Upper Limbs 2 Flashcards
How is the brachial plexus arranged?
5 spinal nerves (C5, C6, C7, C8, T1)
Form 3 trunks
Form 6 divisions
Form 3 chords
Form terminal branches and side branches
What are the different trunks and divisions?
C5 and C6 form superior trunk
C7 forms middle trunk
C8 and T1 form inferior trunk
Each trunk has an anterior and posterior division
What are the different cords?
Anterior division from superior and middle trunk forms the lateral cord
Anterior division from posterior cord forms the medial cord
All 3 posterior divisions form the posterior cord
What are the different terminal branches?
Lateral cord forms musculocutaneous branch and lateral root which joins with medial root of medial cord to give median branch
Posterior cord gives rise to axillary and radial branch
Medial cord gives rise to ulnar banch
Label the following
How are the cords of the brachial plexus named?
Named based on their relationship to the axillary artery
E.g posterior cord is posterior to axillary artery
What does the musculocutaneous branch innervate and what route does it take?
Muscular innervation to anterior muscles of arm
Cutaneous innervation to lateral forearm
Nerve enters axilla and enters anterior arm, piercing coracobrachialis to reach biceps and brachialis
Continues to cross elbow joint to innervate lateral arm- lateral cutanous nerve of forearm
What does the ulnar nerve innervate and what route does it take?
Passes behind medial epicondyle- easily damaged here
Passes towards wrist to innervate flexor carpi ulnaris and medial half of flexor digitorum profundus
Crosses wrist to enter hand
Innervates most of intrinsic muscles
Cutaneous innervation to medial part of hand incuding little finger and medial part of ring finger
What does the median nerve innervate and what route does it take?
No innervation in arm
Crosses elbow to forearm where it supplies anterior forearm muscles
Inervates some intrinsic hand muscles
Cutaneous innervation of lateral hand and 3.5 digits (thumb, index, middle and half of ring finger)
Nerve crosses the wrist and enters hand via carpal tunnel- supplies thenar emminance and lateral 2 lumbricals as well as cutaneous innervation
What does the radial and axillary nerve innervate and what route does it take?
Axillary: innervates deltoid muscle and upper lateral aspect of arm
Radial : innervates all arm and forearm posterior muscles, no intrisic hand muscles. Cutaneous branch in arm and forearm. Cutaneous innervation of lateral hand and 3.5 digits (thumb, index, middle and half of ring finger)
Radial nerve divides in elbow to give:
- superficial branch- cutaneous to dorsolateral hand
- deep branch- motor supply to posterior muscles of forearm
What is the main arterial supply to the upper limb?
Most upper limb blood supply from subclavian artery
Becomes axillary artery on entering arm
Axillary artery seperated into 3 parts: Anterior and posterior circumflex circle superior arm. And scapular which is richly supplied
Label the following arteries
Ulnar gives common interossesus artery which immediately branches to give anterior and posterior interosseus arteries
Label the following
How is venous return in the upper limb arranged?
Deep: accompany arteries
Superficial: in limb surfaces
Insteadof 1 vein theres many small veins known as venae comintantes
Label the following
Label the following
Basilic and cephalic vein joined by median cubital vein (used to take blood)
Label the following and what they drain
Cubital nodes: drain distal limb
Axillary nodes: drain lim and breast
