BVMS1

• Individual muscle firbres arranged in parallel lines
• collected into bundles
• covered by fibrous tissue (fascia)
• attached to rigid structure
• origin- usually proximal
• insertion- usually distal

• Origin or insertion:
• directly to bone (rough surface, boney tuberocity)
• via tendons (condensation of deep fascia into cords, less bulky across joints, small area of attachment, may have separate centre of ossification)
• via aponeurosis: (condensation of deep fascia into sheets, long area of attachment, muscles in areas w/ limited access to bone)
• ex: superficial fascia, and cervico-thoraco-lumbar fascia

• Belly contracts and shortens muscle
• pulls points of attachment close togeter
• pivot at joint (decrease angle- flexion, increase angle- extension)
• action depends on which joints crossed and aspect of joint
• *antagonistic pairs of musciles- opposite action

• origin and insertion w/in appendicular skeleton
• movement and extension

• origin on axial skeleton
• insertion in appendicular skeleton
• movement of limb relative to trunk
• protraction and retraction of limb

• No joint present between forelimb and trunk in domestic animals
• muscular attachements only
• scapular glide over thorax
• PP midway down scapula

• Cephalic= head
• brachium= arm
• origin= cervicothoracic fascia
• insertion= humerus (aponeurosis)
• PROTRACTOR (also acts across shoulder)
• (cleidocervicalis/cleidomastoideus/cleidobrachialis)

• Dog: clavical insertion is a fibrous band
• Cat: has a bony remnant visible on radiographs, cranial to shoulder

• (extrinsic)
• latus= broad
• dorsi= back
• "boradest muscle of the back"
• origin= thoracolumbar fascia
• insertion= humerus (aponeurosis)
• RETRACTOR (also acts across shoulder)
• propulsion

• Extrinsic
• Origin: thoracis wall/ribs and cervical vertiebrae/neck
• insertion: proximal scapula/medial aspect (proximal to pp)
• *muscle is located between forelimb and trunk*
• Function: cranial portion= Retractor, Caudal portion= Protractor

• Abductors: move limb away from midline- muscles located proximal to PP and limb
• Adductors: move limb towards midline- located distal to PP and medial to limb

• Origin= cervicothoracic fascia
• insertion= proximal scapular spine
• 2 parts (cranial and caudal)
• no effect on shoulder

• lies deep to trapezuius
• origin= cervicothoracic fascia
• insertion= dorsal border of scapula
• abductors of limb
• no effect on shoulder

• Origin= sternum
• insertion= medial humerus
• Deep and superficial groups
• adductor of limb

• origin and insertion w/in appendicular skeleton
• no effect on limb relative to trunk
• move joints w/in limb
• (flexion and extension)

• Long Bone
• S-shape
• head, body condyle
• brachial/musculospiral groove
• proximal end: head (artivular surface, convex, smooth surface, articulates w/ glenoid cavity of scapula at shoulder joint, greater tubercle, greater tubercle-lateral, lesser tubercle-medial, intertubercular groove- smooth for tendon of otigin of biceps brachii muscle to pass through)
• distal end: condyle (medial half larger than lateral), medial epicondlylle, lateral epicondyle, articular surface w/ elbow joint, trochlea (larger, located medially, central depression, articulates w/ radius and ulna), capitulum (smaller, located laterally, articulates w/ radius), olecranon/ulnar fossa-caudal, radial foss-cranial/proximal to articular surfaces, spratrochlear foramen (nothing passes through, may not be present in short legged dogs (only in dogs)

• Proximal features and articular surfaces same as dog
• distal end: olcranon fossa, radial fossa, NO supratrochlear foramen~!
• instead they have a supracondyloid foramen (brachial artery, median nerve, vulverable in fractures)

• Centres of ossification: proximal epiphyses, body, condyle (medial epicondyle, medial half, lateral half) 5 total
• Palpation: greater tubercle (shoulder joint), lateral epicondyle and medial epicondyle ( elbow oint

• supratrochlear foramen= weak point
• medial half of condyle larger than lateral half
• fracture most commonly through lateral half
• may involve joint- poorer outcome
• no blood vessels thru

Brain to structure (motor fibres eg.. movement)

• Structure to brain
• sensory fibres eg. pain, temp, pressure, etc
• Proprioception (location of limb in space- automatic)

carry efferent and afferent fibres to structure

carry afferent/sensory from the skin surface

occur w/o brain being involved eg. patellar reflex

• Latissimus dorse (retractor), serratus ventralis (retractor and protractor), pectorals (adductor)
• supplies ALL intrinsic muscles

(DOES NOT supply Brachiocephalicus, trapezius and rhomboideus)

• Fibrous
• Carilagenous
• Synovial

Little Movement (eg. skull sutures)

• Synchondrosis/synarthrosis
• Little movement
• Pelvic/mandibular sumphysis

• Allows large range of motion between bones
• most limb joints
• typical features: Hyaine cartilage (covers articular surfaces, reduce friction, flexible, avascular, no nerves)
• synovial fluid (viscus, nourishes cartilage, lubricates)
• synovial membrane (produces synovial fluid, physical barrier to contain fluid)
• Joint capsule (fibrous layer, incorporates synovial membrane, attaches round osteochondral junction (bone cartilage))

• Fibrous materal condenses to form ligaments
• run from bone-bone
• collateral ligaments support joints (medial and lateral ONLY)

• Flexion: decreased angle, folded limb, non weight bearing position
• Extension: increased andly, streching limb, weight bearing

• Scapula (glenoid cavity), humerus (head)
• palpable landmarks (acromion process, greater tubercle)
• Typical synovial joint features except: poorly developed collateral ligaments
• Bicipital bursa
• muscle support

• Joint capsule extends into intertubercular groove (between greater and lesser tubercles)
• wraps around tendon of origin of biceps brachii (originates on supraglenoid tubercle)
• Held in place by transverse ligament

• Supraspinatous muscle: supraspinous fossa-> I= Greater tubercle
• Infraspinatous muscle: Infraspinous fossa-> I= Distal to greater tubercle
• Suprascapular nerve- motor fibres ONLY

• Subscapularis muscle
• subscapular fossa-> I=lesser tubercle
• subscapular nerve- motor fibres ONLY

• Cross cranial to shoulder joint:
• Brachiocephalicus (extrinsic muscle) nerve non from brachial plexus
• Biceps brachii muscle (O= supraglenoid tubercle, I= Proximal radius, intrinsic muscle) Motor nerve supply- musculocutaneous nerve, motor and sensory fibres
• Bicipital bursa (protects tendon of origin, intertubercular groove, transverse ligament)

• cross caudal to shoulder joint
• Latissimus dorsi (extrinsic muscle) nerve from brachial plexus
• Deltoideus muscle (2 heads) (O1-scapular spine, O2- acromion process, I- lateral aspect humerus)(intrinsic muscle) Axillary nerve, motor and sensory fibres
• Teres Major (O- caudal border of scapula, I- medial humerus) axillary nerve, motor and sensory fibres
• Teres Minor: overlies lateral aspect joint space
• Triceps Muscle: multiple heads, long head: (O- caudal border scapula, I- Olecranon of Ulna) radial nerve motor and sensory fibres

• Osteochondrosis (OCD): developmental dz, erosion of articular cartilage, subchondral bone may be affected, visible on radiograph, characteristic location, pain causes lameness, leads to DJD/arthritis
• Degenerative Joint Disease (DJD): new bone formation around joint capsule attachment, osteochondral junction, characteristic locations on rads, painful while forming, lameness
• soft tissue conditions: bicipital bursitis- U/S used for Dx

• Long bones
• Paired
• Radius is main weight bearing
• Ulna is longer/ leverage

• Head
• Fovea capitis, articular surface (elbow joint)
• Neck
• Body

• Trochlea (articular surface w/ carpus)
• styloid process ("pen") medial, attachment medial collateral ligament or carpus

• Olecranon process
• anconeal process (beak shaped, fits into olecranon/ulnar fossa of humerus)
• trochlear notch (articular surface/elbow joint)
• Lateral coronoid process
• medial coronoid process
• radial notch (articulates w/ radius)
• Proximal articulation (radius/head, radial notch of ulna, held by annular ligament (runs lateral to medial coronoid process, rotation possible)

• Styloid process (attachment lateral collateral ligament of carpus)
• Distal articulation (fibrous joint, some rotation possible)
• interosseous space (between bodies, interosseous ligament, fibrous joint)

• Toes rotated cranially
• elbows rotated caudally
• radius and ulna therefore rotate around eachother
• Proximal: ulna most medial projection
• Distal ulna most lateral projection

• Square olecranon
• radius and ulna similar diameter

• Palpation:
• Ulna: Olecranon process, lateral styloid process
• Radius: Medial Styloid Process
• Development:
• Radius: proximal epiphyses, body, distal epiphyses (3)
• Ulna: Olecranon process, anconeal process, body, distal epiphyses (4)

• Large contribution to limb length
• must grow together
• growth plates= weak point= susceptible to damage
• Ulna in particular due to shape
• if one stops before other= angular limb deformaties
• Fractures: radius bears most weight= requires fixation
• Primary bone tumors (osteosarcoma)- predilection sites (proximal humerus, distal radius, distal ulna)

• Humerus w/ radius & ulna
• Humerus: Trochlea, articulates w/ trochlear notch of ulna & fovea capitis of radius. Capitulum: articulates only w/ fovea capitis of radius
• Typical features of synovial joint (joint capsule- osteochondral jnc, incorporates proximal radio-ulnar articulation)
• stability: collateral ligaments (humerus- radius and ulna), Boney structures (anconeal process (ulna) Olecranon/ulnar fossa (humerous))

• Between humerus- radius & Ulna
• Limited to flexion and extension
• Ulna acts as lever
• Elbow extensors insert into olecranon (avulsion possible)

• Rotation possible
• annular ligament
• interosseous ligament
• fibrous joint distally (pronation= face down, Supination= face up)
• dogs= rotation limited
• cats= large amount rotation eg. climb trees!

• Elbow dysplasia
• OCD
• ununited anconeal process
• fragmented medial coronoid process
• elbow incongruity
• DJD

• Triceps Muscle (long head): O- caudal border scapula
• (lateral head): O- Lateral aspect humerus (only part that effects shoulder)
• (Medial head): O- Medial aspect humerus
• (accessory head)
• Radial nerve supply

• Triceps muscle
• Biceps brachii (O- supraglenoid tubercle, I- Proximal radius) Musculocutaneous nerve
• Brachialis muscle (O- caudal aspect humerus, I- proximal radius) follows musculospiral/brachial groove, musculocutaneous never supply

• Supinator Muscle (O- lateral epicondyle) radial nerve
• Pronator teres muscle (O- medial epicondyle) median nerve
• I- proximal radius

• Dissect between muscles (rather than cutting them)= less damage= faster healing
• Proximal humerus: dissect between brachiocephalicus and deltoideus
• Midshaft: between brachiocehpalicus and brachialis
• distal humerus: between brachialis and triceps

• Limb naturally in extended position
• blood vessels cross flexor aspects of joints (avoids stretching of vessels)
• arterial supply (oxygenated blood from heart to peripheral tissues, major vessel runs down limb, changes name according to region)

• Subclavial artery: runs round 1st rib- axila
• Axillary arter: runs through axilla
• Brachial artery: runs down brachium, branches
• Branches into: Median artery: runs down medial aspect antebrachium, branches- radial artery, terminates in superfical palmar arch, (superficial palmar arch, palmar common digital arteries)
• superficial brachial artery: runs down cranial aspect antebrachium (superficial dorsal supply, dorsal common digital arteries)
• Radial artery: deep palmar arch, palmar metacarpal arteries, ddeep dorsal supply, dorsal metacarpal arteries.

• 4 vessels per digit
• palmar supply most important
• axial palmar proper digital A largest
• implications when wmputating toes

• Veins- take deoxygenated blood back to heart
• deep system: follows arterial supply
• superficial system: cephalic vein, drains into jugular vein/vena cava

• access to systemic circulation
• pressure to raise vein
• valves allow blood to pool
• reslease pressure before inject
• fluid enter vein not SQ tissues!!
• radial nerve runs alongside it- providing cutaneous sensation to cranial aspect of forelimb
• pain and necrosis...

• Composed of Carpal bones
• short bones
• no medullary cavity
• centre= cancellous bone
• Proximal, distal
• dorsal, palmar

• Radial/Intermediate carpal bone (fused) (RCB)
• Ulnar carpal bone (UCB)
• Accessory Carpal bone (ACB)

• 1st carpal bone
• 2nd carpal bone
• 3rd carpal bone
• 4th carpal bone

• single centre of ossification
• except: accessory carpal bone= 2 on all species
• fused radial/intermedial carpal bone=2 due to origin

• Antebrachio-carpal joint: between antebrachium and carpus (radius- RCB & UCB) (Ulna- (UCB & ACB)
• Middle carpal joint: proximal and distal rows
• Carpo-metacarpal joint: distal row and metacarpal bones
• (Intercarpal joints- vertical)

• Standing= extension
• Large range of flexion: most moevement antebrachio-carpal joint, least carpo-metacarpal joint, some between bones)
• ACB acts as lever for distal limb: insertion of some major carpal flexor, counteracting by palmar ligament

• Typical Synovial joint: single joint capsule extending proximally between radius and ulna, distally between metacarpal bones- poor communication between compartments)
• Collateral ligaments: Lateral- ulna (lateral styloid process) to 5th metacarpal bone, Medial radius (medial styloid process) to 2nd metacarpal bone
• Styloid processes vulnerable
• Intracarpal ligaments
• Palmar aspect: Fibrocartilagenous reinforcement (friction free, passive maintenance of joint extension, prevention of collapse)
• Retinaculum= sleeve of deep fascia
• Dorsal retinaculum: dorsal survace, jumps from bone to bone, allows flexion, forms transverse ligaments to hold tendons
• Palmar/flexor retinaculum: runs down caudal surface, attaches to lateral aspect accessory carpal bone, crosses from ACB to medial aspect carpus, forms carpal canal

• Dorsal boundary: Fibrocartilagenous reingorcement of palmar aspect of carpal joint capsule
• Lateral Boundary: ACB
• Palmar boundary: Palmar/Flexor retinaculum

Dog: Deep digital flexor tendon through tunnel, blood vessels and nerves, suprficial digital fleor tendon outside

• Accesory carpal bone
• joint spaces (flexion)
• medial stylid process (radius)
• lateral styloid process (ulna)

• Dogs and Cats= digitigrade (bear weight on digits)
• 4 weight bearing and 1 vestigial
• numbered medial to lateral
• Digit: proximal phalanx, middle phalanx, distal phalanx, sesamoids

• Vestigial
• medial aspect
• non-weight bearing
• has 3 elements (debate as to which is missing)
• commonly removed in puppies

• four metacarpal bones
• long bones
• convex dorsal surface
• base=poximal end (forms carpo-metacarpal joint)
• body= midshaft
• head= distal end
• raiesd sagittal ridge- extends to palmar aspect

• Proximal Phalanx (PP): long bone, sagittal groves at both ends
• Middle Phalanx (MP): Long bone, proximal sagittal ridge, distal- sagittal groove

• Long bone debate
• ungual process
• ungual crest (round root of claw, very vascular)
• extensor process (extensor tendons)
• palmar process (flexor tendons)

• Metacarpo-phalangeal joint
• 2 x proximal sesamoids: palmar aspect, either side of sagittal ridge, protect flexor tendons
• 1 x dorsal sesamoid: protect extensor tendons

• MC(2) body and distal end
• PP (2) Body and Proximal end
• MP (2) Body and proximal end
• DP (1)

• Metacarpo-phalangeal joint
• Proximal Interphalangeal Joint
• Dipstal interphalangeal joint
• All typical synovial joints
• flexion and extension
• stability: collateral ligaments, sagittal ridge/groove

• Resting position= extended
• interosseous muscle and proximal sesamoids
• sling configuration suspends Metacarpo-phalangeal joint
• supported by metacarpal foot pad

• Deep Digital Flexor Tendon
• Common Digital extensory tendon
• Dorsal elastic ligament (proximal end MP, extensor process DP)
• Dog: forces balanced to maintain tip of claw above horizon problem if DDFT is severed
• Cat: claws not visible- very strong dorsal elastic ligament, DIP joint hyperextended, claw rests in skin fold/sheath- not visible- remain sharp for hunting/climbing (to expose DDFT flexes joint, or manual pressure to digital pad)

• Affect joints of carpus and digits
• muscle belly- antebracium
• tendon of insertion- distal to carpus
• extensors of distal limb: originate lateral epicondyle of humerus, run over dorsal aspect carpus, radial nerve
• flexors of distal limb: originate medial epicondyle, run over palmar aspect carpus, median and ulnar nerves

• origin= lateral epicondyle, radial nerve
• extensor arpi radialis muscle (I= metacarpal bones)
• Abductor pollicus longus/Extrnsor carpi obliquus muscle: crosses at level of carpus- useful land mark, sesamoid in tendon of insertion
• extensor carpi ulnaris/ulnaris lateralis muscle (I= 5th metacarpal bone and Accessory carpal bone
• flexion or extension depending on position of limb

• origin= lateral epicondyle, radial nerve
• common digital extensor muscle (I= all digits), distal phalanx- extensor process, brances to all digits
• lateral digital extensor muscle (I= 4th and 5th digits) distal phalanx- extensor process (lateral digits only)

• Origin= medial epicondyle, median and Ulnar nerves
• Flexor Carpi Ulnaris muscle (O= olecranon, I= ACB 2 heads)
• Flexor Carpi radialis muscle (I= metacarpal Bones)

• origin= medial epicondyle, median and ulnar nerves
• Superficial digital flexor muscles (I= all digits (middle phalanx)) runs outwith carpal canal
• deep digital flexor muscle (O- also radial and ulnar heads, I= All digits) distal phalanx- palmar process, tendon runs through carpal canal passes through SDFT

• Carpal/stopper pad
• metacarpad pad x 1
• Digital pads x 4
• functions: resistanct to trauma/wear & tear, traction, anti-concussive, protect deep structures, dupport digit

• Epidermis: cells constantly produced by germinative later, cells age as move outwards, dead at surfact and slough, constant replacement, no blood supply, no nerve supply, insensitive and no bleeding
• dermis: blood supply, nerve supply, sensitive and bleeds, supports germinative layer- active production of skin celss

Trauma resistance: increased skin thickness, increased turnover of cells, deposition of keratin, rough surface, sweat glands, variable amounts pigmentation

• Skin (epidermis, germinative layer, dermis)
• superficial fascia
• Digital cushion (fibrous tissue, elastic tissue, fat, vascular channels)
• Function= shock absorption

• Wounds (elastic tissue and vascular channels)
• sweat (bandaging)
• DDFT (stubbed toe)

• No superficial fascia
• dermis (fused directly to periosteum of ungual process of DP)
• germinative layer (active in 2 areas only)
• epiermis (heavily keratinised= horn)
• stratum tectorum (waterproof surface layer, produced by skin in ungual recesses)

• Area 1: recess between claw and skin, horn grows over dorsal and lateral surfaces of ungual process, horse-shoe shaped in transverse section/short axis
• area 2: palmar surface of ungual process, horn covers palmar surface

• Tip touches ground
• position maintained by dorsal elastic ligament, extensor tendons, balanced by DDFT
• continuous growth
• tips wear naturally
• reduced wear (not walking, walking on soft ground, dew claw, DDFT damage)
• Claw grows in circular fashion (can eventually grow into pad)

• Horn= epidermis (insensitive so can cut)
• Dermis= contains blood and nerve supply- don't cut too far!
• Non-pigmented claws (easier to clip)
• Cats:
• Pressure on pad- unsheath claw

Cardiovascular system: continuous system, leaky capillary bed, exchange of material (eg. fluid, protein), net loss, fluid accumulation (edema and swelling in peripheral tissues)

• Rocovery/scavenging system
• series of individual vessels
• thin walled
• run from periphery to thoracic duct
• thoracic duct empties into caudal vena cava
• transports lost material back into systemic circulation

• Filters
• located where lymph vessels converge
• prevent contaminants reaching systemic circulation
• remove invading organisms/bacteria
• contain defence cells
• forelimb lymph nodes (prescapular, axullary)
• enlarge in response to infection
• can use to differentiate between localised/generalised dz
• important in large animals for meat inspection

• Supplies:
• Selected extrinsic muscles: pectoral, latissimus dorsi, serratus ventralis
• all intrinsic muscles: subscapular nerve, suprascapular nerve, musculocutaneous nerve, axillary nerve, radial nerve, median and ulnar nerve

• Motor nerves only- no cutaneous sensation
• subscapular nerve: medial shoulder support, subscapularis muscle
• suprascpular nerve: laterl shoulder support, supraspinatous muscle, infraspinatous muscle

• Mixed Nerve
• Sensory: cutaneous sensation to: cranial and medial aspect of elbow, medial aspect of antebrachium (see notes)
• motor: elbow flexors (brachialis muscle, bicesps brachii muscle)
• damage (no compensation- loss of elbow flexion)

• Mixed nerve
• Sensory fibres: cutaneous sensation to: lateral aspects shoulder and brachium
• motor supply: dedicated shoulder flexors (deltoideus muscle, teres major muscle)
• damage: compensation by latissimus dorsi, long head triceps

• Mixed Nerves
• Sensory Fibres, cutaneous sensation to: caudal and palmar aspect limb, dorsal aspect 5th digit
• motor supply: carpal and digital flexors (flexor carpi ulnaris muscle, flexor carpi radialis muscle, superficial digital flexor muscle, deep digital flexor muscle)
• damage- no compensation- loss of distal limb flexion

• Mixed Nerve
• sensory fibres, cutaneous sensation to: dorsal and cranial aspect limb except dorsal aspect 5th digit
• motor supply: extensors of elbow (triceps muscle), extensors of carpus and digits (extensor carpi radialis, extensor carpi ulnaris, common digital extensor muscle, lateral digital extensor)

• Starts medial, passes caudal to shoulder, passes through triceps (supplies triceps)
• follows musculospiral grove (and brachialis muscle)
• branch- lateral epicondyle (supplies distal limb extensors)
• branch- cranial/dorsal aspect limb (runs alongside cephalic vein, supplies cutaneous sensation)
• Humeral fx most common cause of damage
• deficits depend on level of damage

• Proximal level:
• all extensor muscles affected
• cannot extend elbow, carpus, or digits
• cannot weight bear
• limb appears longer than opposite one
• Distal Level:
• Extensors of carpus and digits affected
• cannot extend carpus/ digits
• Triceps intact: can extend elbow, can weight bear if limb extended, can learn to swing leg to compensate

• Cranial and dorsal aspect limb
• trauma to dorsal aspect paw if drags
• self mutilation
• check sensation using forceps
• check pre-op humeral fracture repair so cannot be blamed

• Tear/avulsion= stretching: high imact collision, head/neck one direction- limb the other, variable degrees of damage, regeneration possible with time, mismatching may result in aberrant sensation
• turnover- effects depend on which nerves affected
• effect on limb: can protract/abduct limb
• cannot retract/adduct limb
• cannot extend/flex limb
• cannot weight bear
• no cutaneous sensation on limb or lateral thorax to level of 3rd intercostal space