Blood
Functions:
Composition
Transport:
Regulation
Protection
O2 and nutrients TO body cells
Metabolic waste TO lungs and kidneys
Hormones
Temperature. Absorption and heat distribution
pH using buffers
Adequate fluid volume
Clotting to prevent blood loss
Preventing and fighting infections
Antibodies
Complement proteins
White blood cells
Fluid connective tissue
Physical characteristic
Extracellular matric: plasma
Cells: formed elements originate in bone marrow and don't divide
Erythrocytes or Red Blood Cells
Leukocytes or White Blood Cells
Platelets
Sample
Bottom layer (~45%) is RBC
Middle layer (<1%) is WBC and platelets
Top (~55%) is plasma
hematocrit : measurement in percent of blood volume that is RBC. Normal values for males (47%) and females (42%) vary within +/- 5%
Sticky, opaque fluid with metallic taste
Color varies with Oxygen content (higher O2 = brighter red)
pH 7.35-7.45
~8% of total body weight. Males (5-6 L) Females (4-5L)
Straw-colored, sticky fluid (90% H2O)
Over 100 dissolved solutes. Most abundant solutes are plasma proteins (pp)
Produced by liver
Albumin makes up 60% of pp
They lack nuclei and other organelles
Only complete cells
Cell fragments
Biconcave disc shaped, Small-diameter (7.5 μm)
Filled with hemoglobin for gas transport (97% of cell volume) (250 million Hb molecules per RBC)
Plasma menbran spectrin provides flexibility
Without mitochondria, their ATP production is anaerobic. meaning they don't consumed O2 they transport
Bind reversibly with oxygen
Values for male (13-18g/100ml) and female (12-16 g/100ml)
red heme pigment
protein globin
Composed of four polypeptide chains: 2 alpha 2 beta
bonded to each globin chain (4)
Each heme's central iron atom binds one O2 molecule
Types
oxyhemoglobin produced in lungs once O2 is loaded
deoxyhemoglobin produced in tissues when O2 is unloaded
carbaminohemoglobin produced when CO2 loads
Come from Hematopoetic stem cells (hemocytoblast)
Regulation and Requirements
Too few = hypoxia
Too many = viscosity
Balance depends on 1) Hormonal controls and 2) Dietary requirements
Homeostatic Imbalance
EPO increases hematocrit to dangerous leves (clotting, stroke, heart attack)
Anemia: abnormally low O2 carrying capacity
Causes
Polycythemia: Abnormal excess of RBC causing sluggish flow
Blood loss
Not enough RBCs produced
Too many RBCs destroyed
Hemorrhagic (Rapid). Treated by blood replacement
Chronic hemorrhagic(Slight but persistent). Primary problem must be stopped.
Iron-deficiency Anemia. Treat with cupplements
RBCs produced are microcytes which are small, pale and cannot synthesize Hb
Pernicious Anemia
Renal Anemia
Aplastic Anemia
Incompatible transfusions or infections
Hemoglobin abnormalities (usually due to genetic disorders)
Thalassemias
Sickle-cell Anemia
A single amino acid change (Glu to Val) in beta chain in Hb results in sicle shape
Polycythemia vera: Bone marrow cancer. Treat with phlebotomy
Secondary polycythemia: caused by low O2 levels (high altitude)
Blood doping