Upper limb Flashcards
What are the bone(s) that constitute the pectoral girdle?
Scapula and clavicle
What are the bone(s) that constitute the arm?
Humerus
What are the bone(s) that constitute the forearm?
Ulna and radius
What are the bone(s) that constitute the hand?
1) Carpal
2) Metacarpal
3) Phalanges
What are the 6 joints of the upper limb?
1) Scapulohumeral
2) Acromioclavicular
3) Sternoclavicular
4) Elbow
5) Wrist
6) Carpometacarpal
7) Interphalangeal
What are the 3 types of joints?
1) Fibrous
- fibrous tissue → no/little mvt
2) Cartilaginous
- hyaline or fibrocartilage → small amount of mvt
3) Synovial joint
- bones covered by hyaline cartilage, separated by joint cavity → greatest degree of movement
What are 3 factors that determine the stability of a synovial joint?
1) Shape & arrangement of articular surfaces
2) Ligaments
3) Muscle tone
What are 3 factors that limit movement of synovial joint?
1) Shape of bone
2) Adjacent structures
3) Ligaments (intrinsic/extrinsic)
What are the 6 types of synovial joints?
1) Gliding
2) Pivot
3) Hinge
4) Condyloid
5) Saddle
6) Ball and Socket
In a plane/gliding joint, the articular surfaces are _______, permitting bones to slide or glide over one another.
Flat
What type of synovial joint allows for uniaxial flexion and extension?
Hinge joint
Which type of synovial joint allows the greatest range of motion in multiple axes?
Ball & Socket
What is a pivot joint and what type of movement does it allow?
A central bony pivot surrounded by a ligamentous ring.
Allows for rotation
What types of movement are allowed in a condyloid joint?
1) Flexion, extension
2) Abduction, Adduction
3) Small amount of rotation
How are the bones articulated in an ellipsoid joint?
Concave surface of bone articulates with convex surface of other (u-shape)
How are the bones articulated in a saddle joint?
Articular surfaces are concavo-convex (s-shaped like saddle)
What are the borders and angles of the triangular scapula bone?
Borders:
1) Medial
2) Lateral
3) Superior
Angles
1) Superior
2) Inferior
The anterior/costal surface of the scapula forms the ___________________
Subscapular fossa
The posterior surface of the scapula is divided by the spine which laterally projects as the _________________ which articulates with the _____________.
Laterally, the _____ fossa articulates with the head of the humerus. Its superior border is marked by ____________.
Spine → Acromion process → articulate w clavicle
Laterally: Glenoid fossa
Superior: Coracoid process
- projects antero-laterally and scapular notch
What are the rotator cuff muscles and where are their origins?
From posterior surface of scapula:
1) Supraspinatus
2) Infraspinatus
3) Teres minor
From costal surface of scapula:
4) Subscapularis
What is the function of the rotator cuff muscles?
Stabilises glenohumeral joint
- Holds head of the humerus against glenoid cavity of the scapula (stability)
Other than the rotator cuff muscles, what are the other muscles acting on the scapula and what are their actions?
1) Trapezious
- elevates, retracts and depress scapula
2) Levator scapula
- elevates scapula
3) Rhomboids
- retract scapula
What are the muscle(s) that elevate the scapula?
1) Trapezious
2) Levator Scapula
What are the muscle(s) that retract the scapula?
1) Trapezious
2) Rhomboids
What are the muscle(s) that depress the scapula?
Trapezious
What are the points of attachment of the deltoid muscle?
Posterior fibres → spine of scapula
Middle fibres → acromion of scapula
Anterior fibres → clavicle
What are the functions of the deltoid and which fibres mediate which?
All arm
Anterior: (i) Flexion (ii) Medial rotation
Middle: Abduction
Posterior: (i) Extension (ii) Lateral rotation
What is the origin and insertion of the serratus anterior?
Origin: Upper 8 ribs
Insertion: Medial border of scapula
What are 2 functions of the serratus anterior?
1) Rotate scapula
2) Hold scapula against thoracic wall
What does paralysis of the serratus anterior lead to?
Winged scapula
Lesion of long thoracic nerve → weakening of serratus anterior → winging of scapula
What are the 6 scapular movements?
1-2) Elevation/Depression
3-4) Abduction/Adduction
5-6) Upward/Downward rotation
What is the shoulder joint?
Head of humerus articulates with Glenoid fossa to form the glenohumeral joint (ball and socket)
What are the 6 movements of the shoulder?
1-2) Flexion/Extension
3-4) Abduction/Adduction
5-6) Medial/Lateral rotation
7) Circumduction
What are 4 movements of the forearm?
1-2) Flexion/Extension
3-4) Supination/Pronation
What are 8 movements of the hand?
1-2) Flexion/Extension
3-4) Pronation/Supination
5-6) Radial/Ulnar deviation
7) Cylindrical grasp
8) Tip
9) Hook/snap
10) Palmar
11) Spherical grasp
12) Lateral
True or false: The deltoid is multipennate.
True.
Has posterior, middle and anterior fibres
Which nerve innervates the serratus anterior?
Long thoracic nerve
What are 2 joints formed by the humerus?
1) Glenohumeral
2) Elbow
The intertubercular groove of the humerus is formed by the _______________ on the head of the bone. This is the site of attachment for the _________________.
Intertubercular groove formed by greater and lesser tubercle on head of humerus
Site of attachment for long head of biceps tendon
Where does the deltoid muscle attach to on the humerus?
Deltoid tuberosity
Where is the radial groove of the humerus and what is its function?
Posterior diaphysis for radial nerve
Which nerve may be lesioned after a fracture at the surgical neck of a humerus?
Axillary nerve
Which nerve may be lesioned after a fracture at the shaft of a humerus?
Radial nerve
Which nerve may be lesioned after a fracture at the supracondylar ridge of a humerus?
Median nerve
Which nerve may be lesioned after a fracture at the medial epicondyle of a humerus?
Ulnar nerve
The glenoid cavity is deepened by the _________________.
Glenoid labrum (fibrocartilaginous ring)
What is the difference between the surgical and anatomical neck of the humerus?
Surgical: between head and greater tuberosity
Anatomical: below greater and lesser tuberosity
What are the articular surfaces of the glenohumeral joint covered by?
Hyaline cartilage
The humeral head is held in the glenoid cavity by the _________________.
Rotator cuff muscles:
1) Supraspinatus
2) Infraspinatus
3) Teres minor
4) Subscapularis
What are the 4 ligaments associated with the shoulder joint?
Strengthen joint capsule:
1) Glenohumeral (anterior)
2) Coracohumeral (superior)
3) Transverse humeral
Prevents superior displacement of head of humerus:
4) Coracoacromial
A fibrous capsule lined by synovial membrane surrounds the shoulder joint and is attached to __________________________.
Margin of glenoid cavity and anatomical neck of humerus
What muscle(s) facilitate shoulder flexion?
1) Pectoralis major
2) Anterior deltoid
3) Biceps
4) Coracobrachialis
What muscle(s) facilitate shoulder extension?
1) Posterior deltoid
2) Latissimus dorsi
What muscle(s) facilitate shoulder abduction?
1) Supraspinatus
2) Middle deltoid
What muscle(s) facilitate shoulder adduction?
1) Pectoralis major
2) Latissimus dorsi
What muscle(s) facilitate lateral rotation of the shoulder?
Infraspinatus
What muscle(s) facilitate medial rotation of the shoulder?
Subscapularis
How is the arm raised vertically 180 degrees?
1) Scapulothoracic upward rotation → 60°
- by Serratus anterior
2) Glenohumeral abduction → 120°
i) Supraspinatus initiates
ii) Middle fibres of deltoid abducts
What is Hilton’s Law?
The nerves supplying a joint also supply the muscles moving the joint and the skins covering their attachment (myotome=dermatome)
Describe the innervation of the shoulder joint.
Somatic pain:
1) Suprascapular nerve
2) Axillary nerve
(Joints also transmit proprioception)
What is the most commonly dislocated joint and why?
Shoulder joint
i) wide range of movement
ii) inferior aspect unprotected by muscles
Which nerve may be injured in an anterior dislocation of the shoulder?
Axillary nerve
What are 3 factors influencing the stability of the shoulder joint?
1) Tonus of rotator cuff muscle holds the head of humerus in the glenoid cavity
2) Ligament
3) Coracobrachialis, long/short head of biceps resist downward dislocation
Which direction is shoulder dislocation is more common?
Anterior
What is the “stabilising bone” of the elbow?
Ulna
What are 4 components of the ulna?
1) Olecranon
2) Trochlea notch
3) Coronoid process
4) Distal head
The styloid process of the humerus is (smaller/larger) than the ulnar styloid process.
Larger
What type of joint is the elbow joint?
Hinge
What are the 3 articulations of the elbow joint?
1) Trochlea of humerus + Trochlear notch of ulna
2) Capitulum of humerus + Upper surface of radial head
3) Head of radius + Radial notch of ulna
The elbow joint is surrounded by a fibrous capsule which is weak ________________________ allowing for _________________.
Weak anterior and posteriorly → allowing for flexion and extension
What are the ligaments of the elbow joint?
Strengthen elbow joint:
1) Medial and lateral collateral
Hold proximal radio-ulnar joint (radial head against radial notch):
2) Annular ligament (encircles radial head)
What are the nerves of the elbow joint?
1) Musculocutaneous
2) Radial
3) Ulnar
At which joint(s) does elbow flexion and extension occur?
Humero-radial and Humero-ulnar joints
At which joint(s) does elbow pronation and supination occur?
Proximal radio-ulnar joint
What muscle(s) facilitate elbow flexion?
1) Biceps
2) Brachialis
3) Brachioradialis
What muscle(s) facilitate elbow extension?
1) Triceps
2) Anconeus
What muscle(s) facilitate elbow pronation?
1) Pronator teres
2) Pronator quadratus
What muscle(s) facilitate elbow supination?
1) Biceps
2) Supinator
What is a subluxation?
Incomplete or partial dislocation of a joint or organ.
What is the usual consequence of a subluxation of the the radial head from the annular ligament?
Posterior dislocation of the elbow joint
What is the most likely dislocation of a fall with elbows flexed?
Posterior dislocation
What is the carrying angle?
Angle formed by the axes of the arm and forearm when the forearm is in full extension and supination
(Internal angle of deviation of ulna from long axis of humerus)
The carrying angle is generally (wider/narrower) in females.
Wider
What is the function of the carrying angle?
Allows forearms to clear the hips in swinging movements when carrying objects.
In the hand there are:
__ carpal bones
__ metacarpal bones
__ proximal phalanges
__ middle phalanges
__ distal phalanges
In the hand there are:
8 carpal bones
5 metacarpal bones
5 proximal phalanges
4 middle phalanges
5 distal phalanges
Which type of joint is the wrist joint?
Ellipsoid
What are the articulating surfaces of the wrist joint?
Distal end of radius + articular disc of distal radio-ulnar joint + proximal carpal bones (scaphoid, lunate, triquetrum)
What are the 3 nerves that innervate the wrist joint?
1) Median
2) Radial
3) Ulnar
The fibrous capsule surrounding the wrist joint is strengthened by which ligaments?
1) Palmar radiocarpal
2) Dorsal radiocarpal
3) Ulnar collateral
4) Radial collateral
The radial collateral ligament runs from the _______ to the _______ and ___________.
Radius to scaphoid and trapezium
The ulnar collateral ligament runs from the _______ to the _______ and ___________.
Ulna to triquetrum and pisiform
What are the 8 movements of the wrist joint?
1-2) Flexion/Extension
3-4) Pronation/Supination
5-6) Abduction/Adduction
7-8) Radial/Ulnar deviation
What muscle(s) facilitate wrist flexion?
1) Flexor carpi radialis
2) Flexor carpi ulnaris
What muscle(s) facilitate wrist extension?
1) Extensor carpis radialis longus
2) Extensor carpis radialis brevis
3) Extensor carpi ulnaris
What muscle(s) facilitate wrist abduction?
1) Abductor pollicis longus
2) Flexor carpi radialis
3) Extensor carpi radialis longus
4) Extensor carpi radialis brevis
What muscle(s) facilitate wrist adduction?
1) Flexor carpi ulnaris
2) Extensor carpi ulnaris
What is the most common fracture from a fall on an outstretched arm?
Distal radius fracture
What is the most common fracture from a fall on an outstretched arm with the wrist extended and abducted?
Scaphoid fracture
What is the most common fracture from a fall on a dorsiflexed wrist?
Anterior dislocation of the lunate → Carpal tunnel syndrome
What type of joint is the 1st digit carpo-metacarpal joint?
Saddle type
What are the articulating surfaces of the 1st digit carpo-metacarpal joint?
Trapezium + base of 1st metacarpal bone
The fibrous capsule surrounding the 1st digit carpo-metacarpal joint is strengthened by which ligaments?
Anterior and posterior carpometacarpal and metacarpal ligaments
What are the 4 movements of the thumb?
1-2) Flexion/Extension
3-4) Abduction/Adduction
5) Opposition
6) Circumduction
What type of joint is an interphalangeal joint?
Hinge joint
What type of joint is a metacarpophalangeal joint?
Condyloid joint
What are the articulating surfaces of a metacarpophalangeal joint?
Head of metacarpal + base of phalanx
The metacarpophalangeal joints are stabilised by which ligaments?
1) Palmar ligaments
- united by transverse metacarpal ligaments
2) Collateral ligaments
What are the movements allowed by the metacarpophalangeal joint?
1-2) Flexion/Extension
3-4) Abduction/Adduction
What are the 8 carpal bones of the hand?
Some Lovers Try Positions That They Cannot Handle
Lateral to medial
1) Scaphoid
2) Lunate
3) Triquetrum
4) Pisiform
- next row -
5) Trapezium
6) Trapezoid
7) Capitate
8) Hamate
Where is the sesamoid bone?
Between the metacarpal bone and proximal phalanges of the 1st digit of the hand
How can articular pathologies be differentiated from periarticular?
Articular:
1) BOTH passive and active movements painful
2) Tender along joint line
3) Pain in all planes of joint movement
Periarticular:
1) Passive movement is less painful than active movement
2) Tender at structure of involvement
3) Pain in certain planes of movement, stress test positive
What are the signs and a/w of rotator cuff tendinitis?
1) Pain in lateral aspect of arm
2) Weakness
3) Painful arc
4) Night pain
5) Positive impingement sign
6) Age >40
What is the difference between muscular dystrophy and atrophy
Dystrophy: weakness
Atrophy: wasting
What are the muscles of the pectoral girdle?
1) Pectoralis major
2) Pectoralis minor
3) Serratus anterior
Pectoralis major:
Function:
Origin:
Insertion:
Innervation:
Pectoralis major:
Function:
i) adduction of humerus
ii) medially rotates humerus
ii) flexion of arm
Origin: sternum, superior 6 costal cartilage and clavicle
Insertion: Lateral lip of bicipital groove of humerus
Innervation: Lateral and medial pectoral nerve
Pectoralis minor:
Function:
Origin:
Insertion:
Innervation:
Pectoralis minor:
Function: stabilises scapula by drawing it against thoracic wall
Origin: 3-5 ribs near costal cartilage
Insertion: coracoid process of scapula
Innervation: medial pectoral nerve
Serratus anterior:
Function:
Origin:
Insertion:
Innervation:
Serratus anterior:
Function: protraction and upward rotation scapula
Origin: 1-8 ribs on lateral surface
Insertion: Superior/inferior angles and medial border of scapula
Innervation: long thoracic nerve (C5, C6, C7)
What causes the “winged scapula” in a long thoracic nerve lesion?
Paralysis of serratus anterior → unable to pull scapula anteroinferiorly
→ winging of scapula
What are the rotator cuff muscles?
1) Supraspinatus
2) Infraspinatus
3) Teres minor
4) Subscapularis
What are the intrinsic shoulder muscles?
1) Deltoid
Rotator cuff muscles:
2) Supraspinatus
3) Infraspinatus
4) Teres minor
5) Subscapularis
Supraspinatus:
Function:
Origin:
Insertion:
Innervation:
Supraspinatus:
Function: abduction of arm (assist deltoid)
Origin: supraspinous fossa of scapula
Insertion: greater tubercle of humerus
Innervation: Suprascapular nerves (C4, 5, 6)
Infraspinatus:
Function:
Origin:
Insertion:
Innervation:
Infraspinatus:
Function: laterally rotates arm
Origin: infraspinous fossa
Insertion: posterior aspct of greater tubercle and shoulder joint capsule
Innervation: Suprascapular nerve (C5, 6)
Teres minor:
Function:
Origin:
Insertion:
Innervation:
Teres minor:
Function: laterally rotates arm
Origin: Middle portion of lateral border of scapula
Insertion: inferior aspect of greater tubercle
Innervation: Axillary nerve (C5, 6)
Subscapularis:
Function:
Origin:
Insertion:
Innervation:
Subscapularis:
Function:
i) medially rotate
ii) adducts the arm
Origin: subscapularis fossa
Insertion: lesser tubercle of humerus
Innervation: subscapular (C5, 6 , 7)
Deltoid:
Function:
Origin:
Insertion:
Innervation:
Deltoid:
i) Anterior
- flex and medial rotate arm
- from clavicle
ii) Middle
- abducts arm
- from spine of scapula
iii) Posterior
- extends and laterally rotates arm
-acromion of the scapula
Insertion: (all)
- deltoid tuberosity of humerus
Innervation: (all)
- axillary nerve (C5,6)
What are the extrinsic shoulder muscles?
1) Trapezius
2) Latissimus dorsi
What is the main function of the rotator cuff muscles?
Stabilises glenohumeral joint
- holds head of humerus against glenoid cavity of scapula
What are the functions of the trapezius?
1) Elevate shoulder (superior)
2) Retract shoulder (middle)
3) Depress shoulder (inferior)
Trapezius:
Function:
Origin:
Insertion:
Innervation:
Trapezius:
Function: move shoulder
i) superior → elevate
ii) middle → retract
iii) inferior → depress
Origin:
i) superior nuchal line of occipital bone
ii) C7-T12
Insertion:
i) lateral third of clavicle
ii) acromion process of scapula
iii) spine of scapula
Innervation: Accessory nerve (C11)
Latissimus dorsi:
Function:
Origin:
Insertion:
Innervation:
Latissimus dorsi:
Function: moves shoulder
i) adducts
ii) Medially rotates
iii) extends arm
Origin:
i) T7-12
ii) L1-L5
iii) Iliac crest
Insertion: intertubular sulcus of humerus
Innervation: thoracodorsal nerve
What are the functions of the latissimus dorsi?
1) Adduction
2) Extension
3) Internal rotation of arm
What are the muscles involved in shoulder flexion?
1) Deltoid (Anterior)
2) Pectoralis major
3) Biceps
4) Coracobrachialis muscles
What are the muscles involved in shoulder extension?
1) Deltoid (posterior)
2) Latissimus dorsi
3) Teres major
What are the muscles involved in shoulder abduction?
1) Deltoid (middle)
2) Supraspinatus
What are the muscles involved in shoulder adduction?
1) Pectoralis major
2) Latissimus dorsi
3) Teres major
4) Teres minor
What are the muscles involved in shoulder lateral rotation?
1) Infraspinatus
2) Teres minor
3) Deltoid (posterior)
What are the muscles involved in medial rotation of the shoulder?
1) Subscapularis
2) Latissimus dorsi
3) Teres major
4) Deltoid (anterior)
What forms the base and apex of the axilla?
Apex:
1) Clavicle
2) 1st rib
3) Superior border of scapula
Base:
Skin and fascia extending from thoracic wall to arm
What are the bounds of the axilla?
Anterior: pectoralis major/minor
Posterior: Subscapularis and scapula
Medially: Serratus anterior and 1-4 ribs
Lateral: bony wall formed by intertubular groove in humerus
What are the muscles of the arm (not forearm)?
1) Biceps brachii
2) Brachialis
3) Coracobrachialis
4) Triceps brachii
Biceps brachii:
Function:
Origin:
Insertion:
Innervation:
Biceps brachii:
Function: moves forearm
elbow flexed → supination
elbow extended →flexion
Origin:
long head → supraglenoid tubercle
short head → coracoid process
Insertion:
radial tuberosity → bicipital aponeurosis
Innervation: musculocutaneous nerve (C5-7)
Brachialis:
Function:
Origin:
Insertion:
Innervation:
Brachialis:
Function: flexion of forearm
Origin: midpoint of humerus
Insertion:
i) coronoid process
ii) ulnar tuberosity
Innervation: Musculocutaneous nerves (C5-7)
Coracobrachialis:
Function:
Origin:
Insertion:
Innervation:
Coracobrachialis:
Function: move arm
i) adduction
ii) flexion
Origin: tip of coracoid process of scapula
Insertion: mid point of humerus
Innervation: musculocutaneous nerve (C5-7)
Triceps brachii:
Function:
Origin:
Insertion:
Innervation:
Triceps brachii:
Function:
i) main extensor of elbow joint
ii) extension of arm
iii) resist displacement of head of humerus
Origin:
Insertion:
Innervation: radial nerve
What are the bounds of the cubital fossa?
Floor: brachialis and supinator
Roof: deep fascia and bicipital aponeurosis
Medial: pronator teres
Lateral: brachioradialis
Superiorly: imaginary line connecting lateral and medial epicondyles
What are the contents of the cubital fossa?
1) Median nerve
2) Bifurcation of brachial artery
3) Tendon of biceps brachii
4) Radial nerve
Which vein of the cubital fossa is commonly used for venipuncture?
Median cubital vein
What structure separates the median cubital vein from the underlying brachial artery and median nerve?
Bicipital aponeurosis
Along the cubital fossa, the cephalic vein runs (medial/lateral) to the biceps brachii while the basilic vein runs (medial/lateral) when in SAT.
Cephalic: lateral
Basilic: medial
The flexors and pronators are in the _________ compartment of the forearm while the extensors and supinators are in the ______________.
Flexor and pronator: Anterior
Extensor and supinator: Posterior
What are the 5 superficial and 3 deep muscles of the flexor muscles of the forearm?
Superficial:
1) Pronator teres
2) Flexor carpi ulnaris
3) Flexor carpi radialis
4) Palmaris longus
5) Flexor digitorum superficialis
Deep:
1) Flexor digitorum profundus
2) Flexor pollicis longus
3) Pronator quadratus
Pronator teres:
Function:
Origin:
Insertion:
Innervation:
Pronator teres:
Function:
i) pronates the forearm
ii) flexes elbow joint
Origin:
i) medial epicondyle of humerus
ii) coronoid process of ulna
Insertion: lateral surface of radius
Innervation: median nerve
Flexor carpi ulnaris:
Function:
Origin:
Insertion:
Innervation:
Flexor carpi ulnaris:
Function:
i) flexion
ii) adduction of wrist
Origin:
i) medial epicondyle of humerus
ii) olecranon of ulna
Insertion:
i) pisiform
ii) hook hamate
iii) 5th metacarpal bone
Innervation: ulnar nerve
Flexor carpi radialis:
Function:
Origin:
Insertion:
Innervation:
Flexor carpi radialis:
Function: flexes and abducts wrist
Origin: medial epicondyle of humerus
Insertion: base of 2nd metacarpal
Innervation: radial nerve
Palmaris longus:
Function:
Origin:
Insertion:
Innervation:
Palmaris longus:
Function: flexion of wrist
Origin: medial epicondyle of humerus
Insertion:
i) flexor retinaculum
ii) palmar aponeurosis
Innervation: median nerve
Flexor digitorum superficialis:
Function:
Origin:
Insertion:
Innervation:
Flexor digitorum superficialis:
Function: flexion of (i) middle (ii) proximal phalanges
Origin:
i) Medial epicondyle of humerus
ii) coronoid process of ulna
iii) superior half of radius
Insertion: middle phalanges of 4 medial digits
Innervation: median nerve
Flexor digitorum profundus:
Function:
Origin:
Insertion:
Innervation:
Flexor digitorum profundus:
Function: flexes distal inter-phalangeal of medial 4 digits
Origin:
i) ulna
ii) interosseus membrane
Insertion:
i) base of distal phalanges of medial 4 digits
Innervation: median 1/2 → ulnar nerve; lateral 1/2 → median nerve
Flexor digitorum longus:
Function:
Origin:
Insertion:
Innervation:
Flexor digitorum longus:
Function:
i) flexion of phalanges of thumb
ii) flexes metacarpophalangeal and carpometacarpal joints of thumb
Origin:
i) radius
ii) Interosseus membrane
Insertion: base of distal phalanx of thumb
Innervation: median nerve
What are the bounds of the carpal tunnel?
Floor: concavity of carpal bones
Roof: Flexor retinaculum
Medial: hook of hamate and pisiform
Lateral: scaphoid and trapezium
The carpal tunnel contains __ tendons, surrounded by ________ and the ________________.
Carpal tunnel:
- 9 tendons
- synovial sheaths
- median nerve
What are the branches of the brachial plexus?
1) Posterior cord
2) Lateral cord
3) Medial cord
Supinator:
Function:
Origin:
Insertion:
Innervation:
Supinator:
Function: supination of forearm
Origin:
i) lateral epicondyle of humerus
ii) supinator crest
iii) supinator fossa of ulna
Insertion:
anterior, lateral and posterior aspects of proximal radius
Innervation: median nerve
Pronator quadratus:
Function:
Origin:
Insertion:
Innervation:
Pronator quadratus:
Function: initiates pronation of radioulnar joints
Origin: distal 1/4 of ulna
Insertion: distal 1/4 of radius
Innervation: median nerve
What are 3 muscles that extend, abduct and adduct the hand at the wrist joint, their innervation and their (i) origin (ii) insertion.
All by radial nerve
1) Extensor carpi radialis longus
- extend and ABduct
i) lateral SUPRAcondyle of humerus
ii) base of 2nd metacarpal
2) Extensor carpi radialis brevis
- extend and ABduct
i) lateral epicondyle of humerus
ii) base of 3rd metacarpal
3) Extensor carpi ulnaris
- extend and ADduct
i) lateral epicondyle of humerus
ii) base of 5th metacarpal
Extensor digitorum:
Function:
Origin:
Insertion:
Innervation:
Extensor digitorum:
Function:
i) extensor of medial 4 digits
ii) extension of proximal phalanges at metacarpophalangeal joints
iii) extends hand at wrist joint
Origin: lateral epicondyle of humerus
Insertion: extensor expansion of medial 4 digits
Innervation: Interosseus nerve (C7-8)
Extensor digit minimi:
Function:
Origin:
Insertion:
Innervation:
Extensor digit minimi:
Function: extend 5th digit at metacarpophalangeal and interphalangeal joints
Origin: lateral epicondyle of humerus
Insertion: extensor expansions of 5th digits
Innervation: Interosseous nerve
Extensor tendons expand to form extensor expansions which wrap around head of the metacarpals and proximal phalanges. What are the 3 bands that why are divided into and what is their function?
Provides attachment for short muscles of the hand
- 2 lateral bands (distal phalanx)
- 1 median band (middle phalanx)
What are the 4 deep extensors of the forearm and what do they act on?
1) Abductor pollicis longus
- (i) abduct (ii) extends thumb @ CMCJ
2) Extensor pollicis brevis
- extend thumb @ MCPJ
3) Extensor pollicis longus
- extends distal phalanx
4) Extensor indicis
- extends finger @ PIPJ
What are the bounds of the anatomic snuff box of the hand?
Anterior:
i) Abductor pollicis longus
ii) Extensor pollicis brevis
Posterior:
i) Extensor pollicis longus
What are the contents of the anatomical snuff box of the wrist?
1) Radial artery
2) Scaphoid
3) Trapezium
Thenar muscles: _____________________________ are responsible for ___________ of the thumb and are innervated by?
1) Abductor pollicis brevis
2) Flexor pollicis brevis
3) Opponens pollicis
Responsible for:
i) circumduction
ii) opposition
Innervated by median nerve
Abductor pollicis brevis:
Function:
Origin:
Insertion:
Innervation:
Abductor pollicis brevis:
Function: abduct thumb @ CMCJ
Origin:
i) Flexor retinaculum
ii) Tubercles of scaphoid & trapezium
Insertion: base of proximal thumb phalanx
Innervation: Median nerve
Flexor pollicis brevis:
Function:
Origin:
Insertion:
Innervation:
Flexor pollicis brevis:
Function: flex thumb @ CMCJ & MCPJ
Origin:
i) Flexor retinaculum
ii) Tubercles of scaphoid & trapezium
Insertion: base of proximal phalanx of thumb
Innervation: median nerve
Opponens pollicis:
Function:
Origin:
Insertion:
Innervation:
Opponens pollicis:
Function: opposes thumb @ CMCJ
Origin:
i) Flexor retinaculum
ii) Tubercles of scaphoid & trapezium
Insertion: lateral 1st metacarpal
Innervation: median nerve
Adductor pollicis:
Function:
Origin:
Insertion:
Innervation:
Adductor pollicis:
Function: adducts the thumb
Origin:
i) oblique head-bases of 2nd & 3rd metacarpals
ii) transverse head
iii) body of 3rdmetacarpal
Insertion: base of 1st proximal phalanx
Innervation: ulnar nerve
What are the short muscles of the hand?
4 lumbricals
Lumbricals:
Function:
Origin:
Insertion:
Innervation:
Lumbricals:
Function:
i) flex digits @ MCPJ
ii) extend IPJ
Origin: tendons of flexor digitorum profundus
Insertion: lateral extensor expansions of digits 2-5
Innervation:
1&2: median nerve
3&4: lateral extensor expansions of digits 2-5
What are the 2 interossei muscles?
1) Dorsal interossei
2) Palmar interossei
Dorsal interossei:
Function:
Origin:
Insertion:
Innervation:
Dorsal interossei:
Function: abduct digits
Origin: metacarpals
Insertion:
i) extensor expansion
ii) bases of proximal phalanges
Innervation: ulnar nerve
Palmar interossei:
Function:
Origin:
Insertion:
Innervation:
Palmar interossei:
Function: adduct digits
Origin: metacarpals
Insertion:
i) extensor expansion
ii) bases of proximal phalanges
Innervation: ulnar nerve
What are the 3 types of veins in the upper limb?
1) Superficial veins
- dorsal venous network (dorsum of hand) → lateral cephalic / medial basilic veins
2) Deep venae comitantes
- accompany arteries
3) Perforating veins
- communication between superficial and deep veins
Which vein links the cephalic and basilic veins in front of the elbow?
Median cubital vein
The median cubital vein courses along the _________ and drains into the _______________.
along Deltopectoral groove
Drains into axillary vein
What 2 veins form the axillary vein, where?
Basilic + Venae comitantes
@ axilla
What nerve roots form the brachial plexus?
C5-8, T1
What is a brachial plexus block used for?
Upper limb surgeries
What do sudomotor sympathetic fibres supply?
Smooth muscle around sweat gland
What do vasomotor sympathetic fibres supply?
Smooth muscle around vessels
What do pilomotor sympathetic fibres supply?
Arrector pili
What nerves are assessed in a biceps brachii tendon reflex?
C5,6
What nerves are assessed in a triceps tendon reflex?
C6,7,8
What is the most likely diagnosis of a px how presents with:
i) paralysis of deltoid, biceps, brachialis and brachioradialis
ii) abducted shoulder, medially rotated arm and extended elbow (waiter’s tip position)
Erb’s palsy
- injury to superior trunk of brachial plexus (C5, 6)
What (i) nerve roots and (ii) muscles are affected in Erb’s palsy?
i) C5, 6
ii) paralysis of deltoid, biceps, brachialis and brachioradialis
What condition is associated with waiter’s tip position?
Erb’s palsy
- abducted shoulder, medially rotated arm and extended elbow
What is a common nerve condition of both (i) a fall landing on the shoulder and (ii) pulling of a baby’s head during per-vaginal delivery?
Erb’s palsy
- separation of neck and shoulder
What structure is the landmark for differentiating the cords of the brachial plexus?
Axillary artery
What are 2 common etiologies for axillary nerve injury?
1) Anterior dislocation of glenohumeral joint
2) Fracture of surgical shaft of humerus
Which cord(s) of the brachial plexus and nerve roots does the musculocutaneous nerve arise from?
Lateral cord (C5-6)
Which cord(s) of the brachial plexus and nerve roots does the axillary nerve arise from?
Posterior cord
Which cord(s) of the brachial plexus and nerve roots does the radial nerve arise from?
Posterior cord
Which cord(s) of the brachial plexus and nerve roots does the radial nerve arise from?
Posterior cord
Which cord(s) and nerve roots does the median nerve arise from?
Lateral cord and medial cord
Which cords and nerve roots does the ulnar nerve arise from?
Medial cord
What is the neurological condition associated with claw hand?
Klumpke’s palsy (inferior trunk of brachial plexus: C8, T1)
Which nerve roots and muscles are affected in Klumpke’s palsy?
C8, T1 (Inferior trunk) → Ulnar nerve → short muscles (lumbricals, interossei) → claw hand
What is a common nerve condition of both (i) catching a fall from height with 1 arm (ii) breech birth?
Klumpke’s palsy (C8, T1)
- Claw hand
What are the (i) motor and (ii) sensory innervations of the musculocutaneous nerve (C5-7)?
Motor:
i) Coracobrachialis
ii) Bicep brachii
iii) Brachialis
Sensory:
Lateral aspect of forearm
Which movement would be affected in a musculocutaneous nerve lesion?
1) Flexion of forearm
2) Supination of forearm
What are the (i) motor and (ii) sensory innervations of the median nerve (C6-8, T1)?
Motor:
i) All flexors except (1) flexor carpi radialis and (2) ulnar half of flexor digitorum profundus
ii) 3 thenar
iii) radial 2 lumbricals
Sensory:
Palmar surface of lateral 3.5 digits (including nail beds on dorsal side)
How would a median nerve lesion at the elbow and wrist differ?
Elbow:
i) No pronation
ii) Weak wrist flexion
iii) Ulnar deviation at rest
iv) Thumb abducts
v) Wasting of thenar eminence (hand is flat and ape-like)
Wrist: (Carpal tunnel)
- Thenar muscles paralysed → no opposition and abduction of thumb
What are the (i) motor and (ii) sensory innervations of the Ulnar nerve (C7-8, T1)?
Motor:
i) Flexor carpi ulnaris
ii) Medial 1/2 of flexor digitorum profundus
iii) Hypothenar msucles
iv) Interossei
v) 3/4 lumbricals
vi) Adductor pollicis
Sensory:
Both dorsal and palmar side medial 1.5 fingers
How would a ulnar nerve injury at the wrist present?
Injury @ elbow
1) → medial 1/2 of flexor digitorum profundus is paralysed → less unopposed action of extensors on the 4/5th digits → Claw hand
2) Sensory loss over 1.5 fingers
Explain the ulnar paradox.
Injury @ elbow → medial 1/2 of flexor digitorum profundus is paralysed
→ less unopposed action of extensors on the 4/5th digits
→ only hyperextension of MCPJ, no flexion of PIPJ
Explain the pathophysiology of claw hand.
Ulnar nerve injury at wrist → paralysis of all intrinsic muscles of hand (expect 2 radial)
→ unopposed action of extensors and flexor digitorum profundus + paralysis of 4/5 lumbricals
→ MCPJ of 4/5 digits hyperextended + PIPJ flexed
What is carpal tunnel syndrome?
Median nerve entrapment @ elbow
→ numbness and tingling in 4/5 digits
→ LT → muscle wasting → ape hand
What are the (i) motor and (ii) sensory innervations of the radial nerve?
Motor:
i) Extensor muscles of arm
ii) Extensor muscle of forearm
Which nerve of the forearm pierces the supinator?
Radial nerve
After passing behind the humerus in the spiral groove and entering the cubital fossa, the radial nerve divides into the _________ and ____________ which provides ___________ and _____________ innervation respectively
Superficial branch: fully sensory
Deep branch: fully motor
How does a radial nerve injury at the (i) axilla differ from that of the (ii) midshaft of the humerus (iii) radial head?
i) Axilla: paralysis of
a) Triceps
b) Brachioradialis
c) Supinator
d) Extensors of wrist and digits
→ wrist drop
ii) Radial groove:
Weakened:
a) Triceps
Paralysis:
b) Brachioradialis
c) Supinator
d) Extensors of wrist and digits
→ wrist drop
iii) Radial head
- NO sensory loss
a) only unable to extend thumb and MCPJ of other digits
What is the (i) motor (ii) Sensory innervations of the Axillary nerve?
Motor:
i) Teres minor
ii) Deltoid
Sensory:
i) Inferior part of deltoid
Which arteries anastomose with the axillary artery?
1) Dorsal/Suprascapular artery
2) Subscapular artery
- can form collateral circulation if axillary artery is compromised
What is the origin of the axillary artery?
Subclavian artery
Which artery should be compressed to control bleeding due to a stab wound in the axilla?
Axillary artery (3rd part)
What parts of the body do the axillary artery supply?
1) Thoracic wall
2) Shoulder
In the axilla, the axillary artery extends form the ____________ to the ____________.
Lateral border of 1st rib to inferior border of teres major
What are the branches of the axillary artery?
1st:
- superior thoracic
2nd:
- thoracoacromial
- lateral thoracic
3rd:
- subscapular
- anterior circumflex humeral
- posterior circumflex humeral
What are the 2 anastomoses of the brachial artery?
1) Radial recurrent
- with collateral artery from deep artery
2) Ulnar recurrent
- with superior inferior collateral arteries from brachial artery
The brachial artery arises from the __________ and gives rise to the __________.
Axillary artery
→ Radial and ulnar arteries
In the cubital fossa, the brachial artery lies _____ to the median nerve.
Lateral
What are the branches of the brachial artery?
1) Radial artery
2) Ulnar artery
3) Deep artery (accompany radial nerve)
4) Superior and inferior ulnar collateral arteries
Which artery is compressed when taking blood pressure with a sphygmonamanometer?
Brachial artery
What are the arteries that anastomose with both the radial and ulnar arteries at the wrist?
Dorsal and palmar arches
The superficial palmar arch is a direct continuation of the _______ which enters the hand (anterior/posterior) to the flexor retinaculum, while the deep palmar arch is a direct continuation of _____.
Superificial: Ulnar
Deep: Radial (+ anastomoses from ulnar)
Superficial palmar arch anterior to flexor retinaculum
