hello anatomy colleagues this is dr alsup and welcome to station number 13 and we
are at the distal most portion uh regarding the muscles of the upper limb and so we are focusing
on those intrinsic muscles of the hand and again there are certainly more muscles than what we are
going to be discussing here are identifying but we just want to get some of the big picture ideas so
we are looking at a palmer view or an anterior view of the hand this is going to be lateral this
will be medial because that first digit is always lateral with the fifth digit always medial when
in anatomical position so the thenar compartment of the hand or the thenar muscles are going to be
these intrinsic muscles that both have their proximal and distal attachments within the hand
these are going to be the phenom muscles associated with the first digit
and so these muscles there's three separate muscles in this region they will flex abduct a b
duct the first digit as well as play a role in terms of opposition and you will have
a similar set uh associated with the fifth digit and these are the hypothenar muscles of the hand
again there are three and they will also flex abduct and oppose in terms of the fifth digit
now looking at a deeper dissection so you can see some of those hypothenar muscles right here
we're getting down into the deeper muscles of the thenar compartment here
right here you can see where the carpal tunnel has been opened in this region so you can see
some of those tendons specifically these are the tendons of flexor digitorum profundus
and you can see these kind of worm-like muscles that are going to have their proximal attachment
on the tendons of flexor digitorum profundus so unique in terms of where
their proximal attachments are you can see there are going to be four of these
it's a weird looking two sorry three and four so these are going to be the lumbrical muscles
and then in order to see the interossei muscles or the palmer interosseus muscles you have to reflect
these out of the way and truly get to the bone in order to see these as the name would suggest so
it's kind of between the bones and so and we're only going to look at the palmer interossei and
have you identify those because we don't have a very good image of the dorsal interossei but of
course we know there are dorsal interossei but you can see the three palmar interossei here
you're going to have them associated with the second fourth and fifth digits so there will be
one two three of these and recall that palmer interossei will play a role in a few actions
associated with the hand but also they will a deduct the digits so bring those digits back
towards the third digit which is kind of the plane by which abduction and adduction occurs
so if you are down to the bone and you see muscles and they're very similar in terms
of shape as the lumbricals but recall lumbricals are going to be associated with the tendons here
uh the flexor digitorum profundus whereas the interossei are going to be almost directly
on the bone and you would have to be at an extremely deep dissection to be able to see
these okay excellent so that should wrap us up in terms of stations focused on the upper limb
we are going to move now to the lower limb with our next station so i will meet you there
in the meantime if you have any specific questions regarding identifying the
structures here please feel free to reach out to me with any questions thanks for your time