1What type of joint classification is the elbow joint?
Modified hinge type synovial joint
2Where is the elbow joint located relative to the epicondyles of the humerus?
\$2\text{--}3\text{ cm}\$ inferior to the epicondyles of the humerus
3What are the three olecranon bursae of the elbow?
Subtendinous, intratendinous, and subcutaneous olecranon bursae
4What spool-shaped structure on the distal humerus articulates with the trochlear notch of the ulna?
Trochlea
5What spheroidal structure on the distal humerus articulates with the concave superior head of the radius?
Capitulum
6Which humeral epicondyle serves as the common origin for the forearm flexors?
Medial epicondyle
7Which humeral epicondyle serves as the common origin for the forearm extensors?
Lateral epicondyle
8To which margins does the fibrous layer of the elbow joint capsule attach on the humerus?
Margins of the lateral and medial ends of the articular surfaces of the capitulum and trochlea
9How far superiorly does the fibrous layer of the elbow joint capsule extend on the humerus?
Proximal to the coronoid and olecranon fossae
10What type of connective tissue structures are the collateral ligaments of the elbow joint?
Strong triangular thickenings of the fibrous layer of the joint capsule
11What are the two collateral ligaments of the elbow joint?
Radial collateral ligament and ulnar collateral ligament
12Where does the oblique cord extend from and to?
From the lateral side of the ulnar tuberosity to the radius just inferior to the radial tuberosity
13Where does the radial collateral ligament originate and distally blend?
Extends from the lateral epicondyle of the humerus and blends distally with the anular ligament of the radius
14What is the function of the anular ligament of the radius?
Encircles and holds the head of the radius in the radial notch of the ulna
15What joint is formed by the head of the radius, anular ligament, and radial notch of the ulna?
Proximal radio-ulnar joint
16What movements are permitted by the proximal radio-ulnar joint?
Pronation and supination of the forearm
17What are the three bands of the ulnar collateral ligament?
Anterior cord-like band, posterior fan-like band, and slender oblique band
18Which band of the ulnar collateral ligament is the strongest?
Anterior cord-like band
19At what position of the elbow is the anterior band of the ulnar collateral ligament tight?
Endrange extension
20Which band of the ulnar collateral ligament is the weakest?
Posterior fan-like band
21At what position of the elbow is the posterior band of the ulnar collateral ligament tight?
Endrange flexion
22What is the anatomical function of the slender oblique band of the ulnar collateral ligament?
Deepens the socket for the trochlea of the humerus
23What angle does the long axis of the fully extended ulna make with the long axis of the humerus?
Approximately \$170^\circ\$
24What is the frontal plane angle between the fully extended ulna and humerus called?
Carrying angle
25How does the carrying angle differ between women and men?
More pronounced in women than men (approximately \$10^\circ\$ more acute, or \$< 5^\circ\$ in some sources)
26What forearm motion causes the carrying angle to disappear?
Pronation
27What is the typical normal carrying angle range?
\$10\text{--}15^\circ\$
28What carrying angle degree is considered excessive cubitus valgus?
\$> 15^\circ\$
29What clinical term is given to cubitus varus resembling an inverted rifle?
Gunstock deformity
30How many muscles cross the elbow joint and extend to the forearm and hand?
16 muscles
31Which two muscles are the chief flexors of the elbow joint?
Brachialis and biceps brachii
32What is the function of the brachioradialis during rapid elbow flexion without resistance?
Produces rapid flexion
33What is the function of the brachioradialis during resisted elbow flexion?
Assists flexors in producing slower flexion and joint compression
34What muscle is the chief extensor of the elbow joint?
Triceps brachii (especially the medial head)
35Which minor muscle assists the triceps brachii in elbow extension?
Anconeus
36From where is the arterial blood supply to the elbow joint derived?
Peri-articular arterial anastomosis around the elbow joint
37Which four nerves supply the elbow joint according to Hilton's Law?
Musculocutaneous, radial, median, and ulnar nerves
38What anatomical structures form the socket in which the head of the radius rotates during supination?
Anular ligament and radial notch of the ulna
39How is supination defined regarding movement of the radius?
Movement rotating the radius laterally around its longitudinal axis so the palm faces anteriorly
40Which two muscles produce supination of the forearm?
Biceps brachii and supinator
41Which two muscles produce pronation of the forearm?
Pronator teres and pronator quadratus
42How is pronation defined regarding movement of the radius?
Movement rotating the radius medially around its longitudinal axis so the palm faces posteriorly
43Where does the axis of rotary movement for pronation and supination pass proximally and distally?
Proximally through the center of the radial head and distally through the ulnar head
44During pronation and supination, which forearm bone actively rotates around the other?
The radius rotates around the head of the ulna
45What is the resting position of the radio-ulnar joints?
Midway between pronation and supination so that the palm faces the trunk