Final answer:
The normal level for BNP is < 100 pg/mL (A). BNP is released by the heart to regulate blood volume and pressure. Elevated BNP levels may indicate the severity of heart failure, making it an important marker for diagnosis and management.
Step-by-step explanation:
The normal level of brain natriuretic peptide, or BNP, is < 100 pg/mL. Thus, the correct answer to the student's question is A) < 100 pg/mL. BNP is a hormone produced by your heart and is released in response to changes in pressure that occur when heart failure develops and worsens. The higher the BNP levels, the more severe the heart failure is considered to be.
Role of BNP
BNP has similar functions to the related atrial natriuretic peptide (ANP), which is also produced by the heart. Both BNP and ANP help to reduce blood volume, blood pressure, and sodium (Na+) concentration. They achieve this by causing your body to excrete sodium and water, which in turn lowers blood pressure and blood volume. Moreover, these effects are vital in regulating how your body responds to heart failure.
Understanding Blood Pressure Readings
Alex's blood pressure reading of 135/90 mm Hg indicates that his systolic pressure (the top number) is 135 mm Hg and his diastolic pressure (the bottom number) is 90 mm Hg. The systolic pressure represents the pressure in the arteries when the heart muscle contracts, while the diastolic pressure represents the pressure when the heart is resting between beats. While Alex's systolic reading is within the prehypertension range, his diastolic reading suggests stage 1 hypertension. Therefore, it is advisable for Alex to work on lowering his blood pressure to reduce the risk of cardiovascular problems. Methods to lower blood pressure include lifestyle changes like diet modification, regular exercise, stress reduction, and if necessary, medication.