Chapter 33: Respiratory system Flashcards
(55 cards)
natural defense mechanisms for our lungs
mucus membranes and cilia goblet cells produce phlegm sneezing, coughing and swallowing normal bacterial flora produces bacteriocins which are toxic to invading organisms antibodies
most common URTI
Nasopharyngitis: corona virus, rhino virus
pharyngitis: strep pyogenes( Group A beta hemolytic)
risk factors for URTI
cold causes changes in normal flora which predisposes to infections
constant nose blowing causes microbes to be pushed in the sinuses
people with a history of herpes simplex can cause eruption with constant nose blowing
most common bacteria that causes pharyngitis
strep pyogenes (group A strep)
S. pyogenes virulent factors
capsul streptolysin S and O hyaluronidase streptokinase Major one is protein M which lets it escape phagocytosis
rapid tests for S.pyogenes vs cultures
Rapid tests are only sensetive for S. pyogenes even though the causative agent might be different
why do you treat S. pyogenes if its self lmiting
because of the poststreptococcal sequelae (post strep glomerulonephritis and rheumatic fever which are immunologically mediated against protein M)
Is S. pyogenes virulent ?
no, its a-virulent because carriers have diminished Protein M = carriers are not contagious
Other suspected strains if S. pyogenes is not detected when someone has pharyngitis
strep C and G (Beta hemolytic)
Neisseria gonorrhoeae
acanbacterium haemolyticum
what produces a white membrane similar to white exudate of S. pyogenes
Corynebacterium diphtheriae seen in unimmunized individuals
produces exotoxin that damages the hear, nerves and kidneys
are haemophilus influenzae, strep pneumoniae and staphylococcus aureus causative agents of pharyngitis ?
no, they are a part of the normal flora. they might be present as a result of viral infection
whats the most common cause of pharyngitis
viruses rhinovirus coronavirus adenovirus influenza virus
causative agents in sinusitis and pathophysiology
allergens or viruses usually cause the initial damage then sinuses become secondarily infected with bacteria=inflammation (nose blowing causes pressure which pushes bacteria into the sinus)
causative agents: staphylococcus aureus streptococcus pyogenes haemophilus inluenzae fungal caused in the immunocompromised/diabetic patients
complications of sinusitis
could lead to osteomyelitis of the skull
they can enter the nervous system and cause meningitis
can epiglottitis be caused by viruses
No, but previous viral infection can predispose to bacterial infection
what are the causative agents of epiglottitis
Haemophlius influenzae (other than type B) S. pneumoniae S. aureus H. parainfluenzae N. meningitids Candida Spp.
why is epiglottitis considered a medical emergency
inflammation can cause swelling and a complete obstruction of the respiratory tract
major causative agent of laryngitis and are the symptoms
Viral infections but rarely bacteria
noninfectious could be caused by straining the voice
S. pyogenes
Bordetella pertussis
mycoplasma pneumoniae
Corynebacterium diphtheriae
symptoms include: dry cough fever runny nose Hoarse voice
what are the types of bronchitis and their causative agent
Acute type: caused by bacterial or viral infection, amongst which are
Bordetella pertussis
mycoplasma pneumoniae
chlamydophila pneumoniae
viruses: influenza, RSV, Rhinovirus, coronavirus, adenovirus
chronic causes by smoking
what does Bordetella pertussis cause
whopping cough which are intense cough fits followed by vomitting. toxin damages the cilia
usually happens to children (unvaccinated) or young adults
its a gram negative coccobacillus
age group that gets bronchiolitis and its symptoms
mainly infants and young children
those with cystic fibrosis are predisposed
symptoms are cough and wheezing
major causative agent for bronchiolitis
RSV respiratory syncytial virus
what are the symptoms of pneumonia, diagnosis
cough
fever
chills
sputum (might be green duo to the organism or purulent because of WBC, might contain blood duo to coughing damaging capillaries)
crackles (because fluid will be filled as bacteria reproduce in the alveoli)
inflammation (the body tries to fight off the infection)
shortness of breath(blood cells will take up oxygen trying to fight the infection, CO2 is not removed as efficiently)
diagnosis is based on xray to differenciate it from bronchoilitis. pneumonia looks like patchy white areas on xray
classification of pneumonia based on the place of acquisition
community acquired: in a community outside of a hospital (strep pneumonia is the most common, G-positive diplococci)
hospital acquired: nosocomial pneumonia (48h after admission)
ventilator associated pneumonia: develops 48hh after the usage of a ventilator
