Blood Plasma

Blood plasma is

• matrix where blood cells and platelets are suspended

• interstitial/tissue fluid originates from plasma

• 92% water

• 7% proteins

• 1% electrolytes, nutrients, hormones gases etc

Proteins

• maintain a stable pH by binding to H+ ions

• amino acid reserve → broken down by macrophages

• carriers for other molecules to be transported to tissues

• colloidal osmotic pressure - forces water to move from tissue fluid into capillary

• cause blood to coagulate

Types of Plasma Protein

• albumin

• globulin

• fibrinogen

Albumin

• transport molecules as they dissolve in plasma by binding to them → ca2+, hormones, drugs

• colloidal osmotic pressure to maintain water balance between interstitial fluid and blood

  • loss of albumin causes edema (lots of water in interstitial fluid)

• smallest and most abundant plasma protein

Globulins

• a globulin/b globulin

  • regulate cholesterol

  • form lipoprotiens (by binding to a lipid) these can transport cholesterol

  • HDL /LDL -

    • hdl → high density lipoprotein, carry cholesterol to liver (good)

    • ldl → low density lipoprotein carry cholesterol to arterial walls

• y globulin

  • formation of antibodies → bind to antigens(molecule that antibodies bind to because they recognize it as foreign)

Fibrinogen

• soluble precursor to fibrin

  • important for clotting

• thrombin produced by the liver converts fibrinogen into fibrin

Electrolytes

• plasma is a dilute salt solution

  • contains na+, cl_ and hco3-

  • most common is na+

• regulate membrane potentials, osmotic balance Ph buffering

• ca2+ → muscle/nerve cell sensitivity

Nitrogenous Waste

• urea, co2

• toxic so are in the bloodstream to be taken to the kidneys were they are excreted

Hormones

• endocrine hormone are carried to target cell/organ by the blood

Nutrients

• from digestive tract

• glucose

• amino acids

• fats

• cholesterol

• phospholipids

• vitamins and mineral s

Gases

• o2 and Co2

• some nitrogen is dissolved in plasma

Water

• 92%

• universal solvent hence allowing transportation of molecules in the blood

• maintenance in blood pressure and volume

  • less blood volume bcs water leaves means less blood pressure, heart has less fluid to pump

Plasma vs Serum

• Plasma - liquid that remains when clotting of blood is prevented by anticoagulant and other cells are removed by centrifugation

(just the liquid of blood)

• Serum - plasma - fibrinogen (allowed to clot naturally then centrifuge)

Whole blood

• blood outside body with anticoagulant

What is the use of using an anticoagulant

• without it the blood would clot outside the body

• preserves fibrinogen so it can be used in a coagulation test

Serum

• If blood is drawn outside the body it will clot

• this separates the cells from the liquid - serum

• cannot be used in coagulation test - fibrinogen the coagulation factor has already been used up