howy welcome to uh week two of this semester where we will be reviewing the axial skeleton um before we begin I do want to review um things about the skeletal system um the skeletal system is split into two different um Parts you have the axal skeleton which will we which we will review today and then the appendicular skeleton which we will review for lab three um the axle skeleton is composed of it bones and the appendicular skeleton uh is composed of 126 bones and their major functions are to support the body uh provide body movement protect organs um store minerals and to produce um the blood cells now uh these bones uh can be classified into either short bones irregular bones long bones or flat bones and they also have uh different types of markings which are classified into either projections or depressions projections are processes that grow out of the bone and and on these processes either you can have muscles attached muscle uh tendance or ligaments or you can also have um joints form uh joint formation there so two bones coming together to form a joint um you can also have depressions um or indentations or openings in the bone and um these indentations or openings are conduits for nerves and blood vessels so as you can see here in the vertebrae you have this um opening in the bone which is where the spinal cord um comes through now um based on um these different types of classifications the bones are have a different Anatomy so these flat bones are are surrounded by compact bone and with within them you only see um the uh spongy bone while long bones are actually have a little bit more um of structures within it so you H have the long bone divided into the proximal epiphysis and the distal epiphysis um where compact bone is forming and then the inside um in the diaphysis is where you'll see your yellow bone marrow in the medular cavity again you will be reviewing this um Osteen model in while learning how the bone is being made now the axial skeleton um is comprised of the cranium face uh many Associated Bones the thoracic cage and the vertebral column um within the cranium we have eight bones um then you have the face that has 14 small bones and um uh seven Associated bones including the hyid bone that is right under the jaw you have the different parts of the thoracic cage and the vertebral column so anything um on uh running down the skeleton um head thoracic cage and spinal cord and a vertebral colum is what is part of the axal skeleton now cranial bonees you have the frontal you have pardal uh temporal oipal the spinoid and the ethmoid bone um peral and temporal are on each side so you have a perial bone here and then on the other side and then the temporal bone here and on the other side as well um you also have the facial bones you will have your Bomer bone in this area um your catic bone um on each side you have your lumel bones um inside the eye area your nasal bones um the inferior nasal Contra on each side you will have your um paltin bones inside the mouth and then the maxilla and the mandible now uh keep in mind that for both the cranial and the facial bones there are different structures on the bones that you you will also need to know um as well inside um the um head so inside the cranium um from the superior view you will um also need to memorize all these different framen um or openings um inside both from the top of the head so from the superior View and also from the bottom of head which is the inferior View and you will also need to memorize the cranial nerves that go through uh all these different um openings in the head now um in order to um ident before in order to memorize how uh the cranial nerves run and where which frame and they go through um I set up this image so that you can see U next to the L factor of aramina you have cranial nerve one they go in through here you have cranial nerve two that goes through the optic Canal you have cranial nerves three four five and six that go through the superior orbital fissure you have cranial nerve five that goes through the uh frame and rundum and for Amo Valley um you have um seven and eight go through the internal auditory meatus you have um 9 10 and 11 go through the jugler framen and then 12 goes through the hypoglossal canal another way um to memorize they all go in the order from 1 through 12 down from uh the front of the skull all the way to the back so one way to memorize all the nerves and their order is through pneumonic um you can have oh once one takes the anatomy finyl very good vacations are Heavenly um only only one of the two athletes felt very good and healthy um o oh to touch and feel very good felt that such Heaven um are pneumonics that you can go ahead and uh review now the next part of the axos skeleton is the thoracic cage where you have the sternum um made up of the manubrium the body and the cyho process you also have uh the 12 uh ribs attached to to um the sternum so you have um true ribs which are 1 through seven that directly attach to the sternum you have false ribs 8 through 12 which don't um directly attach to the sternum um and then you have floating ribs that do not attach to the sternum or um at all I do want to point out that floating ribs are also known as false ribs um but false ribs are are not known as floating ribs so floating ribs are only 11 and 12 because they do not attach to the um sternum here the next part is the vertebral column which uh is divided into cervical thoracic Lumbar and sacrum and coxic region here the cervical region is made up of seven uh vertebrae the thoracic is made up of 12 the lumbar is made up of five vertebrae the sacrum is made up of five fused um vertebrae and uh the coxis is uh made up of four fused bones so you will need to memorize how many um vertebrae are in each section so one quick way to do that is I eat breakfast at 7 have lunch at 12 and eat dinner at 5: uh for the lumbar region now Not only would you need to know uh the regions in the vertebral column uh but you will also need to be able to identify a single cervical vertebrae a single thoracic and a single lumbar vertebrae so the cervical vertebrae have three different ways that they they look you have your Atlas um vertebrae which is the first vertebrae in the vertebral column you have your axis um which has this dense here a dense of the axis and it's the second um vertebrae in the vertebral column and then the rest of the cervical vertebrae have this look here with the bit spinus process and um these transfers uh for raymen so you should be able to identify your your axis and then uh another the third type of cervical vertebrae um you will also need to uh find the difference between the thoracic and the lumbar vertebrae so the thoracic vertebrae um has a medium-sized body um and the superior articular processes that use see here will face forward so the body is mediumsized and then this Superior articular facet here is facing to the front straightforward the lumbar on the other hand also has it has a larger sized body but the superior articular posses are actually facing inward as you can see here they're facing inward instead of Straight Ahead um so that is one of the ways that you canine the difference between a thoracic vertebrae and a lumbar vertebrae another cool way to remember this is um thoracic is looking more like a giraffe where the superior TI um processes face forward and then uh your lumbar is looking more like a moose and the um Superior articular processes are facing inward so make sure that you're a to not only um identify the different parts of the vertebrae but also be able to determine whether it's a thoracic a lumbar or a cervical vertebrae sacrum and coxics are very easy to identify um you have your sacrum um that it's fused with five bones and then your coxis which is fused with four bones and these are always um found together now that is it for the axial skeleton next week we will go ahead and review the appendicular skeleton um make sure that if you have any questions please let your um ta know and um enjoy the lab