Question

Atrial Natriuretic Factor (ANF) decreases :
A. Blood Pressure
B. Secretion of Renin
C. $N{a^ + }$ excretion
D. Vasodilation

Answer 1

ANF is secreted by cardiac muscle cells in the heart’s atrial walls.
Its primary function is to stretch the atrial walls to increase their volume, so as to ensure easy blood flow without any type of pressure.

Complete answer:

ANF(Atrial natriuretic factor) is a 28-amino acid polypeptide protein hormone which is secreted by the atrial wall following the high blood pressure.
ANF dilates the blood vessels (vasodilation) and thus, decreases the blood pressure.
ANF’s mechanism functions as a control on the mechanism of renin-angiotensin.
ANF reduces the loads of sodium, water and adipose, on the circulatory system, thus decreasing the blood pressure.
ANF hormone consists of mixtures of peptides of various lengths.
ANF is constantly released from the heart’s atria, but any inappropriate mechanical stretching can unhealthily increase the rate of secretion of ANF.
In the kidney, ANF increases the excretion of sodium and the Glomerular Filtration Rate, to act in opposition to renal vasoconstriction, and to hamper the secretion of renin.
ANF in urine increases with increased intake of salt, thus, reflecting its eminent role in natriuresis.
In the cardiovascular system, ANF antagonizes vasoconstriction.
In the adrenal gland, the ANF powerfully inhibits the synthesis of aldosterone.
ANF is significantly involved in the natriuretic response to the chronic as well as acute volume overload.
So, according to the information mentioned above :-
Option A) Blood pressure - is the Correct option.
Option B) Secretion of Renin - is an incorrect option
Option C) $N{a^ + }$ excretion - is an incorrect option
Option D) Vasodilation - is an incorrect option

So, the correct answer is option A.

Note: ANP is a cardiac hormone, and it helps in the regulation of salt-water balance and blood pressure by enhancing renal sodium and water excretion; and also in stimulating the dilation of blood vessels (vasodilation).
It also prevents any type of cardiac hypertrophy.