Explanation
ANF(Atrial natriuretic factor) is a protein hormone which is secreted by the atrial wall in response to the high blood pressure into the circulatory blood. ANF causes vasodilation (dilation of blood vessels) and thereby decrease the blood pressure. ANF mechanism, therefore, acts as a check on the renin-angiotensin mechanism. So, the correct answer is 'Blood pressure'.
$$\textbf{Correct option:A}$$
$$\textbf{Solution:}$$
$$\textbf{Option (A)}$$
$$\bullet$$ Adrenal medulla secretes tyrosine derivatives ,adrenaline and noradrenaline at the time of stress,fright and during strenuous activity where energy is required .
$$\bullet$$ Adrenaline constricts blood vessels and accelerates the heart beat ,so the blood pressure increases which in turn increases oxygen consumption and leads to breakdown of glucose to increase the production of ATP.
$$\textbf{Option (B)}$$
$$\bullet$$ Glucagon converts stored glycogen into glucose in the liver and adipose when glucose level falls in the body to provide a source of energy. It is a catabolic hormone ,which promotes breakdown of amino acids and oxidation of fat.
$$\textbf{Option (C)}$$
$$\bullet$$ Gastrin is a gastrointestinal tract hormone secreted from the mucosa of the pyloric region in the stomach that stimulates secretion of hydrochloric acid and pepsinogen.
$$\textbf{Option (D)}$$
$$\bullet$$ Thyroxine regulates the normal metabolic rate by increasing the activity of heart rate resulting in an increase in the uptake of oxygen by the cells. This causes an increase in respiration and the production of ATP. Prenatal brain development and temperature homeostasis is also controlled by this hormone.
$$\textbf{Hence, the correct option is (A)}$$
Please disable the adBlock and continue. Thank you.
