Module 3 (CKD)

Definition of CKD

involves subtle decrease in kidney function over 3 months

Glomerular Filtration Rate definition

rate at which filtrate is filtered through glomeruli into renal tubule

What is the normal GFR?

100-120mL/minute/m²

CKD GFR

>90mL/minute/m²

How does hypertension cause CKD (process)

increased BP → thicker arterial walls → narrow lumen → less blood and oxygen reach kidneys → ischaemic injury to glomeruli → foam cells and macrophages slip into damaged glomeruli → mesangial cell (glomeruli structural cell) regress → glomerulosclerosis (hardening and scarring) → diminishes ability to filter blood

How does diabetes cause CKD (process)

excess glucose sticks to proteins in the blood → efferent arteriole (collects blood) becomes more stiff and narrow (called hyaline arteriosclerosis) → creates obstruction → harder for blood to leave glomerulus → increases pressure within glomerulus → hyperfiltration → mesangial cells excrete more matrix → expand size of glomerulus

What protein is primarily responsible for maintaining the osmotic blood pressure of blood plasma and aiding in regulation of blood volume?

Albumin

What part of the nephron is primarily responsible for the reabsorption of water and electrolytes, and the secretion of waste products?

Loop of Henle

Which hormone is released by the kidneys stimulating red blood cell production in the bone marrow

Erythropoietin

Four other causes of CKD

1. systemic diseases

2. infections

3. medications

4. toxins

What happens to urea when you have CKD

decreased GFR → less urea filtered → accumulates in blood

potassium balance in CKD

less potassium secreted → build up in blood (hyperkalaemia) → cardiac arrythmias

calcium balance in normal kidney function

kidney activates vitamin D → increased calcium absorption

calcium balance in CKD

decreased vitamin D → decreased calcium absorption → less calcium in blood (hypocalcaemia) → parathyroid hormone release → bones lose calcium → bones become weak

fluid balance in normal kidneys

kidneys sense lower blood volume → releases hormone Renin → increases blood pressure

fluid balance in CKD

decreased GFR → uncontrolled release of Renin → increased blood pressure

red blood cell balance in normal kidneys

kidneys secrete erythropoietin hormone → stimulates production of red blood cells from bone marrow

red blood cell balance in CKD

erythropoietin release levels decrease → lowered production of RBC → anaemia