Muscles Of The Shoulder Region Flashcards
Where is the elbow joint located?
The elbow joint is located 2–3 cm inferior to the epicondyles of the humerus.
What type of joint is the elbow joint?
The elbow joint is a hinge type of synovial joint.
What articulates in the humero-ulnar and humero-radial articulations of the elbow joint?
The spool-shaped trochlea of the humerus articulates with the trochlear notch of the ulna, and the spheroidal capitulum of the humerus articulates with the superior aspect of the head of the radius
What covers the articular surfaces of the elbow joint?
The articular surfaces are covered with hyaline cartilage.
When are the articular surfaces of the elbow joint most congruent?
The surfaces are most congruent when the forearm is flexed to a right angle and positioned midway between pronation and supination.
What does the fibrous layer of the joint capsule of the elbow joint do?
The fibrous layer surrounds the elbow joint and is attached to the humerus at the margins of the lateral and medial ends of the articular surfaces of the capitulum and trochlea.
How is the joint capsule of the elbow joint carried superiorly?
The joint capsule is carried superiorly, proximal to the coronoid and olecranon fossae.
What strengthens the joint capsule of the elbow joint on each side?
Collateral ligaments strengthen the joint capsule on each side.
Where is the synovial membrane of the elbow joint located?
The synovial membrane lines the internal surface of the fibrous capsule and the intracapsular non-articular parts of the humerus. It is also continuous with the synovial membrane of the proximal radio-ulnar joint.
What are the collateral ligaments of the elbow joint?
The collateral ligaments are strong triangular bands that are thickenings of the fibrous layer of the joint capsule.
Where does the radial collateral ligament extend from, and what does it blend with distally?
The radial collateral ligament extends from the lateral epicondyle of the humerus and blends distally with the anular ligament of the radius.
What is the function of the anular ligament of the elbow joint?
The anular ligament encircles and holds the head of the radius in the radial notch of the ulna, permitting pronation and supination of the forearm.
Where does the ulnar collateral ligament extend, and what does it consist of?
The ulnar collateral ligament extends from the medial epicondyle of the humerus to the coronoid process and olecranon of the ulna. It consists of three bands: the anterior cord-like band (strongest), posterior fan-like band (weakest), and slender oblique band.
What movements occur at the elbow joint?
Flexion and extension occur at the elbow joint.
What is the carrying angle of the elbow joint?
The long axis of the fully extended ulna makes an angle of approximately 170° with the long axis of the humerus.
How does the carrying angle of the elbow joint differ between men and women?
The carrying angle is approximately 10° more acute in women than in men.
When does the carrying angle of the elbow joint disappear?
The carrying angle disappears when the forearm is pronated.
How many muscles cross the elbow joint and extend to the forearm and hand?
A total of 17 muscles cross the elbow joint and extend to the forearm and hand.
What are the chief flexors of the elbow joint?
The brachialis and biceps brachii are the chief flexors of the elbow joint.
What is the role of the brachioradialis in elbow flexion?
The brachioradialis can produce rapid flexion in the absence of resistance, even if the chief flexors are paralyzed.