Renal

• What are the afferent and efferent arterioles?

  Afferent arterioles branch off which ultimately leads into the glomerulus of Bowman's capsule. From here, efferent arterioles begin to form the venous system and subdivide into another set of capillaries known as the peritubular capillaries. Blood then leaves the kidney and enters the venous circulation
• Cause of pre-renal AKI

  Reduced perfusion of kidneys and/or hypotension
• Cause of intra-renal AKI

  Structural damage to the kidney
• Cause of post-renal AKI

  Acute urinary tract obstruction
• Management of an AKI (the 5 Rs)

  1. Risk - identify the risk and prevent AKI
  2. Recognition - Recognise signs and symptoms of an AKI
  3. Rapid response
  4. Renal support
  5. Rehabilitation - information and support for the patients and carers
• How blood is filtered within the kidney

  A) Afferent arteriole

  B) Glomerulus

  C) Bowmans capsule

  D) Efferent arteriole

  E) Proximal Convoluted Tubule

  F) Renal Cortex

  G) Renal Medulla

  H) Descending loop of Henle

  I) Distal Convoluted Tubule

  J) Collecting duct

  K) Ascending loop of Henle

  L) Loop of Henle

  
• What is the role of angiotensin II

  1. Vasopressin to increase blood pressure
  2. Stimulates aldosterone release for sodium retention and water absorption
• RAAS regulation of blood pressure

  Angiotensin I -> Angiotensin II increases blood pressure through vasocontriction and aldosterone increases blood volume through water retention
• Vasopressin ADH role 


  Regulates water balance through water absorption in the kidneys, enabling blood volume and blood pressure regulation
• What is the renin-angiotensin-aldosterone system

  A hormone system within the body that is essential for the regulation of blood pressure and fluid balance
• Angiotensin II acts on the adrenal cortex to release aldosterone, which increases sodium reabsorption by the kidneys
• When blood pressure decreases below normal level, the juxtaglomerular cells in the kidney secrete renin into the bloodstream
• Increased sodium reabsorption leads to increased water reabsorption due to osmosis, resulting in an overall increase in blood volume
• The hypothalamus releases antidiuretic hormone (ADH), also known as vasopressin into the bloodstream
• Osmoreceptors detect changes in osmolarity and send signals to the hypothalamus
• Renin converts angiotensinogen to angiotensin I, which is then converted to angiotensin II by an enzyme called angiotensin-converting enzyme (ACE)
• Angiotensin II causes vasoconstriction, increasing blood pressure, and stimulates the secretion of aldosterone from the adrenal glands
• Aldosterone promotes the reabsorption of sodium ions and water by the kidneys, leading to increased blood volume and higher blood pressure
• Role of the baroreceptors

  Detect a drop in BP
• Explain the renin-angiotensin-aldosterone system

  1. Sympathetic nervous system stimulates the juxtaglomerular cells within the kidneys to produce renin
  2. Activates an enzyme in the liver (angiotensinogen)
  3. This then creates angiotensin I
  4. Angiotensin converting converting enzyme (ACE) found on the surface of the lungs and kidneys, which converts angiotensin I to angiotensin II
  5. Angiotensin II acts on smooth vessels which constricts vessels (increasing SVR) and increases blood volume
• Effects on renin-angiotensin-aldosterone system on each organ

  • Kidneys = Retain sodium and water
  • Adrenal gland = Retain sodium and water whilst lowering potassium
  • Pituitary gland = Releases ADH which causes retention of water within the kidneys
• Main organs involved in RAAS

  1. Kidneys
  2. Lungs
  3. Liver
  4. Pituitary gland
  5. Adrenal gland
  6. Blood vessels
• What is the purpose of osmosis? (5)

  • Helps to regulate the balance of solutes and water in the body
  • Maintain proper cell shape and function
  • Filter our excess waste products
  • Regulate blood pressure and blood volume
  • Aid in nutrient absorption and waste removal
• Medical applications of hypotonic solution (4)

  1. IV fluids
  2. Diagnostic testing
  3. Organ perfusion
  4. Intravenous hydration
• Hydrostatic pressure and fluids shifts

  Helps regulate fluid shifts between intravascular and interstitial spaces, maintaining blood volume and blood pressure
• Hydrostatic pressure and blood pressure regulation

  Contributes to blood pressure regulation, prevents blood vessel collapse, and maintains blood flow and circulation
• Example of facilitated diffusion


  Glucose transport from the intestine into the bloodstream, insulin transport across the intestine
• What are the 3 fluid compartments?

  1. Intravascular
  2. Interstitial
  3. Intracellular