Final answer:
Decreased water excretion is NOT a result of the stimulation of atrial stretch receptors. Instead, these receptors' activation leads to increased secretion of ANP, which causes the excretion of sodium and water, reducing blood volume and blood pressure.
Step-by-step explanation:
The question is asking which of the listed options is not a result of the stimulation of atrial stretch receptors. Atrial stretch receptors are activated by an increase in blood volume and blood pressure that causes the atria to stretch. The stimulation of these receptors leads to several physiological responses:
- Reflex tachycardia: This is a compensatory increase in heart rate. However, it is not the primary response to atrial stretch.
- Increased secretion of ANP (Atrial Natriuretic Peptide): This hormone is indeed secreted by atrial cells in response to stretch, leading to increased excretion of sodium and water, which in turn reduces blood volume and blood pressure.
- Decreased water excretion: This would not result from atrial stretch receptor stimulation because ANP promotes the loss of sodium and water.
- Inhibition of ADH (Antidiuretic Hormone): ANP inhibits ADH release, which would typically cause the kidneys to conserve water; by inhibiting ADH, ANP promotes diuresis, not water retention.
Thus, the correct answer to the question is option C, indicating that decreased water excretion is not a result of atrial stretch receptor stimulation.