Elbow, forearm and wrist Flashcards
Name the carpal bones.
1st row – scaphoid, lunate, triquetrum, pisiform
2nd row – hamate, capitate, trapezoid, trapezium
What are the two articular surfaces of the distal humerus and what do they articulate with?
Capitulum – articulates with the head of the radius
Trochlea – articulates with the head of the ulna
What is the importance of the epicondyles of the humerus?
They are important sites of attachment of forearm muscles
Which fossae are present on the anterior side of the distal humerus?
Radial fossa Coranoid fossa (the coranoid process of the ulna slots in here when the elbow is flexed)
Which fossa is present on the posterior side of the distal humerus?
Olecranon fossa – the olecranon process of the ulna slots in here when the elbow is extended
Where are tuberosities found near the elbow joint?
Radial tuberosity
Ulnar tuberosity
What are the two ridges running down the anterior and posterior of the radius?
Anterior oblique line
Posterior oblique line
What does the distal end of the ulna articulate with
An articular disc (not with carpal bones)
What does the distal end of the radius articulate with?
Scaphoid and lunate
What separates the anterior and posterior compartments of the forearm?
Interosseous membrane
Which carpal bone is a sesamoid bone and which muscle tendon is it enclosed in?
Pisiform
It is within the flexor carpi ulnaris tendon
What is the distal attachment of biceps brachii?
Radial tuberosity
What is the distal attachment of brachialis?
Coronoid process of ulna
What is the distal attachment of triceps?
Olecranon process
Which compartment are the pronators and supinators in?
Pronators – anterior
Supinators – posterior
Which muscles are in the superficial anterior compartment of the forearm?
Pronator teres Flexor carpi radialis Palmaris longus Flexor digitorum superficialis Flexor carpi ulnaris
Which muscles are in the deep anterior compartment of the forearm?
Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus
What is the common flexor origin?
Medial epicondyle of the humerus – this is where most of the anterior compartment muscles (particularly the superficial muscles) originate
Which of the superficial anterior compartment muscles do not cross the wrist?
Pronator teres
Describe the attachments of pronator quadratus.
It is attached between the distal ends of ulna and radius
What forms the roof of the carpal tunnel?
Flexor retinaculum
Which tendon is continuous with the palmar aponeurosis?
Palmaris longus tendon
NOTE: palmaris longus tendon isn’t present in everyone and before it spreads to form the palmar aponeurosis, it is attached to the flexor retinaculum
Name all the muscles in the extensor compartment of the forearm.
Muscles that move the wrist: Extensor carpi radialis longus Extensor carpi radialis brevis Extensor carpi ulnaris Muscles that move the fingers: Extensor indicis Extensor digitorum Extensor digiti minimi Muscles that move the thumb: Abductor pollicis longus Extensor pollicis longus Extensor pollicis brevis Others: Brachioradialis Supinator
Where is the common extensor origin?
Lateral epicondyle of the humerus
What can be palpated in the anatomical snuffbox?
Scaphoid (this is often fractured when trying to break a fall)
Which tendons mark the anatomical snuffbox?
Lateral – Extensor Pollicis Brevis + Abductor Pollicis Longus
Medially – Extensor Pollicis Longus
Which blood vessel is present in the anatomical snuffbox?
Branch of the radial artery
What does the head of the radius articulate with?
Capitulum
What are the main ligaments found at the elbow joint?
Radial collateral ligament
Ulnar collateral ligament
Anular ligament
What are the three parts of the ulnar collateral ligament?
Anterior band
Posterior band
Oblique band
What is the role of the anular ligament?
It goes around just under the head of the radius and it helps hold the radius in place
It allows the radius to rotate
Describe the difference in carrying angle between genders.
Men – 10-15 degrees
Women - > 15 degrees
Describe the articulation of the radius and ulna with the carpal bones.
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
What is the name given to the joint between the first and second rows of carpal bones?
Midcarpal joint
Which nerves are responsible for: Elbow flexion Elbow extension Wrist flexion Wrist extension
Elbow flexion C56 Elbow extension C78 Write flexion C67 Wrist extension C67
Which muscles are involved in supination?
Supinator
Biceps brachii
(EPL, ECRL)
Which muscles are involved in pronation?
Pronator teres
Pronator quadratus
(FCR, PL, brachioradialis)
Describe how the biceps contribute to supination.
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
Which muscles are important for: Flexion of the wrist Extension of the wrist Radial deviation (abduction) Ulnar deviation (adduction)
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
What is an important branch of the ulnar artery?
Common interosseous branch
This splits into the anterior and posterior interosseous arteries
What are the arterial arches of the hand made up of?
Anastomosis of the radial and ulnar arteries
What is the name given to the space anterior to the elbow and what are its boundaries?
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
What happens to the biceps aponeurosis in this area?
It merges with the fascia of the region
What important vessels and nerves pass through the cubital fossa?
Brachial artery and veins
Median nerve
Describe the arrangement of superficial veins in the upper limb.
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 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
Describe the deep venous drainage of the upper limb.
The deep venous drainage of the upper limb runs in reverse to the arterial supply
What are the two venous arches present on the palmar side of the hand?
Superficial venous palmar arch
Deep venous palmar arch
Where lymph nodes are found in the upper limb?
Cubital lymph nodes
Axillary lymph nodes
Name the difference subsets of axillary lymph nodes.
Pectoral Central Apical Subscapular Humeral
State which spinal nerves roots make up: Musculocutaneous nerve Radial nerve Median nerve Ulnar nerve
Musculocutaneous nerve C567 Radial nerve C5678 T1 Median nerve C678 T1 Ulnar nerve C8 T1
What is the role of the musculocutaneous nerve in the forearm?
It has a lateral cutaneous branch, which provides sensory innervation to the lateral part of the forearm
Describe the passage of the median nerve through the arm.
Courses through the anterior compartment and lies anterior to the elbow, with the brachial artery
It is the main nerve to the muscles of the anterior compartment of the forearm
Where can the median nerve be damaged easily?
Elbow and wrist
Where is the ulnar nerve easily damaged?
It lies behind the medial epicondyle of the humerus where it can easily be damaged
It can also be damaged at the wrist
Where is the radial nerve easily damaged?
It lies close to the humerus in the radial groove so fractures of the humerus could damage the radial nerve
It can also be damaged in the axillary region
What two branches does the radial nerve divide into?
Posterior interosseous nerve (motor)
Superficial radial nerve (sensory)
Which muscles of the forearm does the ulnar nerve supply?
FCU
Ulnar half of FDP
What is the role of the flexor retinaculum?
It holds down the long tendons and prevents them from bowing
