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:
It supports it by saying that there was once only one mammal but then it reproduced and since different places have different climates they adapted or evolved to the climate changing their form and shape.
The answer is A. flattened maxilla.
<span>. Estuaries have been called the "nurseries of the sea" because the protected environment and abundant food provide an ideal location for fish and shellfish to reproduce. Most commercially important fish species spend some part of their life cycle in estuaries. Besides fish, many species of birds depend on estuaries for food and nesting areas. Migratory birds use estuaries as stopover points for resting and feeding before continuing their journey. Marine mammals also use estuaries as feeding grounds and nurseries.</span>
Answer:
energy pyramid
Explanation:
An energy pyramid is a diagram that compares the energy used by producers, primary consumers, and other trophic levels. In other words, an energy pyramid shows how much energy is available at each trophic level. Energy is lost at each trophic level of a food chain.
