BT_PO 1.66 Outline the endocrine functions of the kidney

And it will come as a surprise to no-one reading the posts this week to find I’ve been reading Ganong again.

Vitamin D is hydroxylated to calcitriol in the proximal tubules of the kidney     T/F

Calcitriol increases calcium reabsorption in the proximal tubules of the kidney     T/F

The O2 sensor to control erythropoietin production is probably a heme protein     T/F

Increasing catecholamines will stimulate erythropoietin production     T/F

Erythropoietin is also produced in the brain     T/F


2018.1 SAQ 9 Renal blood flow

Discuss the determinants of renal blood flow.

Kidneys often receive a multitude of insults in the peri-operative period, both physiological and pharmacological. If you know how normal renal blood flow is controlled, you will be best positioned to preserve it under anaesthesia.

Principles of physiology for the anaesthetist 3e by Power and Kam Ch 7, handles this topic better than many of the other recommended texts. Although this is an important topic, its coverage can be quite confusing.

BT_PO 1.62 Explain the physiology of renal blood flow

Blood flow to the kidneys is regulated to maintain glomerular filtration rather than oxygen supply to the kidney T/F

Renal blood is auto-regulated between a systolic blood pressure of about 80mmHg and 180mmHg T/F

In response to reduced presentation of sodium to the juxtaglomerular apparatus, afferent arterioles will dilate to increase glomerular filtration T/F

Renal blood flow is auto-regulated at the level of the glomerular capillaries T/F

Myogenic regulation of renal vascular resistance is rapid T/F

Proximal Convoluted Tubule

BT_PO 1.63 Describe glomerular filtration and tubular function

Regarding the proximal convoluted tubule:

Q. It reabsorbs 65% of filtered sodium and water.  TRUE/ FALSE

Q. It reabsorbs 65% filtered chloride.  TRUE/ FALSE

Q. Aquaporin channels are found on the luminal surface of the tubule cells.  TRUE/ FALSE

Q. Most of the glucose is reabsorbed via the paracellular route.  TRUE/ FALSE

Q. This is the principal site of urea secretion.  TRUE/ FALSE



BT_PO 1.71 Explain the effects on anaesthesia on renal function

I didn’t realise that this LO existed – found it when I was looking for a renal topic to post on, as there seem to be a dearth of renal posts on this site.

This is actually an important topic as relatively minor reductions in renal function are associated with worse peri-operative outcome.

I don’t have any kidney photos. Below is the best I could do for the genitourinary system. There are a whole series of these (some much more X rated) on view at MONA


BT_PO 1.71  Explain the effects on anaesthesia on renal function

Any anaesthetic agent which results in a reduction of blood pressure is likely to reduce GFR   TRUE/FALSE

Attenuation of the stress response to surgery is renal protective   TRUE/FALSE

Volatile anaesthetic agents may provide protection against ischaemia- reperfusion injury of the kidney TRUE/FALSE

IPPV improves renal blood flow TRUE/FALSE

Metabolic acidosis increases the kidneys’ vulnerability to nephrotoxins TRUE/FALSE

2017.1 : SAQ 13

Describe how the large daily volume of glomerular filtrate is altered by the kidney to form a relatively low volume of concentrated urine.

BT_PO 1.64    BT_PO 1.67

This question just asks for some basic functions of the kidney

Approximately 80% of the glomerular filtrate is absorbed  TRUE/FALSE

The medulla is hyperosmotic due to salt and urea  TRUE/FALSE

ADH plays an important role  TRUE/FALSE

Urea is actively secreted  TRUE/FALSE

The counter-current mechanism creates a hypo-osmotic medulla  TRUE/FALSE

BT_PO 1.63 Describe glomerular filtration and tubular function

Daily glomerular filtration of potassium is approximately 800 mmol/day. TRUE / FALSE

Reabsorption of potassium in the proximal tubule is fixed at 65% of the amount filtered. TRUE / FALSE

Aldosterone controls potassium excretion by altering the amount reabsorbed in the distal tubule. TRUE / FALSE

An increase in plasma potassium concentration directly stimulates the Na-K pumps in the distal tubule, to increase potassium secretion. TRUE / FALSE

During hypokalaemia, the kidneys can achieve zero potassium excretion in the urine. TRUE / FALSE