Blood Flashcards
3 functions of blood
- Transportation
- Maintaining homeostasis
- Protection
Characteristics of Blood
Connective tissue 8% of body weight Volume: average 5 liters 5X more viscous than water 38degrees C 300 mOsm .9% salinity
Composition of Blood
Plasma 55%
Formed Elements 45%
Composition of Plasma
Water 90%
Proteins 8%
Solutes 2%
Composition of Formed elements
RBC 95%
WBC 5%
Platelets
Plasma Proteins (3) and %
Albumin 60%
Globulin 36%
Fibrinogen 4%
other proteins
Albumin
maintains water balance (along with NA+) a good buffer & are carriers for lipids, calcium & hormones
Globulins
immunoglobulins: antibodies
transport globulins: transport of iron, lips, fat soluble vitamins & hormones
Fibrinogen
For blood clotting
RBC!
Function: Transport of respiratory gases
Average 5 million/ul
Hematocrit
F: 42%
M:47%
Structure of RBC
- 5x2.5 micrometers
- no nucleus
- no mitochondria
- biconcave
Hemoglobin
- Protein found only in RBC
- binds and transports O2 and CO2
- Made of 4 protein chains, each chain has an iron-containing heme group that binds the oxygen
Hemoglobin amount
250,000/RBS
1 billion oxygen molecules per rbc
Oxyhemoglobin
HbO2 (ruby red)
deoxyhemoglobin
HHb (dark red- reduced hemoglobin)
Carbaminohemoglobin
HbCo2
-forms easier with reduced Hb
What is the cellular respiration equation?
C6H12O6 + 6O2 –> 6CO2 + 6 H2O + Energy (heat&ATP)
-summation reaction
RBC lifespan
upper limit is 120 days
2.5 million RBC die per second
Regulation of RBC
Erythropoiesis is regulated by the hormone erythropoietin EPO made by kidneys which stimulates increase in rate of production
When is EPO released?
EPO release increase during hypoxia (negative feedback control)
How is hemoglobin recycled?
macrophages in the spleen (RBC graveyard), liver and bone marrow
-AA & Iron are recycled, heme is excreted
How is heme broken down?
Heme–> Billirubin (transported by albumin to the liver where it is secreted with the bile into the small intestine) –> converted to stercobilin (brown bacteria excreted in feces)
- some billirubin is converted to urochrome (yellow pigment in urine)
Causes of Jaundive
- Liver cannot remove billirubin due to liver disease or rapid hemolysis
- Yellow coloration of skin
- neonatal jaundice is treated with blue lights