Upper Limb Anatomy Flashcards
What shape is the axilla?
Pyramidal shape
What are the borders of the axilla?
Has a
Base
Apex
4 walls
What makes up the anterior wall of the axilla?
Pectoralis major
Pectoralis minor
Under which joint does the axilla lie under?
Shoulder joint/ glenohumeral joint
What makes up the posterior border of the axilla?
Subscapularis
Teres minor
Latissimus dorsi
What makes up the medial wall of the axilla?
Serratus anterior
and
Thoracic wall
What makes up the lateral border of the axilla?
Intertubercular groove of humerus
What are the contents of the axilla?
Axillary artery Axillary vein Brachial plexus Biceps brachii and coracobrachialis Axillary lymph nodes
The axillary artery is a continuation of which artery?
Subclavian artery
At which anatomical point does the axillary artery begin?
Lateral edge of 1st rib
At which anatomical point does the axillary artery become the brachial artery?
Lower border of teres major muscle
The axillary artery continues as?
Brachial artery
What does the brachial artery bifurcate into?
Radial artery
Ulnar artery
Where does the brachial artery bifurcate?
As it crosses the cubital fossa
Which plexus innervates the upper limb?
Brachial plexus
Which nerve roots form the brachial plexus?
Ventral rami of C5,6,7,8 and T1
Which nerve roots form the upper/superior trunk?
C5/6
Which nerve roots form the middle trunk?
C7
Which roots form the lower/inferior trunk?
C8 and T1
What is Erb’s Palsy?
Injury to upper trunk (C5/6)
Which palsy is associated with waiter tip
Erbs palsy
Describe waiters tip
Medially rotates upper limb with wrist flexed
How does Erb’s palsy commonly occur?
Birth trauma
Dystocia
Which segmental roots of the brachial plexus contribute to the lower trunk of the brachial plexus
C8 and T1
What is Klumpke’s Palsy
Injury to the lower trunk
How are the cords of the brachial plexus named
Named for their position in relation to the axillary artery
What are the 3 cords of the brachial plexus
Lateral
Medial
Posterior cords
What are the major nerve branches of the brachial plexus
Musculocutaneous nerve Axillary nerve Median Nerve Radial nerve Ulnar nerve
Name the major arteries of the upper limb
Subclavian artery Axillary artery Brachial artery Radial artery Ulnar artery
What are the 2 palmar arches of the hand?
Superficial palmar arch
Deep palmar arch
What are the main superficial veins of the upper limb?
Cephalic vein
Basilic vein
Median Cubital vein
Which vein arises at the lateral end of the dorsal venous arch
Cephalic vein
Which vein arises from the medial end of the dorsal venous arch
Basilic vein
Why do superficial veins assume important in medical practice?
Because they are commonly used for intravenous injections for transfusions and for withdrawing bloods
From which vein to which vein does the median cubital vein shunt blood?
From cephalic to basilic vein
What is a dermatome?
Are of skin supplied by one spinal segment
Which dermatome lies over the nipples?
T4
Which dermatome lies over the umbilicus
T10
Which dermatome supplies the thumb?
C6
Which dermatome supplies the index and middle finger?
C7
Which dermatome supplies the ring and little finger?
C8
Where do lymphatic vessels from the upper limb drain into?
Axillary lymph nodes
What are the 4-5 distinct groups of the axillary lymph nodes/
Apical group Central group Lateral group Anterior/pectoral group Posterior/subscapular group
When is enlargement of the axillary lymph nodes common
During malignancy
Which group of LN would drain the lateral part of the breast?
Axillary lymph nodes
Which group of LN would drain the medial breast close to sternum?
Internal mammary/thoracic LN
Infection around the umbilicus can spread to both superficial inguinal and axillary LN why?
Above it drained by axillary
Below it drains to superficial inguinal LN
What is the pectoral girdle?
Set of bones which connect the upper limb to the axial skeleton on both sides
What are the 2 ends of the clavicle called?
Sternal end
Acromial end
Which end of the clavicle is medial?
Sternal end
Which end of the clavicle is lateral
Acromial end
Which part of the clavicle is the weakest?
Middle 1/3
What type of joint is the acromioclaviclar joint?
Synovial plane
What type of joint is the sternoclavicular joint?
Synovial saddle
What does the acromioclaviclar joint connect?
Lateral clavicle (acromial end)
And
Acromion of scapula
What does the sternoclavicular joint connect?
Sternal/medial clavicle
Manubrium of sternum
Which muscles cause elevation of the scapula?
Upper trapezius
Levator scapulae
Rhomboids
Which muscles cause depression of the scapular
Lower Trapezius
Serratus anterior
Pectoralis minor
Which muscles cause protraction of the scapula?
Serratus anterior
Which muscle causes retraction of the scapula?
Middle trapezius fibres
Rhomboid muscles
Which muscle causes lateral (upward rotation) of the scapula
Upper and middle trapezius fibres
Which muscles cause medial (downward) rotation of the scapula?
Rhomboids
Pectoralis minor
Levator scapulae
With help from gravity
What type of joint is the glenohumeral joint?
Ball and socket
Is the rhomboid major muscle superior or inferior to rhomboid minor muscle
Inferior
Which is the most superficial back muscle?
Trapezius
Innervation of trapezius
Accessory nerve
Cranial nerve 11
How do you test the trapezius muscle
Ask the patient to shrug their shoulders
What do upper trapezius fibres do to the scapula
Elevate it
What do middle fibres of the trapezius do to the scapula?
Retract it
What do lower fibres of the trapezius muscle do to the scapula?
Pull it inferiorly
What is the ball of the glenohumeral joint?
Head of the humerus
What forms the socket of the glenohumeral joint?
The glenoid cavity
The rim of cartilage surrounding the glenohumeral socket is the
Glenoid labrum
What is the function of the glenoid labrum?
To deepen the socket
What nerve is injured in winging of the scapula?
Long thoracic nerve
During which procedure is the long thoracic nerve commonly injured
Axillary nerve clearance in breast surgery
Which aspect of the glenohumeral joint does the glenohumeral ligaments strengthen?
Anterior aspect
What does the coraco-acromial ligament prevent
Superior displacement
What does the coracohumeral ligament strengthen?
Superior aspect of joint capsule
Which part of the shoulder joint capsule is weakest as is not protected by muscles or ligaments
Anterior
Inferior
Name the 4 rotator cuff muscles
Subscapularis
Supraspinatus
Infraspinatus
Teres minor
Where do the 4 rotator cuff muscles extend from to?
Scapula to humerus
What is the most important role of the 4 rotator cuff muscles?
To pull the humeral head into the glenoid fossa
Which 2 intrinsic shoulder muscles extend from the scapula and trunk to the humerus
Deltoid
Teres major
What is the action of anterior fibres of the deltoid muscle?
Flexion and medial rotation of arm
What is the action of middle fibres of the deltoid muscle?
Abduction of arm
Which muscles does the middle deltoid take over from in abduction of the arm
Takes over from supraspinatus which abducts first 15 degrees
What is the action of the posterior deltoid fibres?
Extension and lateral rotation of arm
What is the nerve supply to the deltoid muscle
Axillary nerve
In what common injury is the axillary nerve commonly trapped
Shoulder dislocation
Fracture of surgical neck of humerus
Where would you test for sensation loss in axillary nerve injury?
Regimental badge area
Where do the fibres of the pectoralis major originate from
Medical third of clavicle
Sternum
Ribs
What is the action of the pectoralis major on the shoulder
Flexion
Adduction
Which vein below the clavicle is used for placement of central lines
Subclavian vein
What is the action of the serratus anterior on the scapulae
Protraction
What is the nerve supple of the serratus anterior?
Long thoracic nerve
What are the actions of the teres major on the shoulder joint
Adduction
Medial rotation
What are the actions of the actions of the latissimus dorsi on the shoulder?
Extension
Medial rotation
Adduction
Which muscle causes flexion of the shoulder joint
Pectoralis major
Anterior deltoid
Coracobrachialis
Biceps Brachii
Which muscles cause extension of the shoulder joint?
Posterior deltoid
Teres major
Latissius dorsi
Which muscles cause adduction of the shoulder joint?
Pectoralis major
Latissimus dorsi
Theres major
Coracobrachialis
Which muscles cause abduction of the shoulder joint?
0-15 degrees supraspinatus
15-90 degrees- middle deltoid fibres
Past 90 degrees the scapula needs rotated
Which muscles cause internal/medial rotation of the shoulder
Subscapularis Lattisimus dorsi Pectoralis major Teres major Anterior deltoid
Which muscles cause lateral or external rotation of the shoulder joint?
Teres minor
Infraspinatus
What are the 3 main muscles in the anterior compartment of the arm
Biceps brachii
Coracobrachialis
Brachialis
How many heads does the bicep muscle have?
2
Which is the most anterior muscle of the anterior arm
Biceps brachii
Where does the biceps brachii insert into distally?
Tuberosity of the radius
What are the 2 heads of the biceps brachii muscles?
Long head
Short head
Which head of the biceps brachiii arises from the coracoid process?
Short head
Which other muscle arises at the coracoid process?
Coracobrachialis
Which head of the biceps brachii arises from the supraglenoid tubercle?
Long head
What is the action of the biceps brachii on the shoulder and elbow joint?
Flexion at both joint
What is the action of the biceps on the superior radio ulnar joint
Powerful supinator
What is the nerve supply to the biceps?
Musculocutaneous nerve
Which segmental fibres mainly innervate the biceps brachii muscle
C5,6,7
From which cord of the brachial plexus does the musculocutaneous nerve arise from?
Lateral cord
What is the action of the coracobrachialis on the shoulder joint?
Flexion arm at shoulder
Weak adduction
What is the nerve supply of the coracobrachialis?
Musculocutaneous nerve
What are the BBC muscles?
Biceps Brachii
Brachialis
Coracobrachialis
What is the innervation of the BBC muscles?
Musculocutaneous nerve
Where does the brachialis muscle insert?
To the coronoid process of the ulna
What is the main action of the brachialis on the elbow joint?
Flexion at elbow
Which nerve supplies the brachialis?
Musculocutaneous nerve
