Infectious Diseases

host, pathogen, interaction

Three main factors that influence infectious diseases

exceeds

disease develops when the pathogen’s ability to establish infection ________ the host’s ability to contain it

physical barriers

the first line of defense to infectious diseases

includes skin, oral cavity, stomach, mucosal surfaces, normal flora, sweat/secretions

epidermal surface

what part of the skin provides the protection?

langerhans cells

salivary glands

what part of oral cavity provides the protection?

lysozome

low pH

the ________ of the stomach provides protection from infectious diseases

mucosal epithelium

what part of the mucosal surfaces provide protection?

mucosal tissues

what part of normal flora provide protection?

pathogens

cuts, burns, pressure injuries, and surgical wounds

invasive lines, catheters, and mechanical ventilation

mucosal inflammation or ulceration

reduced gastric acidity

urinary retention or obstruction

alteration of normal microbiota by antibiotics

are all ways _________ can gain access

infants and young children

ways _______ are more vulnerable to infections

• immune defenses are still developing

• limited previous exposure means less adaptive immune memory

• physical barriers may be more easily disrupted

older adults

ways _______ are more vulnerable to infections

• immune responses may become less efficient

• skin/mucosal barriers become thinner or less effective

• chronic diseases and meds use increase vulnerability

pregnancy

ways _______ are more vulnerable to infections

• normal immune adaptations may alter susceptibility to particular infections

• infection may also affect the fetus or pregnancy outcome

virsuses

most common pathogen type to cause illness in humans by FAR

fungal

infections that are fairly uncommon, most often occur in those with an inadequate immune response

parasites

environmental/situational pathogens

phagocytes/immune cells, complement cascade

innate immune system:

if physical barriers are breeched by a pathogen, the next lien of defense is provided by: _____________ and __________

inflammation

the components of the innate system (phagocytes and complement cascade) helps facilitate the process of ________________

active immunity

develops naturally in response to an infection

also develops following immunization (vaccination)

immunological memory

in immunization, nonpathogenic form of a microbe or part of a microbe elicits an immune response to an _____________

passive immunity

you receive antibodies from somewhere else to gain immunity

active immunity

YOUR own body makes immune response

primary

vaccines induce a _________ immune response wtihout causign disease

bacterial

vaccine type:

• killed organisms or extracts of bacterial antigens (ex. pneumococcus)

viral

vaccine type:

• killed virus, attenuated live viruses may cause illness (ex. poliio), purified viral proteins

toxins

vaccine type:

• chemically deactivated but still antigenic (diphtheria, tetanus)

active

vaccines are a type of ________ immunity

passive immunity

provides immediate, short term protection

conferred naturally when IgG crosses the placenta from mother to fetus or when IgA passes from mother to infant in breast milk

It can also be conferred artificially by injecting antibodies into a nonimmune person

passive immunity

occurs when you receive ready-made antibodies from an external source