The Axillary Region Flashcards
Where does the left subclavian artery arise from?
The aorta
Where does the right subclavian artery arise from?
The brachiocephalic trunk
When does the subclavian become the axillary artery?
When it crosses the lateral edge of the first rib.
What arises from the axillary artery at the humeral surgical neck?
Posterior and anterior circumflex humeral arteries
Subscapular artery
When does the axillary become the brachial artery?
At the teres major muscle
Which artery supplies the posterior of the arm and stops at the elbow? Travels in the radial groove?
Profunda brachii
Which nerve does the brachial artery run posteriorly to?
The median nerve
Which digits does the radial artery supply?
The thumb and lateral index finger
What is Volkmann’s contracture?
A result of occlusion of the brachial artery.
Resulting ischaemia causes flexors to be short and fibrotic, leading to uncontrolled flexion of the hand
Name of the cords of the brachial plexus?
Lateral, posterior and medial cords
Names of the trunks of the brachial plexus?
Superior, middle and inferior trunks
What are the different parts of the brachial plexus called?
Roots, trunks, divisions, cords, terminal branches
Roots of the musculocutaneous nerve?
C5 and C6
Roots of the median nerve?
C6, C7, C8, T1
All but C5
Roots of the ulnar nerve?
C8, T1, often C7
Roots of the axillary nerve?
C5 and C6
Roots of the radial nerve?
C5-T1
Musculocutaneous motor functions?
Muscles of anterior compartment of arm (biceps brachii, coracobrachialis and brachialis)
Sensory innervation of musculocutaneous?
Skin of lateral forearm
Motor function of median nerve?
Muscles of anterior forearm compartment
5 intrinsic muscles in thenar half of palm
Motor function of ulnar nerve?
Flexor carpi ulnaris Ulnar half of flexor digitorum profundus Hypothenar muscles Medial two lumbricals Adductor pollicis Interossei of the hand
Sensory function of median nerve?
Lateral three and a half fingers on the palmar surface of the hand and lateral half of the palm
Sensory function of ulnar nerve?
Skin of medial half of the palm
Skin of medial one and a half fingers (baby and ring) (both sides)
Motor function of radial nerve?
Triceps brachii
Majority of extensor muscles in forearm
Sensory functions of radial nerve
Most of the skin on the posterior forearm
Dorsal surface of the lateral side of the palm
Lateral three and a half digits
Sensory function of the axillary nerve?
Regimental badge area
Motor functions of the axillary nerve?
Teres minor and deltoid muscle - both abductors of the arm at the shoulder
What is the apex of the axilla formed by?
Lateral border of the first rib
Superior border of the scapula
Posterior border of the clavicle
What is the lateral wall of the axilla formed by?
Intertubercular groove of the humerus
Tendon of long head of biceps brachii
What is the medial wall formed by?
Serratus anterior and the thoracic wall
Anterior wall?
Pec major and minor
Subclavius muscles
Posterior wall?
Subscapularis
Teres major
Latissiumus dorsi
Give the contents of the axilla
Axillary artery and vein
Biceps brachii and coracobrachialis
Axillary lymph nodes
What is the pathology of thoracic outlet syndrome?
The vessels and nerves may become compressed at the apex of the axilla - there is a narrow gap between the clavicle, first rib and scapula.
What are causes of thoracic outlet syndrome?
Trauma eg fractured clavicle
Repetitive actions
What does thoracic outlet syndrome present with?
Pain
Parasthesia
Muscle weakness
Discolouration
