Joint shapes - Lecture notes 2 PDF

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First semester, Anatomy...

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Joint shapes - Uniaxial joints: Hinge joints (elbow joint) - Biaxial joints: saddle joints (metacarpophalangeal joint of the thumb) - Tri axial joints: ball and socket joints (shoulder joint) Structure of tissues: Muscle and nerve tissue Skeletal muscles (striated) - Muscles of the musculoskeletal system, face, tongue, larynx, pharynx and upper esophagus, the Eyeball, middle ear, pelvic floor, and diaphragm. - Are supplied by the somatic nervous system, largely moved voluntarily. Fine structure of skeletal muscles - Primary bundle sheathed by perimysium intern, internally contains endomysium; secondary bundle surrounded by the perimysium extern surrounded by perimysium; total muscle enveloped by epimysium, which is connected to the muscle fascia. Myofibrils Myofibrils = muscle fibrils = longitudinal, contractile element of the muscle cell, which is composed of actin and myosin II with their associated proteins. Ultrastructure of myofibrils - Each myofibril is composed of many parallel thick and thin filaments. - I-band: thin filaments (actin). - A-band: thick filaments (myosin) Sarcomere large, feather-like coiled protein, anchored in M- and Z-disc, responsible for elastic extensibility of muscles. Filament proteins: myosin filament. Myosin filament consisting of interconnected Tail parts of approximately 300-350 myosin II molecules. Heads protrude laterally from the filament.

Motor terminal Contact site of an axon terminal with a muscle fiber. (schematic representation). The axon terminal descends into the muscle fiber. The membrane of the postsynaptic side is strongly folded tubular system - In the sarcoplasm (cytoplasm) of the muscle cell run 2 separate units of fine channels: transversal and longitudinal system § Transverse system: invagination of the outer membrane into the interior of the muscle fiber o Surrounding I and A bands § Longitudinal system: spins around myofibrils and runs perpendicular to the T- system o Calcium ion storage...