Pain behind one eye is a common complaint among people who suffer with cluster headaches and the one-sided nature does not usually change sides. Eyestrain is one of the common causes of pain behind the eyes and it is prevalent these days with prolonged use of computers and long hours of watching TV. It is due to multiple factors like dry eyes from infrequent blinking and strain of the inner eye muscles due to staring at a fixed distance for a long period of time.
Because these somatic cells do not regularly use telomerase, they age. The result of aging cells is an aging body. If telomerase is activated in a cell, the cell will continue to grow and divide. This immortal cell theory is important in two areas of research: aging and cancer. Cellular aging, or senescence, is the process by which a cell becomes old and dies.
â¢ Myosin heads rotate, bind the actin, and pull the actin fibers toward the center of the sarcomere. â¢ In the presence of Ca ++ , myosin acts as an enzyme. It catalyzes breakdown of ATP. Energy is transferred from ATP to the myosin head; myosin is activated.Steps of Muscle Contraction 1 2 3 4 5 6 7 8 9. AP Biology Reading Guide Chapter 50: Sensory and Motor Mechanisms Fred and Theresa Holtzclaw Copyright Â© 2010 Pearson Education, Inc. 8 22.f your teacher stresses human anatomy and physiology, you may be expected to go into more depth. In this Reading Guide, we will ask you to cover only material that might be on an AP Biology exam. Concept 50.1 Sensory receptors transduce stimulus energy and transmit signals to the central nervous system 1.