Upper Limb MSK Flashcards
Name the 5 superficial back muscles.
- Trapezius
- Latissimus dorsi
- Leavator scapuli superioris
- Rhomboid minor
- Rhomboid major
What is the innervation of trapezius?
Cn 11 - accessory
What is the action of trapezius?
Elevates the scapula and rotates it during abduction of the arm.
Which rhomboid muscle lies most superiorly?
Rhomboid minor lies superior to major.
Name the 4 rotator cuff muscles
- Supraspinatus
- Infraspinatus
- Subscapularis
- Teres minor
What is the function of the rotator cuff muscles?
To give the shoulder joint additional stability.
Where do the rotator cuff muscles originate from and insert?
Origin: scapula, insertion: humeral head.
What is the function of deltoid?
To abduct, flex and extend the arm.
What are the 3 heads of the triceps?
- Long head (most medial).
- Lateral head.
- Medial head.
What is the innervation of triceps?
The radial nerve.
What is the action of teres minor?
External rotation.
What is the action of subscapularis?
Internal rotation.
What is the innervation of the deltoid muscle?
Axillary nerve.
What is the function of latissiums dorsi?
Adduction!
What is the action of triceps?
Extension of the forearm.
What is the axilla?
An area underneath the shoulder joint at the junction between the upper limb and thorax.
Name 5 things contained wihin the axilla.
- Fat.
- Lymph nodes.
- Axillary artery.
- Axillary vein.
- Brachial plexus.
What spinal nerve roots form the brachial plexus?
C5 - T1.
What are divisions of the brachial plexus?
Roots -> Trunk -> Divisions (anterior and posterior) -> Cords -> Branches.
What are the 5 main branches of the brachial plexus?
- Musculocutaneous.
- Axillary.
- Median.
- Radial.
- Ulnar.
What are the nerve roots for the musculocutaneous branch?
C5, 6, 7.
What muscle does the musculocutaneous nerve enter?
Coracobrachialis.
What are the nerve roots for the axillary branch?
C5, 6.
What are the nerve roots for the median branch?
C6, 7, 8, T1.
What are the nerve roots for the radial branch?
C5, 6, 7, 8, T1.
What are the nerve roots for the ulnar branch?
C8, T1.
What are the names of the 3 trunks of the brachial plexus?
- Superior trunk.
- Middle trunk.
- Inferior trunk.
What nerve roots contribute to the superior trunk?
C5, C6.
What nerve roots contribute to the middle trunk?
C7.
What nerve roots contribute to the inferior trunk?
C8, T1.
What are the names of the 3 cords of the brachial plexus?
- Lateral cord.
- Posterior cord.
- Medial cord.
What does the musculocutaneous nerve give motor innervation to?
Anterior flexors - brachialis, biceps brachii and coracobrachialis - BBC.
What does the musculocutaneous nerve give sensory innervation to?
Lateral forearm.
What does the axillary nerve give motor innervation to?
Abductors of the arm at the shoulder - teres minor, long head of triceps and deltoid.
What does the axillary nerve give sensory innervation to?
Innervates the skin over the lower deltoid.
What would be the effect of damage to the axillary nerve?
Unable to abduct the arm 15-90 degrees. Loss of sensation over the lower deltoid region.
What does the median nerve give sensory innervation to?
Lateral palm of the hand and the lateral 3.5 fingers.
What does the median nerve give motor innervation to?
Flexors in the anterior forearm, the thenar muscles and the lateral two lumbricals in the hand.
What does the radial nerve give motor innervation to?
Triceps brachii, responsible for extension at the elbow. It also innervates extensor muscles in the posterior compartment of the forearm.
What does the radial nerve give sensory innervation to?
Skin on the posterior side of the forearm and the posterior aspect of the hand.
What does the ulnar nerve give sensory innervation to?
Medial 1.5 fingers and the medial palm.
What does the ulnar nerve give motor innervation to?
Muscles of the hand, flexor carpi ulnaris (flexes and adducts the hand at the wrist) and medial half of the flexor digitorum profundus (flexes the fingers).
What is the cubital fossa?
An area of transition between the arm and forearm
What is the action of brachialis?
Flexion of the elbow joint.
Biceps brachii: what is the origin of the short head?
Coracoid process of the scapula
What is the action of biceps?
Flexion of the elbow joint and supination of the forearm.
Name 3 nerves closely related to the humerus.
- Radius.
- Ulnar.
- Axillary.
What is the main muscle to abduct the shoulder 0-15 degrees?
Supraspinatus.
What is the main muscle to abduct the shoulder 15-90 degrees?
Deltoid.
What are the main muscle(s) that abduct the shoulder greater than 90 degrees?
Trapezius and serratus anterior.
Name 4 superficial muscles in the anterior compartment of the forearm?
- Pronator teres.
- Flexor carpi radialis.
- Palmaris longus.
- Flexor carpi ulnaris.
What nerve innervates flexor carpi ulnaris?
Ulnar nerve (C8-T1).
What is the action of flexor carpi ulnaris?
Flexion and adduction at the wrist.
What nerve innervates palmaris longus?
Median nerve (C6-T1)
What is the action of palmaris longus?
Flexion at the wrist.
What nerve innervates flexor carpi radialis?
Median nerve (C6-T1)
What is the action of flexor carpi radialis?
Flexion and abduction at the wrist.
What nerve innervates pronator teres?
Median nerve (C6-T1).
What artery is the brachial artery a continuation of?
The axillary artery.
What arteries does the brachial artery branch into?
The radial and ulnar arteries.
Name 3 deep muscles in the anterior compartment of the forearm.
- Flexor digitorum profundus.
- Flexor pollicis longus.
- Pronator quadratus.
What is the action of flexor digitorum profundus?
It flexes the interphalangeal joints and the metacarphophalangeal joints.
What is the action of flexor pollicis longus?
It flexes the interphalangeal joints and the metacarphophalangeal joints of the thumb.
What is the action of pronator quadratus?
It pronates the forearm.
What are the 3 main groups of bones in the hand?
- Carpal bones.
- Metacarpals.
- Phalanges.
How many phalanges does each finger have?
3.
How many phalanges does the thumb have?
2.
How many carpel bones are there? What are they?
8.
Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, trapezoid, Capiate, Hamate
(Some Lovers Try Positions That They Can’t Handle)
Why is the skin of the palm adherent to the underlying connective tissue?
To prevent the skin from slipping off the hand whilst gripping.
What is the carpal tunnel?
A space between the flexor retinaculum and the carpal bones.
What structures pass through the carpal tunnel?
Flexor tendons - Flexor Digitorum and Superficialis, Flexor Pollicus Longus and Median nerve
What is the cause of carpal tunnel syndrome?
Swelling of the tendons increases the pressure in the tunnel and compresses on the median nerve.
What arteries form the superficial palmar arch?
The ulnar artery and a small contribution from the radial artery.
What intrinsic hand muscles are innervated by the median nerve?
The 3 thenar muscles and the lateral 2 lumbricles.
Where are the thenar muscles located?
At the base of the thumb.
What is the action of the thenar muscles?
Fine movements of the thumb.
Name the 3 thenar muscles.
- Abductors pollicis brevis.
- Flexor pollicis brevis.
- Opponens pollicis.
Where do the abductors pollicis brevis and flexor pollicis brevis insert?
The lateral aspect of the 1st phalanx of the thumb.
What is the action of opponens pollicis?
It opposes the thumb by medially rotating and flexing the metacarpal
Where are the hypothenar muscles attached?
The little finger. They are mirror images of the thenar muscles.
What nerve innervates the hypothenar muscles?
The deep branch of the ulnar nerve.
Name the 3 hypothenar muscles.
- Abductor digiti minimi.
- Flexor digiti minimi.
- Opponens digiti minimi.
How many lumbrical muscles are there in each hand?
4 - each associated with a finger.
What is the innervation to the lumbrical muscles.
- The medial 2 = deep branch of ulnar nerve.
- The lateral 2 = median nerve.
What is the origin of the lumbricals?
The flexor digitorum profundus tendon.
What is the action of the lumbricals?
Flexion of the metacarphophalangeal joint and extension of the interphalangeal joints.
What covers the flexor tendons?
A fibrous flexor sheet that fans out into synovial sheaths.
What is the importance of the synovial sheath that covers the flexor tendons?
It reduces friction in flexion and extension.
What is the innervation to the interossei muscles?
The deep branch of the ulnar nerve.
What is the action of the dorsal interossei muscles?
They abduct the fingers at the MCP Joint, Innervated by the Ulnar Nerve ON THE BACK OF THE HAND
PAD, DAB
What is the action of the Palmar interossei muscles?
they adduct the fingers at the MCP joint, also innervated by the ulnar nerve THEY pull their respective finger towards the middle finger (medially) ON THE PALM,
PAD, DAB
Which muscles in the forearm are supplied by the ulnar nerve?
- Flexor carpi ulnaris.
- Medial flexor digitorum profundus.
Define pronation.
Turning the hand so the palm is facing down.
Define supination.
Turning the hand so the palm is facing up.
Which muscles are responsible for pronation?
Pronator teres and pronator quadratus.
What nerve innervates the muscles of the posterior compartment of the forearm?
The radial nerve.
What are muscles of the posterior compartment of the forearm commonly known as?
Extensors - their general function is to produce extension at the wrist and fingers.
What is the action of brachioradialis?
Flexion at the elbow.
Where do the tendons of extensor carpi radialis longus and brevis insert?
The metacarpal bones 2 and 3.
What is the action of extensor digitorum?
Extension of the medial four fingers at the MCP and IP joints.
What is the action of extensor digiti minimi?
Extension of the little finger.
What is the action of extensor carpi ulnaris?
Extension and adduction of the wrist.
What tendons forms the lateral wall of the anatomical snuffbox?
- Extensor pollicis brevis.
2. Abductor pollicis longus.
What tendon forms the medial wall of the anatomical snuffbox?
Extensor pollicis longus.
What bone forms the floor of the anatomical snuffbox?
Scaphoid.
What artery, nerve and vein lie in the anatomical snuffbox?
- Radial artery.
- Branch of the radial nerve.
- Cephalic vein.
What are the movements of the elbow joint?
- Extension of triceps brachii.
2. Flexion of brachialis, biceps brachii and brachioradialis.
What is the dermatome of the thumb?
C6.
What is the dermatome of the middle and index fingers?
C7.
What is the dermatome of the ring and little fingers?
C8.
What does the head of the radius articulate with?
The capitulum of the humerus.
Contraction of the triceps will result in what action at the elbow?
Extension.
What nerve are muscles of the anterior forearm innervated by? What are the two exceptions?
All but two are innervated by the Median Nerve, except the Flexor Digitorum Profundus and the Flexor Carpi ulnaris (they are both innervated by the ulnar nerve)
Where do pretty much all of the anterior flexor muscles of the forearm originate?
MEDIAL epicondyle of the Humerus (AM)
Where do pretty much all of the posterior extensor muscles of the forearm originate?
LATERAL epicondyle of the Humerus (PEL)
What artery mainly provides the Deep perfusion of the palm of the hand?
The radial artery
What structures does the cubital fossa contain?
Mnemonic for contents of the cubital fossa – Really Need (radial nerve) Beer To (biceps tendon) Be At (brachial artery) My Nicest (median nerve).
Briefly describe venous drainage up the arm
Starts with - Cephalic vein on the Thumb /Lateral side and Basilic vein on the Medial/Pinkie side, ==> Join to from the Axillary Vein at the Antecubital Fossa, ==> Subclavian vein ==> Internal Jugular vein ==> SVC
What passes through the quadrangular space? (the space between the Humerus head and Long head of the triceps, and Teres Major and Minor)
The Axillary nerve and the circumflex humeral artery and vein.
