MSK System - Upper Limb Flashcards
Where does the upper limb extend from?
The shoulder girdle to the hand
What is the axilla?
A pyramidal space below the shoulder joint
What is the function of the axilla?
It provides a passageway for vessels and nerves going to and from the upper limb
What are the six boundaries of the axilla?
Apex
Anterior wall
Medial wall
Lateral wall
Posterior wall
Base
What two muscles form the anterior wall of the axilla?
Pectoralis major muscle
Pectoralis minor muscle
What three muscles form the posterior wall of the axilla?
Subscapularis muscle
Teres major muscle
Latissimus dorsi muscle
What two structures form the medial wall of the axilla?
Thoracic wall
Serratus anterior muscle
What structures form the lateral wall of the axilla?
Intertubercular sulcus of the humerus
Name the four contents of the axilla
Axillary Artery
Axillary Vein
Axillary Lymph Nodes
Brachial Plexus
What is the axillary artery a continuation of?
Subclavian artery
At what anatomical point does the axillary artery begin?
The lateral border of the 1st rib
Which muscle divides the axillary artery into three divisions?
Pectoralis minor muscle
Which vessel does the axillary artery continue as?
Brachial artery
At what anatomical point does the brachial artery begin?
The inferior border of the teres major
What are the two main causes for enlargement of the axillary lymph nodes?
Infection in the upper limb
Malignant processes involving breast tissue
Which artery should be compressed when individuals experience profuse bleeding of the upper limb?
Axillary artery
What nerve plexus is found in the upper limb?
Brachial plexus
Where does the brachial plexus begin? Where does it extend into?
Cervical region
Axilla
What ventral rami form the brachial plexus?
C5 to T1
What are the five components of the brachial plexus?
Roots
Trunks
Divisons
Cords
Terminal branches
How many roots make up the brachial plexus?
Five
What forms the roots of the brachial plexus?
Ventral rami of the C5-T1 nerves
How many trunks make up the brachial plexus?
Three - superior, middle, inferior
What forms the superior trunk of the brachial plexus?
The union of the C5 and C6 roots
What forms the middle trunk of the brachial plexus?
The continuation of the C7 root
What forms the inferior trunk of the brachial plexus?
The union of the C8 and T1 roots
What vessels are the trunks of the brachial plexus closely related to?
Axillary artery
Axillary vein
What does each trunk of the brachial plexus divide into?
Anterior division
Posterior division
What do the anterior divisions of the brachial plexus supply?
Anterior (flexor) compartment of the upper limb
What do the posterior divisions of the brachial plexus supply?
Posterior (extensor) compartment of the upper limb
How many divisions of the brachial plexus are there?
Six
How many cords of the brachial plexus are there?
Three - lateral, medial, posterior
What forms the lateral cord of the brachial plexus?
The anterior divisions of the superior and middle trunks
What forms the medial cord of the brachial plexus?
The anterior division of the inferior trunk
What forms the posterior cord of the brachial plexus?
The posterior divisions of all three trunks
How are the cords of the brachial plexus named?
They are named based on their relation to the axillary artery
How many terminal branches of the brachial plexus are there?
Five
What are the five terminal branches of the brachial plexus?
Musculocutaneous nerve
Axillary nerve
Median nerve
Radial nerve
Ulnar nerve
What cord forms the musculocutaneous nerve? What are the roots of this nerve?
Lateral
C5-C7
What cord forms the axillary nerve? What are the roots of this nerve?
Posterior
C5-C6
What cord forms the median nerve? What are the roots of this nerve?
Lateral and medial
C5-T1
What cord forms the radial nerve? What are the roots of this nerve?
Posterior
C5-T1
What cord forms the ulnar nerve? What are the roots of this nerve?
Medial
C8-T1
What three terminal nerve branches form the M shape?
Musculocutaneous nerve
Median nerve
Ulnar nerve
What is the clinical presentation of Erb’s palsy?
Waiter’s tip appearance - medial rotation of the arm with wrist flexion
What causes Erb’s palsy?
An injury to the upper trunk of the brachial plexus, specifically a hyperextension injury of the head from the shoulder
What group of muscles are affected by Erb’s palsy? What nerve roots supply this group of muscles?
Anterior (flexor) compartment
C5-C6
Where is Erb’s point located?
Superior trunk, where the C6 and C7 roots combine together
What is the clinical presentation of Klumpke’s palsy?
A condition which results in the intrinsic muscles of the hand are damaged, resulting in a claw hand
What causes Klumpke’s palsy?
An injury to the lower trunk of the brachial plexus, specifically shoulder dystocia at birth or other arm abduction injuries
In addition to the musculocutaneous nerve, what other two nerve branches arise from the lateral cord?
Lateral pectoral nerve
Lateral root of median nerve
In addition to the ulnar nerve, what other four nerve branches arise from the medial cord?
Medial pectoral nerve
Medial cutaneous nerve of the arm
Medial cutaneous nerve of the forearm
Medial division of median nerve
In addition to the axillary and radial nerve, what other two nerve branches arise from the posterior cord?
Thoracodorsal nerve
Subscapular nerve
What is the dorsal venous arch?
A complex network of veins lying at the distal aspect of the upper limb
What two veins arise from the dorsal venous arch?
Cephalic vein
Basilic vein
What vein arises from the lateral aspect of the dorsal venous arch?
Cephalic vein
What vein arises from the medial aspect of the dorsal venous arch?
Basilic vein
What is the median cubital vein?
A large communicating vein which shunts blood from the cephalic vein to the basilic vein
Where is the median cubital vein located?
Antecubital fossa
Where is the most common site of venepuncture?
Median cubital vein
Where is the cephalic vein located?
On the lateral aspect of the arm (thumb)
What does the cephalic vein pierce into?
Clavipectoral fascia
Which facial layer is divided during surgical approach to the axilla?
Clavicopectoral fascia
What vein does the cephalic vein drain into? What groove does this vein enter before draining into this vein?
Axillary vein
Deltopectoral groove
Where is the basilic vein located?
On the medial aspect of the arm (pinkie)
What vein does the basilic vein eventually become? Where does this transition occur?
Axillary vein
Inferior border of the teres major
List the order of neurovascular structures before they enter the axilla - superior to inferior
Brachial plexus
Subclavian artery
Subclavian vein
Where does the subclavian artery originate from on the right hand side of the body?
Brachiocephalic trunk
Where does the subclavian artery originate from on the left hand side of the body?
Aorta
Which two muscles are the subclavian artery and brachial plexus located between?
Scalenus anterior
Scalenus medius
Where does the subclavian vein lie in relation to the scalenus anterior?
Medial
What rib do the brachial plexus, subclavian artery and subclavian vein lie on?
First rib
What three muscles do the musculocutaneous nerve supply?
Brachialis muscle
Biceps muscle
Coracobrachialis muscle
What is a dermatome?
The area of skin supplied by one spinal segment
What is the anterior dermatome area of C3?
Shoulder
What is the anterior dermatome area of C4?
Shoulder
What is the anterior dermatome area of C5?
The middle (lateral) aspect of the arm and forearm
What is the anterior dermatome area of C6?
The lateral aspect of the arm and forearm
The first digit (thumb) of the hand
What is the anterior dermatome area of C7?
The second digit of the hand
The third digit of the hand
What is the anterior dermatome area of C8?
The medial aspect of the arm and forearm
The fourth digit of the hand
The fifth digit (pinkie) of the hand
What is the anterior dermatome area of T1?
The middle (medial) aspect of the arm and forearm
What is the posterior dermatome area of C4?
Shoulder
What is the posterior dermatome area of C5?
Shoulder
What is the posterior dermatome area of C6?
The lateral aspect of the arm and forearm
The first digit (thumb) of the hand
What is the posterior dermatome area of C7?
The middle aspect of the arm and forearm
The second digit of the hand
The third digit of the hand
What is the posterior dermatome area of C8?
The medial aspect of the arm and forearm
The fourth digit of the hand
The fifth digit (pinkie) of the hand
What occurs when there is injury to a spinal root?
There will be sensory loss (paraesthesia) corresponding to that specific dermatome
What occurs when there is injury to a terminal branch?
There will be sensory loss corresponding to the area of distribution that nerve
What lymph nodes do the upper limb drain into?
Axillary lymph nodes
What are the five groups of the axillary lymph nodes?
Apical axillary lymph nodes
Central axillary lymph nodes
Brachial (lateral) axillary lymph nodes
Pectoral (anterior) axillary lymph nodes
Subscapular (posterior) axillary lymph nodes
Where do lymphatics from the right upper quadrant of the body drain into the venous system?
The angle between the right internal jugular and right subclavian vein
What is the function of the pectoral (shoulder) girdle?
It connects the upper limb to the axial skeleton on each side
What two bones make up the pectoral girdle?
Scapula
Clavicle
What two joints make up the pectoral girdle?
Acromioclavicular joint
Sternoclavicular joint
At what joint does the entire limb articulate with the pectoral girdle?
Sternoclavicular joint
What is the acromioclavicular joint?
Where the clavicle articulates with the scapula
What is the sternoclavicular joint?
Where the sternum articulates with the clavicle
What are the two ends of the clavicle?
Acromial end
Sternal end
What are the two convexities of the clavicle?
Lateral convexity
Medial convexity
At what end of the clavicle of the lateral convexity?
Acromial end
At what end of the clavicle of the medial convexity?
Sternal end
What aspect of the clavicle is flatter - lateral or medial?
Lateral aspect
What surface of the clavicle is smoother - superior or inferior?
Superior surface
What is the conoid tubercle?
The attachment for the conoid ligament on the inferior, lateral aspect of the clavicle
Which part of the clavicle is weakest and commonly fractures during a fall?
The junction between the medial and lateral convexity
What vessel is likely to be damaged in a fracture within the medial third of the clavicle?
Subclavian vein
What type of joint is the acromioclavicular joint?
Synovial plane joint
What type of joint is the steronoclavicular joint?
Synovial saddle joint
What are the two stages of arm abduction, also known as the scapulo-thoracic movement?
The first 30 degrees of abduction is caused by muscles acting at the shoulder joint (glenohuemral joint)
Beyond 30 degrees, abduction relies on the scapula being elevated and lateral rotating on the chest wall (scapula-thoracic movements)
What is the arm abduction ratio?
2:1
For every 3 degrees of abduction (past the initial 30 degrees), 2 degrees occurs at the glenohumeral joint and 1 degree occurs due to scapula-thoracic movement
What is the scapulothoracic joint?
It is the movement of the scapula on the thoracic wall
It is not a true anatomical joint, meaning that movement occurs around a joint (axis), but no joint surfaces or joint structures are present
What are the nine muscles attached to the scapula posteriorly?
Trapezius
Levator scapulae
Rhomboid minor
Rhomboid major
Supraspinatus
Infraspinatus
Teres major
Teres minor
Latissimus dorsi
What are the three fibres that make up the trapezius?
Superior (Descending)
Middle
Inferior (Ascending)
What two muscles are involved in scapular elevation?
Trapezius (Superior)
Levator Scapulae
What muscle is involved in scapular depression?
Trapezius (Inferior)
What muscle is involved in scapular protraction? What is scapular protraction?
Serratus Anterior
Scapula pushing up against the thoracic wall
What nerve innervates the serratus anterior?
Long thoracic nerve
What is the clinical sign that presents when the long thoracic nerve has been damaged?
Winged scapula
What movement are patients unable to conduct when they have a winged scapula?
Arm abduction
What three muscles are involved in scapular retraction? What is scapular retraction?
Trapezius (Middle)
Rhomboid Major
Rhomboid Minor
Scapula moving away from the thoracic wall
What three muscles are involved in scapular medial (downward) rotation?
Levator Scapulae
Rhomboid Major
Rhomboid Minor
What muscle is involved in scapular lateral (upward) rotation?
Trapezius (Superior, Inferior)
What are the attachments of the levator scapulae?
The spine of the scapula
The transverse processes of C1-C4
What are the attachments of the rhomboid minor?
The spine of the scapula
The spinous processes of C7 and T1 vertebrae
What are the attachments of the rhomboid major?
The medial border of the scapula
The spinous processes of T5-T8 vertebrae
What are the attachments of the infraspinatus?
The infraspinous fossa of the scapula
The greater tubercle of the humerus
What are the attachments of the supraspinatus?
The supraspinous fossa of the scapula
The greater tubercle of the humerus
What are the attachments of the teres minor?
The lateral border of the scapula
The lesser tubercle of the humerus
What nerve supplies the teres minor? What one other muscle does this nerve supply?
Axillary nerve
Deltoid
What are the attachments of the teres major?
The lateral border of the scapula
The medial lip of the humerus
What nerve supplies the teres major?
Lower subscapular nerve
What are the attachments of the latissimus dorsi?
The spinous processes of T6-T12
The intertubercle sulcus of the humerus
What type of joint is the glenohumeral (shoulder) joint?
Synovial ball and socket joint
Describe the articulation of the shoulder joint
Ball - The head of the humerus
Socket - The glenoid cavity of the scapula
What is the rim of cartilage that surround the socket of the shoulder joint? What is its function?
Glenoid labrum
To stabilise the joint
What is the function of the ligaments of the shoulder joint?
They strengthen and ease movements at the joint
What are the four ligaments of the shoulder joint?
Coracoacromial ligament
Coracohumeral ligament
Glenohumeral ligaments
Transverse humeral ligament
Where does the coracoacromial ligament extend?
Between the coracoid process and acromion
Where does the coracohumeral ligament extend?
Between the coracoid process and greater tubercle of the humerus
Where does the glenohumeral ligament extend?
Between the glenoid cavity of the scapula and greater tubercle of the humerus
Where does the transverse humeral ligament extend?
Between the greater and lesser tubercle of the humerus
What is the function of the glenohumeral ligaments?
To strengthen the inferior aspect of the shoulder joint capsule
What is the function of the coracohumeral ligament?
To strengthen the superior aspect of the shoulder joint capsule
What is the coraco-acromial arch?
The acromion, coracoid process and coraco-acomial ligament
What is the function of the coraco-acromial arch?
To prevent superior displacement of the humeral head
Which part of the shoulder joint is weakest? Why?
The inferior anterior region
It is not protected by muscles or ligaments
What are the two functions of bursae?
To provide cushioning around joints via their synovial fluid filled interior
Shock absorbers
What are the two main bursa of the shoulder joint?
Subacromial (subdeltoid) bursa
Subscapular bursa
Where is the subacromial bursa located?
It sits between the infraspinatus, supraspinatus and deltoid muscles, extending superiorly to lie below the acromion and coracoacomial ligaments
Which bursa communicates with the shoulder joint cavity?
Subscapular bursa
What is the function of the subacromial bursa?
It protects the supraspinatus muscle from wear
What common sporting injury damages the subacromial bursa?
Overhead athletes - swimming, weightlifting, tennis
What are the four rotator cuff muscles?
Subscapularis
Supraspinatus
Infraspinatus
Teres minor
What is the only anterior rotator cuff muscle?
Subscapularis
What rotator cuff muscle tendon is most likely to rupture?
Supraspinatus
What are the attachments of the subscapularis muscle?
The medial border of scapula
The lesser tuberosity of the humerus
What is the function of the rotator cuff muscles?
To prevent sliding of the humerus head during arm movements
What is the cause of rotator cuff injuries?
Repetitive overhead motions
What are the four shoulder joint muscles?
Deltoid
Pectoralis major
Pectoralis minor
Serratus anterior
What are the attachments of the deltoid muscle?
The spine of the scapula
The acromion
The clavicle
The deltoid tuberosity of the humerus
What are the three fibres of the deltoid muscle?
Anterior fibres
Middle fibres
Posterior fibres
What nerve supplies the deltoid?
Axillary nerve
What injury tends to affect the axillary nerve?
Shoulder dislocation
How to we test for axillary nerve damage?
We test for a loss of sensation over the badge area of the shoulder
What are the attachments of the pectoralis major?
The clavicle
The sternum
The costal cartilage of the first six ribs
The lateral lip of the humerus
What is most anterior - pectoralis major or minor?
Pectoralis major
Why is the pectoralis minor muscle anatomically important?
It divides the axillary artery into three parts
What are the attachments of the pectoralis minor?
The 3rd to 5th ribs
The coracoid process of the scapula
What are the attachments of the serratus anterior?
The 1st to 8th ribs
The medial border of the scapula
What are the attachments of the trapezius?
The spinous processes of C7-T12 vertebrae
The clavicle
The acromion
The spine of the scapula
What are the three fibres of the trapezius?
Superior fibres
Middle fibres
Inferior fibres
Which nerve innervates the trapezius?
CN XI (accessory)
An injury to the CN XI will affect which movement of the scapula?
Upward rotation
What foramen of the skull does CN XI pass through?
Jugular foramen
How do we test CN XI function?
We ask patients to shrug their shoulders
What three muscles are involved in shoulder flexion?
Deltoid (Anterior)
Pectoralis Major
Coracobrachialis
What three muscles are involved in shoulder extension?
Deltoid (Posterior)
Latissimus Dorsi
Coracobrachialis
What four muscles are involved in shoulder adduction?
Subscapularis
Teres Major
Pectoralis Major
Triceps
What two muscles are involved in shoulder abduction?
Deltoid (Middle) - after 15 degrees
Supraspinatus - first 15 degrees
Which muscle initiates abduction of the shoulder?
Supraspinatus
What four muscles are involved in shoulder internal rotation?
Subscapularis
Teres Major
Pectoralis Major
Latissimus Dorsi
What two muscles are involved in shoulder external rotation?
Infraspinatus
Teres Minor
What is the deltopectoral triangle?
The triangular space below the clavicle, between deltoid and pectoralis major muscle
What vein travels in the deltopectoral triangle/groove?
Cephalic vein
Which four structures form the quadrangular space in the shoulder?
Triceps brachii (long head)
Teres minor
Teres major
Humerus
Which structure passes through the quadrangular space near the humeral head?
Axillary nerve
What are the two tubercles of the humerus? Where are the located?
Greater tubercle
Lesser tubercle
Humeral neck
Where is the intertubercular groove of the humerus located?
Between the greater and lesser tubercle
Where is the olecranon fossa of the humerus located?
On the posterior, distal aspect of the humerus
Which two fossa are located on the anterior aspect of the humerus?
Coronoid fossa
Radial fossa
Where is the coronoid fossa of the humerus located?
On the medial, distal aspect of the humerus - above the trochlea
Where is the radial fossa of the humerus located?
On the lateral, distal aspect of the humerus - above the capitulum
Where is the trochlea of the humerus located?
On the medial, distal aspect of the humerus - below the coronoid fossa
Where is the capitulum of the humerus located?
On the lateral, distal aspect of the humerus - below the radial fossa
How do we remember how the teres major, latissimus dorsi and pectoralis major insert into the intertubercular groove?
Lady Between Two Majors
Lady - Latissimus Dorsi
Majors - Pectoralis (Lateral), Teres (Medial)
What are the three muscles contained within the anterior compartment of the arm?
Biceps brachii
Brachialis
Corachobrachialis
What nerve supplies the muscles in the anterior compartment of the arm?
Musculocutaenous nerve
What three joints do the muscles in the anterior compartment of the arm act on?
Elbow joint
Shoulder
Radio-ulnar joints
What is the most superficial muscle in the anterior compartment of the arm?
Biceps brachii
Where do the heads of the biceps brachii unite? What do they form?
At the distal third of the upper arm
A short tendon that inserts onto the radial tuberosity of the radius
Where does the short head of the biceps originate?
The coracoid process of the scapula
Where does the long head of the biceps originate?
The supraglenoid tubercle of the scapula
Where does the long head biceps tendon run?
Bicipital groove (intertubercular sulcus) of the humerus
Which ruptured tendon produces a condition called Popeye deformity?
Long head of the biceps brachii
What is the function of the biceps brachii at the shoulder joint?
Flexion
What is the function of the biceps brachii at the elbow joint?
Flexion
What is the function of the biceps brachii at the superior radio-ulnar joint?
Supination - radius rotates over the ulna
What are the attachments of the corachobrachialis?
The coracoid process of the scapula
The mid-shaft of the humerus
What are the attachments of the brachialis?
The distal shaft of the humerus
The coronoid process of the ulna
What is the most deep muscle in the anterior compartment of the arm?
Brachialis
What is the main function of the brachialis?
Flexion of the elbow joint
How does the musculocutaneous nerve enter the arm?
It perforates the coracobrachialis, descending distally between the biceps brachii and brachialis muscles
Does the musculocutaneous nerve supply any muscles in the forearm or hand?
No
What aspect of the forearm does the musculocutaneous nerve supply cutaneous innervation to?
Lateral
What are the four arteries located within the arm?
Axillary artery
Brachial artery
Profunda brachii artery
Posterior and anterior circumflex humeral arteries
What are the five nerves located within the arm?
Axillary nerve
Median nerve (M shape)
Musculocutaneous nerve (M shape)
Radial nerve
Ulnar nerve (M shape)
What is the brachial artery a direct continuation of?
Axillary artery
Where does the brachial artery begin and end?
The lower border of the teres major
The cubital fossa
What two arteries do the brachial artery divide into at the cubital fossa, near the neck of the radius?
Radial artery
Ulnar artery
What condition arises when the brachial artery is completely occluded or lacerated?
Volkmann ischaemic contracture
What are the three clinical features of Volkmann’s ischaemic contracture?
A permanent shortening of forearm muscles
A loss of hand power
A loss of finger flexion
Which arteries branches off the axillary artery?
Circumflex humeral arteries
What artery branches off the brachial artery?
Profunda brachii
Which artery is used to measure blood pressure?
Brachial artery
Describe the course of the median nerve in the arm
It descends on the lateral side of the axillary artery and the upper part of the brachial artery
In the middle part of the arm, the nerve crosses to the medial aspect of the brachial artery and enters the cubital fossa
Does the median nerve give off any branches in the axilla or arm?
No
Describe the course of the ulnar nerve in the arm
It descends along the medial side of the brachial artery and then it enters the flexor compartment of the arm
It runs along the medial head of the triceps, where it lies behind the medial epicondyle at the elbow
How does the ulnar nerve enter the flexor compartment of the arm?
Medial intermuscular septum
Does the ulnar nerve supply any muscles in the arm?
No
Does the median nerve supply any muscles in the arm?
No
Which nerve is responsible for the ‘funny feeling’ depicted by the humerus?
Ulnar nerve
Name the muscle located in the posterior compartment of the arm
Triceps brachii
What are the three heads of the triceps brachii?
Lateral head
Long head
Medial head
Where does the long head of the triceps brachii originate from?
The infraglenoid tubercle of the scapula
Where does the lateral and medial head of the triceps brachii originate from?
Humerus
Where does the triceps brachii tendon insert?
The olecranon process of the ulna
What is the action of the triceps?
Extension of the elbow joint
Which head of the triceps acts as both an extensor of the shoulder and elbow joint?
Long head of the triceps brachii
What is the anconeus muscle?
A small muscle at the elbow
What is the function of the anconeus muscle?
To aid extension of the elbow joint
What nerve supplies the posterior compartment of the arm?
Radial nerve
How does the radial nerve enter the arm?
It enters the arm anterior to the medial head of the triceps
What artery does the radial nerve follow?
It runs with the profunda brachii artery
Describe the course of the radial nerve
It descends down the humerus in the radial groove, lying between the brachioradialis and FCR
What is the clinical sign of radial nerve injury?
Wrist drop
Which humeral fracture tends to damage the radial nerve?
Fracture to radial (spiral) groove, which is located in the mid-shaft of the humerus
Which humeral fracture tends to damage the ulnar nerve?
Fracture to the medial epicondyle
Which humeral fracture tends to damage the axillary nerve?
Fracture to the surgical neck
What is the cubital fossa?
A triangular depression in front of the elbow
What is the function of the cubital fossa?
A conduit for passage of major neurovascular structures from the arm down to the forearm
What forms the base of the cubital fossa?
An imaginary line that runs from the medial epicondyle of the humerus to the lateral epicondyle of the humerus
What muscle forms the medial border of the cubital fossa?
Pronator teres
What muscle forms the lateral border of the cubital fossa?
Brachioradialis
List the four contents of the cubital fossa from lateral to medial
‘Really Need Beer To Be At My Nicest’
Radial Nerve
Brachial Tendon
Brachial Artery
Median Nerve
Which structure separates the cephalic vein and the brachial artery in the antecubital fossa?
Biceps brachii
What vein lies anterior to the roof of the antecubital fossa?
Basilic vein
Which muscle separates the ulnar artery from the median nerve?
Pronator teres
What type of joint is the elbow joint?
Synovial hinge
Describe the articulation of the elbow joint
The trochlea of the humerus articulates with the trochlear notch of the ulnar
The capitulum of the humerus articulates with the radial head
What two ligaments hold the elbow joint in place?
Radial collateral ligament
Ulnar collateral ligament
What is the function of the radial collateral ligament?
It holds the radius in place
What is the function of the ulnar collateral ligament?
It holds the ulnar in place
What three muscles cause flexion of the elbow joint?
Biceps brachii
Brachioradialis
Brachialis
What muscle is the main flexor of the elbow joint?
Brachialis
What two muscles cause extension of the elbow joint?
Triceps
Anconeus
What is student’s elbow?
A condition in which the subcutaneous olecranon bursa is damaged through excessive pressure and friction. This inflammation is called olecranon bursitis
What is tennis elbow?
A condition in which there is inflammation of the muscle tendons attached to the lateral epicondyle of the humerus. This is caused by repetitive overuse of the forearm muscles
What is golfer’s elbow?
A condition in which there is inflammation of the muscle tendons attached to the medial epicondyle of the humerus. This is caused by repetitive overuse of the forearm muscles
What two joints connect the radius and ulnar bones?
Proximal radio-ulnar joint
Distal radio-ulnar joint
What type of joint are the radio-ulnar joints?
Synovial pivot
What ligament keeps the head of the radius in place, supporting the proximal radio-ulnar joint?
Annular radial ligament
What is the function of the proximal radio-ulnar joints?
Supination
Pronation
What two muscles are involved in supination?
Supinator
Biceps brachii
What two muscles are involved in pronation?
Pronator quadratus
Pronator teres
What happens to the radial and ulnar bones during supination?
The radius rotates over the ulna
What is the clinical feature of ulnar nerve damage?
Claw hand
Which lymph nodes recieve lymph from an infection of the little finger?
Humeral
What compartment of the forearm flex the wrist and digits?
Anterior
What compartment of the forearm pronate the forearm?
Anterior
How is the anterior compartment of the forearm arranged?
Into three groups; superficial, intermediate and deep
What are the four muscles in the superficial, anterior compartment of the forearm?
Pronator teres
Flexor carpi radialis (FCR)
Palmaris longus
Flexor carpi ulnas (FCU)
Do the superficial, anterior compartment muscles lie on the medial or lateral aspect of the forearm?
Medial
Where do the superficial, anterior compartment forearm muscles originate from?
Medial epicondyle of the humerus
What muscle lies on the superficial, lateral aspect of the forearm?
Brachioradialis
What is the most superficial muscle of the forearm?
Palmaris longus
What are the two actions of the pronator teres?
Pronation of forearm
Flexion at elbow
In addition to flexion of the wrist, what is the action of the FCU?
Adduction of the wrist joint
What is adduction of the wrist - ulnar or radial deviation?
Ulnar deviation
In addition to flexion of the wrist, what is the action of the FCR?
Abduction of the wrist joint
What is abduction of the wrist - ulnar or radial deviation?
Radial deviation
What two nerves supply the anterior compartment of the forearm? What muscles do they supply?
Median - Pronator teres, FCR, palmaris longus
Ulnar - FCU
What is the muscle in the intermediate, anterior compartment of the forearm?
Flexor digitorum superficialis (FDS)
Which superficial muscles does the FDS lie under?
Palmaris longus
FCR
What happens to the FDS as it passes distally down the arm into the hand?
It gives rise to four tendons which attach to the medial four digits (2nd to 5th)
On which phalanx does the FDS tendon insert?
Middle
What is the action of FDS?
It flexes the wrist, MCP and IP joints
What nerve innervates the FDS?
Median nerve
What is the main action of the brachioradialis?
Flexion of arm when the forearm is in the mid-pronated position
What joint does the brachioradialis act on?
Elbow joint
What nerve innervates the brachioradialis?
Radial nerve
What muscle is the exception to the rule that all flexors lie in the anterior compartment and that the radial nerve only innervates extensor muscles?
Brachioradialis
What compartment of the forearm is the brachioradialis in?
Posterior
Where does the brachioradialis insert and attach? Does it act on the wrist joint? Why?
Humerus
Radial tuberosity
No - it does not cross the wrist joint
What are the three muscles in the deep, anterior compartment of the forearm?
Flexor pollicis longus (FPL)
Flexor digitorum profundus (FDP)
Pronator quadratus
What deep, anterior muscle of the forearm is related to the radius (lateral)?
FPL
What deep, anterior muscle of the forearm is related to the ulna (medial)?
FDP
What deep, anterior muscle of the forearm is related to both the radius and ulna?
Pronator quadratus
What is FDP covered with?
The aponeurosis of FCU
Which phalanx do the tendons of FDP insert onto?
Distal
What is the main action of FDP?
Flexion of the wrist
Flexion of all the finger joints - PIP, IP DIP
What two nerves supply FDP? Which sections do they supply?
Ulnar - medial part
Anterior interosseous - lateral part
What nerve innervates the FPL?
Anterior interosseous nerve - a branch of the median nerve
What are the attachments of the pronator quadratus?
Ulna - origin
Radius - insertion
What nerve innervates the pronator quadratus?
Anterior interosseous nerve - a branch of the median nerve
What is the action of the pronator quadratus?
It works in synergy with the pronator teres muscle and forms a powerful pair of pronators at both the proximal and distal radioulnar joints
What is the main pronator of the forearm
Pronator quadratus
The pronator teres is involved when there is resistance
On what aspect of the forearm is the radial nerve and artery located?
Lateral
On what aspect of the forearm is the ulnar nerve and artery located?
Medial
What other nerve passes through the forearm - apart from radial and ulnar?
Median
How does the median nerve enter the forearm?
Medial to the brachial artery
Describe the course of the median nerve in the forearm
It heads under the pronator teres muscle and passes down the forearm between FDS and FDP
How does the median nerve enter the carpal tunnel?
Under the flexor retinaculum
What anterior forearm muscles does the median nerve not supply?
FCU
Medial half of FDP
What condyle of the humerus does the ulnar nerve pass posterior to?
Medial
How does the ulnar nerve enter the forearm?
Between the heads of the FCU muscle
At the level of the wrist, what is more medial - ulnar nerve or ulnar artery?
Ulnar nerve
Between which two muscles does the ulnar artery and ulnar nerve run?
FCU
FDP
What does the ulnar artery form after passing through the wrist?
The superficial palmar arch
What does the radial artery form after passing through the wrist?
The deep palmar arch
Where do we locate the radial pulse?
The distal third of the forearm, medial to the tendon of FCR
What is Allen’s test?
The test used to determine the patency of the arteries In the distal forearm
What is the carpal tunnel?
The passageway from the forearm to the hand passing deep to the flexor retinaculum
What is the function of the flexor retinaculum?
To stabilise the carpal bones
What four carpal bones is the flexor retinaculum attached to? On what side?
Scaphoid - lateral
Trapezium - lateral
Pisiform - medial
Hamate - medial
What are the contents of the carpal tunnel?
4 tendons of FDP
4 tendons of FDS
1 tendon of FPL
Median nerve
What is carpal tunnel syndrome?
A condition in which there is a reduction of space within the carpal tunnel. It results in weakness and tingling in the muscles and skin supplied by the median nerve
How do we treat carpal tunnel syndrome?
We dissect the flexor retinaculum
What is the clinical feature of median nerve damage?
Simian hand
What palmar surface is more mobile and looser? Why?
Dorsum
The palmar surface is stabilised and supported by palmar fascia
What muscle of the forearm is continuous with the palmar fascia?
Palmaris longus
What is the clinical feature of palmar fascia disease?
Dupuytren contracture
What are the five muscle compartments of the hand - superficial to deep?
Thenar
Hypothenar
Central
Adductor
Interosseous
Where are the thenar muscles located?
On the lateral (radial) aspect of the palm
What are the two superficial thenar muscles?
Abductor pollicis brevis (APB)
Flexor pollicis brevis (FPB)
What is the deep thenar muscle?
Opponens pollicis (OP)
What nerve supplies the thenar muscles?
Median nerve
Except the deep belly of the FPB, which is supplied by the ulnar nerve
What nerve segment from the brachial plexus provides the majority of the innervation to the thenar muscles?
Medial cord
Where are the hypothenar muscles located?
On the medial (ulnar) aspect of the palm
What are the two superficial hypothenar muscles?
Abductor digit minimi
Flexor digiti minimi
What is the deep hypothenar muscle?
Opponens digiti minimi
What nerve supplies the hypothenar muscles?
Ulnar nerve
What is opposition?
The movement of the thumb or little finger towards other fingers
What four muscles make up the central compartment of the hand?
The tendons of FDS
The tendons of FDP
The tendons of FPL
Lumbricals
What are the lumbricals?
They arise from the medial and lateral aspects of the FDP tendon, between the 1st to 5th metacarpals
Remember: FDP inserts onto the distal phalanx of digits
What are the two actions of the lumbricals?
They flex the fingers at the MCP joint
They extend the interphalangeal joint of 2nd to 5th digits
What nerve innervates the lateral two lumbricals?
Median nerve
What nerve innervates the medial two lumbricals?
Ulnar nerve
Which brachial plexus injury will affect the lumbricals?
Klumpke’s
What muscle makes up the adductor component of the hand?
Adductor pollicis
What are the two heads of the adductor pollicis?
Oblique
Transverse
What is the action of the adductor pollicis?
To adduct the thumb
What nerve innervates the adductor pollicis?
Ulnar nerve
Where do the interossei musscle lie?
Between proximal phalanx and the extensor digitorum expansion of the same digit
How many dorsal interossei are there?
4
How many palmar interossei are there?
3
Which two fingers are not a point of attachment for the palmar interossei?
Middle finger
Thumb
What are the action of the dorsal interossei?
Abduct (DAB)
What are the action of the palmar interossei?
Adduct (PAD)
What nerve innervates the interossei?
Ulnar
Where is the deep palmar arch located?
Anatomical snuffbox, passing between the two heads of the 1st dorsal interossei and two heads of the adductor pollicis
What two nerves supply the muscles of the hand?
Median
Ulnar
What muscles within the hand does the median nerve innervate?
Thenar muscles - except deep belly of FPB
1st and 2nd lumbricals
What muscles within the hand does the ulnar nerve innervate?
Deep belly of FPB
3rd and 4th lumbricals
Interossei
Adductor pollicis
Hypothenar
What is the interosseous membrane? What is its function?
An incomplete fibrous structure
To stabilise the forearm structure and radio-ulnar joints
What are the seven carpal bones?
She Looks Too Pretty Try To Catch Her
Scaphoid
Lunate
Triquetrum
Pisiform
Trapezium
Trapezoid
Capitate
Hamate
What separates the carpal bones from the ulna?
Articular disc
What two carpal bones does the radius articulate with?
Scaphoid
Lunate
What fluid is found between the forearm and carpal bones?
Synovial fluid
What artery lies lateral to the pisiform bone?
Ulnar artery
Which carpal bone is a sesamoid bone in the tendon of flexor carpi ulnaris?
Pisiform
What muscle compartment causes wrist flexion?
Anterior
What muscle compartment causes wrist extension?
Posterior
What two muscles cause ulnar deviation (adduction)?
FCU
ECU
What two muscles cause radial deviation (abduction)?
FCR
ECR
What causes circumduction of the wrist?
Combination of ulnar deviation and radial deviation
Where are the metacarpal bones located?
Between the carpal bones and the phalanges
How many metacarpal bones are there?
Five
Where do the metacarpal bones articulate proximally?
Carpal bones at CMC joints
Where do the metacarpal bones articulate distally?
Phalanges at MP joints
How many phalanges are there in the thumb?
Distal
Proximal
How many phalanges are there in the second to fifth digits?
Distal
Middle
Proximal
What are the interphalangeal joints?
The joints between the phalanges
What are the three compartments of the posterior forearm?
Muscles that extend and abduct or adduct the wrist
Muscles that extend the medial four digits
Muscles that extend or abduct the thumb
What are the three muscles that extend and abduct or adduct the wrist?
Extensor carpi radialis longus (ECRL)
Extensor carpi radialis brevis (ECRB)
Extensor carpi ulnas (ECU)
What are the actions of the ECRL and ECRB?
They extend and abduct the wrist joint, causing radial deviation
What muscle lies lateral to the brachioradialis?
ECRL
What are the three muscles that extend the medial four digits?
Extensor digitorum
Extensor indicis
Extensor digiti minimi
What is the common extensor origin?
The lateral epicondyle of the humerus
Where does the extensor digitorum arise?
The lateral epicondyle of the humerus
What happens to the extensor digitorum as it passes through the extensor retinaculum?
It divides into four tendons for the fingers
What is the action of extensor digitorum?
It extends the wrist joint
It extends the medial four digits at MCP and IP joints
What three muscles extend or abduct the thumb?
Abductor pollicis longus (APL)
Extensor pollicis brevis (EPB)
Extensor pollicis longus (EPL)
What is the action of APL?
Abducts thumb
What is the action of EPB?
Extends thumb
What is the action of EPL?
Extends thumb
Where is the supinator located?
The proximal part of the extensor forearm compartment
What is the action of the supinator?
To supinate the forearm
What muscle is the main supinator of the forearm?
Supinator
The brachial brachii is involved when there is resistance
What is the action of extensor digiti minimi?
To extend the 5th finger at the MP joint
What nerve innervates the extensor compartment of the forearm?
Radial nerve
What is another name for the deep branch of the radial nerve?
Posterior interosseous
What is the main motor nerve of the forearm extensors?
Deep radial nerve
Which muscle does the deep radial nerve lie under and pierce?
Supinator
What is the function of the superficial radial nerve?
Sensory distribution to the skin on the dorsal of the hand
Which muscle does the superficial radial nerve lie under?
Brachioradialis
What two arteries supply the extensor forearm compartment?
Posterior interosseous artery
Recurrent interosseous artery
What does the posterior interosseous artery arise from?
Radial artery
What does the recurrent interosseous artery arise from?
Posterior interosseous artery
What is the role of the extensor retinaculum?
It provides stability and a tunnel for the extensor tendons
What are ganglion?
Non-tender cysts on the synovial sheaths of the hand dorsum
What two veins drain the dorsal venous arch?
Cephalic vein
Basilic vein
On what aspect of the hand does the cephalic vein lie?
Lateral
On what aspect of the hand does the basilic vein lie?
Medial
What is the anatomical snuffbox?
A shallow depression on the lateral aspect of the wrist when the thumb is extended fully
What forms the medial border of the anatomical snuffbox?
EPL tendon
What forms the lateral border of the anatomical snuffbox?
EPB tendon
APL tendon
What forms the floor of the anatomical snuffbox?
Scaphoid
Trapezium
Which artery is found on the anatomical snuffbox floor?
Radial
What nerve innervates the thumb extensors and abductors?
Posterior interosseous nerve
What is the action of EPL?
To extend DIP joints of thumb
What is the action of EPB?
To extend PIP joints of thumb
What is the action of APL?
To extend and abduct CMC joints of thumb
How do distal forearm fractures occur?
Falling on outstretched hand
What are the two types of distal forearm fractures?
Colle’s
Smith’s
What are Colle’s fractures?
Fracture of distal radius, where there is anterior displacement of the radius shaft on the distal bone
What is the cause of Colle’s fractures?
Falling on an extended wrist
What are Smith’s fractures?
Fracture of distal radius, where there is posterior displacement of the radius shaft on the distal bone
What is the cause of Smith’s fractures?
Falling on a flexed wrist or direct blow to the forearm
What distal forearm fracture is more common?
Colle’s
What is the most fractured carpal bone?
Scaphoid
What nerve injury causes a wrist drop?
Radial
What is a clinical feature of carpal bone fractures?
Pain in anatomical snuffbox
What is a common complication of carpal fractures?
Risk of avascular necrosis, which can lead to necrosis
Which common fracture in children increases the risk of Volkmaan’s ischemic contractures?
Supracondylar fracture of the humerus
What type of joint are the CMC joint at the thumb? What type of joints are the CMC joint at the digits?
Synovial Saddle
Synovial Plane
What type of joint is the MCP joint?
Synovial Condyle
What type of joints are the IP joints?
Synovial Hinge
What is the IP joint?
The IP joint is located between the proximal and distal phalanges of the thumb
What is the MCP joint?
The MCP joint is located between the metacarpalbones and the proximal phalanges
What is the CMC joint?
The CMC joint is located between the carpal bones and the metacarpals
What is the PIP joint?
The PIP joint is located between the proximal phalanges and the intermediate phalanges of the four digits
What is the DIP joint?
The DIP joint is located between the intermediate phalanges and the distal phalanges of the four digits
What type of joints exist between the metacarpal bones?
Synovial plane
What two fascia protect the neurovascular structures entering the arm in the flexor compartment and the extensor compartment?
Flexor retinaculum
Extensor retinaculum
What cutaenous innervation does the median nerve supply in the hand?
Lateral three and a half fingers
What cutaenous innervation does the radial nerve supply in the hand?
Dorsal aspect of the base of lateral three and a half fingers
What cutaenous innervation does the ulnar nerve supply in the hand?
Medial one and a half fingers
