MSK anatomy Flashcards
Which nerve runs in the groove of the medial epicondyle of the humorous?
The ulnar nerve
What is the action of the pronator teres?
Pronation of the forearm
The flexor digitorum superficialis is the muscle of the intermediate compartment of the forearm. What makes it a good anatomical landmark?
The median nerve and the ulnar artery pass between its two heads and travel posteriorly
Which muscle group controls the crude movements of the hand e.g. a forceful grip?
The exterior muscles which are located in the anterior and posterior compartments of the forearm
Where is the biceps brachii inserted?
Radial tuberosity
Which action is the best way to think about the biceps brachii?
Opening a bottle of wine. Supernates the forearm to turn the corkscrew and then flexes the elbow to pull the cork
Which bone of the forearm does the brachialis lift up?
The ulnar
Which is the lateral bone of the forearm?
The radius
What are the 2 muscles which attach to the upper projections of the ulnar?
Triceps attaches to the oleceranon Brachialis attaches to the coronoid process
In the anatomical position, is the forearm fully supinated or pronated?
Supinated
Muscles of the forearm: Where is the common attachment of the flexor muscles?
The medial epicondyle of the humerus
Muscles of the forearm: What action do the extensor group initiate?
Supinator
Muscles of the forearm: Where is the common attachment of the extensor muscles?
The lateral epicondyle of the humerus
Briefly describe the carpal bones
They are a set of 8 irregular bones in the wrist area
Briefly describe the metacarpals
There are 5 metacarpals, each related to one digit
Briefly describe the phalanges
Bone of the fingers (most distal) Each finger has 3 but the thumb has 2
Which muscles are responsible for flexion of the wrist?
Flexor carpi radius and ulnaris aided by the long digital flexors
Which muscles are responsible for extension of the wrist?
Extensor carpi ulnaris, radialis longus and brevis assisted by the long digital extensors
Why are dislocations of the wrist uncommon?
It’s supported by capsular ligaments and crossed by many long tendons
Give the innervation to the motor compartments (flexor and extensor) of the arm, forearm and the hand
Which of the following is not part of the thenar muscles of the hand?
a) Abductor pollicis brevis
b) Adductor pollicis brevis
c) Flexor pollicis brevis
d) Opponens pollicis
The adductor pollicis - the ulnar nerve
The thenar muscles:
Abductor pollicis, flexor pollicis bravis and opponens pollicis = Median nerve
(Pollicis think thumb)
Name the 3 hypothenar muscles and give the nerve supply.
Hypothenar muscles:
Abductor digiti minimi, the flexor digiti minimi, the opponens digiti minimi.
These are almot the mirror images of the thenar muscles and are attached to the little finger.
What actions are the 4 lumbrical muscles responsible for?
Give their innervation.
The muscles are used to simultaneously flex the metacarpophalangeal and extend the interphalangeal joints as in making an upward stroke while writing
Where does the flexor digitorum superficialis attach on the phalanx?
The superficialis tendon splits to be attached to each side of the middle phalanx.
(The flexor tendons are held on to the front of the finger by the fibrous flexor sheath)
The profundus tendon passes between the gap in the superficialis tendon to insert onto the terminal phalanx.
Where are the interossei muscles found?
Between the metacarpal bones
- 2 groups = dorsal & palmer interossei
Give the mucle groups responsible for:
a) Adduction of the fingers
b) Abduction of the fingers
Adduction = Palmer interossei (PAD) Moving fingers towards the middle
Abduction = Dorsal interossei (DAD)
All supplied by deep branches of the Ulnar nerve
What would a slash to the wrist likely cut from medial to lateral?
The ulnar nerve
The ulnar artery
The palmaris longus tendon
The median nerve
Tendon of flexor carpi radialis
Radial artery
Give the nerves for the innervation of the hand that are related to the colours shown
Blue = Ulnar nerve (lateral 1 and a half fingers)
Green = Radial nerve (Dorsal tumb and proximal 2 and a half fingers)
Pink = Median Nerve (Palmer skin and dorsal nail beds of the lateral 3 and a half fingers)
What are these muscles collectivly known as?
Extensor carpi radialis longus.
Extensor carpi radialis brevis, the extensor digitorum, the extensor carpi ulnaris and the extensory digiti minimi
The superficial extensor muscles (posterior muscles)
Where are the extensors of the carpus inserted?
The extensors of the carpus are inserted onto the metacarpal bones
Where are the radial (lateral) extensors inserted?
The radial (lateral) extensors are inserted to the base of the 2nd and 3rd metacarpal bones
Where is the ulnar extensor inserted?
The ulnar extensor is inserted into the 5th metacarpal bone
a) Give the nerve which supplies all the posterior muscles of the forarm except one.
b) Give the name of this muscle and the nerve which supplies it.
a) Posterior interosseus branch of the radial nerve supplies all of the extensor muscles except…
b) The extensor carpis radialis longus which is supplied by the radial nerve below the elbow like the brachioradialis
What happens as a result of paralysis of the radial nerve above the elbow?
Paralysis to the radial nerve above the elbow will paralyse all the extensors of the wrist.
The flexors will pull the wrist into a flexed position called ‘wrist drop’
Give the following borders for the anatomical snuffbox
a) Ulnar (medial) border
b) Radial (lateral) border
c) Proximal border
Ulnar (medial) border: Tendon of the extensor pollicis longus.
Radial (lateral) border: Tendons of the abductor pollicis longus and extensor pollicis brevis.
Proximal border: Styloid process of the radius.
Floor: Carpal bones; scaphoid and trapezium.
Roof: Skin.
How does ‘avascular necrosis’ (death of tissue due to no blood vessel) occur in scaphoid fractures?
Scaphoid bone forms in 2 parts, each with their own artery.
They fuse and the artery to the proximal part disapears.
After a fracture the proximal end of the bone may be disconnected to the blood supply at the distal end.
Note: If fractured there will be tenderness in the outstretched hand
Describe the attachments of the extensor digitorum in the hand
Attached to base of proximal phalanx
Divides into a central and 2 marginal slips
Central into the base of middle phalanx
Marginal slips unite and insert into the base of the distal phalanx
Which 2 groups of muscles are inserted into the proximal part of the extensor expansion?
The interossei and the lumbricals
At the superior and inferior radio-ulnar joints, which bone rotates inwards to produce pronation?
a) Radial
b) Ulnar
Radial
(Radial rotates)
Which of the following leads to a weak suprination?
a) Flexed elbow by the biceps
b) Extended elbow and produced by the suprinator muscle
Suprination is week when the elbow is extended and by the suprination
Biceps = powerful suprinator
Radius is rotated outwards
Where are the medial and lateral epidondyles of the humerus?
Processes on the distal end of the humerus
What articulates with the following parts of the humerus:
a) The capitulum
b) The trochlea
a) The capitulum = The radius (more lateral)
b) The trochlea = The ulnar
Identify the following parts of the radius
Which of the following are the green and red areas showing?
a) Olecranon
b) Coronoid process
c) Trochlear notch
d) Radial notch
Give the 2 seperate articulations that the elbow joint consists of.
- *Trochlear** notch of the ulna and the trochlea of the humerus
- *Head** of the radius and the capitulum of the humerus
The wrist is an ellipsoid type synovial joint, allowing for movement along two axes.
Give the muscles responsible for flexion, externsion, adduction and abduction of the wrist
Flexion – Produced mainly by the flexor carpi ulnaris, flexor carpi radialis, with assistance from the flexor digitorum superficialis.
Extension – Produced mainly by the extensor carpi radialis longus and brevis, and extensor carpi ulnaris, with assistance from the extensor digitorum.
Adduction – Produced by the extensor carpi ulnaris and flexor carpi ulnaris
Abduction – Produced by the abductor pollicis longus, flexor carpi radialis, extensor carpi radialis longus and brevis.
Which 2 muscles of the leg attach to the greater trochanter of the femur?
a) Adductor
b) Abductor
c) Medial rotator
d) Lateral rotator
Abductor and lateral rotator muscles of the leg attach to the greater trochanter
Decribe the condyles and the epicondyles of the femur
Condyles = rounded areas at the distal end of the femur. Posterior -> Tibia and menisci of the knee. Anterior -> Patella
Epicondyles = The bony elevation of the non articular areas of the condyles
