Hormonal control of blood pressure (Renin, adrenaline/noradrenaline, ADH, ANP

Question 1

What cells in the kidneys are responsible for producing renin in the kidneys?

Answer 1

Juxtaglomerular cells

Question 2

What are Juxtaglomerular cells, where are Juxtaglomerular cells found? What is their function?

Answer 2

• Specialised smooth muscle cells, found mainly in the walls of the afferent arteriole of the kidney, although some can be found in the efferent arterioles
• Function is to produce, store and seceret Renin

Question 3

Under what circumstances is renin produced by the juxtaglomerular cells of the kidney?

Answer 3

When blood volume is low (when water or sodium is low, when potassium his high)

Question 4

Explain the process by which renin increases blood pressure (mention the effects of angiotensin 2, aldoesterone)

Answer 4

• renin produced when blood volume is low
• Converts angiontensinogen (which is constantly being produced by the liver) to angiotensin 1
• Angiotensin converting enzyme (ACE) found mainly in the lungs (but can be found systemically) converts angioensin 1 to angiotensin 2
• Angiotensin 2 causes vasoconstriction directly , which increases blood pressure
  
  • ​Also promotes systemic activation of the synpathetic nervous system (thereby promoting systemic vasoconstricton
  • Angiotensin 2 Acts on the adrenal gland to stimulate aldosterone
    
    • ​Aldosterone increases Na and Cl resorption, increases potassium absorption and increased water retention
  • Angiontensin 2 acts on the pituitary gland, which increases water absorption at the collcecting duct

Question 5

List the direct effects that angiotensin 2 has on blood pressure