muscle fibre
Quick Summary
A muscle fibre is a long, cylindrical cell that makes up muscle tissue. These fibres are highly organized, featuring alternating dark and light bands due to the arrangement of thick and thin filaments within them. Each fibre is enclosed by a sarcolemma, a complex structure including a plasma membrane that maintains the electrical potential necessary for muscle contraction. The sarcoplasm, the fibre's cytoplasm, contains essential molecules like ATP and enzymes for metabolic reactions, along with ions such as potassium, sodium, magnesium, and calcium. Muscle fibres contain multiple nuclei, a result of their development from fused cells. Mitochondria within the sarcoplasm are crucial for energy production through processes like the Krebs cycle and oxidative phosphorylation, while glycogen granules store carbohydrates for energy. The colour of muscle fibres (red or white) depends on their metabolic activity and the presence of molecules like myoglobin and cytochromes.1
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action potential…a nerve cell (neuron) or muscle cell. In the neuron an action potential produces the nerve impulse, and in the muscle cell it produces the contraction required for all movement. Sometimes called a propagated potential because a wave of excitation is actively transmitted along the nerve or muscle fibre, an…
Read More…a nerve cell (neuron) or muscle cell. In the neuron an action potential produces the nerve impulse, and in the muscle cell it produces the contraction required for all movement. Sometimes called a propagated potential because a wave of excitation is actively transmitted along the nerve or muscle fibre, an…
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reflex…other nerve cells that activate muscle cells (or effectors), which perform the reflex action. In most cases, however, the basic physiological mechanism behind a reflex is more complicated than the reflex arc theory would suggest. Additional nerve cells capable of communicating with other parts of the body (beyond the receptor…
Read More…other nerve cells that activate muscle cells (or effectors), which perform the reflex action. In most cases, however, the basic physiological mechanism behind a reflex is more complicated than the reflex arc theory would suggest. Additional nerve cells capable of communicating with other parts of the body (beyond the receptor…
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human sensory receptionNerve function… spindles consist of small, fine muscle fibres around which sensory fibre endings are wrapped; (2) Golgi tendon organs consist of sensory nerve fibres that terminate in a branching encapsulated within the tendon; (3) joint receptors (as in the knee) consist of “spray-type” Ruffini endings and Golgi-type and Pacinian corpuscles within…
Read More… spindles consist of small, fine muscle fibres around which sensory fibre endings are wrapped; (2) Golgi tendon organs consist of sensory nerve fibres that terminate in a branching encapsulated within the tendon; (3) joint receptors (as in the knee) consist of “spray-type” Ruffini endings and Golgi-type and Pacinian corpuscles within…
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