<span>A disease is a disorder of structure or function in an organism; diseases are especially characterized by different symptoms. Diseases may be caused by a variety of mechanisms including invasion of a foreign organism or substant to genetically inherited diseases.</span>
Answer:
According to research jump rope for a minimum of five minutes a day can improve physical fitness and when you build to ten minutes of nonstop jumping at 120 RPMs it can provide the same benefits as all of the following except:
Answer:
1. spontaneously
2. resting potential
3. action potentials
4. pacemaker potentials
5. K+
6. Na+
7. into
8. Ca+
Explanation:
Pacemaker cells (also known as sinoatrial node cells) are cells that generate rhythmic impulses and set the pace for blood pumping in the heart. These cells have the ability to rhythmically depolarize and initiate action potentials. In pacemaker cells, Ca2+ and Na+ levels are higher in the extracellular environment, while K+ concentration is higher intracellularly. The pacemaker action potentials have three phases: 1-depolarization, where membrane potential reaches -40 mV and voltage-gated Ca2+ channels open, 2-repolarization, where voltage-gated Ca2+ channels close and voltage-gated K+ channels open, and finally 3-gradual depolarization, which is caused by the slow influx of Na+ ions.
