Unit 1: Lecture 13

Question 1

What three joints make up the elbow complex?

Answer 1

• humeroulnar joint (hinge)
• humeroradial joint (not really a functional joint)
• radioulnar joint (symphasis)

Question 2

How many degrees of flexion/extension should the elbow have, in a normal person?

Answer 2

Flexion: ~145°

Extension: ~170° w/ females, and ~175° with males

Question 3

What is the “carrying angle?”

Answer 3

When the elbow is in extension, the forearm abducts a slight amount, but when brought back into flexion, it disappears

Question 4

Articular capsule in the elbow

Answer 4

• loose, and surrounds elbow complex
• thinner posteriorly, thus most dislocations occur posteriorly
• “thick, tough, yet pliable membrane”

Question 5

Anconeus

Answer 5

• attaches to articular capsule of elbow and ulna
• pulls capsule out of the way of elbow joint upon active extension of elbow
• assist triceps in extending elbow

Question 6

Collateral ligaments

Answer 6

• support elbow complex, and may be observed running along either side
• help to strengthen articular capsule medially and laterally
• ulnar collateral ligament of elbow and radial collateral ligament of elbow

Question 7

Large muscles of arm acting on elbow:

Answer 7

Flexion: biceps brachii and brachialis
Extension: triceps brachii

Brachioradialis (of forearm) also helps with extension

Question 8

Borders of cubital fossa

Answer 8

Proximal: line joining the epicondyles of humerus
Lateral: brachioradialis
Medial: pronater teres
Apex: juncture of brachioradialis and printer teres
Floor: supinator and brachialis
Roof: skin and superficial fascia

Question 9

What is found WITHIN the cubital fossa?

Answer 9

• median cubital vein
• tendon of biceps brachia
• brachial artery
• median nerve
• bicipital aponeurosis

Question 10

Joints of the forearm

Answer 10

Proximal radioulnar Joint
Distal radioulnar joint
Middle radioulnar joint

Question 11

Proximal radioulnar joint

Answer 11

• formed by the radial head against the radial notch of the ulna

Question 12

Ligaments of the proximal radioulnar joint

Answer 12

• Annular ligament: encircles and holds radial head agains ulna. Rotation within annular ligament allows rotation around ulna, which produces pronation/supination
• Oblique cord: flattened fibrous cord that extends from lateral border of the ulnar tuberosity to the radial shaft distal to the radial tuberosity. Holds and supports proximal radioulnar joint. TAUGHT/SUPINATION – RELAXED/PRONATION

Question 13

Distal radioulnar joint

Answer 13

• held together only by an articular capsule that has both anterior/posterior thickenings
• articular capsule is chief uniting structure of DRJ, though pronator quadratus also important in stabilizing during supination

Question 14

Triangular fibrocartilage

Answer 14

Articular disc contained in distal radioulnar joint which is attached to the styloid process of ulna, and helps to protect the articular surface during movement

Question 15

Middle radioulnar joint

Answer 15

• supported by interosseus membrane, which attaches parallel shafts of ulna and radius
• Interosseous membrane also serves as an attachment site for some of the deeper muscles of the forearm

Question 16

Anterior flexor compartment of arm - musculocutaneous nerve

Answer 16

• Biceps brachii
• Brachialis
• Coracobrachialis

Question 17

Transverse Humeral Ligament

Answer 17

Bridges bicipital groove, securing long head of biceps brachii

Question 18

Extensor compartment of arm - radial nerve

Answer 18

• Triceps brachii (long, lateral, medial)

Question 19

Cutaneous nerves branching from Radial Nerve

Answer 19

• Lower lateral Brachial cutaneous nerve

- Posterior brachial cutaneous nerve

Question 20

Cutaneous nerves branching from Medial Cord

Answer 20

Medial brachial cutaneous nerve

Question 21

Cutaneous nerves branching from Axillary Nerve

Answer 21

Superior lateral Brachial cutaneous nerve

Question 22

Cutaneous nerves branching from T2

Answer 22

Intercostobrachial cutaneous nerve

Question 23

Branches of Brachial Artery

Answer 23

• Muscular branches (supply flexors of arm)

- Profunda brachii (supply extensors of arm)

Question 24

From where does the brachial plexus initially emerge from muscle?

Answer 24

between the anterior and median scalene muscles. So too does the subclavian artery & subclavian vein (passing anterior to artery)

Question 25

What does “coronoid” mean?

Answer 25

Beak

Question 26

Brachialis inserts onto…

Answer 26

Ulnar tuberosity

Question 27

Biceps brachii inserts onto…

Answer 27

Radial tuberosity

Question 28

When “carrying angle” injuries don’t heal, they lead to…

Answer 28

cubitus varus, or “gunstock” deformity (epicondylar fracture)

Question 29

Tommy John Surgery

Answer 29

transplanting ligament from another part of body to ulnar collateral ligament, which apparently causes no problems.

Question 30

Strongest flexor?

Answer 30

Brachialis

Question 31

At cubital fossa, the median nerve runs WITH…

Answer 31

the brachial artery

Question 32

At cubital fossa, radial nerve is DEEP to what muscle?

Answer 32

brachioradialis

Question 33

Coming off of the deep radial nerve is the posterior interosseous nerve, which supplies…

Answer 33

most extensors of forearm

Question 34

Superficial radial nerve provides…

Answer 34

sensory to dorsolateral aspect of forearm

Question 35

Canal of frosha

Answer 35

Where deep Radial Nerve pierces the Supinator

Question 36

“Supinator Syndrome”

Answer 36

supinator will “choke off” deep radial, so then problems with posterior parts of forearm