Ketones

BT_PO 1.82a  Outline basic cellular physiology, in particular …. energy production by metabolic processes in cells

BT_PO 1.83  Describe the physiological consequences of starvation

 

T / F  ketones are produced from the oxidation of free fatty acids

T / F  the important role of ketones is as an alternative fuel source to glucose for the brain – this decreases the protein catabolism which occurs via gluconeogenesis

T / F  lipolysis is stimulated by insulin, adrenaline, and cortisol

T / F  ketones provide a source of acetyl-CoA for use directly in the TCA cycle (structurally, ketones consist of actetyl groups)

T / F  in poorly nourished patients (frail elderly, alcoholics etc), a short period of fasting can induce starvation ketoacidosis

I’m not sure that taking ketone pills is a good idea!!

Now that you have thought about ketones….
i) find out if any of the glucometers in your hospital can also measure ketones (if not, how else could you diagnose ketosis?) 
ii) how would you treat starvation ketoacidosis in a non-diabetic?

 

BT_PO 1.79 : Acid-base chemistry

BT_PO 1.79 : Describe acid-base chemistry using the Henderson-Hasselbach equation and strong ion difference

 

The SID in NaCl is 0 mmol/L        TRUE/FALSE

Normal Se Cl is approximately 100 mmol/L        TRUE/FALSE

The normal SID in plasma is approximately 40 mmol/L        TRUE/FALSE

Large volumes of NaCl as a replacement fluid can take the Se Cl to around 120 mmol/L (not that I would know as this is not routinely reported in my hospital)…

Administering large volumes of NaCl causes a metabolic acidosis by decreasing the SID    TRUE/FALSE

Administering large volumes of NaCl causes a metabolic acidosis by impairing renal bicarbonate absorption with the chloride load        TRUE/FALSE

Hypoalbuminaemia will give a metabolic acidosis        TRUE/FALSE

 

BT_PO 1.79 : Acid-base chemistry

Third in my series on acid base physiology, see last week’s post for the suggested reading material…

BT_PO 1.79 : Describe acid-base chemistry using the Henderson-Hasselbach equation and strong ion difference (SID)

So Stewart would look at this LO and say, yes, those 2 factors are important, but you also have to consider the dissociation of water, and the amount and dissociation of the non-volatile weak acids in the system. 

The independent variables in his model are SID, and volatile (pCO2) and non-volatile acids.

pCO2 is controlled by the lungs        TRUE/FALSE

SID is controlled by the liver        TRUE/FALSE

Albumin levels are controlled by the kidney        TRUE/FALSE

Acid-base differences across a membrane are predominantly from CO2 as it crosses membranes so easily        TRUE/FALSE

Acid-base differences across a membrane are predominantly from proteins as they cross membranes so poorly        TRUE/FALSE

BT_PO 1.79 : Acid-base chemistry

BT_PO 1.79 : Describe acid-base chemistry using the Henderson-Hasselbach equation and strong ion difference

Strong ion difference (SID) refers to the Stewart approach to acid-base analysis. Stewart’s underlying tenet is that hydrogen ions are the dependent variable in a complex system of physico-chemical interactions, not simply an entity that is shuttled across membranes. He makes the point that water is a practically inexhaustible source of hydrogen ions as it is usually so minimally dissociated. As we saw yesterday, just raising the temperature of an aqueous solution will increase the dissociation of water leading to a higher [H+] – though it’s important to realise that it will remain at a neutral pH as the [OH-] increases equally. 

Peter Stewart’s book is available free on the internet but for the majority of you I would recommend Kerry Brandis’ work on the topic – Quantitative acid-base analysis.

Strong ions in solution are fully dissociated        TRUE/FALSE

Sodium, chloride and lactate are strong ions        TRUE/FALSE

pCO2 determines [H+]        TRUE/FALSE

The SID determines [H+]        TRUE/FALSE

If the SID is non-zero then electro-neutrality requires the presence of weak electrolytes    TRUE/FALSE

These weak electrolytes are predominantly weak acids        TRUE/FALSE

Albumin is the predominant weak acid in the body        TRUE/FALSE

There will be more on this topic after a brief foray into respiratory physiology 🙂

BT_PO 1.78 : Acid Base Regulation

BT_PO 1.78 : Describe the regulation of acid/base balance

Looking at the effect of temperature…

Decreasing temperature will decrease the solubility of carbon dioxide in blood     TRUE/FALSE

Arterial pCO2 will decrease as temperature drops for a given content of carbon dioxide     TRUE/FALSE

As temperature increases the dissociation of water increases      TRUE/FALSE

The pH of neutrality of water at 37 degrees C is 6.8       TRUE/FALSE

Blood at a pH of 7.4 is at a neutral pH       TRUE/FALSE

 

 

 

 

BT PO 1.85 Explain the control of blood glucose

A standard Mars bar (53g) contains 30g of glucose. They used to be given to pregnant women as a component of the glucose challenge test for gestational diabetes. I don’t know if this is still the case.

The glucose transporter, GLUT-4, is ubiquitous and found in most cells in the body TRUE/FALSE

Hepatic uptake of glucose is dependent on the presence of insulin TRUE/FALSE

Glucokinase phosphorylates glucose and is a pivotal enzyme in the glycolysis pathway TRUE/ FALSE

Alterations in glucose transport occur within seconds of insulin release TRUE/FALSE

Insulin has trophic and mitogenic actions TRUE/FALSE

 

A bonus question- are glucose and dextrose the same thing?

BT_PO 1.76 Regulation of osmolarity

I visited Canberra towards the end of last year to watch one of my children run. In my (large) amount of free time, I visited the National Portrait Gallery, where I happened upon this portrait of Derek Denton, the Australian scientist who discovered the mechanism of thirst.

BT_PO 1.76  Describe the regulation of osmolality

The factors that regulate vasopressin secretion also regulate thirst TRUE/FALSE

Vasopressin is synthesised in the posterior pituitary TRUE/FALSE

Most of plasma’s osmolality is due to Na+ and its accompanying ions, CL- and HCO3- TRUE/FALSE

Hypovolaemia stimulates thirst via angiotensin II acting at sites outside the blood brain barrier  TRUE/FALSE

Aldosterone is responsible for regulating plasma osmolality TRUE/FALSE

BT_PO 1.83 Describe the physiological consequences of starvation

Whilst fasting for a minor surgical procedure last week, I had plenty of time to ponder this topic…

BT_PO 1.83 Describe the physiological consequences of starvation
Prolonged starvation reduces immune function TRUE/FALSE

Brain and nerves, renal medulla, red blood cells are obligate glucose consumers TRUE/FALSE

Adaptive reponses to starvation aim for conservation of energy and protein TRUE/FALSE

Muscle glycogen is freely available as a source of blood glucose TRUE/FALSE

During starvation, the gastrointestinal tract has an enhanced ability to digest food TRUE/FALSE