Blood blood connective tissue in fluid form


Functions of plasma proteins


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Blood

Functions of plasma proteins

  • Coagulation of blood – Fibrinogen to fibrin
  • Defense mechanism of blood – Immunoglobulins
  • Transport mechanism – α Albumin, β globulin transport hormones, gases, enzymes, etc.
  • Maintenance of osmotic pressure in blood
  • Acid-base balance
  • Provides viscosity to blood
  • Provides suspension stability of RBC
  • Reserve proteins

Formed Elements of Blood

  • Red blood cells (R.B.C.)
  • White blood cells (W.B.C.)
    • granular leukocytes
      • neutrophils
      • eosinophils
      • basophils
    • agranular leukocytes
      • lymphocytes - T cells, B cells, natural killer cells (N.K.C)
      • monocytes
  • Platelets (special cell fragments)

Functions of RBC

  • Transport oxygen from lungs to the tissues (oxyhemoglobin).
  • Transport carbon-di-oxide from tissues to lungs (carboxyhemoglobin)
  • Hemoglobin acts as a buffer and regulates the hydrogen ion concentration (acid base balance)
  • Carry the blood group antigens and Rh factor

Functions of neutrophils

  • First line of defence against invading micro-organisms.
  • Powerful and effective killer machine – contains enzymes like protease, elastase, metalloproteinase, NADPH oxidase; antibody like substances called defensins.
  • Defensins – antimicrobial peptides active against bacteria and fungi.
  • 3.Secrete Platelet Aggregation Factor (PAF) – accelerates the aggregation of platelet during injury to the blood vessels

Functions of eosinophils

  • Secrete lethal substances at the time of exposure to foreign proteins/parasites
  • Eosinophill peroxidase – detroy worms, bacteria and tumor cells.
  • Major basic protein – damage parasites
  • Eosinophill cationic protein (ECP)- destroys helminths.
  • Eosinophill derived neurotoxin – destroys nerve fibres (myelinated nerve fibres)

Functions of basophils

  • Basophill granules release some important substances like –
  • Histamine – Acute hypersensitivity reaction- vascular changes, increase capillary permeability
  • Heparin – prevents intravascular blood clotting
  • Hyaluronic acid – necessary for deposition of ground substances in basement membrane
  • Proteases – exaggerate inflammation
  • Basophill have IgE receptor – hypersensitivity reaction

Functions of Platelets

  • Blood clotting
  • Clot retraction
  • Defence mechanism
  • Homeostasis
  • Repair and rupture of blood vessel

Gas transport

  • Continuous interchange of CO2 and O2 between lungs and tissues.
  • Oxygen –
      • major e- acceptor
      • indispensable for ATP production.
  • CO2
      • major by product of energy metabolism

pH maintenance

  • Oxygen release helps to maintain pH in tissues
  • Lungs:
    • HHb + O2 = HbO2 + H+
  • Tissues:
    • CO2 forms proton and bicarbonate
    • Proton is bound to Hb, when O2 is released
    • Bicarbonate leaves RBC
  • Cl- / HCO3- interchange - Hamburger effect

Hb

  • Higher ability of Hb to release O2 but lower ability to bind O2 - Right shift
  • Useful at site of O2 release (tissues)
      • higher temperature
      • higher 2,3 BPG level
      • lower pH (Bohr effect)

CO2 transport

  • Bicarbonate formation within RBC and Cl interchange
  • CO2 dissolved in blood plasma
  • Carbaminohemoglobin formation
  • Thanx

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