Upper Limb Flashcards
Where is the only bony articulation b/w the upper limb and axial skeleton?
Where the medial end of the clavicle attaches with the sternum
Clavicle
attaches upper limb to axial skeleton via STERNOCLAVICULAR JOINT (joints to manubrium)
- enables the upper limb to be suspended away from axial skeleton
Structure:
- Sternal end (medial) has sternal facet which articulates with manubrium
- Conoid Tubercule: where conoid ligament attaches to the clavicle
- Trapezoid Line: where the trapezoid ligament attaches
- Acromial End: articulates with acromion process of scapular via acromial facet
Scapula
Flat, triangular bone lying posterior to the ribs
Attaches to the clavicle at the acromio and coracoclavicular joints
Structure:
- Acromion
- Coracoid process
- Glenoid Cavity (where humerus articulates)
- Supraspinous fossa
- Subscapular Fossa
- Spine of Scapula
- Coracoclavicular ligament
Straight edges = borders (superior, lateral, medial)
Corners = angles (superior, lateral, inferior)
Carpal, Metacarpals and Phalanges
8 carpal bones arranged in 2 rows
- proximal row articulates with the base of radius via the LUNATE and SCAPHOID
distal row articulates with metacarpals
Humerus
articulates with the socket of glenohumeral joint
articulates distally with radius and ulna at elbow joint complex
Structure:
- Greater Tubercule
- Less Tubercule
- Anatomical neck (region b/w head and shaft)
- Surgical Neck
- Intertubercular Groove
- Deltoid Tuberosity
Elbow Joint Complex
Made of:
HUMERO-ULNAR JOINT and HUMERO-RADIAL JOINT
and the RADIO-ULNAR joint
Distal articular surface of the humerus is a condyle, specialised to articulate with radius head
Structure: Anterior View: 1. Radial Fossa 2. Coronoid Fossa 3. Lateral epicondyle 4. Capitulum (lateral part of anterior articular surface) 5. Trochlea (medial part of ant. art. surface0 6. Medial epicondyle
Posterior:
1. Olecranon Fossa
Radius and Ulna
Radius = thumb side/lateral Ulna = medial/pinky side
Structure Anteriorly:
1. Head of radius - articulates with capitulum at radiohumeral joint and medially with notch of ulna at the proximal radio-ulna joint
- Radial Tuberosity
- Styloid process of Radius
- Cronoid Process
- Tuberosity of Ulna
- Styloid process of Ulna
Posteriorly:
- Olecranon
- Interosseous membrane
- Dorsal tubercule of radius
- Ulnar notch (notch in the base of the radius that articulates with the ulna
Scaphoid Fracture
the most common upper limb fracture when falling onto the hand
Sternoclavicular Joint
Manubrium and clavicle articulate
Joint = surrounded by a capsule stabilised by the:
- ant. and post. sternoclavicular ligaments
- interclavicular ligament
- costoclavicular ligament
Articular Disc sits within this joint and is where movement of clavicle occurs
Acromioclavicular and Coracoclavicular Joints
Acriomioclavicular: where acromion of scapula articulates with clavicle
- some movement
- joint capsule stabilised by ACRIOMIOCLAVICULAR LIGAMENT
Coracoclavicular Joint: where coracoid process of scapular articulates with clavicle
- coracoclavicular ligament attaches clavicle –> scapula
- made up of trapezoid and coroid ligaments
Shoulder Joint/Gleno-Humeral Joint
head of humerus articulates with glenoid cavity of scapula
Elbow Joint
Hinge Joint b/w TROCHLEAR NOTCH of ulna and TROCHLEA of humerus b/w head of radius and capitulum of humerus
Radioulnar Joints
Join at 3 points:
- Proximal Radio-ulnar Joint - part of elbow joint
- Interosseous Membrane - holds 2 bones together
- Distal Radio-ulnar joint - holes 2 bones together at rist
Wrist Joint
b/w base of radius and lunate, scaphoid and triquestral bones
- head of ulna is involved, but it is covered by a thick, articular disc
Joints of the Hand
Intercarpal Joints
Carpometacarpal
Metacarpophalangeal (MCP)
Interphalangeal (IP)
Movements
Scapula: mainly PROTRACTION/RETRACTION (ant/post), rotation when shoulder joint abducts
Glenohumeral Joint:
- flexion/extension
- circumduction
- rotation
Elbow Joint Proper:
- flexion and extenion
Proximal Radio-ulnar Joint:
- pronation/supination
Wrist:
- Flexion/extension
- abduction/adduction
- circumduction
Carpometacarpal Joints:
Thumb can do: flexion/extension, abduction/adduction and circumduction
- other: only gliding movements
Metacarpophalangeal:
- flexion/extension
- abduction/adduction
- circumduction
IP:
- flexion/extension
Glenohumeral Joint
shoulder joint b/w head of humerus and glenoid fossa of scapula
SCAPULO-HUMERAL RHYTHM: all movement at shoulder joint will move scapula
Pectoralis Major Muscle
Connects Thorax –> Humerus and produces powerful upper limb movements
- abduction/adduction
- flexion/extension
Attaches:
- proximally along clavicle, sternum, costal cartilages
- distally along lateral lip of intertubercular sulcus
Latissimus Dorsii Muscle
connects thorax –> posterior humerus
Attaches:
- proximally to SPINOUS PROCESSES of lower thoracic vertebrae
- thocolumbar fascia
- iliac crest
- inferior ribs
How does the muscle work when arm is by side?
- distal attachment is twisted around itself to attach –> humerus
- -> inf. part attaches superiorly, and vice versa
- —-> creates tension in different parts of muscle in different positions so muscle can produce movement in many positions
Pectoralis Minor
Connects scapula to thorax to hold it in place during movement
Deep to pectoralis major
Attaches:
- to thorax via ribs close to the costal carilages
- to scapula at the coracoid process
Serrator anterior muscle
deep to pectoralis minor
Attaches:
- anteriorly to ribs
- posteriorly to scapula along anterior surface of medial border
What is “winging”
When nerve damage means that serratus anterior is not maintaining the relationship b/w the thoracic wall and scapula
Deltoid Muscle
Divided into 3 parts to allow for flex/ext, abd/add at glenohumeral joint
- Anterior part
- Middle Part
- Posterior Part
Attaches:
- proximally at clavicle, acromion and spine of clavicle
- distally at the deltoid tuberosity of humerus
Rotator Cuff Muscles
allow for fine movements
Role: to limit movement at shoulder joint to confer stability
- keeps the large humeral head centred at small glenoid fossa
- Subscapularis
- attaches on anterior surface in subscapular fossa - Supraspinatus:
- attaches posteriorly abvoe spine of scapular in supraspinous fossa - Infraspinatus
- posteriorly below spine of scapular in infraspinous fossa - Terers Mino
- runs along lateral border of scapula
Where is the shoulder joint most likely to dislocate?
Shoulder joint = limited the most SUPERIORLY as there is a skeletal arch formed by the coracoid process, acromio- and coracoacromial ligaments.
—> useful in preventing shoulder from popping out
Most likely to get an ANTERIOR or INFERIOR shoulder dislocation as scapula is medial and skeletal arch = superior.
Shoulder Joint Stabilisation
- Glenoid Labrum (rim of fibrocartilage deepening socket of glenoid cavity)
- Tendon of Long Head Brachii
- helps stabilise by running through the joint and is held in the bicipital groove by the transverse humeral ligament
Ligaments of Shoulder Joint Capsule
INTRACAPUSLAR LIGAMENTS form joint capsule:
- Superior, middle and inferior glenohumeral ligaments
- Coracohumeral ligaments
- Transverse humeral ligament
Redundant capsule: slack part of capsule that allows upper limb to fully abduct over head
Fibrous Membrane: wraps around joint capsule to hold it tog
Anterior Arm Muscles
BICEPS BRACHII
Attaches Proximally:
- long head’s tendon runs through intertubercular groove to stabilise shoulder joint
- short head attaches to coracoid process of scapula
Distally:
- radial tuberosity
- bicipital aponeurosis
Crosses shoulder and elbow joint
- –> increases stability at shoulder
- –> contributes to flex/supination at elbow
- BRACHIALIS
Deep to Biceps brachii
- doesn’t cross shoulder joint
Attaches:
- from humerus –> ulnar tuberosity and coracoid process of ulna
Ulna = main bone for flexion of elbow, so brachialis contributes significantly to flexion
- CORACOBRACHIALIS
- deepest
Attaches:
- from coracoid process of scapula to humerus
helps with:
- flexion and adduction at shoulder joint (anteromedial)
Posterior Arm Muscles
- TRICEPS BRACHII
Attaches:
- long head to scapula just below glenoid cavity
- lateral and medial heads to posterior surface of humerus
- distally to olecranon of ulna and through some forearm fascia
Function:
- maintain shoulder stability
- main elbow extensor
Brachioradialis Muscle
Acts at elbow joint = a weak elbow flexor
- belly lies in anterior of forearm, but is INNERVATED by the same nerve as posterior forearm muscles
- acts MAXIMALLY during MID-PRONATION of forearm (eg: bringing a glass to your mouth)
What movements are the Biceps brachii, brachialis, coracobrachialis, brachoradialis and triceps brachii involved in?
Bb: supination and flexion of elbow, shoulder stability
Brachialis: flexion of elbow
Coracobrachialis: shoulder flexion, adduction and stability
Triceps brachii: forearm extension, shoulder stability
Brachoradialis: weak elbow flexor, flexion in mid-pronation
Elbow Flexion and Extension
Hinge joint formed by trochlear notch of ulna articulating with trochlea of humerus
- head of radius moves on capitulum of humerus
Pronation and Supination - Elbow
Head of radius rotates with CAPITULUM of humerus
Muscles:
- SUPINATOR: attaches:
- proximally to lateral epicondyle of humerus and to ulna
- distally to radius - PRONATOR TERES:
- more distal
attaches:
- from coronoid process and medial epicondyle of humerus –> lateral surface of radius - PRONATOR QUDRATUS
attaches:
- b/w anterior radius and anterior ulna at distal forearm
Elbow Joint Ligaments and Capsule
- RADIAL/LATERAL COLLATERAL LIGAMENT
- on lateral part of capsule - ANNULAR LIGAMENT: wraps around head of radius to allow head to rotate on capitulum while preventing lateral deviation
- ULNA/MEDIAL COLLATERAL LIGAMENT
- on medial part - Synovial membrane: helps radial head glide smoothly during pronation/supination
Muscles of Anterior Forearm
Medial epicondyle: common flexor tendon where most forearm flexors attach
Superficial:
- Pronator teres (flex wrist)
- Flexor Carpi Radialis (abducts)
- Flexor carpi ulnaris (adducts)
- Plamaris longus (flex)
Intermediate:
5. Flexor digitorum superficialis
Deep:
- Pronator quadratus
- Flexor digitorum profundus (FDP)
- Flexor pollicis longus (FPL)
Muscles of Posterior Forearm
Lateral epicondyle = common extensor origin
Superficial: 1. Brachioradialis 2. Extensor carpi radialis longus 3. Extensor carpi radialis brevis 4. Extensor digitorum 5. Extensor digiti minimi Extensor ulnaris
Deep:
- Abductor pollicus longus
- Extensor pollicus brevis
- Extensor pollicus longus
- Extensor indicus
Carpal Tunnel
A restricted space beneath the FLEXOR RETINACULUM (deep band of fascia the tendons of anterior forearm go under to get to hand to prevent flexor tendons from BOWSTRINGING)
Flexor tendons and median nerve = most susceptible to compression injury
Intrinsic Hand Muscles
- Thenar (thumb/radial side)
- Adductor (deep to thenar, contains adductor pollicus)
- Hypothenar (medial/ulnar side)
- Central
5 Interosseus
Arteries of Upper Limb
- subclavian (from either left or right) –> 2. Axillary –> 3. Brachial –> 4. Radial and Ulnar –> 5. Interconnecting arches to supply hand
Veins of Upper Limb
Dorsal venous network of hand drains to 2 superficial veins:
1. Cephalic vein (lateral)
2. Basilic vein (medial)
both drain via AXILLARY VEIN to subclavian vein in neck
Deep veins: follow arteries as venae comitantes
Brachial Plexus
5 roots which emerge from anterior rami of C5, 6, 7, 8 and T1
- Each root splits –> pos. and ant. for superior, middle and inferior trunks
- Each division then joins back tog to form 3 cords (lat. post, medial)
- Each cord branches into one of 5 terminal branches (musculocutaneous, axillary, radial and medial)
Why do nerves branch?
allows different muscles to contract together and be innvervated from different nerves, but the same spinal root –> can send the right axon to the correct muscle to enable coordinated muscle contractions.
