1B Flashcards
Describe the structure + function of Red Blood Cells (RBC)?
1B.2 Roles of the blood
- Transport oxygen from lungs to all cells
- Contain haemoglobin
- Made in bone marrow
- Biconcave disc shape > larger SA:V ratio
- No nucleus > More space inside haem
- called erthrocytes
Describe the structure + function of White Blood Cells (WBC)?
1B.2 Roles of the blood
- WBC larger than RBC
- Made in bone marrow
-Defend body against infection + inflammatory response to damaged tissue - Have a nucleus
- Have colourless cytoplasm
What are platelets?
1B.2 Roles of the blood
- Tiny fragments of cells
- Found in bone marrow
- Involved in blood clotting
Describe how oxygen is transported?
1B.2 Roles of the blood
- Haemoglobin transports oxygen
- Can collect 4 O2 molecules
- Haemoglobin + Oxygen = Oxyhaemoglobin
- Hb + 4O2 –>< Hb.4O2
What is positive cooperativity in terms of oxygen and haemoglobin?
1B.2 Roles of the blood
- 1st o2 molecule that binds to haemoglobin changes arrangement of molecule
- Easier for O2 molecules to bind afterwards
- Opposite when oxygen dissociates from Hb –> harder to remove 4th oxygen and easiest to remove 1st oxygen
What is CO2 converted into?
- Waste CO2 diffuses from respiring cells of body tissues into blood along conc gradient
- When CO2 dissolves into blood reacts w water –> forms CARBONIC ACID H2CO3-
- The carbonic acid seperates to form H+ and HCO3- ions
- Co2 + H2O = H2CO3 = H+ + HCO3-
What are the 3 ways CO2 in transported out of blood?
1B.2 Roles of the blood
- 5% of CO2 carried in solution in plasma
- 10-20% combines with haemoglobin to form carbaminohaemoglobin
- Most of CO2 transported in cytoplasm of RBC as HCO3 - ions
What does the enzyme carbonic anhydrase do?
1B.2 Roles of the blood
- Co2 + H20 –> H2CO3
- Carbonic anhydrase controls the rate of reaction between CO2 + H2O –> carbonic acid H2CO3-
- In body tissues there is a high conc. of CO2 in the blood so carbonic anhydrase catalyses the formation of carbonic acid
- In the lungs yhere is a low conc of CO2 so carbonic anhydrase catalyses the reverse reaction –> frees the CO2 so diffuses out of blood into the lungs
Describe and explain the bohr effect?
1B.2 Roles of the blood
- Way Hb collects / releases oxygen affected by amount of Co2 in tissue
- When high Co2 level in tissue –> affinity of HB for O2 is reduced
- Hb needs high levels of O2 to become saturated and release oxygen more readily
- More Co2 lower Hb saturation with oxygen
- Co2 level in lungs is low –> easy for Hb to bind to oxygen
- As Co2 builds up –> affects PH –> effects protein structure
- Hb does not work as well –> lower affinity fot O2
How does fetal haemoglobin work?
1B.2 Roles of the blood
- Oxygenated blood from mom flows thru placenta to deoxygenated foetal blood
- Blood of fetus contains special form of Hb –> fetal haemoglobin
- Fetal Hb has higher affinity for O2 than moms Hb
- Mom + baby blood runs in different direction –> makes O2 conc gradient very steep max O2 to baby
How does the bohr effect work in the level of the tissue?
1B.2 Roles of the blood
- IN LEVEL OF TISSUE -
- O2 curve shifts to right
- CO2 increases –> cells respire aerobically
- Partial pressure of O2 decreases + partial pressure of CO2 increases
- O2 dissociates more readily to diffuse into cells (as more CO2)
- Haemoglobin becomes unsaturated
- PH becomes lower
- H+ + Hb –> HHb —–> lower affinity for O2
How does the bohr effect work in the level of the lungs?
1B.2 Roles of the blood
- LEVEL OF LUNGS -
- O2 curve shifts to left
- Partial pressure of O2 increases
- Partial pressure of CO2 decreases
- O2 has higher affinity to Hb (less Co2)
- Positive cooperativity happens
- Hb saturated
- Forms oxyhaemoglobin
Why are there more elastic fibres the closer the artery is too the heart?
1B.3 - Circulation in the blood vessels
- More elastic fibres the closer the artery is to the heart bcoz need to withstand high pressure exerted by ventricles
Why is there more muscle tissue in the artery the further away from the heart?
1B.3 - Circulation in the blood vessels
- More muscle in artery the further artery is from the heart
- Blood flow can be controlled to certain areas by changing the size of the lumen
