IMMUNE SYSTEM CHAPTER 22

bacteria cellular characteristics

unicellular microbe that contain DNA and reproduce! sticky polysaccharide capsule with hairlike pilli.

diseases caused by bacteria

strep throat, staphylococcal, tuberculosis, syphillis, diptheria, tetanus, lyme, salmonella, anthrax.

viruses characteristics

NOT A TRUE CELL, NON-LIVING! BUT contains DNA/RNA in capsid protein with membrane. Must enter a body cell to replicate.

diseases caused by viruses

Common cold, influenza, pneumonia, and hepatitis, COVID 19, polio, mumps, measles, rubella, chicken pox, ebola, herpes, HIV

fungi characteristics

unicellular/multicellular organisms that produce spores. Humans may breathe in spores or through direct contact.

diseases caused by fungi

ringworm, diaper rash, athlete's foot, yeast infection, histoplasmosis

parasite characteristics

multicellular, live within host and grow in size.

diseases caused by parasites

malaria, tapeworms, hookworms

why don't antibiotics kill viruses?

Because viruses use their host cells enzymes and ribosomes which are human cells and we don't want out human cells to die.

what kills viruses?

your immune system

line of defense in immune system

1. non specific external barriers--> Innate immunity (non specific internal barriers)--> Adaptive immunity (specific internal barriers).

1st line of defense

non specific external barriers

non specific external barriers consist of

intact skin, mucus and cilia, and other secretions

Intact skin's physical barrier

epidermis, sebaceous glands, sweat glands

epidermis

constantly falls off/ sloughs off dead skin cells along with invading organisms on top of skin.

sebaceous glands

secrete sebum (oil) which contain ANTIMICROBIAL CHEMICALS.

sebum

an antimicrobial chemical that creates an acidic environment on the surface of the skin to kill foreign substances.

sweat glands

sweat washes away particles, sweat is antimicrobial and anti-fungal, salt inhibits particle growth.

lysozymes

an enzyme that destroys bacterial walls and creates acidic mucus that creates an acidic environment.

mucus

flows and trap pathogens, pathogens interact with lysozymes and kill off!

cilia

move mucus up and out along with bacteria.

where is mucus and cilia found in

mucosal membranes in body passageways.

other secretions that contain lysozymes

lacrimal glands, salivary glands, nasal glands.

second line of defense

non specific internal defense/ innate immunity

innate immunity

second line of defense, provided by various immune cells, antimicrobial proteins, physiological processes.

diapedesis

passage of immune cells through capillary walls

cellular defense of innate immunity

located within tissues, blood, lymph tissue. job is to monitor environment and start an immune response.

macrophages and neutrophils

phagocytic cells

neutrophils

100 billion daily, held in reserve (bone marrow), circulate within blood and tissue.

macrophages

start from monocytes (blood) and become macrophages (once enter tissue)

how do phagocytic cells recognize foreign cells?

identification markers on foreign cells help them recognize.

basophils and mast cells

secrete chemotactic chemicals, don't directly attack, produce other chemicals such as HEPARIN, HISTAMINE, EICOSANOIDS as an inflammatory response.

chemotactic chemicals

attract other immune cells to do the attacking

heparin, histamine, eicanosoids

produce an inflammatory response, increase fluid movement to injured tissue

basophils reside within

blood

mast cells reside within

connective tissue and mucosal lining

eosinophils

parasite destroying cells, immune response for allergies

natural killer cells

immunological surveillance, detect abnormal cells, release cytotoxic chemicals that destroy cells!

antimicrobial proteins part of innate immunity

interferons and complements

interferons (IFNs)

non-specific defense against VIRAL infection

how do IFNs work?

IFN will bind to receptors on neighboring cell to alert that a virus is present, neighboring cell synthesizes a protein that will kill the particular virus. IFN will also trigger macrophages!

complements

groups of plasma proteins (10%) within blood

What do complements do?

opnozation, inflammation, cytoloysis, elimination of immune complexes.

opsonization

plasma proteins bind to bacteria and mark it for destruction!

inflammation

increasing response of inflammation by activating mast cells/basophils and attracting neutrophils/macrophages.

cytolysis

plasma proteins will bind to target pathogen cell, form a new protein channel allowing water to rush into cell which will cause lysis.

elimination of immune complexes

link immune complex to RBC, RBC will move throughout body to spleen where it will be destructed along with the complex.

immune cell complex

when antigens and antibodies come together

physiological process of innate immunity

imflammatory response

inflammatory response effects

immediate, localized, non-specific, response to tissue damage. prevents injury/infection from spreading, disposes cell debris, sets up stage for repair.