Cardiovascular system

• What does RAAS stand for?

  Renin Angiotensin-Aldosterone System
• What are the key cells called in RAAS?

  Juxta Glomerular Cells
• Location of Juxta Glomerular cells

  Blood vessels within the kidney
• What are Juxta Glomerular cells?

  Smooth muscle cells located within the blood vessels in the kidney
• What hormone do Juxta Glomerular cells release?

  Renin
• What is the main function of renin?

  To raise blood pressure
• What 3 things trigger the Juxta Glomerular cells?

  1. Low blood pressure
  2. Sympathetic nerve cells (fight vs flight)
  3. Macula densa cells (low sodium in the distal convoluted tubule)
• What do Macula Densa cells use to send messages to the Juxta Glomerular cells?

  Prostaglandin
• What is Angiotensinagen responsible for?

  Blood pressure
• Where is Angiotensinagen produced and released from?

  Liver
• Renin + Angiotensinagen =

  Angiotensin 1
• What cells convert angiotensin 1 to angiotensin 2?

  Endothelial cells
• What is the primary location of endothelial cells?

  Lungs
• What 2 cell types are affected by the angiotensin 2 hormone and what is the result?

  1. Smooth muscle cells within blood vessels, causing vasoconstriction which increases resistance
  2. Kidney cells, causing them to retain water which increases stroke volume
• What 2 glands are affected by the angiotensin 2 hormone and what is the result?

  1. Pituitary gland which releases the hormone Anti-Diuretic Hormone (ADH). This increases resistance by vasoconstriction and increases stroke volume
  2. Adrenal gland which releases the hormone aldosterone to act on kidney cells to increase volume
• What is the goal of the Juxtaglomerular Apparatus?

  To produce renin
• What does the Juxtaglomerular Apparatus consist of?

  Macula densa cells, endothelial cells, smooth muscle cells and juxtaglomerular cells
• What cells detect low blood pressure?

  Endothelial cells, which triggers the juxtaglomerular cells to release renin
• What nerve endings sit on the juxtaglomerular cells?

  Sympathetic nerve
• What are the 2 triggers for aldosterone production?

  1. Angiotensin 2
  2. High potassium
• Which enzyme sits on the surface of the endothelial cells?

  Angiotensin Converting Enzyme
• What is another name for ADH?

  Vasopressin
• Triggers for release/secretion of ADH

  1. High blood osmolality (concentration)
  2. Low blood volume
  3. Low blood pressure
  4. Angiotensin 2
• Definition of Stroke Volume

  The volume of blood pumped out of the left ventricle of the heart during each systolic cardiac contraction.
• Difference between inotropes and vasopressors

  Inotropes - given to increase myocardial contractility

  Vasopressin - given for vasoconstriction
• Example of Inotropes

  1. Adrenaline
  2. Noradrenaline
  3. Dobutamine
  4. Dopamine
• Examples of vasopressors

  1. Vasopressin
  2. Phenylephrine
  3. Angiotensin 2
• Definition of oliguria

  Urine output of less than 0.5mls/kg/hr
• What is Starlin's law?

  The law states that the stroke volume of the heart increases in response to an increase in the volume of blood within the ventricles
• What is the MAP required for brain perfusion?

  50
• What is the MAP required for kidney perfusion?

  70
• BP = CO X SVR
• Symptoms of shock

  1. Confusion
  2. Feeling of impending doom
  3. Agitation
  4. Lactate of 2 or higher
  5. Low urine output
• Label the Art line tracing

  A) Systolic Upstroke

  B) AV opening

  C) Peak Systolic Pressure

  D) Systolic Decline

  E) Diocrotic Notch

  F) AV closes

  G) Systole

  H) Diastolic Runoff

  I) Diastole

  
• What does the electrical conduction system consist of?

  1. SA node
  2. AV node
  3. Bundle of His/ Pukinje Fibres
• Definition of Starlin's Law

  Under normal circumstances, the heart is able to increase its stroke volume appropriately according to venous return
• What percentage of blood flow is taken by the kidneys?

  40%
• What is a high dicrotic notch a sign of?

  The patient is hypovolemic
• Signs & Symptoms of shock (6)

  1. Confusion and/or agitation
  2. Impending feeling of doom
  3. High Lactate (2 or higher)
  4. Low urine output
  5. High BP
  6. Cool to touch
• What is the shock index equation?

  HR / Systolic BP