Canine Thoracic Limb: Arthrology

Joints

formed when two or more bones are united by fibrous, elastic, or cartilaginous tissue or a combination of these tissues

Three types of joints:

1.) fibrous joints

2.) cartilaginous joints

3.) synovial joints

fibrous joints

a joint that contains a considerable amount of intervening connective tissue with limited movement

example of a fibrous joint

sutures on skull bones

cartilaginous joints

a joint formed by the union of some type of cartilage (hyaline, fribrocartilage)

examples of cartilaginous joints

-temporary fetal joints of growing bone

-symphasises found on jaw and pelvis

-between vertebrae

synovial joints

true joint of the extremities; provide the greatest degree of movement

All synovial joints are composed of (4):

1.) joint cavity

2.) joint capsule

3.) synovial fluid

4.) articular cartilage

joint cavity

space of the cavity

joint capsule

contains an outer fibrous layer and inner synovial membrane

outer fibrous layer of joint capsule

composed of white fibrous tissue containing yellow elastic fibers

The outer fibrous layer of the joint capsule is aka...

capsular ligament

Ligament

thickening of the outer fibrous layer of the joint capsule

collateral ligaments

connect the joint at both sides; they give medial and lateral stability and prevent dislocation; thickening of the outer fibrous layer of joint capsule in areas where bones move the least

inner synovial membrane of joint capsule

vascular connective tissue responsible for the production of synovial fluid

synovial fluid

fluid inside the joint that lubricates the contact surfaces of synovial joints

articular cartilage

covers the articular surfaces of the bones; thickest in the joints that bear the most weight

Artiuclar cartilage is typically what type of cartilage?

hyaline cartilage

glenohumeral joint

shoulder joint; joint between the glenoid cavity of scapula and head of humerus

What type of joint is the glenohumeral joint?

ball and socket joint

Movements of glenohumeral joint

capable of movement in any direction but chief movements are flexion and extension of shoulder

Luxation in the glenohumeral joint is __________. Why?

rare; muscles associated with the joint stabilize it

Muscles that stabilize the glenohumeral joint laterally

1.) supraspinatus

2.) infraspinatus

Muscles that stabilize the glenohumeral joint medially

1.) subscapularis

2.) coracobrachialis

Two ligaments of the glenohumeral joint

1.) medial glenohumeral ligament

2.) lateral glenohumeral ligament

Cubital joint

elbow joint; joint between the condyle of the humerus and the head of the radius and trochlear notch of the ulna

What type of joint is the cubital joint?

hinge joint

Movements of the cubital joint

flexion and extension

Two types of ligaments within the cubital joint

1.) collateral ligaments

2.) interosseous ligaments

Two collateral ligaments of the cubital joint:

1.) lateral (ulnar) collateral ligament

2.) medial (radial) collateral ligament

The lateral (ulnar) collateral ligament runs from the _________ to ________

The medial (radial) collateral ligament runs from the _________ to ___________

epicondyle of humerus; ulna

epicondyle of humerus; radius

Interosseous ligament of the cubital joint

collagenous tissue uniting the radius and ulna proximally

Luxation of the cubital joint is ________. Why?

rare; the anconeal process of the ulna projects into the olecranon fossa of the humerus, stabilizing the joint