Thoracic Limb (Canine, Feline, Equine, Ox) Flashcards
What does ramus mean?
arm or branch
If a horse is putting all it’s weight on it’s heels, what is separating?
The dermal from the epidermal lamina (Laminitis)
A horse has a scar on the wall of it’s hoof, what typically causes this?
A lesion at the coronary band that has broken through the dermal layer
What happened if a horse is not properly bearing weight and the spine of the scapula is very prominent?
Atrophy of the supraspinatus and infraspinatus muscles—Sweeney
What type of injury causes a “flying scapula” in a horse?
If the serratus ventralis ruptures
If a farrier puts shoes on the horse and does not place the nails in the proper location (aka. white line), what types of injuries could occur?
The navicular bursa could be ruptured; the deep digital flexor could be compromised; coffin bone (distal phalanx)/ short pastern bone (middle phalanx) could be ruptured. The impar ligament could be injured.
What is absent on the scapula of the Ox, but not on the equine or canine?
The infraglenoid tubercle located on the caudal distal side of the scapula, caudal to the glenoid cavity
What is absent on the scapula of the equine, but found on the scapula of the canine and ox? What is in place of this part on the equine?
The acromion; the tuber of the spine of the scapula
What is very prominent on the dorsal border of the scapula in the equine and the ox?
scapular cartilage
What is different about the serrated face in the equine and ox relative to the canine?
The serrated face contains a cranial and a caudal triangular area on the proximal medial aspect while the canine only has one proximal caudal rectangular area on the medial aspect of the scapula
On the scapula of the feline, what is the process that extends past the acromion ventrally? What is the process that extends past the acromion laterally?
The hamate process; suprahamate process
What is special about the equine intermediate tubercle on the humerus?
It holds the tendon of the biceps brachii muscle where passes through the intertubercular groove and attaches to the lacertus fibrosus
In the feline, where does the brachial artery pass through?
The supracondylar foramen on the medial part of the distal humerus
What are the two styloid processes in the equine forelimb and which bones are they located on?
The medial (radius) and lateral (ulna) styloid processes
Which two metacarpal bones are partially fused in the ox?
MC III and IV
Which metacarpal bone in the equine bears most of the weight when standing?
MC III
Which metacarpal bones in the ox bear most of the weight?
MC III and IV
Which carpal bones are fused in the Ox?
Carpal II and III
Which split bone in the equine is the most susceptible to injury from downward/compressive force? Why?
MC II due to only one distal carpal bone, carpal bone II, resting entirely on the medial splint bone ( metacarpal II)
What is a hygroma?
Subtendinous bursa of the common digital extensor tendon and lateral digital extensor tendon (synovial effusion)
In the dog, what is the equivalent to the humeral crest in the ox?
The crest of the greater tubercle of the humerus
What acts as the point of the elbow? Why is this an important landmark in equine?
The olecranon tuber; reaches 5th rib and helps with palpation and auscultation
Which muscles has a tendon that originates at the radial tuberosity and inserts on the metacarpal tuberosity?
The biceps brachii m.
Which two tuberosities on the humerus are enlarged on the equine and ox?
Teres major tuberosity (medial) and the deltoid tuberosity (lateral)
What are the distal most palpable projections of the splint bones called?
Buttons
What are the two muscles that inserts on teres major tuberosity?
Teres Major and Latissimus Dorsi
If the forelimb is abducting, which muscles are contracting?
Trapezius m.
If the forelimb is adducting, which muscles are contracting?
Superficial and deep pectoral
Where is the extensor process in the equine located and what muscles inserts at the process?
Distal phalanx; common digital extensor
What extra muscle in the equine causes the rounded appearance of the shoulder?
Subclavius m.; part of the pectoral
Which head of the triceps brachii is not found in the equine?
Accessory head of the triceps brachii
What is the name for the distal sesamoid bones in the equine and what can be found in between those bones and the deep digital flexor tendon?
Navicular bone with a navicular bursa
What is the cuticle of the equine hoof called?
Perioplic Corium
On the palmar surface of the sesamoids, what fibrocartilage can be found which the deep digital flexor slides over?
Scutum
Which lamina of the equine hoof is sensitive?
Dermis
When the hoof capsule and corium are separating due to inflammation, it can cause what disease?
Laminitis (founder)
Where can the superficial cervical lymph node be found?
Deep to the caudal end of the omotransversarius
When bones remodel due to stress, what is this called?
Wolf’s Law
A ligament attaches ______ to ______. A tendon attaches ______ to _______.
bone, bone;muscle,bone
Which two joints connect in the horse with a synovial pouch?
Midcarpal and carpometacarpal joint
Which bursa can cause a capped elbow?
Subcutaneous olecranon bursa
A _______ connects the thoracic limb to the body via extrinsic muscles.
Synsarcosis
Which tendons counteract flexion of the coffin joint (Distal interphalangeal joint) ?
The extensor branches of the interosseous or suspensory ligament.
What are three functions of sesamoid bones?
Prevent tendon shear, increase torque, and redirect force
What is the anatomical name for the fetlock joint?
metacarpophalangeal joint
The layman’s term for the proximal interphalangeal joint is?
The pastern joint
What are the three borders of the carpal canal?
Dorsal border=palmar carpal ligament
Palmer border=flexor retinaculum
Lateral border=accessory carpal bone
What action does the palmar carpal ligament in the equine complete?
Prevents hyperextension of the carpal joint
What is located in the carpal canal of the equine and not in the canine?
Superficial digital flexor
What is the arrested growth of long bones called?
Chondrodystrophy
What action does the passive stay apparatus prevent?
Flexion at the shoulder (glenohumeral) joint
What are the three joints of the carpus called in proximal to distal order?
- Radiocarpal joint
- Midcarpal joint
- Carpometacarpal joint
What are the names of the three distal sesamoidean ligaments and what do they do at the fetlock (metacarpophalangeal) joint?
- Straight
- Oblique
- Cruciate
Counteract hyperextensions of the fetlock joint
What is the sleeve called that is distal to the metacarpophalangeal joint and allows the superficial digital flexor to insert proximally to the deep digital flexor?
Flexor manica
What is the purpose the of palmar annular ligament?
Holds down the superficial and deep digital extensor tendons at the metacarpophalangeal joint
Which ligament holds down the SDD and DDF tendons at the level of the proximal phalanx of the digits? Which ligament holds only the DDF tendon down at the level of the middle phalanx of the digits?
Proximal digital annular ligament/Distal digital annular ligament
(equine) The proximal check ligament is associated with the __________ and the distal check ligament is associated with the _________. The purpose of these ligaments are to?
Superficial digital flexor tendon/ Deep digital flexor tendon
To prevent overextension of the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints
Where is the impar ligament in the equine? What is its purpose?
Small ligament that attaches the navicular bone ( distal sesamoid bone) to the coffin bone (distal phalanx).
What are the three joints of the carpus in the equine and which one permits the greatest movement?
- Radiocarpal joint
- Midcarpal joint
- Carpometacarpal joint
The radiocarpal joint
Is the capitulum on the humeral condyle found on the lateral or medial side? What about the trochlea?
Capitulum is on the lateral aspect, while the trochlea is on the medial aspect
What is the likely cause of a “popped splint bone”?
Damage to the interosseous ligament between the MC II and III or MC III and IV
What is the purpose of the anconeus muscle?
Extends the elbow
What retinaculum extends from the greater to lesser tubercle of the humerus over the intertubercular groove holding the __________ in place?
Transverse humeral; biceps brachii m.
In the equine, which muscle is not divided into acromial and scapular parts? What is the purpose of this muscle?
Deltoideus m./ flexes shoulder
The __________ forms the dorsal bounder of the jugular groove in the equine and ox. The ________ forms the ventral border.
Cleidocephalicus m. / sternomandibularis m.
What is the primary purpose of the deep pectoral muscles when weight bearing and non-weight bearing?
pulls trunk cranially while extending shoulder/ draws limb caudally
Which ligament is responsible for retracting the ungual processes in the feline; holding the interphalangeal joint in hyperextension?
dorsal (elastic) ligament
What is located in the intertubercular groove, deep to and surrounding the tendon of origin of the biceps brachii muscle?
The subtendinous synovial bursa (intertubercular bursa)
What is a “capped” elbow?
Subcutaneous olecranon bursa where the triceps tendon of insertion goes over the olecranon (synovial effusion)
What is synovial effusion?
abnormal accumulation of synovial fluid within a joint, bursa, or tendon sheath
Which carpal joint cavities in the equine communicate with each other?
Midcarpal and carpometacarpal joints cavities
What is the importance of the ligament of ergot?
Palpable landmark for finding the VAN complex
What is diploe?
Cancellous tissue enclosed by two layers of cortical bone
Which ligament would pull the toe of the hoof down? up?
Tension from the deep digital flexor tendon/ extensor branches of the interosseous (suspensory) ligament
If the super digital flexor tendon is cut, what will happen to the fetlock and the toe?
The fetlock will slightly drop and the toe stay on the ground
If the interosseus ligament is ruptured, what will happen to the toe?
The toe will remain on the ground because they extensor branches are still connected to the distal sesamoid bones
Starting from most proximal joint to the most distal joint of the equine forelimb, tell me what the passive stay apparatus is preventing at each joint.
- Glenohumeral joint (shoulder)=flexion
- Humeroradioulnar (elbow) joint=flexion
- Radiocarpal (antebrachiocarpal) joint=flexion (buckling forward)
- midcarpal joint=flexion (buckling forward)
- carpometacarpal joint=flexion (buckling forward)
- Metacarpophalangeal joint (fetlock)= hyperextension
- Proximal interphalangeal joint (pastern)= hyperextension
- Distal interphalangeal joint (coffin)= overextension (since it is already in hyperextension)
______ is the term describing the surface closest to the long axis; _______ is the term describing the surface that is furthest away from the long axis.
Axial; abaxial
In the canine, which two carpal bones are fused? Which aspect are they located on and what is the correct name for this bone?
The radial and intermediate carpal bones are fused to form the intermedioradial carpal bone located on the medial side of the carpus.
On which bone are the coronoid processes located? Which coronoid process is bigger and what aspect is it on?
Ulna; medial; located on proximal medial aspect
Which bony structure on the radius articulates with the humeral condyle of the humerus?
Fovea capitis
The _________ and _________ muscles originates from the lateral supracondylar crest of the humerus.
anconeus m./ extensor carpi radialis m.
What are some clinical applications to joint injections?
To treat osteoarthritis; administer anesthetics for lameness evaluations
What is the fibrocartilage within the synovial cavity of a synovial joint called?
Meniscus/Menisci
The joint capsule consists of a _________layer that blends with the periosteum, sometimes forming ligaments, as well as a ________ layer that is vascularized, contains nerves, and produces fluid for lubrication and nutrition of bone surfaces.
fibrous outer; inner synovial
A synovial joint is considered a __________ joint because it is free moving.
diarthrotic
The perimysium correlates with ________. The ________ surrounds the muscle belly and the endomysium surrounds __________.
Muscle fascicles; epimysium; muscle fibers
