0217 Oxygen delivery

Question 1

Describe some essential body functions that require energy (think broadly)

Answer 1

Protein synthesis, active transport of ions, muscle contraction

Question 2

On a biochemical level, what process constitutes the storage of energy and the release of energy

Answer 2

The adding of phosphate to ADP = storage of energy. The breaking of phosphate from ATP = release of energy

Question 3

What is ATP and what is it made of

Answer 3

Adenosine triphosphate is a chemical compound present in all cells and is the energy currency of our body. It composed of adenine, ribose and phosphate

Question 4

Briefly describe the process of oxygen delivery from outside to mitochondria in our cells (bronwyn has 6 steps)

Answer 4

1. Breathe in air (21% oxygen)
2. Air crosses alverocapillary membrane
3. Oxygen enters capillaries and binds to Hb
4. Transport via blood flow to tissues/organs
5. Offloaded down concentration gradient to cells
6. Utilised in cells to produce ATP

Question 5

Briefly explain the oxygen cascade

Answer 5

Oxygen delivery is a process where oxygen is passed down a concentration gradient with the highest pressure at atmospheric air and lowest pressure at the mitochondria within our cells

Question 6

List some key things we need for effective oxygen delivery

Answer 6

Think CHILD

Cardiac output - sufficient
Haemoglobin - adequate amount and type
Input - patent airway
Lungs - mechanical and parenchymal function of lungs
Diffusion - normal diffusion across capillary membrane and through tissues to cells

Question 7

What is the formula for oxygen delivery

Answer 7

Cardiac output x arterial oxygen content

Question 8

What are the 4 parameters of arterial oxygen content

Answer 8

Haemoglobin conentration (g/L), amount of oxygen carried by Hb when saturated, % saturation and amount oxygen dissolved in plama

Question 9

What is the formula for cardiac output

Answer 9

Stroke Volume x heart rate.

Question 10

What factors can affect arterial oxygen content

Answer 10

Anaemia, percentage saturation of Hb (affected by lung parenchyma/tissue, respiratory effort, oxygen patency, oxygen dissociation curve)

Question 11

What factors affect the stroke volume (and therefore the cardiac output)

Answer 11

Preload, afterload and contractility

Question 12

Describe the cascade effect of inadequate/no oxygen delivery to tissue (5 steps)

Answer 12

1. inadequate O2 delivery
2. inadequate energy production
3. Cell dysfunction
4. Tissue/organ dysfunction or failure
5. Death