Neurovascular anatomy of the upper limb Flashcards
What is the axilla?
An area of transition between the neck and arm
What is the role of the axilla?
Distribution centre for the neurovascular structures that serve the upper limb
What are the four things that form the axilla?
Clavicle
Scapula
Upper thoracic wall
Humerus and related muscles
What is the anterior wall of the axilla?
Lateral part of the pectoralis major
underlying pectoralis minor
What is the posterior wall of the axilla?
Scapula and subscapularis on aterior surface
teres major and latissmus dorsi
What is the medial wall of the axilla?
thoracic wall and overlying serratus anterior
What is the lateral wall of the axila?
Intertubercular sulcus
What is the cervico- axillary canal? and what is it bounded by?
Passageway between the neck and axilla
1st rib
clavicle
superior edge of scapula
What is the brachial plexus?
A network of nerves with motor and sensory nerves
Where is the quadrangular space in relation to teres minor and what is present within it?
Axillary nerve and is inferior teres minor and posterior circumflex humeral artery
What is the inferior boundary of the triangular space?
superior border of the teres major
What is the lateral boundary of the triangular space?
the long head of the triceps
What is the superior boundary of the triangular space?
teres minor/suscapularis
What are the contents of the triangular space?
Scapular curcumflex artery
What is the superior border of the triangular interval?
teres major
What is the medial border of the triangular interval?
long head of the triceps brachii
What are the contents of the triangular interval?
The radial nerve and profunda brachii artery
What is the superior border of the quadrangular space?
Teres minor
What is the inferior border of the quadrangular space?
teres major
What is the medial border of the quadrangular space?
the long head of the tricpes brachii
What is the lateral border of the quadrangular space?
the surgical neck of the humerus
What forms the floor (base) of the axilla?
Concave skin
Subcutaneous tissue
Axillary fascia
What is the base of axilla supported by?
The clavipectoral fascia
What are the contents of the axilla? and what are they embedded in?
Axillary artery Axillary vein Axillary lymph nodes Brachial plexus Biceps brachii – short head Coracobrachialis all embedded in fat
What is the sleeve like extension called that the neurovascular structures are embedded in and what is it made of?
Axillary sheath
made up of connective tissue
What happens to the brachial artery at the elbow?
It becomes the ulna and radial artery
What are the 3 big blood vessels that originate from the aortic arch?
Brachiocephalic trunk
left carotid artery
left subclavian artery
What is meant by the term subclavian?
Under the clavicle
What is the role of the axillary artery?
Supplies the walls of the axilla and related regions
Where and what does the axillary artery start as?
Subclavian artery and starts at the lateral border of the first rib
Where does the axillary artery finish as and as what?
Inferior border of teres major
What is the axillary sheath continuous with as it traces into the root of the neck?
Prevertebral fascia
How many parts is there of the axillary artery and what separates it?
3
pectoralis minor
Describe the position of the first part of the axillary artery
Proximal to pec minor from medial part of pec minor and lateral part of 1st rib
Describe the position of the second part of the axillary artery?
posterior to pec minor
Describe the position of the third part of the axillary artery
distal to pec minor from lateral part of pec minor to inferior border of teres major
How many branches is there in the axillary artery and how many in each part?
6 branches
1 branch in 1st part
2 branches in 2nd part
3 branches in 3rd part
What is the branch(es) in the first part of the axillary artery?
Superior thoracic artery
What is the branch(es) in the second part of the axillary artery?
Thoraco-acromial artery and lateral thoracic artery
What is the branch(es) in the third part of the axillary artery?
Subscapular artery, anterior circumflex humeral artery and posterior circumflex artery
What does the axillary vein start as and where does it start?
Basilic vein and inferior border of teres major
What does the axillary vein finish as and where does it finish?
Subclavian vein and at the lateral border of the first rib
What is the role of the cephalic vein?
Drains deoxygenated blood in vein
What happens when there is dilation of the first part of the axillary artery?
aneurysm- the artery will enlarge and compress the trunk of the brachial plexus, causing pain and anaesthesia in the areas of skin supplied by the affected nerves
What forms the brachial plexus?
Formed by the union of the anterior rami of the last 4 cervical (C5-C8) & first thoracic (T1) nerves which make the roots
From medial to lateral what are the five parts of the brachial plexus?
Roots Trunks Divisions Cords Terminal nerves
What are the trunks and where do they come from?
Superior -C5 and C6
Middle - C7
Inferior - C8 and T1
How is the posterior cord of the brachial plexus formed?
3 posterior divisions come from the 3 trunks to form the posterior cord
How is the lateral cord of the brachial plexus formed?
an anterior division from each the trunk superior and the middle trunk
How is the medial cord of the brachial plexus formed?
it is formed from the anterior division which comes from the inferior trunk