Physiology

Question 0

myocardial blood flow:

1. flow rate
2. % of cardiac output
3. how much is supplied by the RCA?
4. factors that increase or reduce myocardial blood flow

Answer 0

1. 250ml/min
2. 5% of cardiac output
3. RCA supplies 1/3 of blood to LV
4. pain and ADH (vasopressin) reduces blood flow

Question 1

Requirements per kg body weight per day

Water
Nitrogen
K
Na
Fresh frozen plasma

Answer 1

Water 50ml
Nitrogen: 0.5g
K: 1mmol/kg
Na: 2mmol/kg
FFP: 12-15ml/kg in one go (May need FFP in septic states as coagulation is off)

Question 2

What is Crista Terminalis?

Answer 2

rough ridge which runs between the vena cavae, “separates” posterior RA wall which is smooth and derived from sinus venosus, from the other bits of the wall that are rough.

Question 3

What percentage of population has SAN supplied by:

1. RCA
2. Circumflex

Answer 3

1. 60% (gives off a branch to SAN)

2. 40%

Question 4

How much ventricular volume does the atrial contraction contribute

Answer 4

15%

Question 5

Ideal irrigation fluid properties

Answer 5

"TIME THIS"
Transparent
Isotonic
Metabolically stable/ie. not metabolised
Electrically non-conductive
Toxic (non)
Haemolysis (non)
Inexpensive
Sterile

Question 6

3 most commonly used irrigation fluids in the UK

Answer 6

1.5% glycine
5% mannitol
3.5% sorbitol