Muscle Histology PDF - KINESIOL 1Y03 2022

KINESIOL 1Y03 Histology Actin Myofilaments sarcolemma: outer plasma membrane F-actin: linear polymer microfilament; 30: Muscle Histology...

KINESIOL 1Y03 Histology Actin Myofilaments sarcolemma: outer plasma membrane F-actin: linear polymer microfilament; 30: Muscle Histology sarcoplasm: cytoplasm of muscle cell strand of actin molecules; actin has two nuclei: found just deep to the sarcolemma strands coiled together Skeletal Muscle to prevent interference with internal G-actin: globular proteins which make up the function: consciously controlled muscles proteins strands (as opposed to smooth and cardiac) capillary beds: abundant on outside active site: small site on each G-actin surface (and increase with exercise) molecule; where we form the cross-bridge; not body movement: attached to bone; all skeletal mitochondria: THE POWERHOUSE OF THE always open muscles have to cross a joint maintenance of posture: helps stabilize joints CELL (produce ATP) tropomyosin: regulatory protein the first; 2 to maintain body positions; postural muscles myofibrils: series of highly organized long strands of protein which twist around are constantly contracting while awake proteins, which create long cylinders within F-actin to cover all the active sites respiration: diaphragm is the main muscle that the cell cylinder and extend the length of troponin: regulatory protein the second controls breathing the cell; have banding patterns G-actin: binds to circular part of troponin production of body heat: even at rest, muscle transverse tubules: invaginations of the tropomyosin: binds to pill-shaped part of turnover helps set core body temperature; troponin sarcolemma in regions where actin and shivering in the cold calcium: binds to other circular part; activates communication: writing, gesturing, speaking, myosin overlap; allows APs to reach inside tropomyosin to move when Ca from SR binds eye tracking, etc. the cell; 2 T-tubules/sarcomere unit here by changing shape of troponin properties: allow skeletal muscle to sarcoplasmic reticulum: SR; on either side change shape in response to signals of T-tubules; highly organized smooth ER which helps store calcium (which is Myosin Myofilaments contractility: can contract forcefully thick: much more protein in myosin than excitability: can respond to a stimulus by released into myofibrils to stimulate contractions) actin; made up of strands of myosin producing APs (activated by neurons in terminal cisternae: enlarged regions on each molecules; each surrounded by 6 actins skeletal muscle, neurons or hormones in end of SR, in regions where approaching T- rod: straight region; made of two myosin cardiac muscle) extensibility: can be stretched beyond resting tubule; large amounts of Ca storage heavy chains twisted together to form two length and still contract triad: 1 T-tubule + 2 associated terminal alpha-helices elasticity: can recoil to original length after cisternae hinge: region between rod and head where being stretched myofilaments: contractile proteins; highly movement is possible; allows the muscle composition: primarily made of muscle organized chains of proteins; organization to contract cells (fibers) surrounded by connective creates repeating sarcomeres; each one heads: teardrop-shaped ends facing tissues, blood vessels, and nerves does NOT run the full length of the fiber towards the Z-discs; have myosin light muscle fibers: long, cylindrical, actin: thin filament; lighter bands chains attached to them, and myosin multinucleated; very organized myosin: thick filament; darker bands ATPase (allows myosin heads to bind to myoblasts: immature muscle cells; migrate to Z-disc: proteins which cross the myofibril; actin and move it) areas where muscles will form, then fuse hold the myofilaments (particularly actin) grouping: ~300 myosin make 1 together into cells (hence multinucleated) in place; zig-zag shaped myofilament (~150 facing each way); at striations: patterns of light and dark banding M-line: thin layer of protein which spans varying lengths so heads stick out at due to protein organization within the cell different places myofibril; holds myosin in the middle the of structure: everything looks like more sarcomere (where it is located) cylinders but really it's just a Russian cross-bridge: binding of myosin and actin Sarcomeres (more.) nesting doll of screwed up; skeletal muscle to pull actin towards the M-line; in resting geometry: pretty much everything forms > fascicles > muscle fibers > proteins condition, they are not attached nice 6-sided symmetry titin: coiled protein near Z-disc, which then I-band: region around Z-disc where there is Gross Structure continues on and attaches to the M-line; only actin; spans multiple sarcomeres tendon: connective tissue attaching gives muscle elasticity; holds sarcomere H-zone: region around M-line which muscle to bone; dense regular collagenous together (only component that spans the includes only myosin continuity: continuous with periosteum of whole length (albeit in pieces)); 2 per A-band: spans full region of myosin, bone (dense irregular collagenous) and layers sarcomere including places of overlap; never changes extending through the muscle sarcomere: unit of contractile proteins that size muscle fibers: cells; cylindrical; each fiber are connected in series along the length of extends the full length of the muscle up to the muscle to form the myofibril; runs from Blood and Nerves the tendon Z-disc to Z-disc neurons: go into fascicles, then branch out endomysium: loose areolar and reticular myoglobin: used to carry oxygen from to connect with individual muscle cells connective tissue; separates individual blood through muscle cell coordination: one neuron can branch cells from each other glycogen granules: how carbohydrates are several times to reach multiple muscle fascicle: bundle of cells stored in skeletal muscle cells, but each muscle cell has only one perimysium: dense irregular collagenous ; dystrophin: protein which connected actin connection surrounds the cells of a single fascicle and membrane protein in sarcolemma; epimysium: surrounds all the fascicles membrane protein also connects to the muscular fascia: surrounds groups of three connective tissue layers muscles (or just the individual muscle) summary sheet by Jasmine Ah Yong for KINESIOL 1Y03 (2022)