Question

ANF leads to (a) Dilation of blood vessels (b) \downarrowes blood pressure (c) Both (a) and (b) (d) Tes blood pressure

Short answer

The correct answer is (c). Both dilation of blood vessels and decreased blood pressure are effects of ANF.

Step-by-step solution

Understanding Functions of ANF

Comprehend the functions of Atrial Natriuretic Factor (ANF). This hormone is released by the heart upon stretching of the atria. It acts as a vasodilator, meaning it widens (or dilates) the blood vessels, and increases the excretion of sodium by the kidneys. This leads to a decrease in blood volume and thereby reduces blood pressure.

Evaluate the Options

Evaluate the given options against the known functions of ANF. Option (a) - dilation of blood vessels, fits the function of ANF as a vasodilator. Option (b) points to a decrease in blood pressure, which is also correct as explained in step 1. The other options do not correctly describe the function of ANF.

Choosing the Correct Option

Based on the analysis, it is clear that both dilation of blood vessels and decreased blood pressure are effects of ANF. Therefore, the best choice that captures all correct information is option (c), which includes both (a) and (b).

Key concepts

Vasodilation

Vasodilation is a process where blood vessels widen or dilate. This is one of the important functions of the Atrial Natriuretic Factor (ANF). When ANF is released by the heart, particularly when the heart experiences increased blood volume that causes the atria to stretch, it causes vasodilation. This widening of the vessels occurs as the smooth muscles within the vessel walls relax.

Through vasodilation, blood can flow more easily, which helps in reducing blood pressure. It is a natural mechanism the body uses to maintain good blood flow and manage blood pressure levels under various conditions.

Understanding vasodilation helps us see how the body responds to changes in blood volume and pressure, using tools like hormones to ensure all tissues receive adequate oxygen and nutrients.

Blood Pressure Regulation

Blood pressure regulation is crucial for maintaining health and preventing conditions like hypertension. ANF plays a significant role in this by contributing to vasodilation and influencing sodium excretion. By causing the blood vessels to relax and expand, ANF effectively reduces the resistance against which the heart must pump, leading to lower blood pressure.

Moreover, ANF also promotes the excretion of sodium through the kidneys. As sodium exits the body, water follows due to osmotic forces, leading to a decrease in blood volume. With less blood volume, there is less pressure within the vessels, further contributing to lower blood pressure.

• Reduces blood vessel resistance
• Decreases blood volume through sodium and water excretion

These actions work together to help the cardiovascular system maintain stable and healthy blood pressure levels.

Hormonal Functions

Hormonal functions include regulating various bodily processes, and ANF is a hormone with a specific role in the cardiovascular system. Released by the heart, ANF targets several areas in the body, aiding in the control of blood volume and pressure.

ANF does this by guiding the kidneys to increase sodium excretion. This action is part of a broader system where hormones manage how much fluid and electrolytes are kept or released by the body. Additionally, it signals the relaxation of blood vessel walls, contributing to vasodilation.

• Regulates blood volume by influencing sodium retention or excretion
• Promotes vasodilation to ease circulatory strain

These hormone-driven processes are vital for adaptive responses to daily fluctuations in diet, activity, and physiological stress.

Sodium Excretion

Sodium excretion is a key mechanism through which ANF helps control blood pressure. The kidneys play a central role in this process. When ANF is released, it prompts the kidneys to expel more sodium into the urine.

This increase in sodium excretion naturally leads to an increase in water excretion as well, because water tends to follow sodium. As water leaves the body along with sodium, the blood volume decreases. Lower blood volume means there is less blood pushing against the walls of the blood vessels, ultimately reducing blood pressure.

• Sodium removal helps reduce fluid volume
• Lower volume decreases blood pressure

Understanding sodium excretion with respect to ANF illustrates how the body's internal systems work seamlessly to keep physiological variables within a healthy range.