hello anatomy colleagues this is dr alsup and in this mini video we will
be discussing the connective tissue and i often like to abbreviate this to
cet uh so the connective tissue associated with skeletal muscle
and connective tissue is actually quite intimately related to muscle at both a microscopic and a
gross level and we'll talk about kind of from that smaller scale to the larger scale and it
will actually eventually continue past the muscle belly to form tendons of various shapes and sizes
so let's get started at the smallest level with the endomysium sometimes you'll hear
endomysium or endomysium either way same thing and what this does is actually surround
each muscle cell or each muscle fiber so we're looking at one muscle cell here and
it is the connective tissue that's going to surround the cell so microscopic for sure
this layer is very thin and mostly made of reticular fibers and importantly and you can
kind of see this in this image it will have blood vessels associated and kind of traveling along the
endomysium which will be important for the supply of nutrients to these individual muscle cells
continuous when the with the endomysium but thicker and on a more gross scale is the
paramecium and a paramecium a repair machine will surround fascicles and fascicles are a new term
for us so what this means a fascicle is a group of muscle fibers and you may have noticed this
organization yourself if you've ever seen someone kind of pulling apart a piece of cooked meat
it pulls apart in chunks or in groups and these groups are the fascicles so these are collections
of muscle fibers kind of combined into one and the muscle cells within the fascicle are bound
by the paramecium so if we're looking here this is a muscle fiber so this would be the endomysium
and so this would be the paramecium if you get on this larger scale all right and then
continuous with the paramecium is the epimysium which will surround the entire muscle belly
uh so it's going to be it's going to be bound all or bind all of the fascicles together so the
epimysium you can kind of see it here but it would continue along the entirety of the uh muscle belly
um
hold on yes yeah that's right sorry so make a note here not only are the muscle bellies that you can
see made up of collections of muscle fibers but that connective tissue is going to be throughout
so on that smallest scale with the endomysium the paramecium surrounding fascicles and the
epimysium surrounding the entire muscle belly so that's a that's an important thing to consider
is that these are continuous and so if you think about tension occurring because
of contraction of a muscle cell that will kind of spread throughout because you have these uh
the connective tissue binding everything and kind of surrounding all of these areas
connective tissue will continue beyond the muscle belly as tendons and you can see that
here so continuous with the epimysium once we get past kind of the muscle belly region
now we call this a tendon and tendons are going to connect muscle belly to bone and it will
actually be continuous with the periosteum if you recall that periosteum is going to surround
a bone and it actually will extend and become intermingled with the collagen of the osseous
extracellular matrix so this is very important in terms of the function and functioning of the
musculoskeletal system and allowing movement so if you have tension in the muscle because of that
close connection to the periosteum and kind of within to the extracellular matrix if you have
tension in the muscle that will cause for the bone to move as well kind of pulling of the bone
now a few things about tendons this connective tissue is mostly highly organized collagen fibers
and so that's why tendons will have that very distinct whitish appearance
tendons are poorly vascularized so whereas you did have small vessels associated with some of the the
more microscopic scale connective tissue and you still have some associated with the tendons
it's just not as much so poorly vascularized and anytime anything is poorly vascularized
it's slower to heal and lastly there will be no muscle cells associated with tendons so it is past
the muscle belly and that's what characterizes a tendon tendons can have many different shapes
and size sizes some are very rope-like and clearly visible we'll see that with say the biceps brachii
with your gastrocnemius and soleus muscles on your calf those are going to be very distinct very
visible tendons but some tendons are so short and close to the bone you can't see them well at all
but rest assured they are there you're always going to have a tendon associated with the
skeletal muscle attaching to the bone even if it's not as visible there can also be flat
sheets of tendons and we call these aponeurosis or aponeurosis if you're talking about the pleural
and you can see one right here on the palm of the hand you can see it is much flatter but
it still has that very characteristic whitish appearance that a tendon does
and these uh will not only serve the normal functioning function of connecting
muscle to bone but it also can serve as additional protection to other muscles
and neurovasculature in the surrounding area so think there's got to be a lot of structures
that are deep to this aponeurosis so this is just another added protection to the the palmer region
lastly let's discuss fascia which i love fascia this is a this is going to be dense
irregular connective tissue and what it's going to do is it's going to group together
certain structures it could be groups of muscles it could be neurovasculature
in terms of msk a fashion where we're going to kind of focus our attention
in is fascists going to surround groups of muscles that typically have a similar action
innervation and vascular supply so you can see this fascist surrounding this group of muscle here
fascists surrounding this group of muscle and so these are going to kind of be these separate
muscle groups that we'll talk about when we get into the different types of muscles
and like i said what's really neat about these are that they often will have similar actions
similar innervation and similar arterial supply and that really helps in terms of
understanding what's going on in those areas so lots going on in terms of connective tissue
associated with skeletal muscle it is very vital to the function of the musculoskeletal system
all right review and assessment time everyone's favorite so the question uh for today is going
to be muscle tendons are closely associated with which structure of the skeletal system
is it a articular cartilage b endosteum c epiphyseal plate d-medullary cavity
or e-periosteum so you have to kind of remember these structures from when we were talking
about the skeletal system you kind of apply it with now the connective tissue associated with
the muscle so pause the video if needed and when ready i hope that you have landed on that e is the
correct answer the periosteum so remember that periosteum is surrounding the external surface
of a bone a muscle tendon will become continuous with the periosteum in specific places it will
even kind of go in towards the actual bone to intermingle with that so that would be correct
medullary cavity is way too internal as is the endosteum the epiphyseal plate you're not going
to have a muscle tendon attaching right there that's an important area in terms of
growth it's a it's a joint so it this would not be right and you will while articular cartilage is
going to be connective tissue that's going to be on the ends of bones and you typically do not have
tendons associated with that area that's serving a different function so periosteum is right on
that's a very important connection because of that really intimate and close relationship between
the tendons and periosteum you can really allow for the bone to be pulled when muscles contract
all right thank you for your time and attention here and have a great rest of your day