Answer:
When you sit on a plane for 6 hours without moving, blood accumulates in your veins, and the moment you get up, gravitational forces affect venous return, cardiac output, blood pressure, and venous pressure. That way, when you're sitting on a plane, the gravitational force is the same at the upper and lower extremities, such as the chest, abdomen, and legs, causing venous blood pressure and volume to be evenly distributed throughout the body. However, when one gets up, one becomes dizzy because of abnormal regulation of blood pressure. This is because gravity causes blood to accumulate in the lower extremities (veins of the legs and trunk). This lowers the blood pressure and the blood that the heart pumps. By causing blood to accumulate in the lower extremities, and as venous compliance increases, the veins expand with blood that causes the volume of blood to shift in the veins. This increases the volume and venous pressure in the lower extremities when standing. And the volume of thoracic venous blood is less and less central venous pressure. This leads to a decline in stroke volume. Cardiac output and mean arterial pressure also decrease as left ventricular stroke volume decreases, reducing pulmonary venous return. Decreased standing blood pressure, referred to as orthostatic or postural hypotension. Thus, lowering blood pressure decreases cerebral blood flow, which means less range of blood in the brain causing dizziness.
Explanation:
Answer:
When a new and aggressive species is introduced into an ecosystem, it may not have any natural predators or controls. It can breed and spread quickly, taking over an area. Invasive species can change the food web in an ecosystem by destroying or replacing native food sources.
Explanation:
I majored in Biology
Answer:
LDNJSIOAG JHDFJI GIRL PLEASE
Explanation:
girl drop them!! u dont deserve them?? they're clearly not ur "bsf" if they take yo man,, KNOW UR WORTH !!
Chirping, if that's what you mean.
Yes
Explanation:
If two bottles are made up of the same substances, their particles are identical and the same.
According to the law of constant composition "all pure samples of the same chemical compounds contain the same proportions of the elements by mass".
- Every time we have a particular substance, it has the same percentage composition
- If we have two bottles lets say containing water.
- Both bottles would be made up of water molecules with two atoms of hydrogen and 1 atom of oxygen in their composition.
- So they contain the same substances that are the same and identical.
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Compound brainly.com/question/10216585
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