Patho Infection + Immunity

Disease Course of Action

  1. Incubation Pd

  2. Prodromal: replication of illness

  3. Acute: severity of illness

  4. Convalescent: reached after 5 to 7 days

  5. Resolution


  • death may occur before or at peak illness known as CRITICAL THRESHOLD

  • CHRONIC DISEASE: never fully goes away

  • SUBCLINICAL DISEASE: when you get infected but immune system is able to clear it before major symptoms are felt (below clinical threshold)


INATE VS ADAPTIVE

Innate:

  • the first and second lines of defense

  • there is rapid response usually occuring within hours

  • a NON-SPECIFIC response to foreign molecules

  • a fixed response

  • no memory

  • includes cellular and biochemical defenses


1st Line

  • includes the skin and mucous membranes

  • pH of skin

  • sebum which is toxic to bacteria

  • vaginal secretions

  • stomach mucosa that secretes hydrochloric acid

  • saliva and tears that trap and filter pathogens


2nd Line

  • phagocytes

  • natural killer cells

  • inflammatory response

  • antimicrobial proteins


Adaptive

  • includes the 3rd line of defense

  • delayed response usually within days

  • a SPECIFIC response

  • response is adaptive meaning it can change over time

  • has memory through previous exposure


3rd Line

  • antibodies which are immune systems response to threat


SIGNS OF INFLAMMATION (5)

  • Redness (rubor)

  • swelling (tumor)

  • pain (dolor)

  • heat (calor)

  • loss of function (functio laesa)

CAUSES OF INFLAMMATION

  • immune systems response to infectious pathogens

  • trauma

  • surgery

  • caustic chemicals

  • extreme heats or cold

  • ischemic damage to body tissues (lack of o2/tissue death)


ACUTE VS CHRONIC INFLAMMATION

Acute

  • usually short duration

  • non-specific and usually early response

  • aimed at removing agent that is causing harm

  • triggered to limit tissue damage neutrophils to the rescue


CHRONIC

  • longer duration

  • weeks, months, yrs

  • a recurrent or progressive acute inflammatory response

  • macrophages and lymphocytes to the rescue

  • presence of fibroblasts


MEDIATORS OF IMMUNE SYSTEM

Vasoactive Amines

  • Function: increase vasodilation and vascular permeability
    causes redness, heat, and swelling

  • Ex: Histamines + Serotonin

Plasma Protein Systems

  • Function: enhance immune reponse
    promote vasiodilation
    pain and recruit immune cells

  • Ex: complement system + coagulation system

Lipid Derived Mediators

  • Function: mediate pain, fever, vasodilation, leukocyte recruitment

  • Ex: prostaglandins + leukotrines

Cytokine + Chemokines

  • Function: regulate immune cell activation, differentiation, chemotaxis (cell movement), systemic inflam response

  • Ex: interleukins, tumor necrosis factor, interferons, chemokines


VASCULAR CHANGES THAT MAY OCCUR WITH INFLAMMATION

  1. Immediate Transient Response: occurs with minor injury

  2. Immediate Sustained Response: occurs with serious injury and continues for several days, damaging vessels in the area

  3. Delayed Hemodynamic Response: increase in capillary permeability that occurs 4 to 34 hours after an injury


CELLULAR STAGE OF ACUTE INFLAMMATION

  • marked by the movement of phagocytic WBC’s like leukocytes into the area of injury

  • in ACUTE inflam response, granulocytes like neutrophils, eosinophils, or basophils + monocytes participate


LEUKOCYTES

  • granulocytes include neutrophils, eosinophils, and basophils

  • monocytes that can differentiate into dendritic cell and macrophages

  • lymphocytes that can be B or T cells


ANTIGEN PRESENTION

  • macrophages and dendritic cells process and present antigens to CD4 cells

  • can differentiate from self by sensing MHC1

  • APC capture antigens and enable their recognition by CD8 cells to initiate adaptive immunity

ANTIGEN, PATHOGEN + ANTIBODIES

  • Antigen: foreign substance that stims immune system

  • Pathogen: disease causing agent

  • Antibodies: recognize antigens and through receptors on immune cells or secreted proteins


ADATIVE IMMUNITY

Humoral

  • mediated by molecules in blood

  • B cells that differentiate into plasma cells that produce antibodies and memory b cells

Cell Mediate

  • mediated by specifc T lymphocytes

  • specifically against viruses

  • t cells tha can kill and hold memory


ACTIVE IMMUNITY

  • protection/immunity following exposure

PASSIVE IMMUNITY

  • protection/immunity follwing transfer of antibodies

  • Ex: maternal IgG crosses placenta and protects baby

  • IgA in colosteum

  • intravenous immunoglobulin

  • cytokine therapy


CLASSES + FUNCTIONS OF ANTIBODIES (GAMDE)

  • IgG: displays antiviral, antitoxins + antibacterial properties, especially in newborns, and activates complement

  • IgA: predominantly found in body secretions (mucous membranes)

  • IgM: forms natural antibodies, prominant in EARLY IMMUNE RESPONSE (has lots of binding sites)

  • IgD: found in B cells and needed for maturation of B cells

  • IgE: binds to mast cells and basophils, invlved in parisitic infections and allergic reactions


SEPSIS

  • life threatening medical condition when body has extreme reaction to an infection

  • immune system goes into overdrive and starts attacking body’s own tissues and organs

CAUSE

  • triggered by infections

  • Ex: pneumonia, urinary tract, GI or skin infections

PROCESS

  • infection can lead to widespread inflammation causing blood clots, leaky vessels, and poor blood flow leading to organ failure

SYMPTOMS

  • fever or low body temp

  • rapid heart rate

  • rapid breathing

  • confusion and disorientation

  • extreme discomfort or pain

  • clammy/sweaty skin


ACRONYM

  • S- slurred speech/confusion

  • E- extreme shivering, pain, or fever

  • P: passing no urine

  • S- severe breathlessness

  • I- “I feel like im going to die”

  • S- skin mottled, discolored, or very pale