ANATOMY - Forelimb Nerve, Vascular and Lymph Supply Flashcards
Which spinal nerves make up the brachial plexus?
C6, C7, C8, T1 and T2
What are two common causes of damage to the brachial plexus?
Avulsion
Neoplasms
Which three extrinsic muscles of the forelimb are supplied by the brachial plexus?
Latissimus dorsi muscle
Serratus ventralis muscle
Pectoral muscles
Which seven peripheral nerves emerge from the brachial plexus to supply the intrinsic muscles of the forelimb?
Suprascapular nerve
Subscapular nerve
Axillary nerve
Musculocutaneous nerve
Median nerve
Ulnar nerve
Radial nerve
What is the function of the suprascapular nerve?
Motor innervation of the supraspinatous muscle and infraspinatous muscle
What is the function of the subscapular nerve?
Motor innervation of the subscapularis muscle
What are the consequences of damage to the suprascapular and subscapular nerves?
Damage to the suprascapular and subscapular nerves would cause the supraspinatous, infraspinatous and subscapularis muscles to lose tension and no longer provide support to the shoulder joint
What are the functions of the axillary nerve?
Innervation of the deltoideus and teres major muscles and cutaneous sensation of the lateral omo (shoulder region) and brachium regions
What are the consequences of damage to the axillary nerve?
Damage to the axially nerve would lead to a loss of cutaneous sensation at the lateral omo (shoulder region) and brachium regions
Why would damage to the axillary nerve not result in the loss of shoulder flexion?
Latissimus dorsi and the long head of the triceps brachii muscles are both shoulder flexors and would compensate
What are the functions of the musculocutaneous nerve?
Innervation of the biceps brachii muscle and the brachialis muscle. Also provides cutaneous sensation to the medial antebrachium region
What are the consequences of damage to the musculocutaneous nerve?
Loss of elbow flexion and cutaneous sensation to the medial antebrachium region
What are the functions of the median and ulnar nerves?
Innervation of the the flexor carpi ulnaris muscle, superficial digital flexor muscle and deep digital flexor muscle ,and cutaneous sensation to the caudal/palmer limb and the dorsal surface of the 5th digit
What are the consequences of damage to the median and ulnar nerves?
Loss of carpal and digital flexion and a loss of cutaneous sensation to the caudal/palmer limb and the dorsal surface of the 5th digit
What are the functions of the radial nerve?
Innervation of the triceps brachii muscle, extensor carpi radialis muscle, extensor capri ulnaris muscle and the common digital extensor muscle. Also provides cutaneous sensation to the cranial/dorsal limb (except the 5th digit)
(T/F) The radial nerve is very prone to isolated damage
TRUE.
What is the most common cause of radial nerve damage?
Humerus fracture
What are the consequences of proximal radial nerve damage?
Damage to the proximal radial nerve would lead to a loss of elbow, carpal and digital extension and a loss of cutaneous sensation to the cranial/dorsal limb (except the fifth digit)
What are the consequences of distal radial nerve damage?
Damage to the distal radial nerve would lead to a loss of carpal and digital extension and a loss of cutaneous sensation to the cranial/dorsal limb (except 5th digit)
What is a common consequence of the loss of cutaneous sensation seen in radial nerve damage?
Self-mutilation
Describe the organisation of the forelimb arterial supply
The arterial supply for the forelimb is one major artery that runs from the trunk to the forelimb, where the name of the artery changes depending on the region of the forelimb it is located
What are the four main regions of forelimb arterial supply?
Subclavian artery
Axillary artery
Brachial artery
Median artery
Which vein of the forelimb is the most clinically relevant?
Cephalic vein
What are the two main lymph nodes present in the forelimb?
Prescapular lymph node
Axillary lymph node
