8: Musculo-neuro-vascular system of the arm and anterior compartment of the forearm

Question 1

Forearm is surrounded by a layer of fascia called…

Answer 1

Antebrachial fascia

Question 2

Forearm is divided into two compartments by:

Answer 2

Medial intermuscular septum
Ulna
Interossous membrane
Radius
Lateral intermuscular septum

Question 3

What is compartment syndrome?

Answer 3

Excessive swelling or bleeding within a compartment exerts pressure on anything within that compartment and can cause irreversible damage to all tissues

Question 4

How to treat compartment syndrome?

Answer 4

Emergency fasciotomy

Question 5

Anterior compartment of forearm - deep muscles

Answer 5

Flexor pollicis longus
Flexor digitorum profundus
Pronator quadratus

Question 6

Anterior compartment of the forearm - superficial muscles

Answer 6

Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnas
Flexor digitorum superficialis

Question 7

Anterior forearm muscles are innervated by…

Answer 7

The median nerve or the anterior interosseus nerve

Question 8

Flexor carpi ulnaris is innervated by

Answer 8

The ulnar nerve

Question 9

Ulnar half of flexor digitorum profundus is supplied by

Answer 9

The ulnar nerve

Question 10

Origin of pronator teres

Answer 10

Medial epicondyle of humerus
Coronoid process of ulna

Question 11

Insertion of pronator teres

Answer 11

Anterior surface of radial mid-shaft

Question 12

Innervation of pronator teres

Answer 12

Median nerve

Question 13

Actions of pronator teres (2)

Answer 13

Pronates forearm at radioulnar joint
Weak flexor of elbow joint

Question 14

Origin of flexor carpi radialis

Answer 14

Medial epicondyle of humerus

Question 15

Insertion of flexor carpi radialis

Answer 15

Palmar surface of base of metacarpals 2 and 3

Question 16

Innervation of flexor carpi radialis

Answer 16

Median nerve

Question 17

Actions of flexor carpi radialis (2)

Answer 17

Flexes wrist (radiocarpal) joint
Weak radial deviation of wrist

Question 18

Origin of palmaris longus

Answer 18

Medial epicondyle of humerus

Question 19

Insertion of Palmaris longus

Answer 19

Flexor retinaculum
Palmar aponeurosis

Question 20

Innervation of palmaris longus

Answer 20

Median nerve

Question 21

Actions of palmaris longus (2)

Answer 21

Flexes hand at radiocarpal joint
Tightens palmar aponeurosis when gripping

Question 22

How many heads does flexor carpi ulnaris have?

Answer 22

2

Question 23

Origin of humeral head of flexor carpi ulnaris

Answer 23

Medial epicondyle of humerus

Question 24

Origin of ulnar head of flexor carpi ulnaris

Answer 24

Medial and posterior surface of olecranon

Question 25

Insertion of flexor carpi ulnaris

Answer 25

Pisiform Hook of hamate Base of metacarpal 5

Question 26

Innervation of flexor carpi ulnaris

Answer 26

Ulnar nerve

Question 27

Actions of flexor carpi ulnaris (3)

Answer 27

Flexes wrist at radiocarpal joint Flexes 5th CMC joint Adducts hand

Question 28

Origin of flexor digitorum superficialis (3)

Answer 28

Medial epicondyle of humerus Coronoid process of ulna Anterior surface of radial shaft

Question 29

Insertion of flexor digitorum superficialis

Answer 29

Middle phalanges 2-5 (palmar surface)

Question 30

Innervation of flexor digitorum superficialis

Answer 30

Median nerve

Question 31

Actions of flexor digitorum superficialis

Answer 31

Flexes proximal and middle phalanges of digits 2-5

Question 32

Superficial flexor of pointer finger

Answer 32

Pronator teres

Question 33

Superficial flexor of middle finger

Answer 33

Flexor carpi radials

Question 34

Superficial flexor of ring finger

Answer 34

Palmaris longus

Question 35

Superficial flexor of pinky finger

Answer 35

Flexor carpi ulnaris

Question 36

Origin of pronator quadratus

Answer 36

Distal 1/4 of anterior ulna

Question 37

Insertion of pronator quadratus

Answer 37

Distal 1/4 of anterior radius

Question 38

Innervation of pronator quadratus

Answer 38

Anterior interosseus branch of median nerve

Question 39

Actions of pronator quadratus

Answer 39

Pronates forearm at radioulnar joint Stabilises radioulnar joint

Question 40

Origin of flexor Pollicis longus

Answer 40

Mid-anterior surface of radius and adjacent interosseus membrane Sometimes it may also have a narrow slip that attaches to the coronoid process or medial epicondyle

Question 41

Insertion of flexor pollicis longus

Answer 41

Palmar surface of distal phalanx of thumb

Question 42

Innervation of flexor pollicis longus

Answer 42

Anterior interosseus branch of median nerve

Question 43

Actions of flexor pollicis longus

Answer 43

Flexes thumb

Question 44

Origin of flexor digitorum profundus

Answer 44

Proximal 2/3 of anterior ulnar shaft and adjacent interosseus membrane

Question 45

Insertion of flexor digitorum profundus

Answer 45

Palmar surface of distal phalanges 2-5

Question 46

Innervation of flexor digitorum profundus (2 nerves)

Answer 46

Medial 1/2: ulnar nerve Lateral 1/2: anterior interosseus branch of median nerve

Question 47

Actions of flexor digitorum profundus

Answer 47

Flexes distal phalanges of digits 2-5

Question 48

Attachments of flexor retinaculum

Answer 48

Lateral: scaphoid and trapezium Medial: pisiform and hamate

Question 49

Function of flexor retinaculum

Answer 49

Prevents bowstringing of tendons in forearm

Question 50

Forearm nerves (3)

Answer 50

Median nerve + anterior interosseus branch Ulnar nerve Radial nerve and posterior interosseus branch

Question 51

Course of median nerve

Answer 51

Passes over ulnar artery Continues distally between digitorum superficialis and profundus Innervates most of the muscles in anterior compartment Passes distally between flexor digitorum superficialis and profundus and exits forearm through carpal tunnel at wrist

Question 52

Course of anterior interosseus nerve

Answer 52

Runs distally along the anterior part of interosseus membrane and innervates the anterior compartment muscles

Question 53

Course of ulnar nerve

Answer 53

Descends posteriorly to medial epicondyle Enters forearm between two heads of flexor carpi ulnaris Descends distally between flexor digitorum profundus and flexor carpi ulnaris and medial to ulnar artery Ulnar nerve enters the hand superficial to flexor retinaculum and lateral to carpi ulnaris tendon

Question 54

Source of medial cutaneous nerve of the forearm

Answer 54

Direct from medial cord of the brachial plexus

Question 55

Source of lateral cutaneous nerve of the forearm

Answer 55

Continuation of musculocutaneous nerve distal to motor branches in arm

Question 56

Source of posterior cutaneous nerve of the forearm

Answer 56

Branch of radial nerve

Question 57

Where does brachial artery enter the forearm

Answer 57

Deep to bicipital aponeurosis

Question 58

Brachial artery bifurcates:

Answer 58

Radial artery Ulnar artery

Question 59

Elbow joint anastomotic network

Answer 59

Superior and inferior ulnar collateral arteries anastomose with ulnar recurrent arteries Radial collateral artery anastomoses with radial recurrent arteries

Question 60

Common interosseus artery divides into:

Answer 60

Anterior branch Posterior branch

Question 61

Posterior interosseous artery anastomoses with..

Answer 61

middle collateral branch of the profunda brachii

Question 62

Posterior interosseus artery and the middle collateral branch of the Profunda brachii supply....

Answer 62

The middle posterior part of the elbow

Question 63

Course of anterior interosseus branch

Answer 63

Descends on the anterior surface of the interosseous membrane, then pierces through the interosseus membrane and assists the posterior interosseus branch to supply the distal posterior forearm compartment

Question 64

Radial artery location

Answer 64

Proximally lies on muscle, deep to brachioradialis

Question 65

Radial recurrent artery anastomoses with…… to supply…..

Answer 65

Radial collateral branch of brachial artery Lateral elbow

Question 66

Course of ulnar artery

Answer 66

Courses distally from its origin along the ulnar side of the forearm Runs deep to flexor carpi ulnaris but superficial to flexor digitorum profundus

Question 67

Ulnar artery and its branches supply

Answer 67

Muscles, nerves etc. of the medial part of the forearm

Question 68

Deep veins of forearm (6)

Answer 68

Radial veins Ulnar veins Posterior interosseus vein Anterior interosseus vein Brachial vein Axillary vein

Question 69

Superficial veins of forearm (4)

Answer 69

Cephalic vein Median antebrachial Median cubital vein Basilic vein