Elbow, forearm and wrist B

Question 1

Describe the articulation of the radius and ulna with the carpal bones.

Answer 1

The distal end of the radius articulates with scaphoid and lunate
The distal end of the ulna does not directly articulate with the carpal bones, it articulates with an articular disc

Question 2

What is the name given to the joint between the first and second rows of carpal bones?

Answer 2

Midcarpal joint

Question 3

Which nerves are responsible for:
Elbow flexion
Elbow extension
Wrist flexion
Wrist extension

Answer 3

Elbow flexion
C56
Elbow extension
C78
Write flexion
C67
Wrist extension 
C67

Question 4

Which muscles are involved in supination?

Answer 4

Supinator
Biceps brachii
(EPL, ECRL)

Question 5

Which muscles are involved in pronation?

Answer 5

Pronator teres
Pronator quadratus
(FCR, PL, brachioradialis)

Question 6

Describe how the biceps contribute to supination.

Answer 6

The biceps tendon inserts into the radial tuberosity
When prone, the radial tuberosity is turned posteriorly
So then when the biceps contract, it will pull the tuberosity back around

Question 7

Which muscles are important for:
Flexion of the wrist
Extension of the wrist 
Radial deviation (abduction)
Ulnar deviation (adduction)

Answer 7

Flexion of the wrist
FCU, FCR
(APL, PL)
Extension of the wrist 
ECRL, ECRB, ECU 
Radial deviation (abduction)
ECRL, ECRB, FCR, APL
Ulnar deviation (adduction)
ECU, FCU

Question 8

What is an important branch of the ulnar artery?

Answer 8

Common interosseous branch
This splits into the anterior and posterior interosseous arteries . Posterior pierces the interosseous membrane and goes behind

Question 9

What are the arterial arches of the hand made up of?

Answer 9

Anastomosis of the radial and ulnar arteries

Question 10

What is the name given to the space anterior to the elbow and what are its boundaries?

Answer 10

Cubital fossa
Superior border – line between the medial and lateral epicondyles of the humerus
Medial border – lateral border of pronator teres
Lateral border – medial border of brachioradialis

Question 11

What happens to the biceps aponeurosis in this area?

Answer 11

It merges with the fascia of the region

Question 12

What important vessels and nerves pass through the cubital fossa?

Answer 12

Brachial artery and brachial veins (venae comitantes around brachial arteries)
Median nerve
radial nerve
clinical significance: you put stethoscope here during BP measurement to listen to brachial artery

NB the superficial venous system is considered SUPERFICIAL to cubital fossa so not within it (this incl. basilic, cephalic and median cubital v)

Question 13

Describe the arrangement of superficial veins in the upper limb.

Answer 13

The cephalic vein (runs laterally) and the basilic vein (runs medially) originate from the dorsal venous arch of the hand
The basilica vein joins venae commitantes (brachial vein) to form the axillary vein in the arm
The cephalic vein joins the axillary vein at the axilla
The axillary vein becomes the subclavian vein at the level of the 1st rib
NOTE: there is normally a median cubital vein joining the cephalic and basilic at the cubital fossa

Question 14

Describe the deep venous drainage of the upper limb. (arm + forearm)

Answer 14

The deep venous drainage of the upper limb runs in reverse to the arterial supply

Question 15

What are the two venous arches present on the palmar side of the hand?

Answer 15

Superficial venous palmar arch

Deep venous palmar arch

Question 16

Where are the main lymph nodes are found in the upper limb?

What does the lymphatic drainage of the upper limbs follow?

Answer 16

Cubital lymph nodes (in cubital fossa)
Axillary lymph nodes also drain from nodes of the distal parts of the upper limb

The lymphatic drainage of the UPPER LIMB can be split into superficial and deep systems too which FOLLOW THE VEINS

Question 17

Name the difference subsets of axillary lymph nodes.

Answer 17

Pectoral 
Central 
Apical 
Subscapular 
Humeral

Question 18

State which spinal nerves roots make up:
Musculocutaneous nerve 
Radial nerve 
Median nerve 
Ulnar nerve

Answer 18

Musculocutaneous nerve 
C567
Radial nerve 
C5678 T1
Median nerve 
C678 T1
Ulnar nerve 
C8 T1

Question 19

What is the role of the musculocutaneous nerve in the forearm and arm?

Answer 19

It has a lateral cutaneous branch, which provides SENSORY innervation to the lateral part of the forearm

in the arm, it supplies all the muscles in the anterior compartment

Question 20

Describe the passage of the median nerve through the arm and what muscles does the median nerve supply?

Answer 20

Courses through the anterior compartment of the arm (no significant branches) and lies anterior to the elbow, with the brachial artery ie in cubital fossa (easily damaged!)

Main nerve to the anterior compartment (flexor) muscles of the forearm with the EXCEPTION of flexor carpi ulnaris which is supplied by the ulnar nerve AND half of flexor digitorum profundus (other half supplied by ulnar)

Question 21

Where can the median nerve be damaged easily?

Answer 21

Elbow and wrist

Question 22

Why is the ulnar nerve easily damaged? (think of its course)

Answer 22

It goes through the posterior compartment of ARM (doesnt really innervate the arm muscles) and then goes behind the medial epicondyle of the humerus where it can easily be damaged
It can also be damaged at the wrist

Question 23

Where is the radial nerve easily damaged?

Answer 23

It lies close to the humerus in the radial groove (spiral groove) so fractures of the humerus could damage the radial nerve
It can also be damaged in the axillary region

Question 24

What two branches does the radial nerve divide into?

Answer 24

Posterior interosseous nerve (motor to extensor compartment of forearm)
Superficial radial nerve (sensory to dorsum/back of hand)

Question 25

Which muscles of the forearm does the ulnar nerve supply?

Answer 25

FCU

Ulnar half of FDP

Question 26

What is the role of the flexor retinaculum?

Answer 26

It holds down the long tendons and prevents them from bowing

Question 27

what are the two joints between the radial and ulnar bones ?

Answer 27

proximal and distal radio-ulnar joints

Question 28

which ligament is important in the proximal radio-ulnar and what is its function

Answer 28

the annular ligament of the radius
this ligament wraps around the radius and then attaches to the ulna. Its function is to keep the radial head attached to the radial notch of the proximal ulnar bone during pronation

slide 29 picture top right

Question 29

What are the radial and ulnar notches?

Answer 29

radial notch is a depression on the ulnar bone and ulnar notch is a depression on the radial bone. These notches are important for the proximal and distal radio-ulnar joints. eg the radial notch on the ulnar bone allows the radial bone to attach to the ulnar bone

Question 30

what is the main nerve of the hand

Answer 30

ulnar nerve

Question 31

what does the radial nerve supply

Answer 31

ALL muscles in posterior compartment of ARM AND FOREARM

Question 32

course of the radial nerve?

Answer 32

Axillary region:
The radial nerve lies posterior to the axillary artery in the axilla and enters the posterior compartment of the arm under teres major muscle.

Posterior compartment of arm:
In the posterior compartment of the arm, it winds it way around the spiral groove of the humerus, it then enters the anterior compartment of the ARM. Afterwards, it descends inferiorly and courses anterior to the lateral epicondyle at the level of the elbow joint. It enters the cubital fossa, where it divides into superficial and deep branches.

In the forearm:
The superficial branch courses goes all the way down to the hands and provides sensory innervation to back of hand

The deep branch gives off the posterior interosseous nerve (motor-supplies posterior forearm extensors) which terminates at the level of the wrist joint.

Question 33

summarise the innervation of the forearm

Answer 33

The Radial Nerve supplies all posterior muscles.

The Ulnar Nerve supplies only FCU and the Ulnar half of FDP .

The Median Nerve supplies all of the remaining anterior muscles.