Musculo-Skeletal system
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Transcript of Musculo-Skeletal system
Musculo-Skeletal system
• http://kidshealth.org/PageManager.jsp?lic=1&article_set=59302&cat_id=20607
• Skeletal system• http://www.youtube.com/watch?v=UGTenIDJ
BwU
Evolution of the System• Muscles evolved 500-800 million yrs.
ago• Actin muscle protein structure
resembles mreB structure in bacteria– mreB is used to maintain shape of the
bacterial cell
• Myosin resembles Muk and SMC in bacteria– Muk condenses DNA after DNA replication
• 500 million yrs. ago, striated and smooth muscle diverged
Types of Skeletons• Hydrostatic Skeleton– Fluid-filled body cavity– Found in Porifera, Nematoda, and most
other invertebrate phyla
• Exoskeleton– Hard segments cover muscles– Found in Arthropoda
• Endoskeleton– Internal, contains bones and cartilage– Found in Chordata
Types of Bones• Long Bones– Work as levers
• Short Bones– Cube-shaped– In wrists and ankles
• Flat Bones– Protect organs– Broad, have muscles attached
• Irregular Bones
Divisions of Human Skeleton
• Axial Skeleton– Skull– Sternum– Ribs– Vertebral Column
• Appendicular Skeleton– Shoulder Girdle– Pelvic Girdle– Extremities
Types of Muscle• Skeletal Muscle– Voluntary movement– Example: Biceps
• Smooth Muscle– Involuntary contraction– Used in digestion
• Cardiac Muscle– Located in the heart– Pumps blood through the body
http://faculty.etsu.edu/forsman/Histologyofmuscleforweb.htm
Interdependence
• Skeletal muscle is directly controlled by the nervous system– Motor neurons are attached to
muscle at neuromuscular junctions• B cells for the immune system are
produced in bone marrow• Eyes use muscles to move• Digestion and Excretion use
smooth muscles to transport the food
Diseases and Disorders
• Duchenne Muscular Dystrophy– Afflicts skeletal muscle– Person cannot create dystrophin– Muscle cells break down– X-linked genetic disorder
• Cardiomyopathy– Afflicts cardiac muscle– Lower chambers of the heart weaken first
• Osteosarcoma– Type of cancer– Mostly develops in bones near the knee
Bone Cells• Osteoblasts– Create bone– 10 microns diameter– Derived from mesenchymal stem cell
• Osteoclasts– Absorb bone– 20-100 microns diameter– Derived from macrophages
• Osteocytes– Osteoblasts encased in bone matrix
Bone: Connective Tissue
Example of Skeletal Muscle
-Connects muscle to bone
-Connect bones
Myofibrils
• A fiber bundle contains hundreds of myofibrils that run the length of the fiber
• Each myofibril is a linear array of sarcomeres • Each sarcomere is capped on ends by a transverse
tubule (t-tubule) that is an extension of sarcolemmal membrane
• Surfaces of sarcomeres are covered by SR
Muscle Contraction
Muscle Contraction in Actionhttp://www.sci.sdsu.edu/movies/actin_myosin.html
http://www.dnatube.com/video/1306/Muscle-contraction
Works Cited• http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookMUSSK
EL.html• http://kidshealth.org/teen/diseases_conditions• http://www.pubmedcentral.nih.gov/articlerender.fcgi?
tool=pubmed&pubmedid=17158703#id358647• http://www.pubmedcentral.nih.gov/articlerender.fcgi?
tool=pubmed&pubmedid=10677457• http://www.sci.sdsu.edu/movies/actin_myosin.html• http://www.mnsu.edu/emuseum/biology/humananatomy/skeletal/
skeletalsystem.html• http://www.engin.umich.edu/class/bme456/bonephys/bonephys.htm• Garrett and Gershom. Biochemistry.