02: Thoracic Limb

Axial skeleton

Skull and spine

Appendicular skeleton

Limbs

Comparison of dog and cat bones

Cat bones are straighter, dog bones have more prominent features

Regions of the forelimb

• Shoulder

• Brachium

• Antebrachium

• Manus

Part of scapula that makes the socket of the shoulder joint

Glenoid cavity

Joints the scapula participates in

Glenohumeral joint

Clavicle function in small animals

None, it is vestigial

Bones of the brachium

Humerus

Hole at the distal aspect of the humerus

• Supratrochlear foramen in dogs

• Supracondylar foramen in cats

Joints the humerus participates in

• Glenohumeral joint

• Cubital joint

Bones of the antebrachium

Radius and ulna

Which bone of the antebrachium bears most of the weight

Radius

Ulna position at proximal and distal ends

Starts caudo-medial and twists to end up lateral

Joints the radius and ulna participate in

• Cubital joint

• Antebrachial carpal joint

Bones of the manus

• Carpals

• Metacarpals

• Phalanges

Carpal bones

• Intermedioradial carpal

• Ulnar carpal

• Accessory carpal

• Carpal bones I-IV

Position of accessory carpal bone

Caudal to ulnar carpal bone

How are the carpal bones numbered

Medial to lateral

Joints the carpal bones participate in

• Antebrachial carpal joints

• Carpal joints

• Carpometacarpal joints

Metacarpal bones

Metacarpal bones I-V

How are the metacarpal bones numbered

Medial to lateral

Joints the metacarpal bones participate in

• Carpometacarpal joints

• Metacarpophalangeal joints

Phalangeal bones

• Proximal

• Middle (except digit 1)

• Distal

Joints the phalangeal bones participate in

• Metacarpophalangeal joints

• Proximal interphalangeal joint

• Distal interphalangeal joint

  • Except digit 1, only has one interphalangeal joint

When the feline claw is relaxed, where do the bones lie

Distal phalangeal bone is lateral to the middle phalangeal bone

How does a muscle act on a joint

It has to cross the joint

Extrinsic muscle

Muscle that has one attachment to the appendicular skeleton and one to the axial skeleton

List the 8 extrinsic muscles

• Brachiocephalicus

• Omotransversarius

• Trapezius

• Rhomboideus

• Serratus ventralis

• Superficial pectoral

• Deep pectoral

• Latissimus dorsi

Extrinsic muscles that attach to the scapula

• Omotransversarius

• Trapezius

• Rhomboideus

• Serratus ventralis

Extrinsic muscles that attach to the humerus

• Brachiocephalicus

• Superficial pectoral

• Deep pectoral

• Latissimus dorsi