Week 2: Blood and O2 transport Flashcards
How do gases move across membranes?
By diffusion down pressure gradient
What is Henry’s law?
When a mixture of gas is in contact with a liquid each gas dissolves in the liquid in proportion to it’s partial pressure and solubility until equilibrium is achieved.
In relation to the distance away from the heart what area has the largest vessel?
The closer to the heart the larger the vessel
In relation to the distance away from the heart what area has the largest cross sectional area?
The further away from the heart
In relation to the distance away from the heart what area has the highest blood flow velocity?
Closer to the heart, especially leaving the heart initially
How thick are capillaries?
Single cell layer
What is the rate of blood flow in the capillaries beds?
Slower than in capillaries because allows more time for diffusion
Describe the surface area of capillaries
Large surface area
Where do you take capillary blood samples?
Fingertip Ear
Where do you take venous blood samples?
Venipuncture Cannula
What is in plasma?
91.5% Water 7% Proteins 1.5% Other
What is in the buffy coat?
White blood cells Platelets
What is in the hematocrit?
Red blood cells
What are the three main sections of blood?
Plasma
Buffy coat
Hematocrit
What is the concentration of gas dissolved in a liquid proportional to?
Partial pressure and solubility
What percent of oxygen is transported via the oxygen being dissolved in plasma?
1%
What percent of oxygen is transported via it being combined with haemoglobin?
99%
How much oxygen is there in a litre of blood?
3 mL
What does the dissolved O2 in the plasma do?
Regulates breathing Determines loading of haemoglobin
How does O2 move into the RBC?
Via diffusion
Where is the haemoglobin?
In RBC
What is the shape of a RBC?
Biconcave
In a haemoglobin molecule how many iron groups are there?
4 iron groups
What is haemoglobins affinity for O2?
High
What happens to oxygens affinity to Hb when acidity increases?
It decreases
Why does oxygen have a lower affinity to Hb in acidic conditions?
More oxygen is delivered to acidic sites (the working muscle require more oxygen)
When is 2,3-Bisphosphoglycerate produced?
During glycolysis
What does 2,3-Bisphosphoglycerate do?
Helps to unload O2 by binding with Hb
What happens to oxygens affinity to Hb when temperature increases or decreases past homeostasis?
Decreases
When temperature increases where is more oxygen delivered?
To warmed up muscle
What type of globular protein is myoglobin?
Iron containing
What muscle is myoglobin in?
Skeletal and cardiac
How many iron atoms are there in myoglobin?
1 iron atom
What has a higher affinity to oxygen Mb or Hb?
Mb even at low O2
What are the method in which CO2 is transported?
Dissolved Carbamino compounds Bicarbonate ions
What percentage of CO2 is transported via it being dissolved?
7%
What percentage of CO2 is transported via it being bonded to carbamino compounds?
23%
What percentage of CO2 is transported via it being bonded to bicarbonate ions?
70%
What does training elicit regarding oxygen with in the blood?
Hypoxaemia
What do changes in the O2 level cause the kidney to secrete?
EPO (erythroid progenitor)
What does EPO stimulate?
RBC production in marrow of long bones
What does an increase in RBC production lead to?
Increase in RBC mass therefore increase in O2 carry capacity
What happens in a hypobaric environment?
The concentration of gases in mixture stays the same but there is a reduce in pressure therefore there are less molecules
What occurs in anaemia?
Reduced RBCs
What causes gas exchange?
Diffusion down pressure gradient
What is Dalton’s law?
Total pressure of a mixture is equal to the sum of the partial pressures of the individual gases in a mixture
How much more soluble is CO2 than O2?
22 times more
How much oxygen can one haemoglobin molecule transport?
4
What alters haemoglobins affinity to oxygen?
Acidity PCO2 2,3-BPG Temperature
What happens to haemoglobins affinity to oxygen when PCO2 increases?
Affinity decreases
Where does myoglobin transport oxygen?
From the cell membrane to mitochondria
What has a higher affinity to oxygen: Mb or cytochrome C?
Cytrochrome C
What is the normal hematocrit level for males?
42-52%
What is the normal hematocrit level for females?
37-47%
What does cytochrome C do?
The oxygen binds to Haem a3 group with in the cytochrome C
What has a higher affinity to oxygen; cytochrome C or Mb?
Cytochrome C
What happens to the oxygen that is binded to the cytochrome C molecule?
The oxygen is then the final electron acceptor in the ETC
What happens when CO2 and H2O react in the presence of carbonic anhydrase?
They create H2CO3
What type of reaction is it when CO2 and H2O react in the presence of carbonic anhydrase?
An equilibrium reaction
What is the catalyst?
Carbonic anhydrase
What does HCO3- exchange with within the RBC to the blood plasma down the conc gradient?
Cl-
