now scatter muscles are considered in Oregon because they're made up of several different tissue types we have nerves blood vessels connective tissue and the skeletal muscle tissue itself now it turns out that each muscle receives a nerve artery advantage drainage and it turns also skeletal muscles are controlled consciously by the nerves that supply every fiber so every single muscle fiber in a skeletal muscle is connected to some kind of nerve fiber and these nerve fibers are linked up with your nervous system that are ultimately controlled by the conscious brain centers now contracting muscle fibers requires huge amounts of oxygen and nutrients which explains why we need so many arteries and veins to supply blood flow as well as carrying nutrients and wastes too from the tissue and these wastes need to be removed quickly in order to you know keep the skeletal muscle able to function normally now each skeletal muscle is actually covered in a connective tissue sheath and these sheets are called epimysium perimysium and endomysium epimysium is the sheath that extends the entire muscle and it's made of a dense irregular connective tissue that's tough this can blend with the surrounding fascia to help you know hold the muscle in position now perimysium is a fibrous connective tissue that surrounds fascicles which are basically groups of muscle fibers or skeletal muscle cells and the endomysium means means within right within muscle and is actually made of a fine areolar type of connective tissue that surrounds each individual skeletal muscle cell or fiber to help nourish that fiber and supply with nutrients so looking at just a picture of muscle organization we find that the entire muscle is surrounded by epimysium remember epimysium is the dense irregular connective tissue that packages the entire muscle together and if you look at a cross-section of muscle we see that each one of these circles here is represented by this one here and this is actually called a fascicle and a fascicle is essentially a bundle of muscle cells so if you look within here each one of these circles is actually a skeletal muscle cell aka muscle fiber so when many different muscle fibers are package together we call it a fascicle and it's actually perimysium that packages these fascicles and its many fascicles you find within the entire muscles itself which is packaged by a bee museum and then each individual muscle fiber is surrounded by endo Museum and remember endo Museum it's kind of represented here which is basically just a areolar connective tissue that helps to nourish the muscle cell you find that these scowler muscle cells are multinucleated and that's what's shown here in purple and you can see their strided now in terms of muscle attachments we say that skeletal muscles have an origin and insertion the origin is the attachment point of that muscle that is immovable or at least less movable on a bone itself now the insertion is the actually attachment of that skeletal muscle that attaches to a moveable bone right so an example this would be for muscle and your break IAM called brachialis you know this one actually connects to the ulna and because when the brachialis muscle contracts it actually will pull on the ulna and causes the ulna to to move in a manner that allows your elbow to flex so it turns out the OL that would be the insertion point because that's the movable attachment whereas the origin of brachialis is the humerus because this doesn't move when the brachialis contracts now attachments can be both direct or indirect third direct we say that their fleshy and in the sense we see that the epimysium is fused with the periosteum of a bone or the perichondrium of cartilage that way the muscle pulls directly on that structure if it's indirect we say that there's actually a connective tissue wrapping that extends well beyond the muscle as a rope like tendon or a sheet like aponeurosis so tendons are kind of more of a tube of connective tissue whereas aponeurosis are actually a broad and thin sheet of tendon that link up with the muscle through connective tissue so going back here we see then that you know this would be considered in indirect attachment because of the you know the tendon here that's attached into this bone otherwise if this was this muscle were directly attached you know then the muscle be on the bone itself as it would be over here now remember the entire muscle is surrounded by epimysium that's what package is it and within that we have fascicles and each fascicle surrounded by perimysium and that each individual muscle cell is surrounded by endo Museum now if you zoom in here and look at each individual cell you see that the cell itself is actually full of more tubes and these tubes are called myofibrils and myofibrils are basically you know long cylindrical protein structures that are actually the things that are going to produce the contraction itself now just looking at the organization remember epimysium surrounds a whole muscle perimysium surrounds the fascicle endomysium surrounds the entire muscle cell and what's interesting that is actually all of these connective tissues sheets come together to form the tendon itself so tendons are made of the epimysium perimysium and endo museum that actually surround and package the muscle where all those connective tissues come together they converged to form the tendon which is mostly just a connective tissue extension of the muscle that helps the muscle attached to things like skin bone or even other muscles