hello class this is fiona and this is a recording for a nph 1001 unity 2 topic to the skeletal system and the reference for this presentation is your course textbook that is the reason and she i'm sure you now all have the textbook so the content and the pictures used in this presentation are from your course material unless otherwise stated so it's important for you to go to your textbook chapter 7 and try to read through the chapter because this presentation is just a summary of that chapter so this is a list of the specific learning outcomes it's almost like a checklist of the concepts you expected to understand for this topic this topic also includes the topic on the joins or articulation but i have a separate presentation for articulation so that the the presentation is not too long so this will be just on skeletal system i will make a separate presentation for the joints with the skeletal system it's important to stop and think about the main functions of the skeletal system why do we need a skeletal system what would happen if we didn't have a skeletal system because this glitter system is important is a support structure and some major organs they are also found protected by the skeletal system if you think about the thoracic cavity where we have vital organs like the lungs and the heart then our brain is protected by the this cow so this glitter system is important and the first person to illustrate all the bones is leonardo da vinci so he was the first person to illustrate all the bones because the bones are really important they also store the the mineral salts and she they also work with muscles for movement our muscles are attached to bone so that we can move and as i said before for us to be able to move is because our muscles are attached to the bones so our bones provide they leave us with the muscles and to to protect vital organs and also to support tissue like the blood vessels and the the nerves another important aspect of this glitter system is that hematopoiesis which is the process of blood manufacturing occasion in the bone marrow so we can say our skeletal system is important for blood cell formation and it also stores mineral cells another important part of the skeletal system is the the cartilage the cartilage is important because it's found on the chips of the bones so this is the cartilage so the cartilage is important because it prevents friction as the joints are moving to prevent friction we have cartilage which is almost like a cushion then closely associated to this glitter system are the tissues such as ligaments and tendons it's important to know the difference between a ligament and a tendon a ligament is a structure that attaches a bone to another bone what is a tendon attaches muscles to to the bone if you can look at this picture here a muscle is attached to the bone through a tendon however bone to bone attachment is the ligament so it's also important to stop and think about issues of growth and formation of bones to say for example when a woman is pregnant when does bone formation starts because they had three months gestation period when a woman is about three months pregnant the fetal skeletal system is almost completely developed however it's predominantly cartilage however that cartilage does not just turn into a bone but it provides the medium through which bone formation takes place so if a woman is pregnant the tremor extrema's the skeletal system is completely fully developed but is just predominantly cartilage then that cartilage will provide a medium through which bones form and the process of bone formation is called ossification so for ossification what happens is the cells which are responsible for bone formation which are known as ester blasts the osteoblasts then invade the catholics they get into the cartilage and start the bone formation process has bones are formed remember there's also an issue of growth to say the bonds need to elongate for elongation to take place there is a special part of the bond where mitosis or case for elongation and the place is called the growth plate or the epiphyseal line so the epiphyseal line is the pathway new cells are added to make sure that the bones elongate and see you can try to think about the age at which you acquired your adult height at what age did you acquire adult height it also means that at that age you stopped adding new cells at the epiphyseal line to help elongation with the bone in most cases for girls but this is just on average on average most girls acquire their adult height at 15 and most boys acquire their adult height at 16 but this is just an average it's a plus or minus some people continue to add height up until they're 18 some people stop for adding height when they're about 13 so this is just an average on average at 15 girls they've stopped adding height boys at 16 however though we acquire our adult height at these ages the actual maturation of bones is at age 21. so if you are less than 21 it also means your bones have noted matured and the epiphyseal line still has a chance to produce cells but that part the epiphyseal line fuses when we turn 21. remember i said during embryonic development is the osteoblasts that invade the cartilage to start ossification process that is the bone formation process the osteoblast also similar to stem cells so these are very important because these are the cells that help to form the the bonds then the mature bond cells are known as osteocytes osteo for bone and size for the cell another important thing when you think about growth and development is also issues of bone strength to say when those bone cells are formed during skeletal system development how do we make the bones strong issues of exercise are important to say exercise is important to maintain bone strength also issues of diet we need balanced diet foods that are rich in calcium because it helps to strengthen the bones and also issues of proper posture when working and for young people for kids walking and running around is very important for bone strength as well another important type of cells are the osteoclasts these cells are important for bone remodeling for example after somebody is broken their bones we need remodeling to do that we make use of the osteoclasts and this one is easier to remember because if you think of the rhyming of to say you break your bones you need a cast the cells that help us to remodel broken bones are osteoclasts so basically there are two types of ossification ossification is a process of bond formation so one type is intra membranous this is where the bone formation cells known as the osteoblasts they invade membranes to form the bones and this is how our cranial bones are formed in other words criminal bonds the flat bones they were made through the ossification where osteoblasts invaded the membranes during embryonic development the second type is the endochondral endo meaning inside control meaning of cartilage anything chondral means is of cartilage remember i said at three months gestation period this skeletal system is predominantly cartilage so that type of ossification where the osteoblasts invade the cartilage to start the bone formation process and that's called ossification so it's endochondral meaning bone formation is taking place inside the cartilage this is so for all other bones remember we said cranial bones is intra membranous all other bones is endochondral so when you think about the histology of the bones there are two types of tissue there is what we call the compact and the the spongy these are made of similar type of cells so they both have osteocytes what's different is the way the cells are arranged to form that tissue with compact bone tissue the cells are closely packed with spongy tissue the cells are not as closely pegged so when you think about the way we find the bone marrow the bone marrow is found within the the spongy bone so they are the same type of cells they just define the arrangement because the structure is related to function the compact bond the cells are compact they provide a lot of strength to to the bone the cancers or the spongy ones they provide a space for the bone marrow and also the nervous tissue and the blood vessels then bones can be classified by shape to say when you look at those bonds what's their shape then we can classify the the bonds remember we have two or six bonds so if you take all those two or six bonds we can classify them according to how they look so when you classify bones they are what we call long bones these are bones where they have a length that exceeds their width then we call them long bones then when you look at this image of the whole skeletal system the bones that are represented here in grain they represent long bones this is where the length exceeds the width it also includes our phalanges like our fingers and toes they're also classified as long bones so when you look at this this is a typical example of a long bone with a diaphysis which is a shaft then towards the edge is the metaphysis and the epiphysis and then the growth plate will be somewhere here then the outer part will be the combat bone tissue the inner part will be spongy then within that spongy that's where we can have the the bone marrow and then at the tip you can have the the cartilage which helps to prevent wear and tear when the joints move [Music] typical examples of long bones can be the femur then when you look at the percent of the femur they kind of form a v which is very important because the femur is the strongest bone in the body it based a lot of weight for it to be able to care as they are almost shaped like like a way to make a v so that they can both carry the the weight then short bones it's important to note that when we say long and short short bones does not necessarily mean it's a shorter version of the long bone but the most important thing is that they lack an access they lack a long axis so they are somewhat irregular but they are not an opposite of the long bones so when you look at this image the short bones are represented here with the the green color then another type of bones are the flat bones flat bones are important because they are typically found where there is an extensive muscle attachment or where the bones is main function is to protect the vital organs for example we have these tendons the ribs they are flat because they are protecting the major organs which are the lungs and the heart same as the skull it protects a major organ which helps to protect our brain these are flat bones then irregular bones typical irregular bones are found in our vertebral column they are very irregular in shape it means their shape is irregular you can call them long you can't call them short so the vertebral column has got irregular bonds then the sesamoid bones are typically formed in closed in tendons and they are found adjacent to to to joints so this is a way that small bones found adjacent to the bones the vertebral column is almost like a stack of four irregular bonds one on top of each other but when you look at that vertebral column we can actually group these bonds we can start from the top the cervical region the cervical region is got seven then the thoracic region is good 12 and when you look at thoracic region this is where we have the attachment of ribs so we have a 12 vertebral bones and attached to 12 vertebral ribs then when you look at those ribs they are ribs that are attached they go all the way to the stenum in other words all ribs are attached in the vertebral column seven of those they go all the way to this tenon they get attached to the stenum and we call them true ribs then the lower ones we call them false ribs because they don't go all the way to this thinner the last two of those false ribs are just floating because the other three pairs they attach via a cartilage but the last two if you touch it your back we have two pairs of floating ribs these are not attached anteriorly they are just floating then from the thoracic region we move on to the the lumbar the lumbar is got 5 then from the lumbar we move on to the sacrum it is good five but we know there are five but as we during embryonic development it's clear that they are five but as we grow older they kind of fuse same with the tailbone the tailbone we know that there are four pieces but they are fused to form the coxy so this is the coxy and this is the second the green one and as i said before leonardo da vinci was the first person to illustrate all the bonds until we have two or six named bonds to say when you put all those bonds together we can name two or six of them and for this course we don't necessarily have to remember all the two or six bonds but it's important to remember the major bonds to say when you look at this skeletal system are you able to identify the media bones can you identify this call can you identify the pelvis ulna radius phalanges humerus female tibia tubular all those major bones is important to be able to to identify them then when you think about the skeletal system again we can divide it into two major regions there's the axial patch the axial patch is represented in green here this is where we have this cow the ribs this tuna and the the vertebra that's the axial part of the skeletons then the appendicular part of the skeletal system are the extremities and in this image they are represented in green the extremities are the appendicular axial is the major patch [Music] then another important part of the skeletal system is the the skull they are different parts of the skull and is made up of flat bones and during embryonic development they were formed through intra membranous to say during embryonic development if this was a membrane then osteoblast invaded and start forming the osteocytes and then this is an image showing the facial bones the frontal bones so you need to be able to recognize the zygomaticus the psychomatic bones the mandibles the zygomatic bones so the different parts of the the bones so you need to stop the video and try to identify the different structures or you can refer to your textbook and don't confuse zygomatic bone and the the mandible again so this is the kind of a lateral view of the same skull now showing the temporal process of the ear the temporal bone here in the occipital this is the peritoneal the frontal bone is still the same the front frontal another special part of the skeletal system is the hyoid bone this is where we have our tongue attached our tongue is attached to the higher the bone then the thoracic region remember we said we have 12 pairs out of those 12 7 the first seven are two ribs then the fourth ribs is rib eight two to twelve however when you look at those false ribs two of them are floating so the floating ribs are rib number eleven to twelve so you can see the floating part here to say they are not attached to the front patch the other three are attached via the the cutters they join and form a cartilage which goes through to this channel the first seven they attach singularly directly to this thing that's why they are called true ribs then when you look at the extremities it's important to say which bones are part of the appendicular the extremities this is where we have the humerus the radius the ulna the couples and don't confuse the couples and metacouples this diagram i like it because it's colored and it shows which patch is the couples and which part is the metacouples and the challenges same with the our legs it's important to know which part is the female which part is the patera which part is the tibia and fibula please don't confuse tibia from fibula the tibia is the bigger bone and is between the the legs when you are standing in a normal anatomical position so you can stop this video and try to identify the highest arc of this foot to see which part do we call the highest ack many ways you age there are so many changes that take place there are so many changes that take place to our skeletal system so there's actually a shrinkage in height look at this picture to say it's 3 years if you convey a 30 year old this is the same individual what happened to them by the time they turned 70 so there is some kind of reduction or shrinkage in height because of the thinning of the vertebral discs the vertebral discs will be thinning and we end up losing height so in sum we can say we are done with the skeletal system