These fluctuations may also affect the predators that feed on these prey items, such as wolves, foxes and owls. These predators must either find an alternate source of prey or risk starvation and death. Ecological Succession. When changes to either abiotic or biotic factors affect an entire ecosystem, ecological succession occurs.
A temporary decrease in blood flow to the brain results in unconsciousness, or fainting. Many disorders, some of them serious, can cause this.
Why You Faint. Fainting is a temporary loss of consciousness due to a loss of blood supply to the brain. The heart is continuously pumping blood to your brain, delivering oxygen. If for some reason your heart stops pumping oxygen to your brain, youâll start getting woozy or cloudy in about 3 to 5 seconds. Then, all of a sudden, youâve fainted. What Are Some Causes of Fainting. Activities that cause a rapid rise and subsequent drop in blood pressure can cause a fainting spell. Coughing forcefully, straining in the bathroom, standing up suddenly, and being in a hot crowded room can cause you to faint.