4b.) Blood Pressure and Kidney

Question 1

Answer true or false for the following:

Answer 1

• True
• False (increased)
• True (water shifting to ECF will increase osmolality)
• True (water shifted to ECF as osmolality increased)
• False (ECF volume increased)

Question 2

Answer true or false for the following:

Answer 2

• False (major is Na+)
• True (sweat is hypotonic so more water lost than Na+)
• False (sweat is hyposmotic)
• True (water move into ECF as osmolality increased)
• False (increase)
• False (water move out of ICF so will decrease)

Question 3

Answer true or false for the following:

Answer 3

NOTE: ADH does increase Na+ absorption but increases water absorption much more so we consider the Na+ absorption to be negligible

• True (increase water in ECF)
• True
• False (osmolality of ECF has decreased)
• True
• False (would increase)

Question 4

Describe how the kidneys can make oedema in heart failure worse

Answer 4

• Oedema will decrease circulating volume
• Decrease BP
• Low BP detected by grnaular cells of JGA
• Activate RAAS
• RAAS increase blood pressure
• Increased blood pressure will increase hydrostatic pressure and make oedema worse

Question 5

A 36 year old man has hypertension. When his GP reviews his urea and electrolytes she suspects he may have primary hyperaldosteronism.

What do you expect his urea and electrolytes to show?

What would his plasma renin levlel be?

Answer 5

• Increased Na+
• Decreased K+
• Urea= same
• Renin= low

Remember aldosterone:

• Upregulates Na+ channels in collecting ducts and colon
• Stimulates K+ secretion into tubule

Question 6

State the actions of aldosterone on kidneys

Answer 6

Main idea that increases Na+ reabsorption and increases K+ secretion

Question 7

Describe the effect of natriuretic peptides on kidneys

Answer 7

• Reduces sodium reabsorption
• Inhibits aldosterone release
• Inhibits renin production
• Increases glomerular filtration rate by dilating afferent arterioles

Question 8

Describe the effect of vasopression (ADH) on kidneys

Answer 8

• Increases expression aquaporins on collecting ducts

(also causes vasoconstriction of vasculature to help increase blood pressure)

Question 9

Describe the effect of dopamine on kidneys

Answer 9

• Reduces Na+ reabsorption by inhibiting Na+/H+ exchange

Question 10

Where is dopamine secreted from?

Answer 10

Proximal tubule

Question 11

What is hypertensive renal disease

Answer 11

Kidney damage caused by chronic high blood pressure.

High blood pressure damages arteries to kidneys so kidneys don’t get perfused adequetly and so act to increase bp as they think bp is low

Question 12

What type of hormone is aldosterone?

Answer 12

Steroid