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:
The phloem carries important sugars, organic compounds, and minerals around a plant. Sap within the phloem simply travels by diffusion between cells and works its way from leaves down to the roots with help from gravity. The phloem is made from cells called 'sieve-tube members' and 'companion cells'.
According to the blood type chart, if a child has type A blood and one parent in Type O, the possible genotypes for the other parent are type A or type B. I hope my answer has come to your help. God bless and have a nice day ahead!
Complete question:
In bird dogs, barking while trailing (B) is dominant to silent while trailing (b). A heterozygous barking trailer is bred to a silent female trailer. Various offspring resulted.
- What is the genotype of the male animal?
- What is the genotype of the female animal?
- How many different genotypes are possible among the offspring?
- What proportion of the offspring will be heterozygous barkers?
Answer and Explanation:
<u>Due to technical problems</u>, you will find the complete question, answer, and explanation in the attached files.