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