohemoral joint there is a 1 degree lateral rotation of the scapula
(ie) for every 180 degrees of full aBduction there is 120 degrees of rotation of the humerus and 60 of the scapula
Tendons of the rotator cuff:
- strengthen the articular capsule of the glenohumeral joint
- includes: supraspinatus, infraspinatus, teres minor and subscapularis (SITS)
Inflammation of the rotator cuff:
- tendons may become torn or inflamed
- most commonly affects tendon of supraspinatus
- patients experience pain anterior and superior to the glenohumeral joint during aBduction
Capsule of the glenohumeral joint:
- strengthened by ligaments
- glenohumeral bands: strengthen anterior aspects of the joint
- coracohumeral ligament: strengthens the superior aspect of the joint
- coracoacromial ligament: prevents superior displacement of the head of the humerus
humeral dislocation:
- dislocation of the humerus at the glenohumeral joint most commonly displaces the head of the humerus inferiorly and then anteriorly
- becomes positioned just inferior to the coracoid process
- may stretch the axillary nerve or the radial nerve
humeral fracture of the surgical neck of the humerus
-the axillary nerve may be lesioned and the posterior circumflex humeral artery may be lacerated
humeral fracture of the greater tubercle of the humerus:
- may result in avulsion of the greater tubercle and detachment of the rotator cuff muscles from the humerus
- in these patients the remaining rotator cuff muscle. the subscapularis, medially rotates the humerus at the glenohumeral joint
transverse fracture of the humerus:
- distal to the deltoid tuberosity
- may result in aBduction of the proximal fragment by the deltoid muscle
midshaft fracture of humerus:
- the radial nerve may be lesioned
- profunda brachial artery may be lacerated
supracondylar fracture of humerus:
- contractions of the triceps and the brachialis may shorten the arm
- median nerve may be lesioned as a result of intercondylar or supracondylar fracture of the distal end of the humerus
Elbow joints:
- humeroradial joint, humeroulnar joint, and proximal radioulnar joint
- humeroradial and humeroulnar joints are hinge joints that permit flexion and extension
humeroradial joint:
head of the radius articulates with the capitulum of the humerus
humeroulnar joint:
-trochlear notch of the ulna articulates with the trochlea of the humerus
proximal radioulnar joint:
- the radial notch of the ulna articulates with the head of the radius
- pronation and supination occur at this joint and at the distal radioulnar joint
Lateral Epicondylitis:
- tennis elbow
- an inflammation of the common extensor tendon that results from forced extension and flexion of the forearm at the elbow
- patients exhibit pain over the lateral epicondyl (may radiate down the posterior aspect of the forearm)
Medial epicondylitis:
- golfer’s elbow
- an inflammation of the common flexor tendon that results from repetitive flexion and pronation of the forearm at the elbow
Fracture of the medial epicondyle of the humerus:
-ulnar nerve may be lesioned
Articulations of the wrist:
- proximally with the radius at radiocarpal and ulna at ulnocarpal joints
- distally with the metacarpels at caropmetacarpal joints
What forms the radiocarpal joint?
-distal end of the radius, scaphoid, and lunate
What forms the ulnocarpel joint?
-formed by the distal end of the ulna, an articular disk, and the triquetrum
What do the radiocarpal and ulnocarpel joints allow?
- flexion/extension
- aBduction (radial deviation wave hi wrist towards thumb)
- aDDuction (ulnar deviation wave hi wrist towards pinky)
Colles’ Fracture
- fracture of the distal radius
- may result in avulsion of the styloid process from the shaft of the radius
- radius may be shortened and styloid process of the ulna may project further distally than the styloid process of the radius
- fracture of the distal radius, forearm, or hand may exhibit a “dinner fork” deformity as a result of the posterior displacement of the distal part of the radius
How many carpel bones are there?
8
Arrangement of the carpel bones
-into 2 loosely arranged rows: proximal and distal
Proximal row:
- contains (lateral to medial) scaphoid, lunate, triquetrum, and pisiform bones
- pisiform is anterior to triquetrum
- pisiform is a sesamoid bone that is embedded in the tendon of the flexor carpi ulnaris
Distal row:
-contains (lateral to medial) trapezium, trapezoid, capitate, and hamate bones
Lunate dislocation:
- lunate is most commonly dislocated carpal bone
- it is typically dislocated anteriorly into the carpal tunnel
- dislocation may cause carpel tunnel syndrome
carpal tunnel formed by:
- formed posteriorly by the 8 carpel bones
- anteriorly by the flexor retinaculum which attaches medially to the pisiform and hamate, laterally to the tubercles of the scaphoid and trapezium
carpel tunnel contains:
-median nerve and 9 tendons that arise from the 3 flexor muscles
3 flexor muscles of the forearm:
in the anterior forearm:
- flexor digitorum superficialis
- profundus
- flexor pollicis longus
Canal of Guyon:
- situated between the pisiform and the hook of the hamate superficial to the carpel tunnel
- ulnar nerve, artery, and vein cross the wrist and pass into the hand after transversing it
Joints in each of the 4 fingers:
- formed by a metacarpel and 3 phalanges
- metacarpophalangeal (MP) joint
- proximal interphalangeal (PIP) joint
- distal interphalangeal (DIP) joint
MP Joint:
- metacarpels articulate with the proximal phalanges
- MP joints are condyloid joints: permit flexion, extension, aBduction, and aDDuction
PIP Joint:
- proximal phalanges articulate with the middle phalanges
- hinge joint: permits flexion and extension
DIP joint:
- middle phalanges articulate with the distal phalanges
- hinge joint: permits flexion and extension
Thumb joints:
- 3 joints
- carpometacarpal
- MP joint
- interphalangeal joint
- MP and interphalangeal joints of the thumb have actions similar to those in the fingers
Carpometacarpel joint:
- formed by the first metacarpel and by the trapezium
- saddle joint: permits flexion, extension, aBduction, aDDuction, and rotation
Anatomic Snuffbox:
- small region on the posterolateral part of the wrist
- formed by the tendons of the 2 extensor muscles of the thumb and the aBductor pollicis longus
- lateral border: extensor pollicis brevis and aBductor pollicis longus
- Medial border: extensor pollicis longus
What is in the floor of the snuffbox:
-scaphoid and trapezium bones
Blood supply/innervation in snuffbox:
- radial artery passes through the snuffbox
- superficial branch of the radial nerve innervates the skin over the snuffbox
Scaphoid fracture:
- most commonly fractured carpal bone
- patient exhibit pain and tenderness localized over the snuffbox
- proximal part of the scaphoid may undergo avascular necrosis because the blood supply to the bone supplies the distal part first and then the proximal part
Humeral fracture nerves affected:
ARM fracture:
From superior to inferior:
Axillary: head of humerus
Radial: mid shaft
Median: supracondular
Subclavian artery branches:
- arises from the brachiocephalic artery on the right and the arch of the aorta on the left
- becomes the axillary artery at lateral border of the first rib
Thyrocervical trunk of the subclavian:
-gives rise to the suprascapular and transverse cervical arteries which supply muscles that attach to the scapula
suprascapular artery:
- crosses posterior to the triangle of the neck
- passes over the transverse scapular ligament
- supplies the supraspinatus and infraspinatus on the posterior aspect of the scapula
- to remember think Air force = ABOVE while navy = BELOW
- artery is above the suprascapular ligament, nerve is below
transverse cervical artery
- crosses the posterior triangle of the neck
- divides into a superficial branch that supplies the trapezius
- divides into a deep branch (dorsal scapular artery) that supplies the rhomboids and the levator scapulae
- runs with accessory nerve
axillary artery:
-divided into 3 parts by the pec minor and has 6 branchs:
1 from the first, 2 from the second, and 3 from the third
"Screw The Lawyer Save A Patient": Superior thoracic Thoracoacromiol Lateral thoracic Subscapular Anterior circumflex humeral Posterior circumflex humeral
first part of the axillary artery:
-contains the superior thoracic artery which supplies the first 2 intercostal spaces and the serratus anterior