Nerves of the Equine Forelimb. Flashcards
What is the major plexus that supplies the forelimb?
The brachial plexus.
What nerves form the brachial plexus?
Cervical nerves 6, 7 and 8.
Thoracic nerves 1 and 2.
Is the musculocutaneous nerve an independent structure in the equine forelimb?
No.
What forms the musculocutaneous nerve in the equine forelimb?
Branches from the median nerve.
What is innervated by the proximal branch of the musculocutaneous nerve?
The coracobrachialis and the biceps brachii muscles.
The proximal branch of the musculocutaneous nerve branches off what nerve?
The median nerve.
The distal branch of the muculocutaneous nerve is a branch of what nerve?
The median nerve.
Where does the distal branch of the muculocutaneous nerve emerge from on the limb?
Just distal to the elbow.
What innervated by the distal branch of the musculocutaneous nerve?
The brachialis muscle.
The nerves at the level of the scapula tend to be what nerve?
The suprascapular nerve, the subscapular nerve.
The nerves at the level of the shoulder tend to be what nerves?
The axillary nerves and the radial nerve.
The nerves at the level of the brachium tend to be what nerve?
The ulna nerve.
Where is the ulna nerve found on the brachium?
On the caudal border of the long head of the triceps.
What are the 2 major nerves of the distal forelimb in the horse?
The median nerve.
The ulnar nerve.
Are there any independent dorsal nerves in the distal forelimb in the horse?
No.
What are perissodactiles?
Odd toed ungulates.
What are pentadactiles?
Animals with an even number of toes.
What is the manus region of the forelimb/.
The carpus and the area distal to the carpus.
In pentadactiles the axial and abaxial dorsal digital nerves are the terminal branches of what nerves?
Digits 1-4 are supplied by the radial nerve.
Digit 5 is supplied by the ulnar nerve.
In pentadactiles the axial and abaxial palmar digital nerves are the terminal branches of what nerves?
Digits 1 and 2 are supplied by the median nerve.
Digits 3, 4 and 5 are supplied by the ulnar nerve.
What nerves innervate the dorsal aspect of the distal limb of the horse?
The dorsal branches of the ulnar nerve.
The medial cutaneous antebrachial nerve.
The dorsal branches of the medial and lateral branches of the palmar digital nerve.
The medial cutaneous antebrachial nerve is a branch of what nerve?
The musculocutaneous nerve.
What 2 nerves give innervation to the mannus?
The median nerve.
The ulnar nerve.
The median nerve is mainly responsible for innervating what structures of the forelimb?
The distal forelimb (the mannus).
What nerves are formed by the median nerve at the level of the carpus?
It bifurcates at the level of the carpus to form the medial and lateral palmar nerves.
Does the ulnar nerve provide a lot of innervation to the mannus?
No.
It provides little innervation to the mannus.
What happens as the ulnar nerve reaches the mannus?
It overlaps with the median nerve.
What are the 2 major branches of the ulnar nerve?
The ulnar nerve gives off the dorsal branch just above the carpus.
It then continues as the palmar branch which joins up with the lateral palmar branch of the median nerve.
What area of the forelimb is supplied by the deep branch of the ulnar nerve?
The interosseus muscle.
The medial nerve is on what aspect of the forelimb?
The medial aspect.
The ulnar nerve is on what aspect of the forelimb?
The lateral aspect.
What nerves branch off the deep branch of the ulnar nerve?
The lateral and medial palmar metacarpal nerves.
Where are the medial and lateral palmar nerves in relation to the metacarpal bone?
They are palmar to the metacarpal bone.
Where can the medial and lateral palmar nerves be found in the carpus?
In the metacarpal grooves on both sides.
The medial palmar nerve follows what path within the carpus?
It runs past the carpus between the interosseus muscle and the flexor tendons.
What branches off the medial palmar nerve at the mid metacarpal region?
A communicating branch that crosses over the SDFT and attaches to the lateral palmar nerve.
The median palmar nerve originates from what nerve?
The median nerve.
What aspect of the metacarpal bone are the median and lateral palmar nerves found on?
On the palmar aspect.
What is the origin of the lateral palmar nerve?
It has a dual origin and it originates from the ulnar nerve via the palmar branch and from the median nerve.
The lateral palmar nerve travels along what part of the carpus?
Along the axial surfaces of the splint bones and they terminate before the fetlock at the buttons.
What do the medial and lateral palmar nerves become at the level of the fetlock?
The medial and lateral digital nerves.
What is the path of the medial and lateral digital nerves?
The both pass palmar to the digital artery and over the abaxial aspect of the proximal sesamoid bones.
What branches off the medial and lateral digital nerves at P1 and P2?
Dorsal branches.
