W7 - Blood & O2 Transport Flashcards
What is referred to as the O2 cascade?
Process of reducing O2 tension from the atmosphere down to the cellular level of the mitochondria.
Dalton’s law
Total pressure of a mixture is equal to the sum of the partial pressures of the ind gases in a mixture.
Calculation for daltons law t
Partial pressure = % conc x total pressure of mixture
Henrys law
When a mixture of gas is in contact w. a liquid, each gas dissolves in the liquid in proportion to its partial pressure + solubility UNTIL equilibrium is reached + the gas partial pressures are equal in both locations.
What is solubility in Henrys law?
Constant
Ficks law of diffusion
Rate of gas transfer is proportional to:
- Tissue area
- Diffusion coefficient of the gas
- Difference in partial pressure of the gas on the 2 sides of the tissue
+ inversely proportional to the thickness
Ficks law of diffusion equation
V GAS = A x D x (P1-P2) / T
Ficks law of diffusion equation
What does V GAS represent?
Rate of diffusion
Ficks law of diffusion equation
What does A represent?
Tissue area
Ficks law of diffusion equation
What does D represent?
Diffusion coefficient of gas
Ficks law of diffusion equation
What does P1-P2 represent?
Difference in partial pressures
Ficks law of diffusion equation
What does T represent?
Tissue thickness
Tailor Ficks law of diffusion equation to the lungs
V GAS = A X D X (P(little A) - P(little BL)) / T
Little A = Alveoli
Little BL = Bloodstream
Overview of Artery + Vein anatomy
OUTSIDE
Connective tissue
Smooth muscle
Endothelium
INSIDE
Reasons why capillaries are the main site for GE
Single cell layer = thin
Microscopic vessels = 7-10 micrometers in diameter
Slower bf in capillary bed = ⬆️ diffusion time
What are the different blood samples that can be taken?
Capillary
Venous
Where do you take capillary blood samples from?
Fingertip
Ear
Where do you take venous blood samples from?
Venipuncture
Cannula
What is needed for a capillary blood collection?
Disinfectant
Sterile swabs + gloves
Safety-Lancet
Appropriate sample containers (Microvette, minivette, multiverse)
Plasters
Waste container
At what angle should the capillaries or vessels be kept when taking blood samples?
Horizontal or slightly inclined
What must you do with the sample container after being filled with blood?
Invert it
How can the blood components be separated?
Centrifuging it
List the blood components
Top of test tube to bottom
Plasma
Buffy coat
Hematocrit
Plasma content
91.5% h20
7% proteins
1.5 % other
What is found in the Buffy coat?
WBC
Platelets
Hematocrit content
RBC
Hematocrit % for females
37-47%
Hematocrit % for males
42-52%
Between O2 + CO2 which is less soluble?
O2
By how many times is co2 MORE SOLUBLE at 37 degrees celsius than O2
~22
Transport methods for dissolved O2
Plasma = ~1%
Hb = ~99%
How much O2 per litre of blood is dissolved in the plasma?
~3mL
Dissolved O2 establishes the pO2 in the blood, what does this then do?
Regulates breathing
Determines loading of Hb
What factors affect Hb O2 affinity
Acidity
pCO2
2,3 Bisphosphoglyceric acid
Temp
What happens to the affinity of Hb in ⬆️ acidity
⬇️ = O2 unloads
What does it mean that the affinity of Hb ⬇️ in ⬆️ acidity?
More O2 is delivered to acidic sites
What happens to the pCO2 during exercise?
What does this mean for the affinity of Hb?
pCO2 = ⬆️
⬇️ affinity of Hb
= The harder the tissue is working = more O2 is released
When is 2,3 bisphosphoglycerate formed?
During glycolysis
How does 2,3-bisphosphoglycerate help unload O2 from Hb?
It binds to Hb itself
What happens to the affinity of Hb to O2 as temp increases?
What does this mean?
Affinity ⬇️
= More O2 delivered in warmer muscles
During hypothermia = more O2 remains bound
Where can myoglobin be found?
Skeletal + cardiac muscle
How many iron atoms does myoglobin have?
1
Which has a higher affinity? Myoglobin or Hb?
Myoglobin
What does myoglobin do?
Transfers O2 from cell membrane to mit/muscles
What is the cytochrome C oxidase?
Terminal complex of ETC
Where does O2 bind to on cytochrome C oxidase?
Hb a3 group
Which has a higher affinity? Myoglobin or cytochrome C oxidase?
cytochrome C oxidase
Who can blood type A+ give blood to and receive blood from?
To = A+ and AB+
Receive from = A+, A-, O+ and O-
Who can blood type O- give blood to and receive blood from?
To = Everyone
From = O-
Who can blood type AB+ give blood to and receive blood from?
To = AB+
From = Everyone
Transport methods for CO2
Dissolved CO2 ~7%
Carbamino compounds ~23%
Bicarbonate ions ~70%
H2CO3
Carbonic acid
HCO3-
Bicarbonate ions
What is the process of the chloride shift?
Exchange of bicarbonate + chloride across the membrane of RBCs.
What is a hypobaric environment?
Env w. low atmospheric pressure
i.e high altitude
What is polycythemia?
Elevated hematocrit %
