so for example we have the external intercostals and we have the internal interco hey guys welcome to another video i'm dr gonzalez and today in this video we are going to talk about the following topics but before we get started don't forget to subscribe like and share because in that way you will never miss a new video when i post it all right let's get started so skeletal muscles produce movements by exerting force on tendons and these tendons attach to and pull on bones and movement can occur most muscles cross at least one joint and are attached at articulating bones as you can see in this example this is the biceps brachii and you got the triceps brachii attached to here the humerus right and when a muscle contracts it draws one articulating bone toward the other so this is the reason why muscles have an origin and an insertion and origin is the attachment to the stationary bone and an insertion is the attachment to the movable bone and so the action is going to take place on the insertions so for example in this case the bicess brachii has an insertion over here and therefore this area of the elbow can move here we have some muscles that are known as the arm prime movers such as the pectoralis major muscle latissimus dorsi and deltoid notice that three these three muscles you have the pectoralis major on the thorax anteriorly latissimus dorsi is posteriorly on your back and the deltoid it's over the shoulder in the arm we also have other muscles that are known as the synergists or fixators which are muscles that are deeper to the muscles i just show you and these are additional muscles in the shoulder girdle and arm to stabilize and assist in movements of the humerus so for example we have the supraspinatus here over the scapula superior to the spine we also have the infraspinatus inferior to the spine on the scapula we have the tethers minor subscapularis anterior on the scapula teres major and the coricobrachialis out of all of those muscles in the arm we have a group of muscles that we call the rotator cuff and these muscles of the rotator cuff assist in rotation of the arm and prevent the dislocation of the shoulder joint so out of those muscles we have the supraspinatus infraspinatus teres minor and subscapularis as part of the rotator cuff in the thorax we have another group of muscles that are deep and these muscles are part of the shoulder girdle movements and they are going to be anterior for example we have the subclavius muscle attaching over the clavicle pectoralis minor with an attachment here on the scapulas and the serratus anterior muscle posteriorly we also have a group of muscles that are known as the shoulder butyl movements and like i said they are going to be located posteriorly in your back so there is the trapezius muscle levator scapula rhomboid mayor and rhomboid minor in the back we have a group of muscles that are helping the vertebral column for example we have the splenius cavities and the splenium surfaces these plenus muscles laterally flex extend and rotate the neck in the back we also have another group of muscles that are called the erector spina and these are superficial back muscles that act as prime movers in the extension of the vertebral column this muscle erector spina is divided into three parts we have this spinalis lung histamines and iliocostalis out of all of the muscles in our back we have some that are very deep muscles for example we have the semi-spinales muscles that are deep back muscles that extend and rotate the vertebral column as well as the rotaries these rotaries are deep back muscles that extend and rotate the vertebral column we also have muscles known as the spinal flexors such as the longus capitis and longus coli these muscles will flex the neck and the quadratus lumborum which is a muscle that will flex the vertebral column now we also have a group of muscles that are part of your respiration and these are muscles located in the thorax so for example we have the external intercostals and we have the internal intercostals deep to those external intercostals and there's also this one called the diaphragm which is the prime mover of inspiration meanwhile the external intercostals assists in inspiration and then the internal intercostals assists enforced expiration [Music] in the abdomen anteriorly we have muscles that have several functions for example some of these muscles will be compressing and protecting the viscera that we have inside our abdomen and also these muscles can aid in force respiration and they can also work in rotation of the trunk for example we have the outermost muscle which is the external oblique and if you notice the fibers are going down kind of like when you put your hands on your pockets then we have the rectus abdominis which is also known as the six-pack we have the internal oblique muscle which the fibers go in the contrary direction to the external oblique and notice how both of these muscles can also go from the anterior wall of the abdomen all the way to the posterior wall of the abdomen and then we have the transverse abdominis in the pelvis the levator anion and the coccygeus are the muscles that form the pelvic diaphragm that support the pelvic floor and draw it upward during the vacation in the case of the elevator ani this one has three parts one of those is the one you're observing which is the pubococcygeus it also has the pupil rectalis and the iliococci in the pelvis males have also superficial peroneal muscles that support the central tendon of the perineum for example there is the bulbal spongiosus and the ischiocarbonosis that maintain the erection in the penis or in the case of female in the clearest lastly there are muscles in the pelvis that are known as the deep perineal muscles because these deep transverse peroneal muscles support the central tendon of the perineum and the external anal sphincter that closes the anus so as you can see this is the deep transverse perineal muscle and this is the external anal sphincter and if you want to know more about this topic click on the card on top of this video so that you can see and check out other videos related to this one alright so that's it thank you for watching don't forget to subscribe like and share and also if you have any comments or suggestions you can leave them on the comment section below thank you for watching and if you want to know more about this system like the skeletal system um the superficial perineal guessing that [Music] our shoulder girdle movement for the shoulder how to study and how to [Music] uh when without lucky