Urinary/renal system 4 Flashcards
What percent of urine is water
95-98%
What is in normal urine
Water Creatinine Uric acid H+, NH3, Na+, K+ Drugs (anti-viral, diuretics) and toxins
What is in pathologic urine
Glucose Protein Blood Haemoglobin Leucocytes Bacteria
What does erythropoietin (EPO) do
Released by kidneys when it detects low oxygen levels - stimulates bone marrow to produce RBC
What is anaemia
Chronic renal failure - low levels of RBC
Why is K+ concentrations important
Resting membrane potential is based on K+ gradient
What secretes potassium
Kidneys
What is hyperkalemia
Kidney disease/failure - leads to death
What is Lidocaine
Local anaesthetic - Fat soluble - excreted by the kidneys after metabolisation in the liver
Describe aspirin
Pain killer - Water soluble - excreted by kidneys
What drugs and toxins are metabolised where in the body
lipophilic - metabolised in liver
hydrophilic - metabolised in kidneys
What are the levels of pH that make the blood alkalosis or acidosis
Alkalosis -blood pH > 7.4
Acidosis - blood pH < 7.4
What controls the concentration of bicarbonate in the blood
Lungs - exhalation of CO2
Kidneys - reabsorption of bicarbonate or secretion of hydrogen ions (H+)
What are the three main functions of the kidney
Filtration
Secretion
Re-absorption
Describe kidney filtration
Plasma-like filtrate of the blood
Describe kidney reabsorption
Removes useful solutes from filtrate and returns them to the blood
Describe kidney secretion
Adds additional waste from blood to filtrate
When are substances not filtered at a constant rate
When bound to proteins
What substances are partly re-absorbed
Na+
K+
What substance in entirely re-absorbed
Glucose
What substance is entirely secreted
PAH - many drugs
What is the role of the glomerulus
Filtration
What is the role of the proximal tubule
Bulk reabsorption - electrolytes (sodium/potassium)
Secretion of metabolites (drugs/toxins)
What is the role of the distal tubule
Fine-tuning of electrolytes/water reabsorption
What is the role of the collecting duct
Fine-tuning of electrolyte/water eabsorption
Where is glucose reabsorbed
Proximal tubule