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WLHS/A&P/OppeltNameLAB: The Skeletal System SystemBackground: The skeletal system is primarily responsible for supporting the body and protecting vitalorgans. We are bone with more than 270 bones that eventually fuse together as we grow, leaving adulthumans with 206 bones. Bones are made up of a complex arrangement of inorganic minerals and avariety of tissues including bone, bone marrow, nerves, blood vessels, endothelial, and cartilage. Theycome in a variety of shapes and sizes depending on their location and function, but all bones arelightweight, strong, and hard. Bone has a variety of functions that include: Protection of organs (skull protects brain, ribs protect heart, etc ) Support and framework for the human body Movement by providing attachment points for muscles pH balance of the blood by absorbing or releasing bone minerals Hematopoiesis (blood production) in blood marrow Fat storage in yellow bone marrow Sound transduction through small bones located in the ear canal Removal of heavy metals or foreign chemicals to detoxify blood and release slowly for excretion Mineral storage of calcium and phosphorus Production of hormones such as osteocalcinBone Structure: Bone mineral is created from several minerals, most notably calcium and phosphorus,that form carbonated hydroxyapatite or Ca10(PO4)6(OH)2. Bone mineral is created by osteoblasts andallows bones to withstand large amounts of compressional force. The other major component of bonematrix is organic collagen, which is a protein that gives bone the ability to withstand stretching forces.The major cells that contribute to building andbreaking down bone matrix and bone structure areosteoblasts, osteocytes, and osteoclasts.Osteoblasts are responsible for creating bone matrix,and therefore building bone. Once osteoblasts havebecome trapped in the bone matrix they created,they become osteocytes. Osteocytes function tomaintain the bone matrix and calcium homeostasis.They are unable to move from their assigned locationor space, which is called the lacunae. Osteoclastsare large cells that are capable of reabsorbing boneminerals, and therefore remodeling bone structure.Osteoclasts also remove minerals to the bloodstreamfor a variety of bodily functions, such as musclecontractions.The bone matrix can be arranged into two classifications of bone; compact and trabecular bone.Compact bone, also known as dense or cortical bone, is extremely hard and compact with very littlespace. Bone mineral in compact bone is arranged into tight circles called osteons, with nerves and bloodvessels passing through the center. Compact bone accounts for 80% of the total bone mass.HASPI Medical Anatomy and Physiology 08a Lab ActivityMOD EJO 2017

Trabecular bone, also known as spongy or cancellous bone, is porous and more like a network thatallows nerves, blood vessels, and bone marrow to easily fill trabecular bone. Stress on trabecular bonecauses it to create new and stronger networks, making it extremely adaptable. Although trabecular boneaccounts for 20% of the total bone mass, it has a much greater surface area than compact bone.Bone Types: There are 5 main types of bone based on their shape. These include long bones, shortbones, irregular bone, sesamoid bones, and flat bones.Bone TypeLong BonesDescription and ExamplesBones which are longer than they are wide and made up primarily ofcompact bone. Examples include arm bones, leg bones, and phalangesCube-shaped with a thin layer of compact bone. Examples include wrist andankle bones.Bones embedded in tendons. Examples include patella and pisiformThin and curved with parallel layers of compact bone. Examples include thesternum and bones of the skullBones that do not fit in any of the other categories. Examples include thevertebra and bones of the sinus.Short BonesSesamoid BonesFlat BonesIrregular BonesProcedure: Visit each of the stations and follow the instructions at each station.Station 1: The Skeletal System Use “the Skeleton Chart”, your textbook, and internet to identify thefollowing SPI Medical Anatomy and Physiology 08a Lab ActivityMOD EJO 2017

Bone Types – Using the “Bone Types” chart, identify the bones types A-E in the table below.A.B.C.D.E.Compact Bone – Using the “Compact Bone” chart, identify bone types A-H in the table below.A.B.C.D.E.F.G.H.HASPI Medical Anatomy and Physiology 08a Lab ActivityMOD EJO 2017

Station 2: Long Bone StrengthThe construction materials and shape of bone give it its strength and the ability to withstand greatamounts of force. The presence of collagen fibers allow bone to endure stretching forces, while theharder mineral salts allow bone to endure compression forces. Bone construction is similar to that ofreinforced concrete in that steel rebar allows concrete to resist stretching forces, while the cement resistscompression. In addition to the construction materials, the circular shape of osteons, and thereforebone, are able to resist greater amounts of force. Unfortunately, this construction does not tend to resisttwisting forces, and in fact this is the primary cause of bone fractures. In this activity, you will examinethe ability of the concentric circular shape of bone to withstand direct forces.Procedure:1. Obtain 20 sheets of recycled paper, tape, and string.2. Start with the first sheet of paper, roll it longwise as tightly as possible. The paper roll should be 11”long. If needed, use a small piece of tape to hold it together.3.Roll the second sheet of paper around the first as tightly as possible. If needed, use a small piece oftape.4. Continue rolling sheets of paper around the paper roll using tape as needed, until all 20 sheets havebeen added, to create a very thick roll of paper. This paper represents the concentric shaped of a longbone and/or osteon.5. Cut about a 24” section of string and tie it tightly around the center of the paper roll. Tie the other endof the string around the handles of the bag. Make sure there is enough room to fit textbooks in the bag.6. Place the very ends of the paper roll (long bone) at the ends of two desks or two chairs so that the baghangs between the desks/chairs and does not touch the ground.7. Place a textbook into the bag. Continue to place textbooks into the bag until the paper roll (long bone)bends and falls off the desk/chairs. If you completely fill the bag and the paper roll still has not bent, addanother strong and bag to the paper roll and continue filling the bag with textbooks.8. Record the number of textbooks before the paper roll (long bone) bend in the table below.9. Use the scale to weight one of the textbooks and records its weight.10. Multiply the number of textbooks it took to bend the paper roll by the textbook weight and determinehow much total weight the paper roll was able to withstand before bending.Table 1: Long Bone StrengthNumber of TextbooksWeight of Each TextbookHASPI Medical Anatomy and Physiology 08a Lab ActivityTotal Weight to Bend PaperRoll (Long Bone)MOD EJO 2017

Station 3: Skeletal System HistologyThe cell and tissue structures of the skeletal organs are suited for the function performed. Using thepictures on the lab table, draw and label the pictures in the space below.Compact BoneUsing colored pencils, draw the histology Image Bfrom the “Compact Bone” chart in the spacebelow. Using Image A as a reference, label yourdrawing with the canaliculi, oestocyte, lacunae,and Haversian canalRed Bone MarrowUsing colored pencils, draw the histology Image B“Red Bone Marrow” chart. in the space below.Using image A as a reference, label the following:compact bone, megakaryocytes, developingblood cells, and vascular sinus.Trabecular BoneUsing colored pencils, draw the histology Image Bfrom the “Trabecular Bone” chart in the spacebelow. Using image A as a reference, label thefollowing: yellow bone marrow and trabeculaePeriosteumUsing colored pencils, draw the histology Image Bfrom the “Periosteum” chart in the space below.Using image as a reference, label the following:bone and periosteum.HASPI Medical Anatomy and Physiology 08a Lab ActivityMOD EJO 2017

Station 4: Bone Length and HeightInferring the height of an individual based on the length of long bones is common in forensic pathology.When skeletal remains are found, the sex, race, and height can be crucial clues to identify the victim. Infact a single long bone can be used to calculate approximate height. Gender and race also contribute tothese numbers to give a close approximation of height. In this activity, you will calculate your heightusing the length of your long bones.Procedure:1. Select a partner and yard stick.2. Use the yard stick to determine the length of the radius on your partner. To do this, measure from thewrist to the elbow. Have your partner also find the length of your radius. Record the measurement ininches in the table below.3. Determine the length of the humerus by measuring from the elbow to the shoulder on both you andyour partner. Record measurements in the table below.4. Determine the length of the femur by measuring from the knew to the hip on both you and yourpartner.5. Using the following formulas, calculate your approximate height from your radius, humerus, and femurmeasurements. Record your calculations in the table below.Male(Length of radius x 3.3) 34 Height(Length of humerus x 2.9) 27.8 Height(Length of femur x 1.9) 32 HeightFemale(Length of radius x 3.3) 34 Height(Length of humerus x 2.9) 27.8 Height(Length of femur x 1.9) 32 Height6. Use the yard stick to measure you and your partner’s actual heights and record in the table below.7. Use the following formula to calculate the percent error for each calculated height measurements fromyour actual height.(Calculated Height Measured Height) x 100 – 100 Percent ErrorExample: (60 65) X 100 – 100 7.69% errorWhich means that the calculated height was 7.69% off of the actual height.Table 2: Bone Length and HeightYour MeasurementsBoneLength (in)CalculatedHeight (in)MeasuredHeight (in)Partner’s MeasurementsPercentError(%)Bone Length(in)CalculatedHeight (in)MeasuredHeight (in)RadiusHumerusFemurHASPI Medical Anatomy and Physiology 08a Lab ActivityMOD EJO 2017PercentError(%)

Station 5: Skeletal DiseaseUsing the skin disease charts complete the following table. List ONLY THREE causes or Risk Factors,Symptoms and Treatment Options for each disease.DescriptionOSTEOARTHRITISCauses or Risk Factors SymptomsTreatment OptionsApproximately how many MORE people are expected to be diagnosed with osteoarthritis by 2030 than 2005?Hypothesize why.DescriptionOSTEOGENESIS IMPERFECTACauses or Risk Factors SymptomsTreatment OptionsFrom Table 3-4, which types of OI is the worst? Is it dominant or rececessive?DescriptionOSTEOSARCOMACauses or Risk Factors SymptomsTreatment OptionsAccording to the graph, what is the most common age for males to be diagnosed with osteosarcoma? Females?DescriptionOSTEOMYELITISCauses or Risk Factors SymptomsTreatment OptionsWhat is the most common bone site for osteomyelitis?DescriptionPAGET’S DISEASECauses or Risk Factors SymptomsTreatment OptionsWhat is the most common age for males to be diagnosed with Paget’s disease? Females?HASPI Medical Anatomy and Physiology 08a Lab ActivityMOD EJO 2017

Station 6: Skeletal ProportionsHumans have used the proportions of skeleton throughout history to predict adult height or evendetermine the size of the “ideal man”. The scientific accuracy of these proportions is questionable. In thisactivity you will look at 3 common skeletal proportions and determine whether they have any accuracy indetermining your actual heightProcedure:1. Find a partner, a piece of string, and a yard stick.2. Use the yard stick to determine the heights of you and your partner. Record the measurements in thetable below.3. Spread your arms to the side and measure your wingspans from fingertip to fingertip. Record themeasurements in the table below.4. Use the following formula to calculate the percent error of your wingspan measurement and from yourmeasured height. Record the measurements in the table below.(Wingspan Measured height) x 100 – 100 Percent Error5. Measure the circumference around the foreheads of you and your partner. Then multiple thatmeasurement by 3 and record calculated height in table.6. Use the following formula to calculate the percent error of your calculated height measurement andfrom your measured height. Record the measurements in the table below.(Calculated height Measured height) x 100 – 100 Percent Error7. Measure the height of you and your partner’s head from the chin to the top of the head. Then multiplethat measurement by 7 and record the calculated height in the table.8. Use the following formula to calculate the percent error of your calculated height measurement andfrom your measured height. Record the measurements in the table below.(Calculated height Measured height) x 100 – 100 Percent ErrorTable 3: Skeletal ProportionsYour HeightMeasuredHeightWingspanPartner’s Head HeightCalculatedHeight%(x7)Error%ErrorHASPI Medical Anatomy and Physiology 08a Lab enceCalculatedHeight(x3)Head HeightCalculatedHeight%(x7)ErrorMOD EJO 2017%Error

Analysis QuestionsStation 21. Explain how the structure of bone is similar to reinforced concrete?2. What types of force do collagen and bone mineral resist?3. How much weight was your paper roll (long bone) able to hold? Hypothesize how much more wight itwould be able to hold if your taped 5 paper rolls together?Station 34. What passes through the Haversian canal?5. What is created in red bone marrow?6. What is found throughout trabecular bone? 7. What is the function of the periosteum?Station 48. Explain why calculating height from bone length is useful to a forensic pathologist.9.