Host Defense

7/31/2019 Host Defense

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The protection of anorganism is affordedagainst infection is calledhost defense.

There are two types of hostdefense or immunity:-

1. INNATE (NONSPECIFIC) IMMUNITY

2. ACQUIRED (SPECIFIC)IMMUNITY


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DEFINITION:-

The term innate immunity

refers to resistance to diseases thata species possesses. This is the firstline of defense against infection.


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ANATOMICBARRIERS:-

. SKIN

. EPIDERMIS

. DERMIS

. MUCOUS

MEMBRANE. PH


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. TEMPERATURE

. ELEVATED BODY TEMPERATURE

. PH

. OXYGEN TENSION


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The humoral factors are found in serum and they are formedat site of infection.

1. COMPLEMENT SYSTEM:-This is the major humoral non specific defense

mechanism it leads to increased vascular permeability onactivation. Recruitment of phagocytic cells, lysis andopsonization of bacteria.

2. COAGULATION SYSTEM:-Depending on severity of tissue injury coagulation

system may or may not be activated. It acts aschemotactic agents for phagocytic cells.


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3. LACTOFEERIN AND TRANSFERRIN:-By binding iron an essential nutrient of bacteria,

these proteins limit bacterial growth.4. INTERFERONS:-

They are proteins that can limit virus replication incell.

5. LYSOZYME:-Lysozyme breaks down the cell wall of bacteria.

6. INTERLEUKIN 1 AND 2:-

Induces fever and production of acute phaseproteins, some of which are anti microbial because they canopsonize bacteria.


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1. NEUTROPHILS

2. MACROPHAGES

3. NATURALKILLERS

4. EOSINOPHILS


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MEANING :-Latin word inflammare means to set

on fire.DEFINITION:-

Inflammation is a part of complexbiological response of vascular tissues toharmful stimuli such as pathogens, damagecells or irritants.

Inflammation is protective attemptby the organism to remove the injuriousstimuli and to initiate healing process.

CAUSES:-1. burns2.chemical irritants3. frost bite4. toxins5. foreign bodies

6. immune reactions due to hypersensitivity


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There are 2 types of inflammation.

1. ACUTE INFLAMMATION

2. CHRONIC INFLAMMATION


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It is the initial response of body toharmful stimuli and is achieved byincreased movement of plasmaand leukocytes especiallygranulocytes from the blood intoinjured tissues. It is short term

process.The traditional names for signof inflammation comes from latinwords

1. DOLAR2. CALOR3. RUBOR

4. TUMOR5. FUNCTIO LAESA


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Prolonged inflammation, known aschronic inflammation, leads to

progressive shift in the type of cellspresent at a site of inflammation andis characterizes by simultaneousdestruction and healing of tissuesfrom inflammatory process.


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Inflammatory response must be activelyterminated when no longer needed. Mechanismwhich serve to terminate inflammation include:-

production and release of (TGF) from

macrophages. production and release of interleukins apoptosis of pro inflammatory cells de sensitization of receptors

cleavage of chemokines lead to production of antiinflammatory factors.


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1. Acute appendicitis

2. Acute dermatitis

3. Acute infectiveMeningitis


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1. Auto immune disease

2. Asthma

3. Glomerulonephritis4. Chronic prostatitis

5. Inflammatory bowel disease.


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It is also called as specific immunity.It results from exposure to organism

or by receiving preformed antibodiesmade in another host. Acquiredimmunity may be active or passive.


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ACTIVE IMMUNITYOne which results from exposure toorganism.

PASSIVE IMMUNITYIt is kind of a temporary protection againstan organism and is acquired by serumcontaining prepared anti bodies fromanother person or animal.


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Host Defense

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