Forearm

Question 1

What is the common origin of the flexor muscles of the forearm?

Answer 1

Medial epicondyle

Question 2

How many layers of muscles are there in the anterior compartment of the forearm?

Answer 2

3 - superficial, intermediate & deep

Question 3

What are the superficial muscles of the anterior compartment of the forearm?

Answer 3

Med to lat;

• FCU
• Palmaris longus
• FCR
• Pronator teres

Question 4

What characterises palmaris longus?

Answer 4

Small muscle with long tendon

Question 5

Which muscle makes up the intermediate layer of the anterior compartment?

Answer 5

Flexor digitorum superficialis

Question 6

How many tendons does flexor digitorum superficialis form, and where do they pass?

Answer 6

4 tendons

-through the carpal tunnel

Question 7

What lies on the underside of flexor digitorum superficialis?

Answer 7

Median nerve

Question 8

Which muscles make up the deep layer of the anterior compartment?

Answer 8

Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus

Question 9

How many tendons does flexor digitorum profundus split into and where do they pass?

Answer 9

4 tendons

-through the carpal tunnel

Question 10

Which muscle lies deepest in the deep layer of the anterior compartment of the forearm and where does it run from and to?

Answer 10

Pronator quadratus

- runs from radius to ulnar

Question 11

What is the common origin of the extensor muscles of the forearm?

Answer 11

Lateral epicodyle

Question 12

Which muscle is most lateral/radial in the superficial layer of the posterior compartment of the forearm?

Answer 12

Brachioradialis

Question 13

What is unusual about brachioradialis?

Answer 13

Part of posterior compartment, but acts as a flexor of the arm

Question 14

How many layers of muscles make up the posterior compartment of the forearm?

Answer 14

2 - superficial and deep layers

Question 15

Which muscles make up the superficial layer of the posterior compartment of the forearm?

Answer 15

Lateral to medial;

• Brachioradialis
• Extensor carpi radialis longus
• Extensor carpi radialis brevis
• Extensor digitorum (lies in the midline)
• Extensor digiti minimi
• Extensor carpi ulnaris

Question 16

How many tendons does extensor digitorum split into where do they pass?

Answer 16

4 - deep to extensor retinaculum

Question 17

Which 4 muscles make up the deep layer of the posterior compartment of the forearm?

Answer 17

Medial to lateral;

• Extensor indicis
• Extensor pollicis longus
• Extensor pollicis brevis
• Abductor pollicis longus

Question 18

What does abductor pollicis longus wrap around?

Answer 18

Radius

Question 19

Which tendons form the medial and lateral boundaries of the anatomical snuff box?

Answer 19

Medial - extensor pollicis longus

Lateral - extensor pollicis brevis and abductor pollicis longus

Question 20

What is the role of supinator muscle and what compartment is it found in?

Answer 20

Wraps around radius and works with biceps to supinate forearm
- deep layer of post compartment

Question 21

What are the boundaries of the cubital fossa?

Answer 21

Lateral = brachioradialis
Medial = pronator teres
Superior = imaginary line between epicondyles

Question 22

What muscle forms the floor of the cubital fossa?

Answer 22

Brachialis

Question 23

What forms the roof of the cubital fossa?

Answer 23

Deep fascia and bicipital aponeurosis

Question 24

What is the bicipital aponeurosis?

Answer 24

Thickening of deep fascia running medially from bicipital tendon

Question 25

What are the contents of the cubital fossa?

Answer 25

Lat to med; Biceps brachii tendon Brachial artery Median nerve

Question 26

Which superficial veins lie laterally and medially to the cubital fossa?

Answer 26

``` Lat = Cephalic vein Med = Basilic vein ```

Question 27

Which vein joins the cephalic and basilic vein?

Answer 27

Median cubital vein

Question 28

Which ligament holds the radius in place at the superior radioulnar joint and what are its attachments?

Answer 28

Annular ligament - PROX: ant margin of radial notch (ulnar) - DIST: post margin of radial notch

Question 29

Which carpal bones articulate with the radius at the radiocarpal joint?

Answer 29

Lunate and scaphoid

Question 30

How can a FOOSH result in compression of the median nerve?

Answer 30

Dislocation of lunate bone >> median nerve compression

Question 31

What effect would median nerve damage from dislocation of the lunate bone have on movements of the digits?

Answer 31

Supplies 1st and 2nd lumbricals; lose flexion at MCP joint and extension at IP joint. Suplies thenar muscles; wouldn't be able to abduct, flex or oppose thumb

Question 32

What effect would damage to the median nerve in the cubital fossa have on the movements of the upper limb?

Answer 32

Difficulty flexing wrist, and flexing/extending MCP/IP joints

Question 33

Where does the ulnar nerve run past the elbow joint?

Answer 33

Behind medial epicondyle

Question 34

Other than pronating the arm what else does pronator teres do?

Answer 34

Weak flexor of forearm

Question 35

Palmaris longus is present in approximately what percentage of individuals?

Answer 35

85%

Question 36

Brachioradialis is particularly important in what action?

Answer 36

Returning arm to midprone position

Question 37

What is the nerve supply of brachioradialis?

Answer 37

Radial nerve

Question 38

To which phalanges does flexor digitorum superficialis attach?

Answer 38

Mid phalanges of II-V

Question 39

Where does the median nerve lie in relation to flexor digitorum superficialis?

Answer 39

Deep to the muscle

Question 40

Which neurovascular bundle lies median to flexor digitorum superficialis?

Answer 40

Ulnar nerve and artery

Question 41

Where do the tendons of flexor digitorum profundus insert?

Answer 41

Palmar surfaces on distal phalanges of II-V

Question 42

In which direction do the collagen fibres run in the interosseous membrane?

Answer 42

Mainly inferior from radius to ulna (transfers forces from radius to ulna)

Question 43

Which 4 structures run through the carpal tunnel?

Answer 43

- Flexor pollicis longus tendon - Flexor digitorum superficialis tendons (4) - Flexor digitorum profundus tendons (4) - Median nerve

Question 44

Which structures pass deep to the extensor retinaculum?

Answer 44

Tendons of extensor digitorum and digiti minimi

Question 45

Which compartment is anconeus muscle part of?

Answer 45

Superficial posterior compartment

Question 46

Where does anconeus insert and what is its function?

Answer 46

Into olecranon and prox post ulna. | Function: abduction of ulna and accessory flexor at elbow

Question 47

Where do the deep extensors generally arise?

Answer 47

Shaft of radius and ulna, and interosseous membrane

Question 48

Which vein runs over the anatomical snuff box?

Answer 48

Cephalic vein

Question 49

What bony elements can be palpated in the floor of the anatomical snuff box?

Answer 49

Scaphoid and trapezium

Question 50

Which 2 muscles are responsible for pronation of the forearm?

Answer 50

Pronator teres | Pronator quadratus