Forearm

Question 1

Where do the superficial veins lie within the forearm?

Answer 1

Within the subcutaneous fat

Question 2

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

Answer 2

Medial epicondyle

Question 3

How many layers of muscles are there within the anterior compartment, what are they?

Answer 3

1) Superficial
2) Intermediate
3) Deep

Question 4

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

Answer 4

Medial to lateral

1) Flexor carpi ulnaris
2) Palmaris longus
3) Flexor carpi radialis
4) Pronator teres

Question 5

What shape is the pronator teres muscle?

Answer 5

Cyclindrical

Question 6

What characterises the palmaris longus muscle?

Answer 6

Small muscle with very long tendon

Question 7

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

Answer 7

Flexor digitorum superficialis

Question 8

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

Answer 8

Splits into 4 tendons, they pass through the carpal tunnel

Question 9

What lies on the underside of flexor digitorum superficialis?

Answer 9

Median nerve

Question 10

Which muscle lies deep to flexor digitorum superficialis?

Answer 10

Flexor digitorum profundus

Question 11

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

Answer 11

Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus

Question 12

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

Answer 12

Splits into 4 tendons, pass through the carpal tunnel

Question 13

Which muscle lies in the deep layer of the anterior compartment lateral to flexor digitorum profundus?

Answer 13

Flexor pollicis longus

Question 14

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

Answer 14

Pronator quadratus, can be viewed by separating flexor digitorum profundus and flexor pollicis longus, runs from radius to ulnar

Question 15

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

Answer 15

The lateral epicondyle

Question 16

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

Answer 16

Brachioradialis

Question 17

What is unusual about brachioradialis muscle?

Answer 17

So far to the radial side that its almost in the anterior compartment
Considered part of the posterior/extensor compartment but it acts as a flexor of the arm

Question 18

How many layers of muscles make up the posterior compartment of the forearm what are they called?

Answer 18

1) Superficial layer

2) Deep layer

Question 19

Which muscle lies medial to brachioradialis in the posterior compartment of the forearm?

Answer 19

Extensor carpi radialis longus

Question 20

From lateral to medial which muscles make up the superficial layer of the posterior compartment of the forearm?

Answer 20

1) Brachioradialis
2) Extensor carpi radialis longus
3) Extensor carpi radialis brevis
4) Extensor digitorum (lies in the midline)
5) Extensor digiti minimi
6) Extensor carpi ulnaris

Question 21

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

Answer 21

Splits into 4 tendons which pass deep to the extensor retinaculum

Question 22

Which 4 muscles make up the deep layer of the posterior compartment of the forearm from medial to lateral?

Answer 22

1) Extensor indicis
2) Extensor pollicis longus
3) Extensor pollicis brevis
4) Abductor pollicis longus

Question 23

Abductor pollicis longus muscle wraps around what?

Answer 23

The radius

Question 24

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

Answer 24

Medial boundary - Tendon of extensor pollicis longus

Lateral boundary - tendons of extensor pollicis brevis and abductor pollicis longus

Question 25

Why is the anatomical snuff box important clinically?

Answer 25

Running along the floor of it is the radial artery so its a pulse point Its also an area to palpate the carpal bones in suspected fractures

Question 26

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

Answer 26

Found in the deep layer of extensor compartment | Wraps around the radius, works together with biceps brachii to supinate the forearm

Question 27

What is the cubital fossa?

Answer 27

Triangular shaped area anterior to the elbow

Question 28

What are the boundaries of the cubital fossa?

Answer 28

``` Lateral = brachioradialis Medial = pronator teres Superiorly = imaginary line between the 2 epicondyles of the humerus ```

Question 29

What muscle forms the floor of the cubital fossa?

Answer 29

Brachialis

Question 30

What forms the roof of the cubital fossa?

Answer 30

Deep fascia of the forearm and the bicipital aponeurosis

Question 31

What is the bicipital aponeurosis?

Answer 31

Thickening of the deep fascia that runs medially from the bicipital tendon

Question 32

What are the contents of the cubital fossa?

Answer 32

``` Tendon of biceps brachii (most lateral) Brachial artery Median nerve (most medial) ```

Question 33

What happens to the brachial artery at the level of the cubital fossa?

Answer 33

At this level the brachial artery divides into the radial and ulnar arteries

Question 34

Do superficial veins lie within the cubital fossa?

Answer 34

No they lie superior to the roof, they lie within the subcutaneous fat

Question 35

Which superficial vein lies laterally?

Answer 35

Cephalic vein

Question 36

Which superficial vein lies medially?

Answer 36

Basilic vein

Question 37

Which vein joins the cephalic and basilic vein, why is it important clinically?

Answer 37

Median cubital vein | Blood is normally sampled from the median cubital vein

Question 38

Why is the median cubital vein still a safe place to sample blood from in spite of lying superficial to the brachial artery and median nerve?

Answer 38

The brachial artery and median nerve are protected by the roof of the cubital fossa

Question 39

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

Answer 39

Annular ligament Proximal attachment = anterior margin of radial notch of ulnar Distal attachment = posterior margin of radial notch of ulnar from trochlear notch to supinator crest

Question 40

In pronation what happens to the position of the ulna and radius?

Answer 40

Radius crosses over the top of the ulna

Question 41

What is the anatomical name for the wrist joint?

Answer 41

Radiocarpal joint

Question 42

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

Answer 42

The lunate and scaphoid bones

Question 43

Why are multiple x-rays of the scaphoid necessary?

Answer 43

Because of the small size and shape of scaphoid, you would need a series of x rays to identify a fracture

Question 44

How can a fall on an outstretched hand result in compression of the median nerve?

Answer 44

Because a fall on an outstretched hand can result in dislocation of the lunate bone leading to compression of the median nerve

Question 45

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

Answer 45

Would affect digit 1 and 2 Supplies 1st and 2nd lumbricals so lose flexion at the metacarpophalangeal joint and extension at the interphalangeal joint Wouldnt be able to abduct, flex or oppose thumbs as thenar muscles are supplied by the median nerve

Question 46

Other than brachioradialis what other muscle may be considered to make up the lateral border of the cubital fossa?

Answer 46

Supinator

Question 47

What happens to the brachial artery at the level of the cubital fossa?

Answer 47

Brachial artery normally bifurcates into the radial and ulnar arteries at the apex of the fossa

Question 48

Which superficial vein runs more medially on the anterior forearm?

Answer 48

The basilic vein

Question 49

Which superficial vein runs more laterally on the anterior forearm?

Answer 49

The cephalic vein

Question 50

Which vessel joins the basilic and cephalic vein?

Answer 50

Median cubital vein

Question 51

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

Answer 51

Difficulty in flexing the wrist as the median nerve supplies many of the anterior flexors of the wrist Difficulty flexing the digits at the metacarpophalangeal and interphalangeal joints

Question 52

Where does the ulnar nerve run past the elbow joint?

Answer 52

Behind the medial epicondyle

Question 53

What divides the arm into anterior and posterior compartments?

Answer 53

The deep fascia

Question 54

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

Answer 54

Acts as a weak flexor of the forearm

Question 55

Other than flexion of the wrist, what actions do flexor carpi radialis and ulnaris produce?

Answer 55

Flexor carpi radialis - flexes and abducts the wrist | Flexor carpi ulnaris - flexes and adducts the wrist

Question 56

Palmaris longus is present in approximately what percentage of individuals?

Answer 56

85%

Question 57

What is the nerve supply of brachioradialis?

Answer 57

radial nerve

Question 58

Brachioradialis is particularly important in what action?

Answer 58

Returning the forearm to the midprone position from either full supination or full pronation

Question 59

To which phalanges does flexor digitorum superficialis attach?

Answer 59

Middle phalanges of digits 2-5

Question 60

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

Answer 60

Deep to flexor digitorum superficialis

Question 61

Which neurovascular bundle lies median to flexor digitorum superficialis?

Answer 61

Ulnar nerve and artery

Question 62

Where do the tendons of flexor digitorum profundus insert?

Answer 62

Onto the palmar surfaces on the distal phalanges of digits 2-5

Question 63

What is the interosseous membrane and where is it located?

Answer 63

A thin, fibrous sheet which connects the medial border of the radius with the lateral border of the ulna Free upper margin is situated just inferior to the radial tuberosity, it also has a small circular aperture in the distal 1/3

Question 64

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

Answer 64

Run predominantly inferiorly from the radius to the ulna

Question 65

What are the 3 roles of the interosseous membrane?

Answer 65

1) Connects the radius and ulna restricting pronation and suppination 2) Provides attachment for muscles in the anterior and posterior compartments 3) Orientation of the collagen fibres is consistent in its role of transferring forces from the radius to the ulna and ultimately from the hand to the humerus

Question 66

Which 4 structures run through the carpal tunnel?

Answer 66

1) Flexor pollicis longus tendon 2) Flexor digitorum superficialis tendons 3) Flexor digitorum profundus tendons 4) Median nerve

Question 67

Which structures pass deep to the extensor retinaculum?

Answer 67

Tendons of extensor digitorum and digiti minimi

Question 68

Which compartment is anconeus muscle part of and where is it situated?

Answer 68

Superficial posterior | Small muscle located on the posterior compartment of the elbow

Question 69

Where does anconeus insert and what is its function?

Answer 69

Inserts into the olecranon and proximal posterior surface of the ulna Its function is abduction of the ulna and is an accessory extensor of the elbow joint

Question 70

The deep extensor muscles arise from what generally?

Answer 70

The shaft of the radius and ulna and the interosseous membrane

Question 71

Which vein runs over the anatomical snuff box?

Answer 71

The cephalic vein

Question 72

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

Answer 72

Floor is formed by the scaphoid and trapezium carpal bones

Question 73

Which 2 muscles are responsible for pronation of the forearm?

Answer 73

Pronator teres and pronator quadratus

Question 74

Which 2 muscles are responsible for supination of the forearm and how powerful are they?

Answer 74

Biceps - superficial and powerful | Supinator - deeper and less powerful