Upper Limb Flashcards
What are the 4 major segments of the upper limb?
- Shoulder
- Pectoral (shoulder) girdle
- Arm (brachium)
- Forearm (antebrachium)
- Hand (manus)
What is the 1st and 2nd segments of free upper limb?
1st: Arm (brachium)
2nd: Forearm (antebrachium)
What are the bones of the upper limb?
Clavicle, Scapula, Humerus, Ulna, Radius, Carpal Bones, Metacarpals, Phalanges.
Where is the weakest part of the clavicle?
Junction between its middle and lateral thirds.
What elevates the medal portion of the clavicle when broken?
Sternocleidomastoid
The scapula overlies what ribs?
Ribs 2nd-7th.
What is the point of communication between supra- and infraspinous fossae?
Spinoglenoid notch
Shallow, concave, oval depression that articulates with humerus?
Glenoid fossa
What is the largest bone in the upper limb?
Humerus
What are the types of fractures of the Humerus, the results of fracture and what nerves are at risk for damage.
- Surgical neck: common in elderly due to fall on hand with forces being transmitted upward. Axillary n. at risk for damage
- Transverse fractures of shaft: results from direct blow. deltoid m. will cary proximal fragment laterally (ABD) . Radial n. at risk
- Spiral fractures of shaft: indirect resulting from fall on outstretched hand.Radial n. at risk
- Intercondylar fractures: result from severe fall on flexed elbow that may separate condyle from shaft completely. may damage median or ulnar nn.
What is Colle’s fracture? (most common in forearm)
- Who is it most common in?
- Name for posterior angulation happening in the forearm just proximal to the wrist.
A complete transverse fracture of the distal 2cm of the radius.
- Common in adults 50 and over - more common in women due to osteoporosis.
- Dinner fork deformity.
- healing is good due to rich blood supply.
What are the 8 carpal bones?
Scaphoid, Lunate, Triquetrum (triquetral), Pisiform, Trapezium, Trapezoid, Capitate, Hamate.
(So long to pinky here comes the thumb)
What carpal bones articulate with the radius?
Scaphoid and Lunate.
What carpal bones articulate with 1-5 metacarpals?
1-2: Trapezium
2:Trapezoid
3: Capitate
4-5: Hamate
Whats the most commonly fractured carpal bone?
Scaphoid
What are the joints of the Upper Limb? Name each joint type.
- Scapulothoracic Joint: phsiological (muscular)
- Sternoclavicular Joint: synovial
- Acromioclavicular Joint: synovial
What muscles act upon the scapular thoracic joint?
Trapezius, Rhomboids and Serratus Anterior mm.
What joint of the upper limb provides base from which upper limb operates?
Scapulothoracic joint.
What joint provides only articulation between upper limb and axial skeleton.
Sternoclavicular Joint.
What are the 4 ligaments of the sternoclavicular joint?
Costoclavicular l., Ant/Post sternoclavicular l., Interclavicular l.
What are the two ligaments of the Acromioclavicular joint?
Coracoclavicular l. and Acromioclavicular l.
What two ligaments compose the caracoclavicular l.?
- Trapezoid l. (more lateral of the two) - horizontal
- Conoid l. inverted triangle with base being at conoid tubercle.
A factor of the surgical neck of the humerus might injure which n.?
Axillary nerve
Where is the head of the ulna located?
Located distally
Which bones form the wrist?
Scaphoid, lunate, radius…?
Where is the radial styloid process located?
Distal end of radius on lateral side.
Which carpal bones are found in the proximal row?
Scaphoid, Lunate, Triquetral, Pisiform.
What are phalanges?
Little bone making digits typically there are 3 (proximal, medial, distal) thumb only 2.
The Glenoid fossa accepts little more than a third of humeral head, what muscles via tonus hold it in?
Supraspinatus m., Infraspinatus m., Teres minor m., Subscapularis m.
What slightly deepens the glenoid fossa?
Glenoid labrum (ring-like fibrocartilaginous lip)
What ligaments make up the glenohumeral joint and what is there location and function?
- glenohumeral ll.: strengthen capsule anteriorly, only visible from interior of capsule (intrinsic)
- coracohumeral l.: (intrinsic) strengthens joint superiorly, supporting weight of arm when hanging.
- caracoacromial l.: from coracoid process to acromion of which the inferior aspects form an coracoacromial arch.
- transverse humeral l.: converts IT groove into a canal holding synovial sheath and tendon of long head of biceps brachia m. in the groove.
What are the 4 rotator cuff muscles?
Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.
The deltoid fascia inferiorly is continuous with?
- Pectoral fascia anteriorly
- Infraspinous fascia posteriorly
What are the 6 scapulohumeral muscles?
Deltoid, Teres Major, Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.
What bone protects the neuromuscular bundle?
Clavicle
Which ligament usually prevents dislocation at AC joint?
Caracoclavicular ligament
What does the sternoclavicular joint function as?
Ball-and-socket
The humeral head is held in fossa by tonus of the following…?
Supraspinatus, Infraspinatus, Teres minor, Subscapularis.
What slightly deepens the glenoid fossa?
Glenoid labrum: ring-like fibrocartilaginous lip
Where are the two apertures (opening or gap) of the glenohumeral joint?
- Between tubercles to allow for tendon of long head of biceps brachii m.
- Anteriorly (inferior to caracoled process) that allows communication between sub scapular bursae and synovial cavity.
Deltoid
O: Lateral 1/3 clavicle; acromion and spine of scapula
I: Deltoid tuberosity of humerus
A: Anterior (clavicular) fibers - flexion and MR of humerus. Middle (acromial) fibers - ABD (15-90 degress). Posterior (spinal) fibers - extension and LR of humerus
N: Axillary n. (C5, C6)
B: Anterior and posterior humeral circumflex aa.; acromial and deltoid branches of thoracoacromial trunk.
Teres Major
O: Posterior suface of inferior angle of scapula
I: medial lip IT groove of humerus
A: ADD and MR of humerus; assists with extension from flexed position
N: Lower subscapular n. (C5,C6)
B: Thoracodorsal a.
Supraspinatus (S)
O: supraspinous fossa of scapula
I: Superior fact greater tubercle of humerus
A: Initiates ABD of humerus (first 15 degrees)
N: Suprascapular n. (C4, C5, C6)
B: Suprascapular a.
Infraspinatus (I)
O: infraspinous fossa of scapula I: middle facet greater tubercle of humerus A: LR of humerus N: Suprascapular n. (C5, C6) B: Suprascapular a.
Teres Minor (T)
O: Middle part, lateral border of scapula
I: Inferior facet greater tubercle of humerus
A: LR of humerus; assists with ADD of humerus
N: axillary n. ( C5, C6)
B: Circumflex scapular aa.
Subscapularis (S)
O: subscapular fossa (most of anterior surface of scapula)
I: lesser tubercle of humerus
A: most powerful MR of humerus; assists with ADD of humerus
N: Upper and lower sub scapular nn. (C5, C6, C7)
B: Subscapular a.
Vasculature of scapula humeral muscles?
- Suprascapular a.
- Dorsal scapular a.
- Thoracoacromial trunk
- Subscapular a.
- Thoracodorsal a.
- Ciruculfex scapular a.
- Anterior humeral circumflex a.
- Posterior humeral circumflex a.
Where is suprascapular a. located and what does it innovate?
- From thyrocervical trunk (or directly off subclkavian a.)
- Passes superior to transverse scapular l. (spans suprascapular notch) to supraspinous fossa.
- passes through spinoglenoid notch to infraspinous fossa.
Where is Dorsal scapular a. located and what does it innovate?
- from subclavian a.
- passes through trunks of brachial plexus
- runs along medial border of scapula
- participates in scapular anastomoses
Where is Thoracodorsal trunk located and what does it innovate?
- from 2nd part of axillary a.
- gives off clavicular, acromial, deltoid and pectoral branches
Where is Subscapular a. located and what does it innovate?
- from 3rd part of axillary a.
- descends along lateral border of subscapularis m.
- Terminates as: Thoracodorsal a. , circumflex scapular a.
Where is thoracodorsal a. located and what does it innovate?
- from sub scapular a.
- continues path of sub scapular a.
Where is Circumlflex scapular a. located and what does it innovate?
- from subscapular a.
- curves around lateral border of scapula
- found in triangular space
- key paler in scapular anastomoses
Where is anterior humeral circumflex a. located and what does it innovate?
- from 3rd part of axillary a.
- encircles surgical neck of humerus (passes deep to long head of biceps brachia t.)
- anastomoses with posterior humeral circumflex a. laterally
- often shares a common trunk with posterior humeral circumflex a.
Where is posterior humeral circumflex a. located and what does it innovate?
- from 3rd part of axillary a.
- encircles surgical neck of humerus
- transverses quadrangular space
Innervation of scapulohumeral muscles:
- Suprascapular n.
- Axillary n.
- Upper subscapular n.
- Lower subscapular n.
The muscular spaces of the upper limb are and in general where are they found on the body?
Found posteriorly
- Quadrangular space
- Triangular space
- Triangular interval
What are the borders for the quadrangular space and what does it contain?
Superior - teres minor m. Inferior - trees major m. Lateral - surgical neck of humerus Medial - long head triceps brachia m. -contains: axillary n. and posterior humeral circumflex a.
What are the borders fro the triangular space and what does it contain?
Base - long head triceps brachia m.
Superior - teres minor m.
Inferior - trees major m.
-contains: circumflex scapular a.
What are the borders fro the triangular interval and what does it contain?
base - trees major m.
medial - long head triceps brachii m.
lateral - lateral head triceps brachia m.
-contains: radial n. and profundra brachii a.
Injury to Axillary n. (C5, C6) is usually by what?
- fracture of surgical neck
- dislocation of glenohumeral joint
- compression by improper use of crutches
- intramuscular injections
Injury to axillary n. causes what?
- Deltoid m. atrophy
- Also may cause a loss of sensation over lateral part of proximal arm.
- ABD of humerus from 15-90 degrees would be affected.
Rotator cuff injury is usually caused by?
Continual use of the limbic a position above horizontal.
Trauma to the Rotator cuff may tear one or more of the —– muscles? *hint: SITS
(S) supraspinatus
(I) infraspinatus
(T) Teres minor
(S) subscapularis
What tendon is most commonly injured in a rotator cuff injury?
Supraspinatus tendon
