Page 84 - Clinical Biochemistry 08PB804

What gets filtered in the glomerulus?

Freely filtared (filterd = passed)
• H2O
• Elements : (Na+, K+, Cl-, Mg2+ , PO4)
• Glucose
• Urea
• Creatinine
• Insulin
Not filtred (not passed)

• Protein
• Blood cells
- The renal tubules are presented with this volume of water, most of which needs to be
reabsorbed containing complex mixture of ions and small molecules, where small molecules
of protein are reabsorbed.

Function of the kidney

1- Excretory: excretion of protein product and nucleic acid metabolism (urea, creatinine and
uric acid).
2- Regulatory: regulation of water, electrolytes and acid-base balance.
3- Endocrine

Endocrine Function of Kidney
Kidney is an endocrine organs producing number of hormones
1- Renin catalyzes the formation of angiotensin I and aldosterone synthesis controlling blood
pressure.
2- Erythropoietin is a glycoprotein hormone that targets the stem cells in the bone marrow
that give rise ultimately to erythrocytes.
3- Synthesis of 1, 25 dihydroxy cholecalciferol which regulate Ca2+ absorption by the gut.
Kidney is subject to be controlled by other hormones:
1- Vasopressin (ADH) acts to influence water balance
•Low H2O intake conc. urine
•High H2O intake diluted urine
2- Aldosterone affect sodium reabsorption
3- Parathyroid hormone promotes tubular reabsorption of Ca2+, phosphate excretion