micro exam 4

what is the upper respiratory tract composed of

the nose, pharynx, middle ear, and eustachian tubes

larynx and above = upper respiratory tract

what is the lower respiratory tract composed of

the trachea, bronchial tubes, and alveoli

trachea and below = lower respiratory tract

what is the alveoli

it is the spot where 02 is exchanged

and is also where microbes can cross into the bloodstream

what are the anatomical defenses against pathogens in the respiratory system

nasal hairs trap particles

cilia moves the particles upward toward the throat (like an elevator)

mucus is a natural trap for invading microbes

what are the secondary and third line of defenses in the respiratory system

complement proteins, antimicrobial peptides, cytokines, macrophages, and IgA

what are the lungs normal biota like

it has a limited normal microbiota but the biota can cause disease in the upper respiratory system

what are the diseases of the upper respiratory system

pharyngitis, rhinitis (common cold), sinusitis, otitis media

what is pharyngitis caused by

irritation from shouting, drainage from sinus cavity

most serious cause is Streptococcus pyogenes

what are the signs and symptoms of pharyngitis

pain, inflammation of the throat, red or swollen mucosa

types of pharyngitis

streptococcal pharyngitis, scarlet fever

Streptococcal pharyngitis

is strep throat

what causes strep throat

streptococcus pyogenes

how is strep throat transmitted

through respiratory secretions

what are the symptoms of strep throat

local inflammation, fever, tonsilitis, enlarged lymph nodes, and otitis media

how do you treat strep throat

with penicillin

what causes scarlet fever

streptococcus pyogenes that produces a erythrogenic (reddening) toxin

what are the symptoms of scarlet fever

pink-red skin rash, high fever, strawberry like tongue

why does scarlet fever require treatment

without treatment it can turn into rheumatic fever

what is rhinitis

the common cold

what is the most prevalent human disease

rhinitis

what can cause rhinitis

there are over 200 different viral causes

30-50% are rhinovirus

10-15% are coronaviruses

what are the symptoms of rhinitis

sneezing, nasal secretion, congestion

can lead to laryngitis and otitis media

can you use antibiotics for rhinitis

no

what causes sinusitis

virus, bacteria, fungi, allergies, structural abnormalities

what is otitis media

an infection of the middle ear where pus puts pressure on the eardrum

what causes otitis media

streptococcus pneumoniae

when are otitis media infections most common

during childhood due to the smaller auditory tubes

what are the diseases of the lower respiratory tract

bronchitis, pneumonia, influenza, pertussis, RSV, and tuberculosis

What is bronchitis

a respiratory infection that involves the bronchi

what is pneumonia

a severe complication of bronchitis that is an inflammatory condition of the lungs where fluid fills the alveoli

what is a complication of pneumonia

pleurisy where the pleural membranes are inflamed

what are the types of pneumonia

community acquired pneumonia, healthcare associated pneumonia, covid 19 pneumonia, pneumococcal pneumonia, legionellosis, mycoplasmal pneumonia, pneumocystis pneumonia,

community acquired pneumonia

develops in the healthcare setting

healthcare associated pneumonia

develops in a health care setting

Covid-19 Pneumonia is caused by

SARS-CoV-2

how is covid 19 pneumonia transmitted

through droplets and airborne contact

what causes pneumococcal pneumonia

is caused by streptococcus pneumoniae

what are the symptoms of pneumococcal pneumonia

infected alveoli fills with fluids and RBC which interferes with oxygen uptake, rust colored sputum, high fever, breathing difficulty, chest pain

Legionellosis is also called what

Legionnaires’ disease

what causes legionellosis

legionella

how is legionellosis transmitted

by inhaling aerosols

what are the symptoms of legionellosis

high fever and cough

what is mycoplasmal pneumonia also known as

walking pneumonia or primary atypical pneumonia

what causes mycoplasmal pneumonia

mycoplasma pneumoniae

what kind of symptoms are there for mycoplasmal pneumonia

low fever, cough, headache - mild but persistent

who is mycoplasmal pneumonia most common in

children and young adults

how does mycoplasmal pneumonia appear on media

like a fried egg

what causes pnymocystis pneumonia

pneumocystis jirovecii

what kind of infection is pnymocystis pneumonia

fungal

who does pnymocysts pneumonia cause pneumonia in

the immunocompromised and it is a primary indicator of aids

where is pnymocystis pneumonia found

in the lining of the alveoli

why should you treat pnymocystis pneumonia

because without treatment it is fatal

what is healthcare associated pneumonia often associated with

mechanical ventilation via an endotracheal or tracheostomy tube

what usually causes healthcare associated pnuemonia

MRSA strains of staphylococcus aureus

what is influenza caused by

influenza virus

what are the symptoms of the flu

chills, fever, headache, muscle aches

what are the three types of strains of the flu

avian, swine, and mammalian

what kind of spikes are found on the flu virus

hemagglutinin (HA) spikes and Neuraminidase (NA) spikes

what do hemagglutinin (HA) spikes do

they recognize and attach to host cells

what do neuraminidase (NA) spikes do

they help the virus separate from the infected cell

how is influenza A identified

by HA and NA

what is antigenic drift do for the flu

it allows for minor antigenic changes in HA and NA which allows the virus to elude some host immunity

what does antigenic shift do for the flu

it changes the flue enough to really evade most immunity, it leads to pandemics, and involves the reassortment of the eight RNA segments

what is the mortality rate for the flu

1%

what kind of vaccine is there for the flu

a multivalent vaccine which means its against 3-4 strains

the composition is determined by circulating vaccines annualy

how is the flu treated

with Relenza and tamiflu which inhibits neuraminidase (NA)

what is pertussis also called

whooping cough

what causes pertussis

bordetella pertussis which produces a capsule that destroys ciliated cells in the trachea which shuts down the ciliary elevator

what toxins are produced during pertussis

tracheal toxins that damages ciliated cells and pertussis toxins that enter the bloostream

what are the three stages of pertussis

1. catarrhal stage - like common cold

2. paroxysmal stage - violent coughing and gasping for air

3. convalescence stage - can last for months

how is pertussis prevented

by the DTap vaccine

what is the most common viral respiratory disease in infants

Respiratory Syncytial Virus (RSV)

what does RSV cause in cell culture

cell fusion (syncytium)

what are the symptoms of RSV

coughing and wheezing for more than a week

what causes tuberculosis

mycobacterium tuberculosis and mycobacterium avium-intracellulare complex

who is most effected by mycobacterium avium-intracellulare complex TB

people with late stage HIV infection

what are the steps of TB pathogenesis

1. inhaled bacteria are phagocytized by alveolar macrophages

2. bacteria multiplies in macrophages

3. organisms are isolated in the walled off tubercle (usually latent TB)

4. tubercle breaks down and releases bacteria into the lungs

what are the symptoms of TB

chest pain, coughing bloodstained sputum, weight loss, fatal hemorrhage

how is TB diagnosed

through a skin test that is then follow with an Xray or CT Scan, sputum staining, and bacterial culture

how is TB treated

with 6 months of drug therapy

first line drugs are used to potentially cure the disease but resistance often develops due to patients not following the schedule

second line drugs are used for resistant strains and are often less effective with toxic side effects

susceptibility

is a lack of resistance to a disease

immunity

is the ability to ward off disease

innate immunity

defenses against any pathogen it is rapid and present at birth

adaptive immunity

is an immunity or resistance to a specific pathogen and is slower to respond and has a memory component

toll like receptors on host defensive cells attach to what

pathogen associated molecular patterns (PAMPs)

what are PAMPs

molecular structures that are common to pathogens

TLRs binding to PAMPs cause the release of what

cytokines from the hosts defensive cells (innate immune system)

cytokines

small cell signaling proteins that regulate the intensity and duration of immune responses

what is the first line of defense for the immune system

skin, mucous membranes, physical factors, and chemical factors

the skin is made up of what

epidermis and dermis

epidermis

outer portion made of tightly packed epithelial cells containing keratin, a protective protein

dermis

is an inner portion made of connective tissue

how is the shedding and dryness of the skin act as a protective defense

because it inhibits microbial growth

mucous membranes

is the epithelial layer that lines the GI, respiratory, and genitourinary tracts

mucus that traps microbes and prevents the tracts from drying out

ciliary escalator

physical factors of the first line of defense are

the lacrimal apparatus which drains tears and washes the eyes

peristalsis, defecation, vomiting, diarrhea, earwax, urine, vaginal secretions, saliva

chemical factors that are the first line of defenses are

sebum forms a protective film and lowers the pH of the skin

lower pH inhibits or destroys microbes

lysozyme destroys bacterial cell walls

normal microbiota

competes with pathogens via microbial antagonism and is a first line of defense

probiotics

are live microbial cultures that are administered to exert a beneficial effect

what is the second line of defense in the immune system

blood composition, formed elements, lymphatic system, phagocytosis, inflammation, fever, antimicrobial substances

blood composition

plasma (fluid portion)

formed elements (cells and cell fragments in plasma)