Flashcards
Red Blood Cells
Cards in this deck (51)
- 1When does Hb bind O2 in the lungs?When PO2 is high
- 2When does Hb unbind O2 in the tissues?Where PO2 is low
- 3What does cooperativity mean?Once one O2 has bound to a Hb it is easier for subsequent O2 to bind
- 4Is oxygen soluble in plasma?Poorly (normal arterial blood carries 70x more O2 on Hb (on RBC's) than in the plasma
- 5What is the function of Hb?To carry O2
- 6How many ATP are produced in aerobic resp?~36
- 7How many ATP are produced in anaerobic resp?4 net 2
- 8How much of the weight of RBC's does b take up?95%
- 9Describe haem (3)Coloured, contains one iron atom, is the site of O2 binding
- 10How many subunits does myoglobin have?1
- 11How many subunits does Hb have?4
Adult: 2 alpha, 2 beta
Foetal: 2 alpha, 2 gamma - 12What is a tetramer?A protein with four peptide subunits
- 13What is the bohr effect?Increase in CO2 decreased Hb affinity for O2
Decreased blood pH (due to CO2) leads to decreased affinity for O2
High blood CO2 means low blood pH - 14How much CO2 is dissolved in blood?10%
- 15How much CO2 is carried as carbamino?22%
- 16How much CO2 is carried as HCO3-?68%
- 17Why is myoglobin curve hyperbolic?It can only bind one O2 before it becomes saturated
- 18Why is the Hb curve sigmoidal in shape?It has 4 spaces for O2 - as one binds it makes it easier for the subsequent O2 to bind
- 19What causes decrease in affinity for O2?Rightward shift
- 20What leads to rightward shift?CO2
H+
Cl-
2,3-DPG - 21What is 2,3-DPG?2,3-diphosphoglycerate
Binds to Hb
Lowers affinity of Hb for O2
Found in erythrocytes
Tiny molecule - 22What affinity does foetal Hb have for 2,3-DPG?Low therefore foetal Hb has a higher affinity for O2 than adult Hb
- 23Describe active musclesO2 levels are low
CO2 levels are high
Blood is slightly acidic
Temperature is higher
There is myoglobin (Hb in muscle) - 24What happens as blood runs along the capillary?O2 leaves the capillary
CO2 and H+ bind to the Hb and Hb saturation is shifted to the right
HCO3- leaves the RBC and enters the plasma
Cl- leaves the plasma and enters RBC (chloride shift) - 25How is breathing controlled?CO2 gas enters the cerebrospinal fluid (CSF) and makes carbonic acid
The H+ is picked up by the brain as the medulla samples the CSF as well as the interstitial fluid - 26What do RBC's look like?Mature
Biconcave disc
Lack of organelles
7um diameter
2um height
Contain Hb
Red when oxygenated - 27What is the function of RBC's?Transport O2 and CO2
Fold and stack in blood vessels called rouleau
Survive around 120 days - 28How many RBC's per uL blood?5,000,000
- 29How many leukocytes per uL blood?9,000
- 30How many platelets per uL blood?300,000
- 31What is haematocrit?The packed cell volume
- 32What are normal Hb levels for a man?13-17g/dL
- 33What are normal Hb levels for a woman?12-16g/dL
- 34What is the mean cell Hb value?27-34 pg
- 35What is the mean corpuscular volume?80-100 fL
- 36What is erythropoiesis?Development of RBC's
- 37When a baby is growing where do RBC's develop?Liver
Spleen
Yolk sac
Lymph nodes - 38What is erythropoietin?The protein responsible for RBC growth
- 39What are the precursors to RBC's?Erythroblasts - Reticulocytes - RBC's
- 40How long do reticulocytes last in the blood?2 days
- 41Why are reticulocytes important in anaemia?Indicator of bone marrow activity
High in haemolytic anaemias (where blood cells are broken down prematurely)
Low when erythropoeisis is low
Machine counts cells and detects those with DNA in them - 42What is methaemoglobinaemia?Hb cannot transport O2
Fe is Hb is oxidised
Due to globin mutaton, hereditary decrease in NADH or toxic substances - 43What is carbon monoxide poisoning?Hb cannot transport O2
CO displaces O2 from Hb
Affinity for CO is 250x stronger than that for O2
Blood turns bright red
Leads to disorientation and death - 44What is polycythaemia? (general)Increased number of RBC's
Increased velocity of blood
Blood vessels become clogged - 45What is physiological polycythaemia?Occurs when living at high altitudes
- 46What is polycythaemia vera?Often asymptomatic
Risk of thrombotic events
No cure
Treat with blood letting (venesection)
Increases with age
Possibly genetic - 47How is Fe stored intracellularly?As ferritin and haemosiderin
- 48Where is Fe stored in the body?Liver
Spleen
Erythrocytes
Bone marrow
Macrophages
Monocytes - 49What can iron deficiency lead to?Iron deficient anaemia
- 50What is vitamin B12 and Folic acid essential for?Rapidly dividing tissue
- 51What does Vitamin B12 and Folic acid deficiency cause?Megaloblastic cells (massive cells which are fragile)