(2) Gross Anatomy Of the Upper Limb Flashcards
What is a nerve plexus?
What to plexuses supply?
A Nerve plexus is formed by the merging of peripheral spinal nerve roots which split to produce a network of nerves from which new multi segmental peripheral nerves emerge.
Both Upper and lower limbs are supplied by plexuses
The brachial plexus:
How many trunks? What are they?
How many cords? What types of cords?
How many divisions? What types?
How many roots and what are they?
What region is it in?
3 trunks: superior, middle, inferior
3 cords - lateral, medial, posterior
6 divisions - has anterior and posterior divisions
5 roots: C5, C6, C7, C8, T1
Brachial plexus is in the shoulder/clavicle region
The brachial plexus:
The cords of the brachial plexus are named according to their relationship to what?
What are the two main groups of nerves that branch from the brachial plexus?
The cords of the brachial plexus are named according to their relationship to the axillary artery
Eg posterior cord is posterior to the artery
Two main groups of nerves that branch from the brachial plexus:
-supraclavicular branches: from the roots and the trunks eg dorsal scaviculad nerve, long thoracic nerve
-infraclavicular branches: side branches to pectoral girdle muscles and the main peripheral nerves.
Eg branches to some scapular muscles, and the large terminal branches eg radial, ulnar, median
Which artery supplies most upper limb blood? It is a branch of which arch? What type of artery does it become on entering the arm?
Subclavian artery
Branch of the aortic arch
Becomes an axillary artery on entering arm
List the arteries of the shoulder and arm (5)
Subclavian artery Axillary artery Anterior and posterior circumflex humeral arteries Brachial artery Profunda brachii artery
List the arteries of the forearm (5)
Brachial artery Radial artery Ulnar artery Anterior interosseous artery Posterior interosseous artery
List the arteries of the hand and wrist (7)
Superficial palmar arch Deep Palmar arch Ulnar artery Radial artery Anterior interosseous artery Posterior interosseous artery Dorsal carpal arch
Musculocutaneous nerve:
Which cord is it a branch of?
What does it innervate?
A terminal branch of the lateral cord
Muscular innervation to the anterior muscles of the arm
Cutaneous innervation of the lateral forearm
Musculocutaneous nerve:
Describe it positionally in relation to other structures
The musculocutaneous nerve pierces coracobrachialis to reach biceps and brachialis muscles
Continues to cross the elbow joint to innervate the lateral arm
Ulnar nerve:
Which cord is it a branch of?
What does it innervate?
Describe where it passes and where it crosses
Terminal branch of the medial cord
No innervation on the arm
Cutaneous innervation of the medial Hand
Limited innervation in the forearm
Passes behind the medial epicondyle of the humerus - easily damaged here (funny bone)
Crosses wrist to enter the hand
Median nerve:
Which cords does the median nerve descend from?
What does it innervate?
Where can the median nerve be commonly damaged?
From lateral and medial cords
No innervation in the arm
Innervates:
most of the anterior forearm muscles
Some intrinsic hand muscles
Cutaneous innervation of the lateral hand and 3 1/2 digits
Commonly damaged at the wrist and also in the distal arm
Radial nerve in the forearm
What cords are they branches from?
What do they innervate?
Radial and axillary nerves are from the posterior cord
Axillary nerve innervates:
- deltoid muscle
- upper lateral aspect of the arm
Radial nerve:
- innervates all arm and forearm posterior muscles, NO intrinsic hand muscles
- cutaneous branches in arm and forearm
- cutaneous innervation of the lateral hand and 3 1/2 digits
Radial nerve in the forearm:
Radial nerve divides in the elbow region to give what two branches and what do they supply?
Superficial branch - cutaneous to the dorsolateral hand
Deep branch - motor supply to the posterior muscles of the forearm
What are two venous return types in the limbs?
Deep (accompanying the arteries)
Superficial (on the limb surface)
List the deep veins of the upper limb (arteries of the upper limb)
Axillary vein Anterior and posterior circumflex humeral veins Profunda brachii vein Brachial vein Radial and ulnar veins Brachial vein Subclavian vein Posterior interosseous vein
What are venae comitantes?
What do connections between the VC allow?
What promotes venous flow?
Venae comitantes (VC) = accompanying veins
Multiple veins form a network of smaller veins w arteries which they accompany
Connections between the VC allow heat exchange
Artery pulse promotes venous flow
List the superficial veins
What connects the superficial veins?
Dorsal venous network of hand
Basilic (medial)
Cephalic (lateral)
Superficial veins are connected by the median cubital vein (not always present)
What are the lymphatics of the upper limb?
Generally the lymphatic vessels run w the veins in most organs and tissues
Cubital nodes - drain distal limb
Axillary nodes - drain limb and breast
The axillary vein is formed by the union of which downstream veins?
The venae comitantes of the brachial artery and the basilic vein
A patient shows signs of infection and her cubital lymph nodes are enlarged. From which part (or parts) of the upper limb is the infection most likely to be located?
Hand or forearm
The lymphatic vessels from the hand and medial forearm run with the basilic vein towards the cubital fossa and drain through the cubital nodes. So, enlarged nodes would suggest infection from hand and forearm
