Question

Case study

You are working on a medical-surgical unit and have been assigned to care for Mr. T. He has multiple
health problems, including postural hypotension. You are mentoring a new nurse and assign the new
nurse to care for Mr. T. The new nurse would like more information on postural hypotension and how the
heart works before going in to care for Mr. T. The following are the new nurse’s questions:
1. What is postural hypotension, and how does it occur?
Answer:
Rationale:

2. What comprises the circulatory system?
Answer:
Rationale:

3. I read about Starling's law of the heart. Can you explain this law?
Answer:
Rationale:

Answer 1

1. Posture hypotension is the fall in blood pressure when a person changes his posture usually supine to standing or sitting. A fall in blood pressure of 20 mmhg systolic or 10mmhg diastolic is considered postural hypotension.
Rational : In normal condition, when a person assumes standing or sitting posture, the blood pools into lower extremity. This causes decreased venous return and low cardiac output resulting in hypotension. But the activation of baroreceptors and increased sympathetic activity increases the heart rate, stroke volume and peripheral resistance which helps to maintain the normal blood pressure.
In pathological situations decreased sensitivity of baroreceptors and inability to vasoconstrict  the vessels impairs body response to maintain blood pressure and hypotension.

2. The circulatory system is one pf the most important organ system of the body. It consists of two systems:

- cardiovascular system comprising of heart and blood vessels

- lymphatic system comprising of lymph, lymph nodes, lymphatic vessels and  lymphoid organs.
Rationale : the cardiovascular system helps to circulate blood to different parts of the body and helps supply important nutrients and oxygen to the body tissues.
Lymphatic system carries the interstitial known as lymph to heart after filtering it in lymph nodes. Lymph nodes and lymphoid organs produce lymphocytes that are circulated in the body through lymphatic system.

3. The Frank starling of heart states that the stroke volume or the volume of blood ejected by left ventricles is directly proportional to the volume of blood contained in left ventricle before contraction known as end diastolic volume. Increase in stroke volume is directly associated with increase in end diastolic volume.
Rationale : Frank starling law helps the heart to accommodate to the blood filling through venous return. It helps in maintaining a balance between right and left side cardiac output of heart. This helps to prevent blood accumulation in the pulmonary and systemic circulation.