HS1 The Skeletal Bones

The skeletal bones. Is formed of the axle skeleton, which is the main trunk of the body. The axle skeleton contains 80 separate buns, these form the skull. The spinal column, the ribs, the sternum, and the hyoid bone. The skull consists of 22 binds which form the cranium and the face. The skull protects and surrounds the brain, which is a vital organ. During infancy, the cranial bones are held together by sutures, which are bands of connective tissue, and as children age, these sutures ossify and harden appearing to form one individual bone. The cranium is actually made of 8 separate bones. One frontal bone which forms the forehead, two period bones which form the roof and the sides of the skull. The two temporal that are from the temple to the ears, the occipital, which forms the base of the skull, the ethmoid forming the nasal bone, and the sphenoid, which is a bat or butterfly shaped bone, it's a key band and the other facial binds connect to it. The facial bones consist of 5 nasal bones, two that form the bridge of the nose, one which forms the lower part of the nasal septum, the divider between the nares and then two smaller bones which form the sides of the nose. There's two maxilla, they form the upper gel and come together right underneath the nose, the two lacrimal, which form the inner aspects of the eyes, the two zygomatic bones, these form the cheekbones and depending on the shape of the zygomatic bone, depends on how high someone's cheekbones are. To Palatine, which form the hard palate, a mandible, which is the lower jaw, and it's the only movable bone in the face. Some of the facial bones are made of bone and collagen. Facial bones have sinuses in the areas, which are large spaces, and they're lined with mucosa membranes. If you recall, mucosa membranes secrete a mucus on one side as the membrane lines a bony surface. When you have a cold or the flu, these mucosa membranes become inflamed or swollen, producing large amounts of fluid or mucus. You may feel a stuffiness in your nose or your forehead and your voice may sound different because the sinus cavities are actually echo chambers for the voice, so when the size of the echo chamber is altered, then in turn the voice sounds different. The spinal column is made of individual vertebra. It supports the head and provides attachment for the ribs. The spine is strong, yet flexible, and consists of small bones called vertebra, which protect the spinal column. Which protects the spinal cord. The spinal column consists of individual vertebra. As noted here in the diagram, the cervical vertebra, there are 7 and their orange, the first vertebra, which is a cervical, which means Nick. Allows you to nod. The second cervical vertebra is the axis and it allows you to rotate your head from side to side. The olive green section here are the thoracic and if you recall thoracic does indicate the chest, there's 12 individual vertebra. The lumbar vertebra in the more lime green are the lower portion of the back, but also if you remember the abdominal regions, this was the middle section, and they were named for this area at the back. The sacrum, which are actually 5 individual bones that have been fused or ossified together, are loaded here in the blue, and then the coccyx which are also four small vertebra, and they are fused together as if one bone and are referred to as the tailbone. The structure of each individual vertebra consists of the body. The foramen, which is an opening and it allows for nerves, blood vessels to pass through or the spinal cord. Then you have the processes. The processes on bones are areas that portrayed or stick out. And these are from protection with the spinal column, these vertebra actually help stack on top of each other and the processes help them to maintain that shape. The vertebra are separated by pads of cartilage, and these are called intervertebral disc. You may hear people refer to, they have a slipped disc. They're referring to these pads of cartilage. The cartilage or desk acts as a cushion, and outside provides some shock absorption. The hyoid bone is U shaped and is in the front of the neck. It's the only free floating bone in the body. The hyoid bone is not connected to any other bone in the body. These are the bones that form the axle skeleton. And we will finish with the ribs and the sternum. The ribs, excuse me, the sternum, or breastbone is divided into three separate sections. We have the upper portion, the middle portion or body, and the lower portion, which is the xiphoid process. You can not, by the structure here, that the xiphoid bone is the bone that's most often broken off during chest compressions when someone is receiving CPR. Finally, the ribs, they are 12 pairs of ribs, men and women do have the same number of sets of ribs. And the top 7 pairs are true ribs. Each one of the ribs starts at the vertebra, and then encircles to protect the heart and lungs. And the come around to join the sternum or breastbone located here in the front. Each one of the 7 pairs of true ribs comes around and directly joins the sternum with a small portion of cartilage, which allows your chest to expand when you take a deep breath. The next three pairs of ribs are called false ribs. This is pair number 8, 9 in ten. They're count files ribs because they do not directly join the sternum, but they join in to rib number 7. And then they join the sternum by being attached to the 7th rib. The two final pairs are called floating ribs. Ribs number 11 and 12, and they're very short. They extend from the vertebra, roughly to each one of your sides. The append acular skeleton is the portion of the skeletal bones, which is the upper and lower extremities, the shoulder girdle, the pelvic girdle. This is your arms and legs, and then the areas where they attach. The pectoral or shoulder girdle consists of four separate bones. There are two carved clavicles which you can see here, and these are known as collar bands. Two triangular scapula, which are the shoulder blades. The white, the scapula, form with the clavicle, there's a recessed area or a socket and a scapula then allows for attachment of the arm bones. The arms consist of three bones age, the largest is the humerus. It's the upper arm, and it's the second largest bone in the body. The lower arms consist of the radius and the ulna. The radius is located on the lower arm on the thumb side. This is where you can palpate or feel the radial pulse. Beside the radial bone. The armor forms the outer portion of the lower arm. And the end upper end of the ulna, the proximal portion closer to the trunk of the body, is called the olecranon process. This process or protrusion sticks out in such a form that it helps to shape the elbow. The hands H consist of 27 individual bones. The 8 bones that form the carpals are the wrist are in two separate rugs. The metacarpals, which are 5 individual buns, and they form your palm, which are located in this area. The phalanges are your fingers, they're 14 to each hand. There are only two in the thumb, which is the distal phalanges and the medial phalanges. In each of the fingers, you have the distal phalanges, the medial phalanges, and then the proximal phalanges which then attaches to the metacarpal. Of course, with your thumb being the two bones, but at the placement it has with the metacarpals, it allows the mouse flexibility and is the most opposable. You're able to bring it across the palm of your hand. The pelvic girdle is the hip bones, and this is formed from three separate buns. As you age these bones fuse together with the site from if you recall the lower portion of the spinal column are vertebra, and they form together to shape like a ball as you can see in this structure. Here, the vertebra of the lumbar spinal column, and then here is the sacrum, where these bones form together, it appears to be almost bow shaped. The ilium or hip binds, the ischium, the acetabulum, which are these areas, and they're recessed once again like in the scapula for attachment of the femurs. The femurs are the largest bone in the body and these are the thigh bones. The female pelvis is wider than the male pelvis. And the reason for that is for vaginal delivery of children. That is why when you see all the different TV shows and they look at in a forensics, they look at the pelvis and they're able to normally judge from the shape and the size, whether it was a male or a female. The legs, each consist of four bones, and as I just mentioned, the femur, which is the largest and the strongest bone in the human body, and it equals about 25% of your hide. When physicians are pediatricians try to judge the height of an infant, they use the femur length as the portion to judge at the growth. The patella is the kneecap and it is attached to the tibia, one of the lower bones in the leg by a ligament. The tibia forms the Sheen, it's the largest of the two lower leg binds and it comes down in such a fashion that it also forms the inside ankle. The fibula is the outer portion of the lower leg and it forms the outside ankle. Finally, the foot, just like the hand, each one consists of 27 bones. You have the tarsals which are 7 bones that form the ankle, the metatarsals, which are 5 bones, and they form the end step. Or this portion of your foot, the calcaneus, which is the heel and that's the largest bone in the foot, and then once again, the phalanges. There are three and each time and then two in the great toe or the big toe. Those are distal medial in the great toe and then distal medial and proximal phalanges in each of the additional ties.