Question

. Diabetes mellitus type 2 is the most common type of diabetes. The disease is characterized by high levels of glucose in the blood (hyperglycemia) that exceed the renal threshold. Common symptoms for someone that might have type 2 diabetes include increased urination (polyuria) and increased thirst (polydipsia). Because of this, individuals with diabetes are at risk for dehydration.

a. Explain how hyperglycemia causes polyuria and polydipsia.
b. Provide a mechanism for how the body might compensate for the altered blood osmolarity due to hyperglycemia.
c. Provide a mechanism for how the body would compensate for the altered blood volume and blood pressure due to hyperglycemia (While this mechanism provided in 'b' might also be used to compensate for altered blood volume and blood pressure, provide an alternative mechanism).
d. What effect might hyperglycemia have on aldosterone secretion? Explain

Answer 1

Type 2 diabetes leads to polyuria and polydipsia due to the kidneys filtering high glucose, which increases urine production and thirst. The body compensates for altered blood osmolarity through increased water intake and for blood volume and pressure changes via heart rate modification and the renin-angiotensin-aldosterone system. Aldosterone secretion is increased to help retain sodium and water.

Step-by-step explanation:

Understanding Type 2 Diabetes
Type 2 diabetes is characterized by high blood sugar levels, often leading to polyuria (increased urination) and polydipsia (increased thirst). This is because the kidneys filter out high glucose, which draws water into the urine, causing more frequent urination and leading to dehydration. In response to the altered blood osmolarity due to hyperglycemia, the body compensates by encouraging water intake to reduce glucose concentration, thereby trying to normalize osmolarity.

Mechanisms of Body Compensation
For altered blood volume and blood pressure, the body may increase heart rate and contractility (strength of heart contractions) to maintain blood pressure, engaging the sympathetic nervous system. Another mechanism involves the renin-angiotensin-aldosterone system, where decreased kidney perfusion leads to renin release, ultimately increasing blood volume and blood pressure. Regarding aldosterone secretion in hyperglycemia, high blood sugar can lead to increased urination and loss of fluids, prompting the release of aldosterone to promote sodium and water retention, thus helping to maintain blood pressure and volume.