Infection and disease 2

Lethal dose.

number of pathogens that infect 50 pecent of hosts within a specified period of time

abiliity of microorganisms to establish an infection

ability of microorganisms to spread to adjacent tissues or other anatomical areas

any deviation of the host from a healthy state to an unhealthy state (health vs. unhealthy).

abnormal state where part or all of the host is unable to perform the normal functions of the body

morbid state (indicating diseased or unhealthy condition)

this change is manifested by signs and symptoms

• evidence of disease
• characteristics of a disease that can be observed by someone else in addition to the patients

redness, runny nose, swelling, rash, couphing, pus formation,fever, vomiting, diarrhea

characteristics of disease that can only be determined by the patient.

pain, shortness of breath, nausea, sore throat, headache, malaise (discomfort)

a nonspecific defense mechanism by the body in response to infection, injury or chemical irritation.

• dolor, soreness or tenderness from injury to local nerve.
• calor: heat (warmth generated from the blood due to vasoconstriction)
• tumor: swelling (edema, from the accumulation of fluid in surrounding tissue)
• Rubor: redness from blood accumulation
• itching

• vascular changes (vasoconstriciton)
• increase in vacular permeability (results in edema)
• Leukocyte migration
• Chronic inflamation
• resolution/healing

• Extravasation: movement of cells out of blood vessels (neutrophils)
• Edema
• local swelling caused by the accumulation of plasma nad blood components in extracellular spaces (white blood cells come for attack)

• Leukocyte migration
• Macrophages and neutrophils are the primary leukocytes that infiltrate the damaged area.

phagocytize pathogen

• remove dead and damaged cells
• allows for the growth of new cells and thereby aiding in tissue repair
• leukocytes aid in tissue repair

• pus formation
• purulent or suppurative

Granuloma and abscess

Collagenation: deposition of collagen matrix to allow for the building of new tissue

Angiogenesis: new glood vessels are formed

Proliferation: sustained collagen building and revasularization.

remodeling: newly generated cells cells must be structurally arranged to perform the function of the tissue of organs.

vasolilation delivers more oxygen and nutrients to injured tissue.

edema delivers more phagocytes to tiddues and organs

• kills invading pationgens
• clears away tissue debris

repairs damaged/injured tissue

swelling of protective membrans (brain or spinal cord) can interfere with function.

swelling in the lungs can constrict airwayse and interefere with breatining.

can help pathogens to thrive by bringing increased oxygen and nutrients.

can restrict access of white blood cells to infected sites.

granuloma small mass or nodule of inflamed tissue; due to the action of phagocytes and the subsequent accumulation of pus

abscess a collection of pus in a tissue, cavity or confined area surrounded by inflamed tissue

is what occurs when the immune system's response to an infection hurts the host cells and tissues

is damage to the host, mediated by the immune system in response to the pathogen.

tfbvs

• Toxemia
• Fungemia
• Bacteremia
• Viremia
• Septicemia

The study of diseased states.

the study of the structural and functional manifestations of disease

a branch of medicine that examines the nature of disease, how the disease is manifested, and changes to the body that occur as a result of disease

Premature cell death

cell death, due to trauma or injusry  to the cell

damage to the plasma membrane; cell rupture.

programmed cell death

cell membrane remains intact; cell blebbing occurs

cytopathic effects

• Viral overload
• Cytocidal effects
• non-cytocidal effects

the virus multiplies rapidly within the cell

number of viruses (virus overload) exceeds the dimensions of the cell causes cell lyses

then the virus infects surrounding cells, starting a new growth cycle.

• when host immunwhen host immune cells identify virally-infected cells and kills them.
•   cytotoxic t-cells
•   natural killer cells

cell death then occurs by apoptosis.

when the virus inhibits the metabolic functions of the host cell

• dna replication
• transcription
• translation

is giant, multinucleated cells

resulting from fusing of several virally-infected cells

are inclusion bodies; ovservable viral particles

combination of signs and symptoms, occur together and are indicative of a diseased or abnormal condition

complex of symptoms indicative of a morbid state.

permanent damage to tissues as a result of infection and disease

process of determining the cause of disease

commonly involves the use of chemical or immunological tests

projected outcome of a diseas, prospect of recovery from a disease.

based on the nature (pathology) of the disease.

prevention

prevent the spread and development of disease

based on understanding the etiology and mode of transmission

includes the vaccination, improving hygiene and sanitation, standards of living, and education.

relieving or soothing the symptoms of a disease or disorder without affecting a cure

providing relief from pain and other distressing symptoms

a disease with an unknown etiology, pathology, and prognosis

• study of how diseases are caused.
• factors include: 
• pathogens (infection)
• Genetics (genetic disordera)
• immune dysfuntion (autoimmune diseases)
• Biochemical/physiological deficiencies or changes
• psychological dysfunciton

the study of the frequency and distribution (spread) of disease and other health-related problems within human populations.