SOLDIERS OF DEFENSE:sslc important points

• Body coverings (Skin and mucous membrane)
• Body secretions (Mucus, lysozyme in saliva, tears
  and urine, sweat, sebum, ear wax, HCl …)
• Body fluids (Blood and lymph)

1. Skin :- The outer most keratin layer (protein)
   prevents germs from entering it.

• Sebum makes skin oily and water proof.
• Sweat have disinfectants to destroy germs.

1. Mucus and cilia in the respiratory tract prevent and
   wipe out germs and dust.
2. Useful bacteria in skin and mucous membrane.
3. Cough and sneezing to expel foreign bodies.
4. Ear wax and hairs prevent the entry of substances.
5. The enzyme, lysozyme, in the tears, saliva and urine
   destroy germs.
6. HCl in the stomach fight against germs.
   Action of WBCs :-

• Neutrophils – Engulfs and destroys bacteria,
  Produces chemicals against bacteria
• Basophils -Stimulates the other white
  blood cells, Dilates the blood vessels.
• Eosinophils – Destroys foreign bodies.
  Produces chemicals for inflammatory
  response.
• Monocytes – Engulfs and destroys germs.
• Lymphocytes (B and T) act specifically against
  antigens.

nflammatory Response
The dilation of the blood vessels by certain
chemicals, when a cut or wound occur, blood
flow increases to the wound site and more white
blood cells can reach there.

2. Phagocytosis
   [the process of engulfing and destroying germs
   by certain white blood cells (phagocytes)]

Phagocyte reach near the
pathogen.

• Engulfs the pathogen
  in the membrane sac.
• Membrane sac combines
  with lysosome.
• The enzyme in the lysosome
  destroys the pathogen.
• Phagocyte expels the remnants

2. Blood clotting

• Tissues of the wounded part degenerate to form
  an enzyme, thromboplastin.
• With calcium ions and vitamin K, thromboplastin
  converts prothrombin to thrombin.
• Thrombin converts fibrinogen to fibrin.
• In the fibrin net, RBCs and plateletes entangled
  to form the blood clot.

2. Healing of wounds
   (When connective tissues form to heal the wound,
   scar remains there)
3. Fever
   Toxins of pathogens stimulate WBC to produce
   chemicals for raising body temperature.
   Fever prevents the rapid multiplication of bacteria
   and increases the effect of phagocytosis

Action of
B Lymphocytes
B lymphocytes, (which mature in the bone marrow)
produce antibodies, which destroy germs by

• disintegrating bacterial cell membrane,
• neutralising their toxins and
• stimulating the other white blood cells.
  Action of
  T Lymphocytes
  T lymphocytes,(which mature in the thymus gland)
  stimulate the other white blood cells and destroy
  cancer cells as well as virus affected cells.
  Lymph helps in defense mechanisms:
  Lymphocytes in the lymph nodes and spleen
  destroy bacteria
  B. VACCINES for Induced Immunity
  Vaccines are substances,given in advance to prevent
  certain diseases.
  Dead, inactive, alive but neutralized germs or toxins
  are used as vaccines.
  By the presence of these antigens, lymphocytes
  become activated and produce antibodies. These
  antibodies remain in the body for long time to
  provide immunity against antigens.
  [ Smallpox vaccine , the first vaccine, was invented
  by the scientist Edward Jenner.]
  BCG, OPV, Pentavalent, MMR, TT are vaccines.

DIAGNOSIS & TREATMENT
Systems of medicine
• Allopathy (Modern Medicine) Hippocrates
• Ayurveda (A life style to maintain the body fit.
Majority of medicines are herbal. Indian)
• Homeopathy – Samuel Hanniman.
• Unani etc.
Some specialisation in Modern medicine :
Cardiology – (treatment of heart)
Ophthalmology – (treatment of eye)
Neurology – (treatment of brain or nerves)
Oncology – (treatment of cancer)
E.N.T – (treatment of ear, nose and throat)
Diagnosis

• Equipments (Stethoscope, Sphygmomanometer,
  Digital manometer, Thermometer, ECG, EEG,
  Ultra Sound Scanner, CT Scanner, MRI
  Scanner, …)
• Lab tests (blood, urine …)
  Normal value of blood cells and haemoglobin :-
  Haemoglobin – 12-17gm/100ml of blood.
  RBCs count – 45-60 lakhs/ml of blood.
  WBCs count – 5000-10000/ml of blood.
  Platelets count – 2.5-3.5 lakhs/ml of blood.

Therapy

• Using Antibiotics
  Antibiotics are effective medicines used to resist
  bacterial diseases.
  The first antibiotics -penicillin – was synthesized by
  Alexander Fleming (in 1928).
  Side effects:
• Regular use develops immunity in pathogens
  against antibiotics.
• Destroy useful bacteria in the body.
• Reduces the quantity of certain vitamins in the
  body.
• Radiation Therapy (for cancer and eye disease)
• Surgery
• Transplantation of organs
• Blood Transfusion
  Carl Landsteiner proposed A,B,AB, O blood
  grouping on the basis of A, B antigens seen on the
  surface of the RBC.
  Those blood with Rh factor (antigen D) on the
  surface of RBC are termed as positive group blood
  and those with out Rh are termed as negative group
  blood.
  If blood is not compatible, the antigen in the
  received blood will react with the antibody in the
  recipient’s blood of so as to clot RBC
  (agglutination).

Defense Mechanisms in Plants
• Bark protects the inner cells.
• Cuticle and wax on leaves, defends the attack
of microorganisms.
• Cell wall, made up of cellulose, is rigid coat by
the deposition of lignin, cutin or suberin.
• Callose, a poly saccharide, prevents
the germs which have crossed the cell wall.