Patient Care

Question 1

Define chronic kidney disease and its stages.

Answer 1

According to the NKF, Chronic Kidney Disease (CKD) is either kidney damage or a glomerular filtration rate (GFR) of less than 60ml per minute for a three month period.
•Stage1- Kidney damage with normal or increased GFR > 90 ml/min
•Stage 2 - Kidney damage with mild decrease in GFR of 60-89ml/min
•Stage 3- Moderate decrease in GFR of 30-59ml/min
•Stage 4- Severe decrease in GFR of 15-29ml/min
•Stage 5-Kidney failure, decrease in GFR below 15ml/min or dialysis.

Question 2

Discuss normal blood flow to the kidney.

Answer 2

Adult humans have about 5 liters of blood in circulation The entire circulation courses through the kidneys 20 times per hour.
The kidneys receive 25% of the total resting cardiac output, approximately 250-300ml/min. Blood flow is as follows:-
Aorta—renal artery—segmented arteries— interlobar arteries— arcuate arteries— interlobular arteries— afferent arterioles— glomerulus— efferent arteriole— peritubular —capillaries—(vasa recta—) interlobular veins—arcuate veins—interlobar veins— segmented veins— renal vein— inferior vena cava.

Question 3

List the functions of the normal kidney.

Answer 3

• Eliminate urea
• Eliminate most drugs
• Most poisons and their metabolites are excreted by the kidneys.
• Regulate fluid balance by reabsorption or secretion.
• Regulate acid-base balance of the body.
• Maintain electrolyte concentration of the blood.
• Produce hormones renin and erythropoietin. Renin regulates BP through the renal artery. Erythropoietin stimulates the bone marrow to produce red blood cells.
• Acts as receptor sites for the hormones ADH, PTH and aldosterone.

Correct dialysis done three times a week only replaces 10-15% of normal renal function.

Question 4

Define osmosis and diffusion

Answer 4

Osmosis is the movement of water from a lesser concentration of solutes to a higher concentration of solutes across a semipermeable membrane. If water keeps trying to enter a red blood cell that has accepted the maximum amount it can, the pressure inside the cell will increase until it bursts, releasing hemoglobin. [hemolysis]

Diffusion is the movemyof molecules from an area of high concentration to an area of low concentration across a semipermeable membrane. Movement of particles and water stop when the concentrations on each side of the membrane are equal.

Question 5

Define nephron and explain its anatomy.

Answer 5

The nephron is the area of the kidney where all the functional processes of filtration and waste removal take place. It has a vascular element and a tubular element.
The vascular element = the afferent arteriole, the glomerulus, the efferent arteriole, the peritubular capillaries.
The tubular element = Bowman’s capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule.
The glomerulus = congregation of tiny capillaries encased by Bowman’s capsule.

Capillaries +Bowman’s capsule = renal corpuscle

The amount of filtrate that the kidneys produce each minute is called the GFR and normally is around 125ml/min.