 Hello. In this video I will identify the eight bones of the cranium, 14 facial bones, 26 bones of the vertebral column, and the 25 bones of the thoracic cage. The axial skeleton are the bones found along the midline in contrast to the appendicular skeleton that are the bones found in the limbs and the girdles that connect the limb bones to the axial skeleton. There are eight cranial bones and six names of those eight cranial bones to learn because there are two a left and a right for the parietal bone as well as two a left and a right for the temporal bone. A pneumonic device that you could use to help you remember the names of the cranial bones is pest of six P E S T O F six. And so six because there's six different names to learn and then P stands for the parietal bone. So I'll highlight that here. You can see the parietal bone and we're looking at a right parietal bone in this view but there is also a left parietal bone. The parietal bones are the large flat bones that form the convex superior lateral walls of the cranium. Then E stands for ethmoid bone. So we can see here the ethmoid bone. So there's just one ethmoid bone and it's located in the superior roof of the nasal cavity. It does contain air filled sinuses that connect with the nasal cavity. So the ethmoid sinuses are one set of sinuses that are air filled spaces inside of our bones that connect to the nasal cavity. Then S stands for sphenoid bone. So we just have one sphenoid bone. You can see right here the greater wing of the sphenoid bone is visible on the right side with this lateral view of the skull. The sphenoid bone is a medium sized irregular shape bone that forms the anterior floor of the cranium and contacts all seven of the other cranial bones. Then T stands for temporal. So right here we can see the temporal bone is a purple color here in the illustration. The temporal bone, we have a right temporal bone as well as a left temporal bone. So there are two temporal bones just like there are two parietal bones in the cranium. Each temporal bone is a medium sized irregular shape bone that forms the inferior lateral wall of the cranium and the temporal bones contain the middle ear and inner ear and there are three small bones within the middle ear known as the auditory ossicles. So now O stands for occipital bone. Here we can see the occipital bone is a large flat convex posterior wall and base of the cranium. The occipital bone contains a very large opening for the brain to contact with the spinal cord. The last bone in the mnemonic here F stands for frontal bone. So we have one frontal bone that's the large flat bone forming the convex anterior roof of the cranium. So here we have a posterior view of the skull where we can see the occipital bone is forming that posterior wall and then the parietal bones are forming the superior and lateral walls of the cranium whereas the temporal bones are located just on the inferior lateral walls of the cranium. Another major feature that stands out here is this large opening right here that's the foramen magnum it's part of the occipital bone. So occipital bone has a large opening foramen magnum. Magnum meaning really large and foramen meaning an opening a hole through the bone. This is the large opening where the brain connects to the spinal cord. Now here we have an inferior view of the skull so again we have a nice perspective on this foramen magnum that allows the brain to come down out of the cranium and contact with the spinal cord. So that foramen magnum is a part of the occipital bone and that will help you remember which bone is found there on the posterior and inferior region of the cranium. Now we'll go through the 14 facial bones and I also have a mnemonic device a memory tool that will help you remember these bones the mnemonic device is Virgil can not make my pet zebra laugh and the first letter from each of those words is the first letter of the name of one of the facial bones and there are 14 facial bones we have some facial bones that are unpaired there's only one and some facial bones are paired meaning we have a left and a right. So let's start off with v v stands for vomer so here you can see the vomer bone it's located in the inferior of the nasal cavity right along the midline so there's only one vomer bone and it has a plow shape that's where the word vomer comes from it's forming the inferior portion of the bony nasal septum that separates the left and the right halves of the nasal cavity. So next we have c c stands for inferior nasal concha so the c stands for the last word in this name concha and inferior nasal concha is a facial bone there is also a middle nasal concha and a superior nasal concha but those are parts of the ethmoid bone so the inferior nasal concha is its own facial bone and there are two inferior nasal concha a left and a right for the inferior nasal concha the inferior nasal concha are small irregular shaped bones that form a scroll shaped extension that projects out into the inferior lateral wall of the nasal cavity and it functions to produce turbulence in the air as we're breathing through our nose this helps to warm and humidify the incoming air if you look into the nasal cavity of a dog or a seal these animals have really elaborate nasal concha in order to help them with breathing very cold air helping to warm that air up so that it's not too harsh for the respiratory system so now in the mnemonic device we've gone through v and c next is n so that n stands for nasal and right here we can see the nasal bone there is a right nasal bone as well as a left nasal bone so there's two nasal bones and they're forming the bridge the nasal bridge just superior to the nasal cavity okay so next on our list is an m and m can stand for maxilla we have two maxillary bones two maxilly so let's find where did we label the maxilla on this there we have it so the maxilla is the upper jaw bone and there are two maxillia left as well as a right you can see that the maxilla also forms the medial portion of the inferior margin of the orbit or eye socket and it's well as it's also forming this lateral border of the entrance to the nasal cavity so there's another m the next m stands for mandible and we just have one mandible it's the lower jaw bone so here we can see mandible is the lower jaw bone and a interesting thing about the mandible is the mandible contacts the temporal bone to form the only movable joint of the skull the the jaw joint the temporal mandibular joint is the joint that enables us to chew our food or to talk to move our jaw so next we have p p stands for palatine bone now I can highlight here palatine bone and there's a very small part of the palatine bone that's visible when looking into the orbit looking into the eye socket but the word palette means roof of the mouth and if we were looking at the roof of the mouth we would see the palatine bone is forming the posterior third of the bony hard palate the portion of the roof of the mouth that's formed from bone the anterior portion of the hard palate is formed from the maxilla and the palatine bone just forms the posterior third of the hard palate and there are two palatine bones both a left and a right okay so next in our mnemonic device we have z z stands for zygomatic bone we have two zygomatic bones let's highlight with yellow instead of red so we have two of these zygomatic bones and the zygomatic bones are your cheek bones located just lateral to the maxilla they're just anterior to the temporal bones and they do form the lateral margin the lateral wall of the orbits now last on our list here we see L and the L stands for lacrimal bone so lacrimal bone is found in the medial margin of the orbit and there's a nasal lacrimal duct that is an opening through the lacrimal bone into the nasal cavity which allows tears to drain into the nasal cavity so the lacrimal gland produces tears that wash across the eyes from the superior lateral region of the eye and drains down to the medial region into this lacrimal bone through the nasal lacrimal duct into your nasal cavity those tears are constantly draining through that pathway as a way of just lubricating nourishing and cleaning the anterior surface of your eye but the word lacrima means tear so lacrimal gets its word gets its name from the word for tear and it's found there in the medial part of the orbit of the eye socket and there's one in each orbit so we do have two of these two of these lacrimal bones as well so next we'll move on to study the bones of the vertebral column so there are 26 bones in the vertebral column seven of them found in the cervical region 12 in the thoracic region five in the lumbar region and then the sacrum is one bone formed from five sacral vertebrae that fuse together and then the the coccyx or tailbone is the most inferior of the vertebrae so here we can see the structure of a cervical vertebrae cervical vertebrae are relatively small compared to the other vertebrae they don't have to support a large amount of body weight essentially it's just the weight of the head that's supported by the cervical vertebrae and the vertebral foramen the large opening in the center of the cervical vertebrae is relatively large because the spinal cord is relatively large at this region close to the brain so here we see the structure of thoracic vertebrae the most unique feature of thoracic vertebrae that really helps them stand out from other vertebrae is they have costal facets that is they have these little indentations that are the locations that the ribs attach so the ribs attach to the thoracic vertebrae and those little costal facets are the locations where the ribs attach then the lumbar vertebrae are relatively large they're much larger than cervical vertebrae and even a little larger than the thoracic vertebrae because the lumbar vertebrae have to support a relatively large amount of our body weight here we can see the structure of the sacrum and coccyx so the sacrum is found in the posterior pelvic region whereas the lumbar vertebrae would be in the posterior of the abdominal region and then just inferior to the sacrum is the coccyx the tailbone and so the coccyx is the most inferior of the vertebrae so next we'll move on to the thoracic cage which contains 25 bones these are all flat bones and the large flat bone found on the anterior of the thoracic cage this is the sternum so then attached to the sternum and the thoracic vertebrae are the ribs although only the first 10 ribs the most superior 10 ribs will connect to the sternum the the ribs are all attached to the thoracic vertebrae and ribs one through seven are known as the the true ribs we call those the true ribs because they have a costal cartilage attaching directly to the sternum then ribs eight nine and ten all share the costal cartilage of rib number seven and last rib 11 and 12 are the most inferior of the ribs and these are floating ribs that do not attach to the sternum at all so the ribs provide a bony wall to the thoracic cage to the thorax which helps to protect the organs the lungs and the heart that are deep within the thoracic cage