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Similar to human movement or The Human System for ergonomics 1.ppt
human movement or The Human System for ergonomics 1.ppt
- 2. Skeletal and muscularsystem
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- 4. What is skeleton? Skeleton: collection of bones that holds our body up. Baby has 305 bones and an adult has 206 bones Why ? because as we grown some of our bones join together to form one bone
- 5. Types of skeletons Exo-skeleton: animals that have shells Endo-skeleton: hard structure inside the animal. Hydrostatic skeleton: Fluid held inside the body No skeleton
- 6. Five functions ofour skeletons 1. Protect the vital organs 2. Give us shape 3. Allow us to move because our muscles are attached to our bones 4. Storage of nutrients such as calcium and silicon 5. Formation of blood cells
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- 8. X-rays The tool usedto examine bones
- 9. 6-9 Components of SkeletalSystem Bone Cartilage: three types Hyaline Fibro cartilage Elastic
- 10. Bone Shapes Long/ Pipe Ex. Upper and lower limbs Short Ex. Carpals and tarsals, bones in wrist and ankles Flat Ex. Ribs, sternum, skull, scapulae Irregular Ex. Vertebrae, facial 6-10
- 11. Long Bone Structure Longbone surrounds by tissues called periosteum Under periosteum is tissues called compact bone/ hard bone which contains bone cells, blood vessels, Ca, Phosphorus, and elastic fibers Ends of long bone covered by tissues called cartilage
- 12. What is bonemarrow? Fatty tissue, located in the cavities in the center of long bones or spaces of spongy bones Red marrow produce erythrocytes, most of leucocytes and platelets Yellow marrow produce some leucocytes. It colors is due to the much higher number of fat cells
- 13. No diaphysses and notelongated
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- 15. Central orHaversian canals: parallel to long axis Perforating or Volkmann’s canal: perpendicular to long axis. Both perforating and central canals contain blood vessels. Direct flow of nutrients from vessels through cell processes of osteoblasts and from one cell to the next. Lamellae: concentric, circumferential, interstitial Osteon or Haversian system: central canal, contents, associated concentric lamellae and osteocytes Osteocytes. Mature bone cells. Surrounded by matrix Lacunae: spaces occupied by osteocyte cell body Canaliculi: canals occupied by osteocyte cell processes
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- 17. Bone Histology Bonematrix. Like reinforced concrete. Rebar is collagen fibers, cement is hydroxyapetite Organic: collagen and proteoglycans Inorganic: hydroxyapetite. CaPO4 crystals Bone cells (see following slides for particulars) Osteoblasts Formation of bone through ossification or osteogenesis. Osteocytes Osteoclasts Resorption of bone Stem cells or osteochondral progenitor cells Woven bone: collagen fibers randomly oriented Lamellar bone: mature bone in sheets Cancellous bone: trabeculae Compact bone: dense 6-17
- 18. Bone Matrix If mineralremoved, bone is too bendable If collagen removed, bone is too brittle Extracellular matrix contains mineralization by crystal which contains Ca, Phosphate, and Carbonate (Hydroxyapetite) 6-18
- 19. Cancellouss (Spongy) Bone Trabeculae: interconnecting rods or plates of bone. Like scaffolding. Spaces filled with marrow. Covered with endosteum. Oriented along stress lines 6-19
- 20. Bone Development cartilages (beforeborn) Osteoblast (bone forming cells contains Ca and P) Osteocytes (bone cells) Osteoclast (destroy bone tissues and release Ca and P in blood circulation)
- 21. Chicken Bone Experiment Aim Tosee what happens to bones when we leave them in acid (vinegar) and water. This experiment can be set up and left in your classroom for the next four days after which the students will see the results. Students mission is to write up what they think will happen to the chicken bones in each bottle and why? Materials and Equipment Clean chicken bones ( thigh bones) Two glass jars with lids per group Water White vinegar Paper towels
- 22. PROCEDURE Place somechicken bones in each jar. Label one jar with your groups name, date and ‘water’ – add the bones and water Label the second jar with your groups name, date and ‘vinegar’ – add bones and vinegar Leave the jars for about 3 weeks after which you can remove and dry the bones on some paper towels Observe the difference in the two sets of bones DISCUSSION What has happened to each set of bones and why?
- 23. 6-23 Factors Affecting BoneGrowth Size and shape of a bone determined genetically but can be modified and influenced by nutrition and hormones Nutrition Lack of calcium, protein and other nutrients during growth and development can cause bones to be small Vitamin D Necessary for absorption of calcium from intestines Can be eaten or manufactured in the body Rickets: lack of vitamin D during childhood Osteomalacias: lack of vitamin D during adulthood leading to softening of bones Vitamin C Necessary for collagen synthesis by osteoblasts Scurvy: deficiency of vitamin C Lack of vitamin C also causes wounds not to heal, teeth to fall out
- 24. 6-24 Factors Affecting BoneGrowth, cont. Hormones Growth hormone from anterior pituitary. Stimulates interstitial cartilage growth and appositional bone growth Thyroid hormone required for growth of all tissues Sex hormones such as estrogen and testosterone Cause growth at puberty, but also cause closure of the epiphyseal plates and the cessation of growth
- 25. 6-25 Bone Fractures Open(compound)- bone break with open wound. Bone may be sticking out of wound. Closed (simple)- Skin not perforated. Incomplete- doesn’t extend across the bone. Complete- does Comminuted fractures: complete with break into more than two pieces
- 26. Joints Joints arethe point were bones meet. There are two groups, movable and immovable joints Ball-and-socket joints- formed when a rounded head of one bone fits into the rounded cavity of an jointed bone. Hinge joints-would include elbow, knee, ankle, and fingers. Allows extension and retraction of apendage Sadle joints- A saddle joint allows movement back and forth and up and down, bot does not allow for rotation like a ball and socket joint.
- 27. Gliding joints-In a gliding or plane joint bones slide past each other. Midcarpal and midtarsal joints are gliding joints. Pivot joints- allow limited rotation or turning of the head Ellipsoidal joints- bone in wrist, and a oval shaped part that fits in a curved space, the joints slide over each other
- 28. Functions of theMuscular System Involuntary Some involuntary functions of the muscular system are muscles to help you breathe, make your heart beat, and help move food through the digestive system. Voluntary Some voluntary functions of the muscular system are like playing piano, running, playing video games, and throwing a ball. Muscles Muscles An organ that can contract to become shorter
- 29. Muscles An organ thatcan contract to become shorter
- 30. Cardiac Muscle • One, centrallylocated nucleus • Presence of striations • Short, branched cells • Presence of intercalated discs • “involuntary” • Myogenic (contraction originates within the muscle cell) • Does not fatigue
- 31. Skeletal Muscle Many, peripherallylocated nuclei (develops from many myoblasts) Presence of striations Long (up to 30 cm), thin cells “voluntary” Neurogenic (contraction is initiated my motor neuron input) Can fatigue
- 32. Smooth Muscle • One,centrally located nucleus • No striations • Short, tapered cells • “involuntary” • Myogenic with some neurogenic modulation • Does not fatigue
- 34. Synergists =muscles that work together to produce certain movements (ex. Multiple arm muscles are needed for flexion of the antibrachium) Antagonists = muscle(s) that work(s) to oppose certain actions = moves the structure in the opposite direction (ex. Triceps brachii is an antagonist to the biceps brachii and causes extension of the antibrachium)
- 35. Muscles consist ofa – Belly = the region with the muscle fibers Tendon = connective tissue at the ends of the muscle that is continuous with the muscle and the connective tissue layer of the bone to which the muscle attaches Fascia = connective tissue layer that surrounds the muscle
- 36. Fractures Joints Dislocation- is whenthe ligaments attached to the bone are torn or out of place Torn cartilage- is a sharp blow or twisting of the joint Arthritis- inflammation of the joint and is a result of natural wear and tear
- 37. Fasiculus = abundle of muscle fibers, many per muscle Muscle Fiber = a single muscle cell Epimysium (fascia) = connective tissue layer that holds many fasiculi together, with the associated nerves, arteries and veins, to form a muscle (an organ) Perimysium = connective tissue layer that surrounds and produces a fasiculus Endomysium = connective layer surrounding a single muscle fiber
- 38. Microscopic anatomy ofmuscle cells Sarcomere = smallest contractile unit in a muscle fiber; extends from Z-line to Z-line A (anisotrophic band) band = “without change band” = at low magnification it looks the same regardless of the contractile state of the muscle; contains thick myofilaments overlapped with thin myofilaments I (isotrophic band) band = “with change band” = density changes at low magnification depending upon the contractile state of the muscle; at rest, contains only thin myofilaments Z-lines = dense regions at the ends of sarcomeres, serve as sites of thin filament attachment H-zone = region in the middle of the A-zone that at rest contains only thick filaments
- 39. Muscular Contraction Impulsefrom nervous system
- 40. Sliding Filament Theoryof Muscular Contraction Muscle contraction occurs when thick (myosin) and thin (actin) myofilaments are allowed to interact; thin filaments “slide” along thick filaments to the center of the sarcomere, thus shortening the contractile unit
- 41. 1. Gastrocnemius 2. Sartorius 3.Deltoid 4. Sternocleidomastoid 5. Tibialis 6. Hamstring group 7. Rectus Abdominus 8. Triceps 9. Biceps 10. Extensor Group
Editor's Notes
- #8 Some examples of x-ray images. Get the students to bring in some if they have them at home.
- #21 Experiment to show that calcium is an important chemical which given bones it’s hardness and strength. Over a period of 3 weeks, vinegar breaks down calcium in bones which causes them to become soft and pliable. Water has no effect on them so bones in water remain hard.
- #41 Show students some of the major muscles. Use books, internet and pictures to explore other muscles.