Unit 1 Musculoskeletal System - Dog & Cat (Flashcards)

A set of practice flashcards covering terminology, bones, joints, muscles, radiographic anatomy, and key landmarks from the Dog & Cat Unit 1 musculoskeletal notes.

What is protraction of the thoracic limb?

The limb swings cranially/forward (propulsion for the pelvic limb).

What is retraction of the thoracic limb?

The limb swings caudally (repulsion for the pelvic limb).

What is adduction in limb movement?

Movement of the limb toward the median plane (toward the body).

What is abduction in limb movement?

Movement of the limb away from the median plane (away from the body).

What does elevation of the shoulder region describe?

Movement where the scapula moves upward relative to the body. Depression is the opposite.

What is meant by proximal and distal in limb terms?

Proximal: closer to the body; distal: farther from the body along a limb.

What does dorsal/ventral mean in limb regions?

Dorsal: toward the back (top) of the body; ventral: toward the belly (bottom).

What are the axial and abaxial surfaces?

Axial surface is toward the limb axis; abaxial surface is away from the axis.

What is the median plane?

An imaginary plane that divides the body into left and right halves (midline).

What is the sagittal plane?

A plane parallel to the median plane; sagittal/paramedian distinctions are used in anatomy.

What is the transverse plane?

A plane that cuts perpendicular to the longitudinal axis of the body or limb (cross-section).

What is synsarcosis?

Attachment of the thoracic limb to the trunk via muscles, with no bony articulation to the axial skeleton.

Which bone forms the pectoral girdle in dogs and cats?

The scapula (shoulder blade) forms the main part of the pectoral girdle.

What is the glenoid cavity?

The shallow socket on the scapula that articulates with the humeral head (shoulder joint).

What is the supraglenoid tubercle?

A tubercle on the scapula from which the biceps brachii tendon originates.

What is the scapular spine and its clinical landmark?

The scapular spine divides the lateral surface into supraspinous and infraspinous fossae; the acromion is at its distal end and is a palpable landmark for shoulder approaches.

How does the dog’s clavicle differ from the cat’s clavicle?

Dog: clavicle is vestigial/cartilaginous and often not visualized; may ossify in aged dogs. Cat: clavicle is small, curved, and present with no articulation to the skeleton.

What are the major humeral landmarks?

Head, neck, greater and lesser tubercles; intertubercular groove, deltoid and teres major tuberosities, and distal condyle with epicondyles.

What is the supratrochlear foramen?

A foramen in the dog between the radial and olecranon fossae; not present in all breeds and no major neurovascular passing through it.

What joints compose the elbow joint in dogs/cats?

Humeroradial, humeroulnar, and proximal radioulnar joints; stability from ligaments and the interosseous membrane.

What are the proximal carpal bones in the dog/cat?

Radial carpal (intermedioradial), ulnar carpal, and accessory carpal bones in the proximal row.

What are the carpal bones in the distal row?

First to fourth carpal bones (I–IV) from medial to lateral.

What is the carpal canal and flexor retinaculum?

The carpal canal is formed by carpal bones with the flexor retinaculum; the flexor tendons pass through/under it; the SDF tendon runs superficial to the canal while DDF passes through it.

Where are the palmar and dorsal sesamoid bones located in the manus?

Palmar (proximal) sesamoids develop within interossei tendons at the metacarpophalangeal joints (II–V, with two per digit); dorsal sesamoids form on the dorsal side at these joints (one per digit except digit I). Digit I has a single palmar sesamoid and no dorsal sesamoid.

What is the fabella?

A small sesamoid bone in the gastrocnemius tendon (present variably in dogs; larger in the lateral head).

What is the common calcanean tendon?

A tendon formed by the gastrocnemius and tendons of biceps femoris, semitendinosus, and gracilis; inserts on the calcanean tuberosity.

Name the main extrinsic thoracic limb muscles and their primary actions.

Brachiocephalicus protracts the limb; Latissimus dorsi retracts the limb; Trapezius elevates the scapula and can abduct the shoulder; Omotransversarius contributes to protraction; Serratus ventralis acts as a sling for weight transfer.

Which muscles flex and extend the hip in the pelvic limb?

Iliopsoas flexes the hip; middle and deep gluteal muscles extend the hip and can abduct; hamstrings (biceps femoris, semitendinosus) extend the hip during weight-bearing.

What is the pelvic outlet and which muscles comprise the pelvic diaphragm?

The pelvic outlet is the boundary of the pelvic cavity; the pelvic diaphragm comprises coccygeus and levator ani (and associated support structures) and helps contain pelvic contents; rectococcygeus supports the rectum.

What is the vertebral formula for dogs/cats?

7 cervical, 13 thoracic, 7 lumbar, 3 sacral; total around 20–23 vertebrae.

What are the atlas and axis, and what do they do?

Atlas (C1) supports the skull and forms the atlanto-occipital joint; Axis (C2) has the dens and forms the atlanto-axial joint for head rotation.

What is the nuchal ligament?

An elastic ligament extending along the dorsal midline from the occipital bone to the spine; it is absent in cats.

What are intervertebral discs and their components?

Each IVD consists of a central nucleus pulposus and a peripheral annulus fibrosus; they cushion and allow mobility; rupture/herniation can occur with aging or injury.

Describe the temporomandibular joint (TMJ).

A true joint between the mandible and the temporal bone; synovial with an articular disc (meniscus); primarily a hinge with limited lateral movement.

What are the major skull bone classifications, and what do they enclose/protect?

Cranial bones enclose the brain; facial bones form the boundaries of the oral and orbital cavities; bones can be endochondral or intramembranous in origin.

What are the basic radiographic views used for limbs?

Mediolateral (M/L); Craniocaudal (cr/cau); Dorsopalmar (D.P.) or dorsoplantar (D.Pl); Ventrodorsal (V/D) for pelvis; oblique views may be used for specialized structures.

What are the main types of synovial joints?

Ball-and-socket (enarthrodial), ellipsoidal, hinge (ginglymus), condylar, pivot (trochoid), saddle, plane.

What is a synovial bursa and what is its function?

A fluid-filled sac that reduces friction where tendons pass over bony prominences or processes.

What composes the stifle joint and why is it clinically important?

The stifle is a complex synovial joint with the femoropatellar joint, femorotibial joint, and cruciate ligaments; contains menisci and fabellae; clinically important due to cruciate injuries.

Where are the fabellae located?

Fabellae are sesamoid bones in the gastrocnemius tendon around the stifle region.

What is the carpal organ in cats?

A carpal organ is a cutaneous nodular pad overlying the accessory carpal bone, with tactile hairs similar to whiskers.

Which nerve supplies trapezius?

Accessory nerve (cranial nerve XI).