Nursing Pharmacology:  Introduction to Autonomic Pharmacology Practice Questions

Choose the correct answer for each question.

 

Preload and Contractility


  •  As blood volume returning to the heart
    increases, preload increases and there is enhanced
    filling with ventricular dilation. 

  • According to Starling's Law, increased
    ventricular stretch usually leads to increased
    contractility.
    Increased preload and
    increased contractility lead to increased stroke volume
    and ultimately an increase in arterial pressure, all
    other factors remaining equal.    

  • Some antihypertensive drugs decrease
    preload.

  • Heart rate: Since the product of heart rate and
    stroke volume equals cardiac output, an increase in heart
    rate will increase arterial blood pressure, all other
    factors remaining equal.

  • Some antihypertensive agents decrease heart rate
    (ß-adrenergic receptor antagonists, e.g.).

  • Recall: Heart Rate X Stroke Volume = Cardiac
    Output

  • Cardiac Output X Peripheral Resistance = Arterial
    Pressure

  • Peripheral resistance:

    • For a given cardiac output, blood pressure
      depends only on peripheral resistance. Some
      antihypertensive drugs act to reduce peripheral
      resistance.