In our overview of the skeletal system, we talked about the different parts of the skeletal system, bones, joints, cartilages, and ligaments and how these are divided into two different skeletons, the axial skeleton and the appendicular skeleton. The axial skeleton can be thought of as the bones straight down the body, the skull, hyoid bone, rib cage, and vertebrae column. The appendicular skeleton, however, is the skeleton that supports the appendages such as your arms and legs. We also talked about the basic functions of bones, such as support of the body, protection of soft organs, and so on. Then, more specifically, we talked about the bones of the human body. We learned that the human body has 206 bones and that there are two basic types of bone tissue, spongy and compact. Then, we talked about the Haverisan System (Osteon) which is an organized system of interconnecting canals. Finally, we talked about the different types of bones. Bones are classified into four different types based on size. First you have the long bone, then the short bone, next you have the flat bone, and finally, you have the irregular bone. At the start of this unit, we did two labs to help us better understand the skeletal system. The first one we did was the Skeletal System Lab, which essentially helped us to begin to understand how the system worked and where each of the bones was located. We also did the Owl Pellet Lab http://hayleysanatomyblog.blogspot.com/2017/03/owl-pellet-lab.html that helped us to identify bones as well as try and figure out what type of animal our animal ate based on bone type and shape.
Next, we learned about some of the disorders of the skeleton system. We began by talking about arthritis, which is inflammation of the joints due to age, trauma, or infection to the joints. Then, we talked about osteoporosis, a condition in which bones have lost minerals, especially calcium, causing them to become weaker and more brittle and in turn makes them more susceptible to fractures. The most common places that people with osteoporosis break their bones in their hip, wrist, or spine. After, we talked about scoliosis which is a disorder in which there is an abnormal curvature of the spine. The cause of this is unknown but it is known that it occurs more often in girls rather than boys. We learned next about kyphosis which is a disease in which your spine can look completely normal or you may develop a hump on the top of your back. This disorder is something that can affect children, adolescents, and adults. We also talked about lordosis which is the excess curvature of the lumbar spine which in turn causes a forward pelvic tilt and swayed back appearance. Finally, we talked about rickets, a disorder that occurs in children, usually due to a vitamin D deficiency, that causes the softening and weakening of bones.
After talking about skeletal disorders, we learned about the process of bone remodeling. We first talked about ossification, which is the process by which bones forms. Minerals are deposited and are able to turn cartilage into bone. This occurs 6-7 months into pregnancy all the way till adulthood, approximately 25 years old. When the ossification process is complete, that means you are done growing. We also talked about the bone cells that are responsible for bone remodeling. It begins with the osteogenic cells which are dividing cells that eventually develop into osteoblasts. Osteoblasts are the cells found on the surface of the bone that is responsible for bone building. These cells then develop into osteocytes which are mature bone cells that help to carry out daily activities of bone tissue. Lastly, we have osteoclasts which are the cells that break down bone tissue and are necessary for development, growth, maintenance, and repair of bone. In this lecture, we also talked about some crucial vitamins such as vitamin D, which is needed to absorb calcium, vitamin C, which is critical to making collagen, and finally calcium, which is necessary for heart function, muscle contraction, nerve function, blood clotting, and much more.
Then, we learned about fractures. We learned about many different types of fractures, such as the closed fracture, where the broken bone pieces stay in the skin. We also learned about compound fractures where the broken bone pierces through the skin. Other types of fracture types we discussed were transverse, oblique, and greenstick. We also talked about the bone repair process. This process being with bleeding and inflammation and the bleeding produce a blood clot. Then, after 24 hours, the clot softens and produces a mass of protein fibers called a procallus. Next, fibroblasts arrive and secrete dense connective tissue to replace the procallus. Finally, chrondroblasts and osteoblasts arrive next.
Lastly, we talked about joints. We first talked about the classification of joints, specifically the functional classification. Synarthroses are immovable joints, amphiarthroses are slightly movable joints and diarthroses are freely movable joints. There is also the structural classification of joints known as the fibrous, cartilagenous, and synovial joints. One lab that we did during this section was the Mini Joint Lab which helped us to understand the different types of joint classification.
I believe that this has been a very strong unit for me. All the labs have really helped me to better understand the skeletal system. In particular, the first lab really helped me to begin to understand where all the bones were located in the body. Being able to understand that really helped me later on in the unit when we began to learn about joints. The joints section was something that I found a little more difficult to understand but was made much easier with the lab and previous knowledge from other sections.
My New Years Goals are still going well. I have still been making sure to put in my best effort at school and maintain a healthy lifestyle in all aspects of my life. Although that last part may be difficult at times, I have been able to be pretty healthy, making sure to balance school, sleep, and my social life as well as eat healthy and workout.
