Unit 11: Distal upper limb Flashcards
What is the function od the radio-ulnar joint?
Pronation and supination
What is the function of the wrist or carpus joint?
Flexion
Extension
Abduction and adduction
What is the function of the digitorum joint (extrinsic and intrinsic)?
Flexion Extension
Abduction Adduction
What is the function of the pollicis joint?
Flexion /extension
Abduction /Adduction
Oppose
What is the anterior compartment of the forearm associated with?
Pronation
What are the three layers of muscles in the forearm?
Superficial
Intermediate
Deep
What is the common origin of the muscles in the superficial compartment of the anterior forearm?
The medial epicondyle of the humerus
What are the four muscles in the superficial compartment of the anterior forearm
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
What is the function of flexor carpi radialis?
Flexes and abducts the wrist joint
What is the function of flexor carpi ulnaris?
Flexion and adducts the wrist joint
What is the function of pronator teres?
Pronation of the forearm
What is the function of palmaris longus?
No specific function
Evolutionary importance in resisting shearing forces with gripping gripping
Is residual
If present contributes to palmar aponeurosis.
What muscle is in the intermediate compartment of the anterior forearm?
Flexor digitorum superficials
What is the origin and insertion of the flexor digitorum superficialis?
Origin: Medical epidcondyle of humerus and well as ulnar and radius
Insertion: middle phalanx of each digit (not thumb)
What are the muscles found in the deep compartment of the anterior forearm?
Flexor digitorum profundus
Flexor pollicis longus
Pronator Quadratus
What is the relationship between the insertion of the flexor digitorum superficialis and flexor digitorum profundus?
Superficialis - inserts onto middle phalanx
Profundus - inserts onto distal phalanx
Hence the superficialis tendon splits into two (on the the medial and lateral side of each phalanx) to allow the profundis to pass through
What innervates the posterior forearm?
The radial nerve
What innervates the anterior forearm?
Mainly the median nerve
Some contribution from the ulnar (the flexor carpi ulnaris and 1/2 the flexor digitorum profundis)
What is the relevant anatomy of carpal tunnel syndrome?
Cut in transverse section the carpal bones make a U boat like shape
The flexor retinaculum forms a roof over this boat shape
The space contains the tendons from all the flexor muscles of the anterior forearm
And the median nerve
What is the clinical importance of carpal tunnel syndrome?
Inflammation from repetitive strain injury in the wrist
Narrows the space deep to the flexor retinaculum - puts pressure on the medial nerve within the space
Loss of median nerve function to the hand
What is the presentation of carpal tunnel syndrome?
Pain or parasthesia (numbness and tingling) , or weakness in the median nerve territory.
Involves the first 3.5 digits.
Is progressive
What is the common origin of the superficial muscles in the extensor/posterior compartment of the forearm?
The lateral epicondyle and the supraepicondylar ridge.
What is the main function of the posterior forearm muscles?
Extensors of the fingers and thumb
Movement of the wrist joint
Supination
What muscle is the anomally of the posterior compartment of the forearm?
The brachioradialis muscle
Is a flexor not an extensor
Is located at the junction between the anterior and posterior compartment
But is innervates by the radial nerve.
What are the two different layers of the muscles in the posterior compartment of the forearm?
The superficial
The deep
Some people may consider the outcropping muscles a third category (from the deep muscles)
What are the seven muscles in the superificial layer of the posterior compartment of the forearm?
The brachioradialis
The extensor carpi radialis longus
The extensor carpi radialis brevis
Extensor digitorum
Extensor digiti minimi.
Extensor carpi ulnaris
Anoconeus
What is the anatomy relating to the tendons from the posterior compartment of the forearm?
Pass under the extensor retinaculum
Also insert into the extensor hood**
What is the common insertion of the deep layer of muscles in the posterior forarm?
Posterior radius / ulnar and the
Interosseous membrane.
What are the muscles in the deep compartment of the posterior forearm?
Supinator
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Extensor indices
What is the innervation to the extensor compartment of the forearm?**
The radial nerve
Branches into the muscular branch (for extensors of the arm and forearm)
Branches into the cutaneous branch for portion of the arm, forearm and
dorsum hand.
What are the alternative names for radial nerve palsy?
Crutch palsy
Saturday Night Syndrome
Due to causes: pressure in axilla from crutch or drunk sleep position with arm over chair
What are the potential causes of radial nerve palsy?
Impinge within axilla e.g poorly fitted crutches
Broken humerus
How does radial nerve palsy present?
Motor loss: unable to extend the wrist so presents with wrist drop
Sensory loss: most noticeable on the dorsum of the hand.
Describe the innervation of the superficial anterior compartment of the forearm.
All muscles are innervated by the median nerve
Except the flexor carpi ulnaris which is innervated by the ulnar nerve.
What is the function of the flexor digitorum superficialis?
Flexes proximal interphalangeal joint of the index, middle, ring and little finger
What innervates the intermediaite anterior compartment of the forearm?
The median nerve C8, T1
Describe the innervation of the deep anterior compartment of the forearm?
Mainly the median nerve (C7,8)
However, half the flexor digitorum profundus by the ulnar nerve.
What is the action of the flexor digitorum profundus?
Flexes distal interphalangeal joints of index, middle ring and little finger
Also flex the metacorpophalangeal joints of the same fingers and wrist joint
What is the function of the flexor pollic longus?
Flexes interphalangeal joint of the thumb.
Can also flex the metacarpophalangeal joint of the thumb.
What is the function of the pronator quadratus?
Pronation
What is the function of the brachioradialis muscle?
Accessory flexor of the elbow joint when forearm is midpronated (e.g when drinking wine)
What is the function of the extensor carpi radialis longus?
Extends and abducts the wrist
What is the function of extensor carpi radialis brevis?
Extends and abducts the wrist
What is the function of the extensor digitorum muscle?
Extends the index, middle, ring and little fingers.
Can also extend the wrist
What is the function of extensor digiti minimi?
Extends the little finger.
What is the function of extensor carpi ulnaris?
Extends and adducts the wrist
What is the function of the anconeus muscle?
Abduction of the ulna in pronation**
Accessory extensor of the elbow joint.
What three muscles in the deep posterior compartment of the forearm are considered to by the outcropping muscles?
The abductor pollis longus
The Extensor pollis brevis
The Extensor pollis longus
What is the importance of the radial tuberosity? (osteology)
Site of attachment for the biceps brachii muscle, due to rotation of the radius in supination/pronation the location of this insertion site changes, therefore the biceps can only help with flexion in supination.
What is the main joint involved in flexion and extension of the elbow?
The joint between the ulnar and the humerus
What are the key bony features of the proximal radius?
Head - thick and flattend disk shape in horizontal plane, concave for articulation with the humeus although tend to only articulate fully in flexion, also medially is broadedne for articulation with the radial notch on ulna
Neck
Radial tuberosity - biceps brachii attachment.
What are the key bony features at the proximal end of the ulnar?
The olecranon (prevent over extension)
The coronoid process (prevent over flexion)
The trochlear notch (attachment to humerus)
The radial notch (attachment to radius)
Tuberosity of ulnar
What are the bony features of the distal radius?
Radial styloid process - for attachment of the radial collateral ligament of the wrist
Facet for articulation with the scaphoid and another for the lunate bone
What are the bony features of the distal ulnar bone?
Ulnar styloid process - for attachment to ulnar collateral ligament of the wrist
What bony features are important in the shaft of the ulnar and radius?
Radius - pointy medial border called the interosseous border
Ulnar - point lateral border called the interosseus border
These two borders are connected by the interosseus membrane.
Why is the difference in size between the radial and ulnar styloid process important?
Radial styloid process is larger - more of a bony barrier to movement
Explains why able to adduct hand (ulnar deviation) more than abduction (radial deviation)
Label the feature of the distal ulnar.
Ulnar styloid process
Label the features of the proximal ulnar
Trochlear notch
Coronoid process
Radial notch
Interosseous border
Tuberosity of ulnar
Olecranon
label the features of the distal radius
Radial styloid process
label the features of the proximal radius
Head
Neck
Interosseous border
Radial tuberosity
What is the major content of the cubital fossa?
From lateral to medial
- tendon of biceps brachii muscle
- brachial artery
- median nerve
What forms the borders of the cubital fossa?
The brachioradialis muscle laterally
The pronator teres medially
The biceps brachii inserts down into the fossa so forms the floor.
Label the key structures in the image.
Radial nerve
Radial artery
Median nerve
Ulnar artery
Ulnar nerve
Identify the terminal branches of the brachial plexus
Musculocuntaneous nerve
Axillary nerve
Median nerve
Radial nerve
Ulnar nerve
Name the muscle
Flexor digitorum profundis
Name the muscle
Flexor pollicis longus
Name the muscle
Pronator Quadratus
Name the muscle
Supinator
Name the muscle
Anoconeus
Name the muscle
Abductor pollicis longus
Name the muscle
Extensor pollicis longus
Name the muscle
Extensor indices
Name the muscle
Pronator Teres
Name the muscle
Flexor carpi radialis
Name the muscle
Palmaris longus
Name the muscle
Extensor carpi radialis longus
Name the muscle
Extensor carpi radialis brevis
Name the muscle
Flexor carpi ulnaris
Name the muscle
Brachioradialis
Name the muscle
Flexor digitorum superficialis
Name the muscle
Extensor carpi radialis longus
Name the muscle
Extensor carpi radialis brevis
Name the muscle
Extensor digitorum
Name the muscle
Extensor digit minimi
Name the muscle
Extensor carpi ulnaris
Name the muscle
Flexor carpi ulnaris
Name the muscle
Extensor pollicis brevis
