Lecture 6 - Brachial Plexus Flashcards
(13 cards)
What does the Musculocutaneous Nerve innervate and where does it originate?
Roots: C5, C6, C7.
Motor Functions: Innervates the brachialis, biceps brachii and coracobrachialis muscles.
Sensory Functions: Gives off the lateral cutaneous branch of the forearm, which innervates the lateral half of the anterior forearm, and a small lateral portion of the posterior forearm.
What does the Axillary Nerve innervate and where does it originate?
Roots: C5 and C6.
Motor Functions: Innervates the teres minor and deltoid muscles.
Sensory Functions: Gives off the superior lateral cutaneous nerve of arm, which innervates the inferior region of the deltoid (“regimental badge area”).
What does the Median Nerve innervate and where does it originate?
Roots: C6 – T1
Motor Functions: Innervates most of the flexor muscles in the forearm, the thenar muscles, and the two lateral lumbricals associated with the index and middle fingers.
Sensory Functions: Gives off the palmar cutaneous branch, which innervates the lateral part of the palm, and the digital cutaneous branch, which innervates the lateral three and a half fingers on the anterior (palmar) surface of the hand.
What does the Radial Nerve innervate and where does it originate?
Roots: C5 – T1.
Motor Functions: Innervates the triceps brachii, and the muscles in the posterior compartment of the forearm (which are primarily, but not exclusively, extensors of the wrist and fingers).
What does the Ulnar Nerve innervate and where does it originate?
Roots: C8 and T1.
Motor Functions: Innervates the muscles of the hand - flexor carpi ulnaris and medial half of flexor digitorum profundus.
What does the Suprascapular Nerve innervate and where does it originate?
C5-C6
Innervates: supraspinatus and infraspinatus muscles.
What nerves innervate the pecs?
Lateral Pectoral Nerve: Pec major
Medial pectoral nerve: pec major and pec minor
What does the dorsoscapular nerve innervate?
- levator scapulae
- the rhomboids (minor superior to major).
What is the innervation and function of the Latisssimus dorsi?
thoracodorsal nerve
- adduction, horizontal abduction, flexion from an extended position, and (medial) internal rotation of the shoulder joint.
What does the long thoracic nerve innervate and what would be the result to trauma of this nerve?
serratus anterior
A direct blow to the ribs could damage the long thoracic nerve and can lead to loss of shoulder movement.
Laceration of the long thoracic nerve can lead to winged scapula
What is the difference between Dermatomes and Cutaneous nerves?
Cutaneous nerves may carry two or more spinal nerves
- Dermatones are supplied by a single spinal nerve
What is the blood supply for the upper limb?
The blood supply for the upper limb originates from the subclavian artery, which becomes axillary after it crosses 1st rib and then brachial artery -> radial and ulnar artery meeting at the hand
What nerve is at the highest risk of injury during a fracture to the surgical neck of the humerus?
The axillary nerve
