Cubital fossa and anterior forearm Flashcards
What 4 muscles make up the superficial layer of flexors of the forearm
pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris
Where does pronator teres have its attachments
On the medial epicondyle of the humerus, and on the mid shaft of the radius
Describe the fibres of the pronator teres
They extend laterally and inferiorly
Why is the pronator teres called this
Pronator - its role in pronation
Teres - cylindrical in cross section
Where is flexor carpi radialis situated in relation to pronator teres
medial side of pronator teres
Where are flexor carpi radialis attachments
Medial epicondyle of humerus then extends down to the radial side of the forearm
Where is flexor carpi radialis attachment, once it has passed the wrist
to the base of the second and third metacrapal
Where is palmaris longus in relation to flexor carpi radialis
on the medial side
What is the attachment of palmaris longus
onto the medial epicondyle and then extends distally down the middle of the forearm to cross the wrist joint and attaches to the palmer aponeurosis
Where is the tendon of the palmaris longus in relation to the others
more superfiical
What is the palmer aponeurosis
a small muscle that helps flex the wrist. Useful for reconstructive surgeries
Where are the attachments of the flexor carpi ulanris
on the medial epicondyle, the fibres come down the ulnar side of the forearm and crosses the wrist joint. It attaches onto the pisiform bone
From its attachment on the pisiform bone what happens to the flexor carpi ulmaris
it is transmitted to the hamate bone and to the base of the fith metacarpal by the piso-amate ligament and the piso-metacarpal ligament
What does the flexor carpi ulnaris do
produces the flexion movement of the wrist
What is the muscle of the intermediate layer
flexor digitorum superficialis
Where is the flexor digitorum attached
at the medial epicondyle of the humerus
What happens to the flexor digitorum superficialis in the mid forearm
divides into 4 segments that go into each finger
What does the flexor digitorum superficialis do
flexes the wrist and small joints of the fingers
Where do the tendons of the flexor digitorum superficialis attach on the fingers
attach on the middle phalanges of each finger
What muscle does the flexor digitorum superficialis lie on top of
the flexor digitorum profundus
What are the 2 heads of the flexor digitorum superficialis
a radial head (arises from long oblique line on radius) and a humero-ulnar head (arises as part of the common flexor tendon from medial epicondyle and adjoining ulna)
What passes through the gap between the 2 heads of the flexor digitorum superficialis
ulnar artery and median nerve
What are the 3 deep flexors of the forearm
flexor pollicis longus, flexor digitorum profundus and pronator quadratus
What is the interosseous membrane
Membrane between radius and ulna
What does the interosseous membrane do
It provides support for the bones (in terms of their movements) and is a site of attachment for some of the deep muscles.
Where is the pronator quadratus attached
distal (anterior surface) radius, it then goes across and attaches to the anteromedial surface of the ulna
Why is the pronator quadratus called that
it is quadrangular in shape and pronates
What covers the pronator quadratus
flexor pollicis longus and the flexor digitorum profundus
Where are the attachments of the flexor pollicis longus
longus attaches onto the radius and the interosseous membrane and has a tendon which goes up to the distal phalanx of the thumb
What does the flexor pollicis longus do
has a little bit of movement of the wrist and small joints of the thumb
Where are the flexor digitorum profundus attachments
more on the ulnar side and has its attachment on the anterior and medial surface of the ulnar and interosseous membrane
Where on the fingers does the flexor digitorum profundus attach
the distal phalanges of the 4 fingers
What is the innervation of the flexor digitorum profundus
. Innervated by the median nerve (the side that provides tendons to the index and middle finger) and ulnar nerve (more of the ulnar side – side that provides tendons to the ring finger and little finger).
What is the common flexor tendon
the common point of origin for 4 muscles that start on the medial epicondyle of the humerus
What does the ulnar nerve pass through
the 2 heads of the flexor carpi ulnaris until it enters the forearm
What is the head of the flexor carpi ulnaris
an extensive ulnar head
What does the flexor carpi radialis pass through when it crosses the wrist
a deep ligamentous tunnel
What lies between the flexor carpi radialis and the flexor carpi ulnaris
palmaris longus
What happens when the flexor carpi radialis and flexor carpi ulnaris act together
they flex the wrist
What happens when the flexor carpi radialis and flexor carpi ulnaris act separately
contribute to ulnar abduction and radial abduction
What are the 3 wrist extensors
extensor carpi radialis longus, extensor carpi radialis brevis and extensor carpi ulnaris
Where does extensor carpi radialis longus arise from
lateral epicondyle ridge, just below brachialis
Where does extensor radialis bravis arise
lateral epicondyle
Where does extensor carpi ulnaris arise from
the lateral epicondyle and has an ulnar head
What do the extensors pass under as they cross the back of the wrist
extensor retinaculum which acts as a pulley
Where do extensor carpi radialis longus and brevis insert on to
the second and third metacarpals
Where does extensor ulnaris insert
on to the base of the 5th metacarpal
What happens when all extensors act together
they extend the wrist
Why is extension of the wrist important
important to grip because when the wrist is flexed the gripping muscles are slack and feeble.
What happens when the radial or ulnar extensor contract separately
they help produce radial or ulnar abduction of the wrist, they do this alongside the corresponding flexor
Where else does the pronator teres have a head of origin
on the ulnar
What passes between the 2 heads of pronator teres before it enters the forearm
the median nerve
Where does the supinator arise from
the lateral epicondyle, anular ligament and from the supinator crest on the ulnar
Where does the supinator insert
on the radius, above insertion of pronator teres
Which nerve runs through the supinator
the deep branch of the radial nerve
What are the 2 supinator muscles
the supinator and the biceps brachii
How do the biceps have the power to supinate
due to its insertion on the radial tuberosity gives it the power to rotate the radius - especially when elbow is flexed
When the biceps are acting as a supinator how is the flexing action held in check
by the action of the tricpes
which is a more powerful action - pronation or supination?
supination
As the flexor digitorum superficialis/profundus pass through the carpal tunnel what are they enfolded in
a common synovial sheath which extends into palm of hand
What are the 4 tendons the flexor digitorum profundus/superficialis divide into called
the lumbricals
What do the flexor digitorum profundus/superficialis enter before reaching the MP point
the flexor tendon sheath
When does the flexor digitorum superficialis tendon split into 2 and what do the branches pass round
over the proximal phalanx. They pass round the profundus tendon
When do the 2 halves of the flexor digitorum profundus reunite and insert
on the middle phalanx
Where does the profundus tendon emerge
between the 2 halves of superficialis and continues distally to insert on the base of the distal phalanx
What is the action of the flexor digitorum superficialis
to flex the proximal IP joint and MP joint
What is the action of the flexor digitorum profundus
to flex both IP joints and MP joints
What is the cubital fossa
Area of transition between the anatomical arm and the forearm - depression on anterior surface of elbow joint
Is the cephalic vein lateral or medial
lateral
is the basilic vein lateral or medial
medial
What is the relationship of the median cubital vein with the basilic and cephalic vein
initially runs along with basilic vein then runs along side the boundary of the cubital fossa to join the cephalic vein
What is the superior, medial, lateral and inferior border of the cubital fossa
superior - fascia
lateral - brachioradialis
medial - pronator teres
inferior - muscle
Where is the ulnar nerve compressed and pinched
pinched against medial epicondyle and compressed by the 2 heads of the flexor carpi ulnaris
What does the median nerve or branch of innervate
pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum superficialis, flexor digitorum profundus (lateral part), pollicis longus, pronator quadratus
What does the ulnar nerve innervate
flexor carpi ulnaris and flexor digitorum profundus (medial part)
