Chapter 24 : structures of the upper respiratory system

upper respiratory system

include the nose, pharynx, middle ear and Eustachian tubes

• saliva and tears protect mucosa surfaces

• usually transmitted via droplets or vehichial transmition

• very common and more mild

lower respiratory system

include larynx, trachea, bronchial tubes, and aviloi

• more sever

• mostly sterial

actions to prevent pathogen in the lower respiratory system ( 4)

• ciliary escalator

• alveolar macrophages

• respiratory mucus

• competitive exclusion

Epiglottitis

the most life-threatening of the upper respiratory system

• infmammationn

• leads to the blocking of the airways, suffocation

• hemophilus influenza

Pharyngitis ( soar throat)

caused by : streptococcus pathogens ( Step throat )

• multiple pathogens ( why common)

• capsule

• streptokinesis ( digesting blood clots )

• hemolycine : helps burst red blood cells

  • known for producing SLO and SLS

  • SLO: active in anaerobic environments

  • SLS: will work in the presence of oxygen ( aerobic,) oxygen stable

• If left untreated, it leads to scarlet fever

Scarlet Fever

• fever

• rash

• systemic infection associated with specific strains of s.pyogene

• producing an erythrogenic toxin ( SPE) and SPEA

Diphtheria

caused by : Corynebacterium diphtheriae

type: gram positive rod; pleomorphic the

main concern is the formation of the pseudomembranous

• tough garyish membrane on throat

• white patches on the lining

• combination of dead tissue and cells from the bacteria ( blocking the trachea) suffocation

• diphtheria toxin

DTAP vaccine

Diphtheria toxin

• AB toxion

• stops protein synthesis in cell causing them to die

  • has the ability to circular the blood stream, damages the other organs

• can lead to myocarditis

Otitis

Caused by: Streptococcus pneumonia, nonencapsulated Haemophiles influenzae, s.pyogenes

• Infection of the middle ear

• common complication of pharyngitis

• much more common in children due to their short ear canal

The common cold

200 different viruses

Rhinoviruses ( the most common) :

• ICAM1 receptor - commonly found in epithelial cells that are line the respiratory system

• don’t have spikes, attach like a corkscrew( hidden)

• canyon hypothesis

Canyon hypothesis

hidden binding site to prevent adaptive immunity

Lower respiratory system

caused by the same bacteria and viruses of the upper system

• more damaging

  • compromise oxygen uptake '

  • difficulting breathing

• usually the same signs and symptoms

• Brochittic

• bronchocototcs

• Pneumonia

Pertussis ( whooping cough)

Caused by: Bordetella pertussis

• target ciliated cells ( cillary escolater )

  • causing an accumulation of mucuse ( coughing eposides )

• produce two toxions '

  • tracheal cytotoxion

  • pertusis toxion

tracheal cytotoxin

kills ciliated cell ( cell wall damages )

Pertussis toxin

enter bloodstream causing systemic symptoms ( primally fever)

• causes lipocyctosis

lymphocytosis

elevated white blood cell count

stage 1 of whooping cough :

common cold

stage 2 whooping cough :

violent coughing

stage 3 of whooping cough:

covalence stage ( ciliary escalator recovers )

Tuberculosis

Caused by: mycobacterium tuberculosis

type : acid fast rod, obligate aerobe

• allows to causes infection by attacking avlior macrophages

• live within macrophages

  • causing them to release cytokines to call other macrophages

  • end up accumulating —> forming a tubercle (granuloma)

• takes a long time due to mycolic acid

what are the two pathway tubercules can end up on ?

• calcification ( gaunt complex ) - dormant

• liquefaction ( active) exits the tubercle and enters the bloodstream to spread

Pneumococcal Pneumonia

Caused by : s. pneumonia

type: gram positive; encapsulated diplococci

• targets the Avelois

  • causes inflammation avelois —> fluid builds —> difficulty breathing

• Virulence

  • capsule ( used to target for vaccines )

  • Lyt A ( hemolysis : pores on red blood cells)

  • proinflammatory response to target white blood cells ( release systokines)

Pneumocystis

pore formation, pro-inflammatory

Psittacosis ( ornithosis ) Parrot fever

Caused by: chlamydia pisittaci

Type: gram negative, obligate intercellular bacterium

• intercellular pathogen

  • works in viruus

  • multiples then ruptures the cell

• has two forms

  • elementary body

  • reticulae

• released in bird feces—> bacteria becomes air borne —> inhealed

• mild in most cases, but can be sever

influenza ( flu)

high mutation rate bc of RNA polymerase (doesn’t have an editing ability )

• segmented genetic information ( 8 strands)

• enveloped viruses

• two spikes

  • hemoagglutination spikes ( H1)

  • neuraminidase ( H2)

• 3 types

• utilizes antigenic drift and shift

Covid 19

Caused by Betacornavirus SARS-COV-2

• RNA viruses

• 2 different s spikes

  • S1

  • S2

• 2 proteins

  • M & E

• utilises ACE-11 to effect the RAAS system

m-protien and E-protien

help ensemble the viruses

ACE-11

• found all over the body

  • angiotensin - converting enzyme ( very important for physiology)

RAAS system

• dual mechanisms that helps maintain homeostasis within the body

• regulate blood pressure

Histoplasmosis

off brand tuberculosis

caused by: Histoplasma capsulatum

• uses endospores

• similar tuberculosis

• airborne

  • related to construction sites

• treatment

  • antifungal

Pneumocystis Pneumonia ( PCP)

Caused by : Pneumocystis Jurevicius

type: yeast-like fungus ( like histoplasma capsulata)

• primary signs of AIDs

  • affects the immunocompromised

• similar to protozoans

• has two forms

  • cysts

  • tropizotes

• mochi donut