Flashcards in Forearm & posterior hand-->sievert Deck (102)
T/F There are no muscles in your posterior hand.
So, if there are no muscles in your posterior hand, what are there?
tendons from muscles of the forearm
What are phalanges & where are they found?
basically, parts of a finger.
3 phalanges per finger
2 phalanges per thumb
What are the names associated with each phalange of the fingers?
What are metacarpals & how many of them are there?
there are 5
they are the bones that go in your hand up until the point of phalanges.
What are the joints of the fingers?
MP: metacarpal phalangeal joint
PIP: proximal interphalangeal joint
DIP: distal interphalangeal joint
Can the MP, PIP, & DIP joints be acted on separately? Explain.
**they can be flexed individually
**they are all extended at once b/c of the extensor hood arrangment
Which muscle extends the MP, PIP, & DIP joints all at once?
the extensor digitorum
What is the thing that can pull on the extensor hood & cause extension of the fingers?
long extensor tendon
What are the 2 continuations of the extensor hood onto the fingers?
Central band: connects to middle phalanx
Lateral bands: connects to distal phalanx
What are the 2 muscle types that act on the extensor hood? What is their action when they act together?
Together: extend interphalangeal joints
flex metacarpophalangeal joints
What does the flexor digitorum profundus flex?
What does the flexor digitorum superficialis flex?
T/F Without extensor tendons at your wrist, you couldn't make a tight fist.
What is the retinaculum? Where is it located?
Retinaculum is a tendon that keeps the tendons from moving around underneath.
It is is right before the wrist. It runs transversely.
On the posterior side of the hand: called extensor retinaculum.
What protects the tendons underneath the retinaculum from being torn up by the retinaculum moving against it?
it is protected by synovial tendon sheaths that surround it. there are a lot of these & they can become infected.
Most posterior forearm muscles come from where?
common extensor tendon
Where does the common extensor tendon attach?
the lateral epicondyle or the supracondylar ridge of the humerus
What are the exceptions to the rule, which muscles of the posterior forearm don't come from the common extensor tendon? What are some places where these come from?
3 thumb muscles
**radius, ulna, interosseus membrane
What position is your hand in when it is supinated?
it is in a position to hold a soup bowl!
All posterior forearm muscles are innervated by what nerve?
Radial nerve, mainly the deep branch.
What is the posterior forearm's rule of 3s?
there are 3 muscles that go to the thumb
there are 3 muscles that go to the fingers
there are 3 muscles that go to the wrist
there are 3 muscles that don't cross the wrist joint
What are the 3 posterior compartment forearm muscles that go to the thumb?
extensor pollicis longus
extensor pollicis brevis
abductor pollicis longus
What are the 3 posterior compartment forearm muscles that go to the fingers?
What are the 3 posterior compartment forearm muscles that go to the wrist?
extensor carpi radialis longus
extensor carpi radialis brevis
extensor carpi ulnaris
What are the 3 posterior compartment forearm muscles that don't cross the wrist joint?
T/F In the anatomical position, the thumb is in the same plane as the fingers.
FALSE. It is in a different plane. off by 90 degrees, why we are humans & not chimps or something.
What does abduction & adduction look like for fingers?
So...the midline in this case is the middle finger. Abduction is spreading the fingers out & adduction is smooshing the fingers closer together.
What does flexion & extension of the fingers look like?
Flexion: bending fingers @ creases, almost making a fist
Extension: straightening out your fingers.