Forelimb Flashcards
Name the nerves of the brachial plexus.
Subscapular, suprascapular, musculocutaneous, axiliary, radial, median ulnar
Which nerve supplies the trapezius and omotransversarius?
Accessory CN
Which nerve supplies the rhomboideus and serrated ventralis?
Cervical and thoracic spinal nerves
Which of the pectorals is supplied by the cranial pectoral nerve?
Superficial
The pectoral nerves arise from which nerve bundle?
Brachial plexus
Infraspinatous
Infraspinatus fossa > greater tubercleSuprascapular
Supraspinatus
Supraspinatus fossa > greater tubercleSuprascapular
Subscapularis
Subscapular fossa > lesser tubercleSubscapular
Coracobrachialis
Coracoid process of the scapular > lesser tubercleMusculocutaneous
Brachialis
Proximal caudal humerus > proximal cranial ulna (in musculospinal groove)Musculocutaneous
Bicep brachii
Supraglenoid tubercle of the scapula > medial tuberosity of the radius Musculocutaneous
Deltoideus
Scapular spine and acromion process > deltoid tuberosity Axillary
Teres major
Caudal border of the scapular > teres tuberosity of the humerusAxillary
Teres minor
Distal caudal border > deltoid tuberosityAxillary
Name the four heads of the tricep brachii in the dog.
Long, lateral, medial, accessory
Long head of the tricep
Caudal border of the scapula > olecranon fossaRadial
What is the action(s) of the long head of the tricep?
Elbow extension and shoulder flexion
Lateral, medial and accessory tricep
Humeral shaft > olecranon fossaRadial
Tensor fascia antebrachium
Latissimus Dorsi > olecranon fossaRadial
Extensor carpi radialis
Lateral supracondylar crest (humerus) > proximal metacarpal 2/3 Radial
Ulnaris lateralis
Lateral epicondyl > accessory carpal bone and lateral metacarpal boneRadial
Extensor carpi obliquus
Cranial radius (lateral) > medial metacarpal Runs obliquely over the antebrachium Radial
Common digital extensor
Lateral epicondyl > extensor process of DP 2-5 Radial
Lateral digital extensor
Lateral epicondyl > Distal phalanx 3-5 Radial
Supripnator
Lateral epicondyl > cranial radiusRadial
When facing the lateral distal limb of the dog name the muscle groups that can be seen from cranial to caudal.
Extensor carpi radialisCommon digital extensorLong digital extensorUlnaris lateralis
Extensors of the distal limb all originate from which humeral structure?
Lateral epicondyl
Superficial digital flexor
Medial epicondyl > Palmer middle phalanx (1-5)Median/ulnar
Deep digital flexor
Medial epicondyl > distal phalanx 1-5Median/ulnar
Pronator teres
Medial epicondyl > cranial radiusMedian/ ulnar
Flexor carpi radialis
Medial epicondyl > proximal metacarpal 2
Flexor carpi ulnaris
Medial epicondyl > accessory carpal bone Median/ ulnar
When looking at the medial aspect of the distal limb of a dog name the muscles which can be seen from cranial to caudal.
Pronator teresFlexor carpi radialis Superficial digital flexor (overlying the DDF) Flexor carpi ulnaris
Which spinal nerves feed into the brachial plexus?
C6, 7, 8, T1, 2
Which five structures run together on the medial aspect of the proximal forelimb?
Musculocutaneous n. Brachial artery Brachial veinMedian n. Ulnar n.
Which of the spinal nerves do the pectoral nerves arise from?
T1
This nerve give cutaneous sensation to the cranial/ medial elbow and medial antebrachium.
Musculocutaneous
This nerve gives cutaneous sensation to the lateral shoulder and brachium.
Radial
Which muscles of the forelimb occupy the caudal antebrachium?
Flexor of the carpus and digits
A dog comes into your practice and is unable to extend its elbow and with knuckled digits. Of which limb nerve do you suspect damage? Proximal or distal?
Distal radial nerve damage
Interosseous
Proximal MCB > proximal sesamoid and common digital extensor
Which ligaments give stability to the joint capsule of the elbow?
Collateral Annular
Why is the suprascapular nerve prone to damage?
It is on the lateral side of the limb and hooks round the scapular notch of the cranial scapular.
What would be noticed on clinical examination of a dog with suprascapular nerve damage?
Atrophy of the supraspinatous and infraspinatous muscles, lameness.No sensory deficits since it is a motor only nerve.
Which of the intercarpal joints shows the most flexibility?
Antebrachio-carpal joint
Describe the structures of the distal palmar forelimb associated with the digital flexor tendons.
Scutum - cartilagenous structure found palmar to the jointTendon sheath - wraps around the flexor tendons (both superficial and deep) beneath he annular ligamentsAnnular ligaments - proximal, proximal phalangeal and distal hold the digital flexor tendons against the bone
Describe the nerve block positioning for assessing lameness in the distal equine limb.
Palmar digital - blocks the palmar branch of the palmar digital nerve (below bifurcation) - knocks out the palmar region of the hoof.
Abaxial sesamoid - before the bifurcation of the palmar digital nerve (dorsal and palmar branches targeted) - knocks out whole hoof.
Palmar metacarpal - (four point) blocks the palmar and palmar metacarpal branches of median and ulna nerve - knocks out entire digitFurther bursa and nerve blocks can be found.
The interosseous muscle of the dog has two tendonous insertions, name them.
Inserts onto the proximal sesamoids and onto the extensor tendon of the common or long digital extensor .
What is the lacertus fibrosus?
A tendonous portion of the bicep brachii muscle of the horse which inserts onto the extensor carpi radialis. Helps maintain carpal extension during prolonged standing.
What function does the bicep brachii muscle play in the stay apparatus of the horse?
Prevents collapse of the shoulder joint under the weight of the trunk
In which of the carpal joints would you find most felxion?
Antebrachio-carpal joint
Bursitis of the subcutaneous and tricipital bursa of the horse can lead to what clinical condition?
Capped elbows
The carpal canal of the forelimb is bordered by which structures?
Palmer fibrocartilagenous plate and palmer retinaculum.
How do the horse and the dog differ regarding the carpal canal?
In the dog the cc only houses the DDFT whereas in the horse both the DDFT and SDFT run through this structure.
A thoroughpin of the horse is a swelling of which structure?
Inflammation of the tendon sheath of the DDFT and SDFT.
Outline how the suspensory ligament of the horse runs.
Originates from palmer MC3 and runs down the palmer surface of this bone, at the distal end it bifurcates sending a branch dorsally which inserts onto the common digital extensor tendon.
Name the ligaments which support the proximal sesamoids.
Intersesamoidean, collateral sesamoidean (onto MC and PP) and distal sesamoidean (cruciate, oblique, short, long)
What is the function of the digital cushion of the hoof? What is it made up of?
Shock absorption and protection of tendonous structures overlying it. It is made up of elastic tissue, fat and vascular tissue.
Sidebone
Mineralisation of the ungual cartilages of the foot (lateral and medial to the digital cushion)
Outline the structure of the coronary band.
Dermal papillae which extend into the epidermal tubes and intertubular horn of the hoof wall.
Interdigitation of the primary and secondary laminae with the epidermal horn is known as what?
The white line
True or false. Ruminants do not posses secondary laminae.
True
Outline the arterial branches which supply the forelimb.
The axillary artery arises from the subclavian, it has four branches which supply the proximal forelimb and extrinsic muscle before the brachial artery arises, this has 6 branches and supplies brachial muscle and skin. Next the medial artery which branches twice, one branch, the radial artery bifurcated forming carpal arteries, the Palmer carpal fuses with Interosseous of the brachial to for, the deep Palmer arch which supplies the metacarpals and distally forms the common digital arteries.
