Answer:
The order of events would be:
4.Threshold stimulus, Na+ channels open. This is the first event
5.Na+ influx, Depolarization. Second event
2.Na+ channels close, K+ channels open. This is the third event
1.K+ efflux, Repolarization. Fourth event
3.Hyperpolarization, K+ channels close
Explanation:
In resting state, the membrane is negative inside, and K+ concentration is higher than outside. Na+ concentration is higher outside instead.
Sodium influx is responsible for membrane depolarization. It's the event to produce the action potential. When sodium channels are closing, potassium channels open and K+ go outside until repolarization occurs. But now we have both ions in different sides of the membrane, and this can't be stimulated again to produce other action potential. The membrane will remain refractory to respond to the adequate stimulus until ions migrate to their original sites. This is Na+ outside, and K+ inside. This is responsibility of the Na+/ K+ pump, that uses ATP to pump Na+ out, and K+ in. Once both ions had been relocated in the membrane, this is ready to receive a correct stimulus to produce a new action potential.
Answer:
Your heart is a single organ, but it acts as a double pump. The first pump carries oxygen-poor blood to your lungs, where it unloads carbon dioxide and picks up oxygen. ... The second pump delivers oxygen-rich blood to every part of your body. Blood needing more oxygen is sent back to the heart to begin the cycle again.
Explanation:
Answer:
Explanation:
1.) All organisms differ in traits such as size and behavior.
2.) No two individuals are exactly alike.
3.) There was a gradual change in each species.
4.) Fossils were different from the living animals. However, these fossils had many similarities to modern forms of life.
5.) Species on the Galapagos Islands resembled species on the mainland but they were different in certain characteristics.
6.) Some organisms became isolated on many islands.
Answer:
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The ureter is the tubes that connect the kidneys the the bladder
The urethra is the exit point for excess water that goes through your ureter
