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Musculoskeletal System - Coggle Diagram
Musculoskeletal System
Muscles
Skeletal Muscle
attached to bones by tendons. Function is to allow for movement and maintain body posture and support of skeleton
long and cylindrical, striated because of sarcomeres (contractions), muscle fire multi nuclei, voluntary
Cardiac Muscle
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branched system, striated because of contractional units, intercalated discs to connect single nucleus cells. involuntary
smooth muscle
Founds in the walls of hollow organs. Function depending on organ, peristalsis and lining organs
spindle shaped, single nucleus, non-striated, involuntary slow contractions
Muscle structure
made up of bundles called muscle fascicles. which are made of muscle fibres which are the skeletal muscle cells.
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Sarcomere- contractile unit of the muscle. contains thick filament called myosin and thin filament called actin.
Myosin have myosin heads, and actin have myosin binding sites. tropomyosin wraps around actin, covering binding sites. troponin is directly attached to the tropomyosin
Sliding Filament Theory
- muscle contraction is initiated by nerve impulses
- sarcoplasmic reticulum is triggered to release calcium ions into muscle fibre
- once released, calcium ions bond to troponin found on actin
- calcium binding causes troponin to change shape and move slightly. troponin pulls tropomyosin along with it, exposing myosin bonding sites to the actin
- at rest the myosin is bound to ATP. when the myosin binding sites are exposed, this ATP is broken down to make ADP and a phosphate
- the phosphate is released. myosin head binds to actin
- ADP is released. myosin performs powerstroke, myosin head pull actin pulling sarcomeres closer together
- myosin stays bound to actin until a new ATP molecule binds, this causes the myosin head to let go of actin. returns to origional position
Muscle Relationships
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Stabilisers
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during arm flexion and extension, muscles in shoulder work tp stabilise shoulder joint.
Skeletal System
Bone
composed of collagen rich fibres, minerals, hard and strong
contents: cells, collagen fibers, extracellular material (matrix)
bone marrow on inside (yellow and red, soft and flexible which produces blood cells and stores fat) > surrounded by spongy bone (meshwork of intercrossing, connecting bars of bone, minerals and collagen for strength)> covered by compact bone (solid matrix, calcified matrix arranged in layers, very strong)
Cartlidge
composed of collagen rich fibres, no minerals, soft and flexible
no nerves or blood vessels, cells rely on diffusion for nutrients from nearby blood vessels
Ligaments
composed of fibrous connective tissue, connect bones to other bones, found at joints
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Joints
Fibrous Joints
Connected by a strong, inflexible fibrous tissue
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Synovial Joint
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ligaments and joints form a joint cavity that is filled with synovial fluid, nourishes the joint and allows gliding movement
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ball and socket: shoulder and hip, free moving all directions
Hinge Joint: move one axis, elbow
Pivot Joint: bones pivot around each other, neck
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