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:
What ar the answer choices?
Explanation:
In the development of a cancer cell, the formation of new blood vessels is called Angiogenesis, option B. When tumors are present in the body, circulation and the distribution of nutrients in the body is altered; thus, resulting in different kinds of disorders associated with cancer. With the presence of cancer, these tumors need more nutrients to spread and grow, which results in the formation of more blood vessels.
Primary succession occurs in areas without life, while secondary succession occurs in places that were previously inhabitated.
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Answer:
40: 3
41: 1
Explanation:
40: When trying to achieve a better or sharper image on a microscope, the part of the microscope that needs to be adjusted is the "fine focus" which is responsible for better/sharper image by either moving the stage or the eyepiece. The fine focus is labelled C in the image.
41: Chromosomes contain hereditary materials (genes) that are responsible for an organism's trait. All organisms have their individual genetic materials in their cells and in the case of the onion cells, it's genetic materials (genes) are stored in the chromosomes hence it is important the cells have these chromosomes. Thus, the correct option is 1
