Describe the role of calcium in the regulation of the troponin-tropomyosin complex
What will be an ideal response?
Calcium binds troponin upon its release from the sarcoplasmic reticulum when the skeletal muscle fiber is excited. As a result of the binding, tropomyosin shifts and moves revealing active sites on actin. As the muscle relaxes, calcium ions are pumped back into the sarcoplasmic reticulum. Without calcium, troponin and tropomyosin return to their positions blocking the active sites on actin. Myosin heads are prevented from binding and muscle contraction is inhibited.
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Imagine a patient who loses lots of blood and therefore has less stretch of their aorta with each heartbeat. What reflex will result?
A. Baroreceptors increase firing, the vasomotor center increases firing, and skin blood vessels will dilate to cause a compensatory increase in flow. B. Baroreceptors decrease firing, the cardioacceleratory center increases firing, and cardiac output will exhibit a compensatory increase. C. Baroreceptors increase firing, the cardioinhibitory center increases firing, and the heart slows significantly to prevent further bleeding. D. Baroreceptors decrease firing, the cardioinhibitory center and vasomotor centers increase firing, the heart slows, and
Visible cytoplasmic granules are NOT present in ________
A) basophils B) monocytes C) eosinophils D) neutrophils
Teleosts have a bewildering variety of patterns of sex change, but protogyny and protandry are the most common. Describe the evolutionary principle that underlies those two patterns
What will be an ideal response?
What indicates that a long bone has reached its adult length?
the presence of osteons the presence of osteoblasts closure of the epiphyseal plate the presence of hyaline cartilage on the ends of the bone