Question

E. The "All or None" Law of the Heart Threshold = Volts, produced -. mV force. (1 pt) Voltage 0.1 V 0.2 v 0.3 0.4 0.5 0.6 0.7 V 0.8 V 0.9 V 1.0 V Force (mv) o o o o o olo 1.225.118 1.251 Prepare a graph of these data. Don't forget to include species used! (Fig. 2) (5 pts) The frog heart rate only increases two or three times even when electrically stimulated at frequencies that tetanize skeletal muscle. What prevents heart muscle from tetanizing? (1 pt)

Answer 1

Answer: 2 sconto 1) This is because of its unique refractory period I where after an activation of about 300 milliseconds It į Bunresponsive to any further stimule until it resets and come back to normal. - Contrast to skeletal muscles which can be tetanized by multiple raped stimuli reaching a manirnal conteartion limit and going the muscle spasm. 2) Acetylcholine cant not increase stokke volume An increase in Sympathetic Activity increases Stroke volume. ad which can only be increased by the release of norepinephrine by the adrenal medulla Epinephrine, like norepinephrine will stimulate an increase in the strength of myocardial contruction and this increase stroke volume. - Acetylcholene on the other hand e a neuro- transmitter and can lower the heart rate Instead of increasing the stock volume. please rate my Answer