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Respiratory Exam 1. Flashcards. felton. microbiology. What is the most common infectious disease of humans?. The common cold Also, the leading cause of acute morbidity and of visits to a physician in the US Major cause of industrial and school absenteeism.

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Respiratory Exam 1

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Respiratory Exam 1




What is the most common infectious disease of humans?

  • The common cold

    • Also, the leading cause of acute morbidity and of visits to a physician in the US

    • Major cause of industrial and school absenteeism

What microorganism grows optimally at a temp lower than normal core body temp?


    • In tissue culture grow optimally at 33C, the temperature of the nasal mucosa of humans

Where does the rhinovirus multiply?

  • In the cytoplasm of host cells

What type of virus is the rhinovirus

  • Small, single stranded RNA virus

  • Related to poliovirus

  • Member of the family: picornaviruses

What types of viruses are coronaviruses?

  • Single stranded RNA viruses

  • Round or petal shaped projections around the viral capsid resembling a crown

  • Lipid envelopes are labile to ether or chloroform

  • SARS-CoV: caused by coronavirus

Respiratory syncytial virus

  • Infects infants and children more

  • Causes colds, bronchopneumonia, or bronchitis

  • Paramyxovirus

    • RNA, enveloped

  • Two antigenic types


  • Influenza viruses

  • 3 antigenic types


  • Parainfluenza viruses

  • 4 antigenic types

  • Enveloped, SS RNA viruses

  • In kids, can cause severe diseases:

    • Croup, bronchitis, pneumonia

  • In adults: can cause adult respiratory diseases

  • Are one of the major causes of viral laryngitis and pharyngitis in adults

List the possible modes of transmission of a virus:

  • Direct contact with infectious secretions on skin and environmental surfaces

  • Large particles of respiratory secretions that are briefly transported in air

  • Infectious droplet nuclei suspended in air

  • Combination of these methods

How long is the incubation period for the common cold?

48-72 hours

What are the symptoms of the common cold?

  • Nasal discharge

  • Nasal obstruction

  • Sneezing

  • Sore or scratchy throat

  • Cough

  • Anorexia and slight fever may be present

What is sinusitis?

  • Acute, inflammatory affliction of one or more of the paranasal sinuses

  • Usually after:

    • Rhinitis

    • Dental extraction

    • Or in pts with predisposing factors such as: nasal polyps, deviation of the nasal septum, tumors, foreign bodies, trauma, abrupt change of pressure in the nasal passages, and conditions such as cystic fibrosis

What bacteria most commonly cause acute sinusitis?

  • Strep pneumoniae and H. influenzae

Things that can predispose you to purulent sinusitis

  • Nasal polyps

  • Deviation fo the nasal septum

  • Tumors

  • Foreign bodies

  • Trauma

  • Abrupt change of pressure in the nasal pasages

  • Cystic fibrosis

Type of bacteria more commonly associated with chronic sinusitis

  • Anaerobic bacteria

    • Often as a combined infection with aerobes

What is the pathogenesis of sinusitis?

  • Obstruction of the paranasal sinusal ostia impedes drainage

  • Infections impair the cilliary activity of the sinuses

  • Results in accumulation of mucous secretions

  • Mucus converted to mucopus by bacterial multiplication in the sinus cavities

  • The pus irritates the underlying mucosa causing further edema and aggravating the obstruction

When is sinusitis most prevalent?

  • Fall, winter, and spring

Clinical manifestations of sinusitis:

  • Facial pain

  • Purulent nasal discharge

  • Photophobia and tearing may be present

Diagnosis of sinusitis:

  • Can be made without radiographic exams when there is a hx of upper respiratory tract infection or allergic rhinitis, pain and tenderness over a sinus, and purulent discharge

  • Microbial etiology is determined by culture of an exudate or a rinse obtained by sinus puncture and aspiration

    • Cultures obtained from nasal pus or by rinsing of the nose are unreliable because of contamination with resident bacterial flora

Tx of sinusitis:

  • Responds well to antimicrobial therapy

Bacteria that causes mostly asymptomatic pharyngitis:

  • N. gonorrhoea

    • Occasional case of mild pharnygitis

When does most pharyngitis occur?


Type of pharyngitis most commonly caused by adenoviruses

  • Pharyngoconjunctival fever

    • Usually more severe than the common cold

    • Temperature elevations persist for 5-6 days

    • MARKED sore throat

    • Distinguishing feature:

      • CONJUNCTIVITIS which occurs in 1/3 to ½ of cases

        • Follicular type

        • Bilateral

    • Cough, hoarseness, and substernal pain occur in acute respiratory disease [ARD] in military recruits.

Symptoms of pharyngitis with influenza:

  • Sore throat = major complaint

  • Coryza symptoms may be present

  • Temperature elevations are common in children and adults

  • Edema and erythema of the pharynx is NOT marked

  • NO pharyngeal exudates or painful exudate

  • Recovery in 3-4 days

Symptoms of pharyngitis with the common cold:

  • Mild to moderate pharyngitis discomfort, but not the primary complaint

  • Rhinorrhea and post-nasal discharge usually present

  • NO:

    • Severe pharyngeal pain or dysphagia

    • Pharyngeal and tonsillar exudates or painful lymphadenopathy

Adenoviruses can cause what 3 types of respiratory diseases?

  • Acute, febrile, self-limiting condition

  • Pharyngoconjunctival fever

  • Pertussis-like syndrome indistinguishable clinically from infection with Bordetella pertussis

    Adenoviruses are major etiologic agents of acute respiratory disease [ARD] and pharyngitis. Also indicated in pathogenesis of : epidemic keratoconjunctivitis, hemorrhagic cystitis, gastroenteritis, and rashes.

Symptoms of acute herpetic pharyngitis:

  • Primary infection may present as acute pharyngitis

  • Severe cases: inflammation and exudate may mimic full blown streptococcal pharyngitis

  • Vesicles and ulcers of the palate

  • Vesicles and ulcers on the labial and buccal mucosa when there is an assoc. gigivostomatitis

Characteristics of herpes simplex viruses:

  • Large DNA virus

  • Lipid containing capsids

  • Inactivated by ether

  • Will see:

    • eosinophilic intranuclear inclusion bodies in infected cells

  • Tend to produce latent infection

  • Role in recurrent fever blisters

What type of pharyngitis is caused by coxsackieviruses?

  • Herpangina

    • Small vesicles on soft palate, uvula, and anterior tonsillar pillars

    • Lesions rupture to become small, white ulcers

    • Mostly in kids: severe, febrile illness with marked sore throat with dysphagia


  • Picornaviruses

  • Can cause:

    • Aseptic meningitis

    • Myocarditis

    • Upper respiratory tract infections

  • Group A:

    • Types 2,4,5,6,8,10 can cause aherpangina

    • Type 10 is also associated with a summer febrile disease in children called acute lymphonodular pharyngitis

Symptoms of infectious mononucleosis:

  • Exudative tonsillitis or pharyngitis in about ½ the cases

  • Fever and cervical adenopathy usually present

  • Enlargement of spleen in ½ the cases

What does the presence of eosinophilic intranuclear inclusion bodies suggest?

  • Infection with herpes simplex virus

Symptoms of anaerobic pharyngitis:

  • Pharyngeal and tonsillar infection

  • Mix of anaerobic bacteria and spirochetes

  • Purulent exudate coats the membrane

  • May be a foul odor to the breath

  • With development of an abscess, pharyngeal pain is usually severe, dysphagia and low grade fever are common

  • Infection usually limited to one side, but when bilateral, partial obstruction of the pharynx occurs

Symptoms of streptococcal pharyngitis:

  • In severe cases: marked pharyngeal pain, dysphagia, and a temperatures of 39.4C or greater

  • Pharyngeal membrane is fiery red

  • A thick exudate covers the posterior pharynx & tonsilar area

  • Edema of uvula is often pronounced

  • Tender, enlarged cervical nodes

  • A leukocyte count of over 12,000/mm3

  • Infection with S. pyogenes that produces erythrogenic toxin results in the characteristic erythemetous rash of scarlet fever.

Symptoms of DIPHTHERIA:

  • Low grade temperature elevation

  • Tonsillar or pharyngeal pseudomembrane varies from light to dark gray and is firmly attached to the tonsil and pharyngeal mucosa

Mycoplasma pneumoniae

  • Pharyngitis is usually mild with no distinguishing clinical features

  • M. pneumoniae characteristically causes bronchitis and primary atyptical pneumonia

What does the presence of exudate suggest?

  • Streptococcal pharyngitis

  • Vincent’s angina

  • Pharyngoconjunctival fever

  • Herpes simplex virus infection

  • Infectious mononucleosis

What does the presence of small vesicles or ulcers suggest?

  • Herpes simplex virus infection

  • Herpangina

What does the presence of exudate and small vesicles or ulcers suggest?

  • Herpes simplex virus infection

    • Will also see: eosinophilic intranuclear inclusion bodies

Medial displacement of one or both tonsils is seen with:

  • Peritonsillitis

  • Peritonsillar abscess

Type of agar that can be used to detect N. gonorrhoea:

  • Thayer-Martin agar

HOW is Vincent’s angina diagnosed?

  • Crystal violet stained smear of the pharyngeal or tonsillar exudate showing the presence of numerous fusobacteria and spirochetes

Medium used to detect DIPTHERIA:

  • Loeffler’s medium

Small, pleomorphic, gram negative rod that is nonmotile, nonsporulating, and usually capsulated:

  • H. influenzae

    • Aerobic or facultative

    • Requires

      • Iron protoporphrin compound [X factor]

      • Pyridine nucleotide [V factor]

What is the virulence of H. influenzae associated with?

  • Capsulation

    • 6 antigenic types [a-f]

    • Type b formerly accounted for almost all serious infection in humans

      • Vaccination has reduced the frequency of this disease in young children

Drugs used to treat respiratory airway infections caused by H. influenzae:

  • Chloramphenicol

  • Ampicillin

  • Penicillin G

  • Tetracycline

  • Sulfonamindes

Classic sites for localization of diptheria infection:

  • Larynx and pharynx

What microorganism causes whooping cough?

  • Bordetella pertussis

    • Small, ovoid

    • Nonmotile

    • Nonsporeforming

    • Gram NEGATIVE rod

    • Fastidious requirements for grouth

    • Phase I: virulent, encapsulated, piliated

      • produces several toxins

    • Phase IV: pleomorphic, noncapsulated, avirulent


What is the major cause of bacterial pneumoniae in adults and children?

  • Strep. Pneumoniae!

Paramyxoviruses with binding sites for erythrocytes

  • Parainfluenza viruses

    • Contain RNA core enclosed in an ether sensitive envelope

    • Multiply in the cytoplasm of infected cells

    • 4 types that parasitize humans: 1,2,3,4

Clinical symptoms associated with parainfluenza viruses:

  • 1,3,4: common cold and pharyngitis

  • 1,2,3: croup

  • 1,3: bronchitis and bronchopneumonia

Crystal violet stained smear of the pharyngeal or tonsillar exudate showing the presence of numerous fusobacteria and spirochetes suggests:

Vincent’s angina

Do influenza viruses normally cause upper or lower respiratory tract infections?


Respiratory infections caused by RSV:

  • Usually bronchiolitis or bronchopneumonia in infants

  • Sometimes croup

What are the symptoms of acute laryngitis?

  • Barking cough and hoarseness

  • In kids: airway obstruction due to infection of the larynx and tracheobronchial tree

    Diagnose by clinical characteristics of the illness and may be confirmed by examination of the larynx

How do you treat acute laryngitis?

  • Rest the voice until hoarseness and aphonia have subsided

  • Inhalation of moistened air on a regular basis may give relief

What is acute epiglottitis?

  • Rapidly progressive cellulitis of the epiglottis and adjacent structures that has the potential of causing abrupt, complete airway obstruction

    Frequency has decreased dramatically since the introduction of the H. influenzae vaccine

What are the clinical manifestations of epiglottitis?

  • Typically, a 2-4 year old child with a 6-12 hour hx of fever and dysphagia

  • Sore throat is the most prominent symptom in older children and in adults

  • Varying degrees of respiratory distress may be present

How do diagnose epiglottitis?

  • By finding an edematous “cherry red” epiglottis

  • Labs

    • Leukocytosis

    • Positive cultures of blood and epiglottis

    • Evidence of pneumonia on CXR

    • H. influenzae type b is isolated from cultures of blood and/or the epiglottis in most pts with acute epiglottitis

    • Others: pneumococci, staphylococci, streptococci

How do you treat acute epiglottitis?

  • Establish airway

  • Culture blood & epiglottis

  • IV antibiotic therapy against H. influenzae

Is immunity conferred after an episode of H. influenzae epiglottitis?

  • Yes!

  • High levels of serum antibody to capsular polysaccharide make second cases of epiglottitis very rare.

What is CROUP?

  • Acute laryngotracheobronchitis

    • Age specific viral infection of the upper & lower respiratory tracts

    • Produces inflammation in the subglottis

    • Results in dyspnea accompanied on inspiration by the characteristic stridulous notes of croup

What virus most commonly causes CROUP?

  • Parainfluenza type 1

    Parainfluenza type 3 is the 2nd most frequently associated agent.

    Influenza A produces this disease in a broader age range of children and with a higher frequency of hospitalization and tracheotomy.

Epidemiology of CROUP

  • Mostly in kids 3 months - 3 years

  • Peak occurrence in the 2nd year of life

  • More common in boys than girls

Clinical manifestations of CROUP:

  • Hoarseness

  • Deepening, non-productive, brassy-tone cough

  • Most kdis have fever

  • Resp rate is elevated

  • Fluctuating course of infection


  • Inflammatory condition of the tracheobronchial tree

  • Usually associated with a generalized respiratory infection

  • Occurs most commonly during winter months

  • Common during influenza epidemics

  • Rhinoviruses are an important cause of acute bronchitis

  • Among military recruits, adenovirus infections are a major cause of acute bronchitis

  • Mycoplasma pneumoniae & Bordetella pertussis are nonviral causes of severe acute bronchitis

What are the clinical manifestations of ACUTE BRONCHIITIS?

  • Cough begins early and tends to become prominent as the illness progresses

  • Frequency and duration of cough is prolonged in cigarette smokers

  • In adults, influenza virus, adenovirus, and M. pneumoniae infections are commonly associated with temperature elevation

How do you diagnose and treat ACUTE BRONCHITIS?

  • Diagnosis of exclusion

  • Tx is symptomatic


Condition in which cough


a chronic and excessive secretion of mucus

is present in the tracheobronchal tree

& is NOT due to specific diseases such as asthma or TB

Pts who have coughed up sputum on most days during at least 3 consecutive months for more than 2 successive years.

Etiologic factors in CHRONIC BRONCHITIS:

  • Cigarette smoking

  • Infection

  • Inhalation of dust or fumes in the workplace

Clinical manifestations of CHRONIC BRONCHITIS:

  • Incessant cough = advanced bronchitis

  • Emphysema

  • Patients maintain normal body weight and tend to be obese


  • Acute LOWER respiratory illness of VIRAL etiology occurring within the first 2 years of life

Major etiologic agents of BRONCHIOLITIS:

  • Viruses

    • RSV

    • Parainfluenzae virus type 1 and 3

    • Adenoviruses

  • M. pneumoniae

    These make up 87% of the isolates obtained from children.

    In the hospital, RSV involvement is higher.

BRONCHIOLITIS is a common illness during what age?

  • First year of life

  • Peak rate between 2 and 10 months of age

What are the clinical manifestations of BRONCHIOLITIS?

  • Coryza and cough = onset

  • Mild fever = Prodromal period

  • Dehydration

    • from paroxysms of coughing that may trigger vomiting

    • Poor oral intake related to respiratory distress and lethargy

  • Acute course lasts 3-7 days

How do you diagnose and treat BRONCHIOLITIS?

  • Diagnosis:

    • Characteristic clinical and epidemiologic findings

    • Viral isolation from nasal wash

  • Therapy

    • Oxygen administration with careful supportive care

    • Aerosolized ribavirin is approved for treatment of infants with more severe bronchiolitis due to RSV.

    • Monoclonal antibody and polyclonal immune globulin are available for passive immunization.









which of the following is least likely to be directly affected by CROUP?

What virus has the most number of antigenic types?

  • RHINOVIRUS: over 110 different types

    • Parainfluenza: 3

    • RSV: 2

    • Corona: 3 or 4

What virus can cause severe pharyngitis with fever and conjunctivitis?

  • Adenovirus

    • Pharyngoconjunctival fever

Is recurrent infection common in cases of acute epiglottitis?


Microorganism resistant to drying and harsh chemicals:

  • Mycobacterium tuberculosis

What is the most common cause of BRONCHIOLITIS in infants and kids?




Partial pressure of gas equation

  • Pgas = fractional concentration x barometric pressure

Equation or inspired Pgas

Fractional concentration x [barometric pressure - 47mmHg]

What is the partial pressure of water vapor at body temp [37C]?

  • 47mmHg

    • regardless of the ambient barometric pressure

Effect of water vapor pressure:

  • Inspired air is rapidly saturated with water vapor

  • Partial pressure of water vapor at body temp of 37C is 47mmHg regardless of ambient barometric pressure

  • Total pressure of the DRY gases in the airways is reduced by 47mmHg

  • Inspired Pgas = Fractional concentration x [barometric pressure - 47mmHg]

How does altitude affect barometric pressure?

  • Increased altitude = decreased barometric pressure

Equation for respiratory exchange ratio

R = pulmonary CO2 elimination rate

pulmonary O2 uptake rate

What is the volume of anatomic dead space in the normal adult?

  • 150 ml

How is anatomic dead space volume measured?

  • Fowler’s method

What is the physiological dead space volume?

All portions of the system not available for gas exchange


the sum of the anatomic dead space and the alveolar dead space volumes

What is alveolar dead space?

  • Any ventilated alveoli which are not perfused with pulmonary capillary blood

How is physiological dead space volume measured?

  • Bohr method

  • VD = VT[(PaCO2 – PECO2)/PaCO2]

  • Dead space volume increases slightly during inspiration as the airways expand. It then decreases again during expiration.

What is alveolar ventilation?

  • The rate at which the alveoli are ventilated

  • Alveolar vent = expired volume – dead space volume

  • Alveolar ventilation brings fresh air into the gas exchange areas of the lungs. Dead space ventilation does not.

What happens to alveolar air composition as alveolar ventilation increases?

  • Alveolar air composition becomes more similar to inspired air.

  • As alveolar ventilation decreases, gas tensions become similar to those in systemic venous blood.



What does the endoderm form?

  • Lines the inner portions of the embryonic pharynx

What does the ectoderm form?

  • Lining of the outer and part of the inner oral cavity

What does the stomadeum form?

  • Embryonic mouth

    • after rupture of oral plate

What does the failure of the secondary palate to fuse with the primary palate cause?

Cleft palate

Failure of fusion of the nasolabial grove will result in:

  • Cleft palate

  • Cleft lip

  • Agenesis of the nasal septum

  • Agenesis of the nasal concha

What are the alveoli of the lung derived from?

What does the muscular part of the diaphragm arise from?

  • Cervical wall

    • C3,4,5

The bud that will eventually develop in to the trachea, bronchi, and lungs arises from the:

  • Dorsal surface of the esophagus

The new limiting factor for which fetuses slightly below 500g weight still cannot survive is:

  • The kidney is not functioning

What are the divisions of the external nares in the early stages?

  • Frontonasal prominence

  • Maxillary division: branchial arch I

  • Buccopharyngeal plate

  • Mandibular division: branchial arch I

From what branchial arch does the thyroid arise?


From what brachial arch does the cricoid cartilage arise?


Where do the arytenoid cartilages arise from?

Arytenoid swellings

Where does the epiglottus arise from?

Epiglottoid swelling

What nerve innervates the internal muscles of the larynx?

  • Recurrent laryngeal nerve

    • Goes inferior to aortic arch 6 to enter the larynx

What nerve innervate the internal mucosa of the larynx?

  • Internal br. of superior laryngeal nerve

    • From the vagus n, which travels superior to branchial arch 4

What nerve innervates the cricothyroid?

  • External br of superior laryngeal n

Where does the trachea arise from?

  • Epithelium and glands from the endoderm of the laryngiotracheal grove

  • Everything else from splanchnic mesoderm

What do the lungs arise from?

  • Primary bronchial buds

When is surfactant 1st produced?

  • 20 weeks

What happens during the canalicular period [16-25 weeks]?

  • Enlargement of the terminal bronchioles

  • Somewhat increased vasculature

  • Surfactant produced at 20 weeks

  • Only fetuses born at the end of this period have a chance of survival

How far have the lungs developed during the pseudoglandular period [5-17 weeks]?

  • Broncholes developed

  • No alveoli

  • Poor vascular

  • Birth during this phase results in death of fetus

What happens during the terminal sac period [24 weeks to birth]?

  • Terminal sacs develop

  • Epithelium becomes squamous

  • Improvement of vasculature

  • Surfactant producing cells increase in number

  • Births during this period usually survive

When is the alveolar period?

  • Birth to 8 years

    • Increase in size of lung

    • Formation of mature alveoli [superior parts of lung develop 1st]

What has to happen at birth to establish respiration?

  • Increased surfactant production

  • Lungs go from being primary secretory to being a gas exchange organ

  • Mature pulmonary circulation is established

What does the diaphragm arise from?

  • Cervical region

    • Septum transversum  middle of central tendon

    • Pleuroperitoneal folds seal off edges of central tendon

    • Mesoesophagus crura

    • Cervical body wall [C3,4,5] muscular diaphragm

What does a cleft palate result from?

  • Failure of the secondary palate to fuse with the primary palate



Where is histamine found in the periphery?

  • Mast cells [bronchioles, skin, intestinal mucosa]

  • Basophils

Where is histamine found in the brain?

  • Cell bodies of histaminergic neurons are in:

    POSTERIOR basal hypothalamus


What is the consequence of having histaminergic neurons in the reticular formation?

  • The reticular formation plays a role in the level of arousal

  • Histamine pays a role in keeping you alert

  • So… if you take an ANTI-histamine, it could make you drowsy!

What is the main stimulus for histamine release?

Ag  IgE crossbridging  degranulation of mast cell  release of histamine

What drugs stimulate the release of histamine?

  • Neuromuscular blockers [for use during surgery]

  • Morphine [TX dyspnea with left ventricular failure]

  • Vancomycin [cell wall inhibitor]

What drug can cause “red man syndrome”?

  • Vancomycin

    • Typically after rapid IV infusion

    • Characterized by flushing of the upper body and facial area, hypOtension, & tachycardia

Why is morphine sometimes used to tx dyspnea with LV failure?

  • Will allay anxiety

  • Histamine release with cause vasodilation, which decreases preload and afterload

How does vancomycin cause tachycardia?

Histamine  vasodilation  drop in BP  reflex tachy

What are the symptoms of a drug induced anaphylactoid rxn?

  • Burning, itching sensation in the hands face, scalp and ears

  • Followed by a feeling of intense warmth

  • These areas and the whole trunk turn red

  • BP falls  reflex tachy

  • Headache

  • Hives accompanied by nausea

  • Acid secretion

  • Bronchospasms

What does the H3 receptor do?

  • Regulates the release of various NTs thru autoreceptor and heteroreceptor mechanisms

Blockage of which histamine receptor may decrease the release of neurotransmitters?


Stimulation of what receptor causes increased gastric acid secretion?


Which histamine receptor mediates rapid onset but short lived vasodilation?


Which histamine receptor mediates slow onset but sustained vasodilation?


Mechanism of H1R

  • Coupled to phospholipase C

  • Hydrolyzes membrane phospholipids to form IP3 and DAG

What does IP3 do?

  • Releases Ca from the sarcoplasmic reticulum

    • Ca will activate myosin light chain kinase and phospholipase A2

What does myosin light chain kinase do?

  • Phosphorylates myosin

    • Causes bronchoCONSTRICTION and increased peristalsis

What does phospholipase A2 do?

  • Produces NO and prostacyclin [PGI2]

    • Vasodilators!

What does DAG do?

  • Activates protein kinase C which facilitates Ca release from the SR

What is the mechanism of H2R?

  • Stimulates adenylyl cyclase  increase in cAMP activates a protein kinase that:

    • Phosphorylates and ACTIVATES a Ca pump that pumps Ca out of the cell and into the SR

    • Phosphorylates and INACTIVATES myosin light chain kinase inhibits contraction, causes vasodilation

What 3 things characterize the allergic response to histamine?


  • vasoDILATION

  • Increased capillary permeability [see edema, swelling]


  • Flare and wheal reaction: seen in bee stings, insect bites

    • Localized red spot

      • Few seconds

      • Few mm

      • Immediate vasodilation

      • Stimulation of H1

    • Bright flare

      • Delayed

      • Few cm

      • Stimulation of H2

    • Wheal

      • 1-2 minutes

      • From edema

What are the (+) inotropic/chronotropic effects of histamine?

  • Direct:

    • Increased automaticity of SAN, atria, ventricle

  • Indirect:

    • Baroreflex increases heart rate

      Due to actions at the H2 site

Stimulation of which histamine receptor can cause pain & itching?

  • H1 receptors

    • in the dermis  pain

    • In the epidermis  itching

What are the physiological effects of histamine?

  • Allergic response

  • Triple response

  • + ino/chrono effects

  • Histamine shock

  • Increased gastric secretion

  • Pain and itching

Common effects of 1st generation H1 antagonists

  • Penetrate CNS- highly sedating

  • Anticholinergic activity

    • antiemetic

    • Can cause cognitive decline in elderly

Characteristics of 2nd generation H1 antagonists

  • Poorly penetrate CNS- little or no sedation

  • Little or no anticholinergic or antiemetic activity

List the 1st generation H1 antagonists

  • Diphenhydramine [benadryl]

  • Doxylamine

  • Dimenhydrinate

  • Meclizine

  • Hydroxyzine

  • Promethazine

  • Chlorpheniramine

  • Prompheniramine [dimatapp]

  • Cyproheptadine

  • Azelastine

  • olopatadine

What are the uses of diphenhydramine?

  • Type I IgE mediated hypersensitivity reactions

  • Motion sickness

  • Night time sleep aid

  • Antitussive

  • Topical antipuritic

  • Topical with maalox for canker sores in kids

What 1st generation H1 antagonists are the most sedating?




What is doxylamine used for?

Night time sleep aid

What is dimenhydrinate used for?

  • NV

  • Dizziness and vertigo

  • Very sedating!!!

What drugs are used for motion sickness?

  • Diphenhydramine

  • Meclizine

  • Hydroxyzine

  • Promethazine

1st generation H1 antagonist that also blocks α1 receptors

  • Promethazine

    • Used for:

      • Type I hypersensitivities

      • Sedative

      • Anti anxiety

      • Antiemetic: used preop to prevent NV associated with general anesthetics

      • Motion sickness

What is the mechanism of the antiemetic effect of promethazine?

Blocks dopamine receptor in the

chemoreceptor trigger zone

[in area postrema, which is not protected by the blood brain barrier]

What is APAP?

  • Acetyl para amino phenol

  • Aka: tyelenol

1st generation H1 antagonist known to cause weight gain and block 5-HT2 receptors

Cyproheptadine [periactin]

Uses of Hydroxyzine

  • Motion sickness + pruritis

  • Preop and postop sedation

  • antianxiety

What 2 drugs can you use for preop/postop sedation and anxiety?



Drug that blocks 5-HT2 receptors


What are azelastine and olopatadine used for?

Itching with allergic conjunctivitis

What are the side effects of 1st generation H1 antagonists?


    • Other sedating drugs

    • Narrow angle glaucoma

    • Other anticholinergic drugs

  • Anticholinergic SE:

    • Blurred vision

    • Dry mouth

    • Constipation

  • CNS stimulation

    • Restless, sleeplessness, hallucinations, ataxia

    • CONVULSIONS in kids

List the 2nd generation H1 antagonists

  • Fexofenadine

  • Cetirizine

  • Loratadine

  • Desloratadine

Which 2nd generation H1 antagonist is the active metabolite of hydroxyzine?


  • Hydroxyzine is a 1st generation H1 antagonist

Other drugs with antihistaminic activity

  • ß agonists

  • Cromolyn

  • Nedocromyl

    All block degranulation of mast cells

What are H2 antagonists used for?

  • Block H2 component of allergic response

    • Which is… inactivation of MLCK which causes vasodilation

  • Inhibit gastric acid secretion by parietal cells in tx duodenal and gastric ulcers

List the H2 antagonists

  • Cimetidine [tagamet]

  • Ranitidine [zantac]

  • Famotidine [pepsid]

  • Nizatidine [axid]

What are the side effects of H2 antagonists?

  • Headaches

  • Diarrhea/constipation

  • Drowsiness

  • RARE: CNS effects, more in elderly

Which H2 antagonist has the worst side effects?


    • Only in high doses

    • Binds cytochrome P450 significant inhibition of drug metabolism

What is pepsid complete made of?

  • Famotidine

  • Calcium carbonate

  • Magnesium hydroxide

Which H2 antagonist binds to cytochrome P450?


What are the side effects of Cimetidine?

  • Increased estradiol levels in MEN

    • Mech: inhibits cyt P450, causes failure to hydroxylate

  • Increased prolactin  gynecomastia [high doses]

    • High doeses are used to treat Zollenger-Ellison Syndrome

  • Inhibits conversion of testosterone to dihydrotestosterone [DHT]

    • DHT is the form used by the testes

    • Mech: inhibits 5α reductase

  • Inhibits binding of DHT to receptor

    • Impotence and decreased libido

  • CAUTION: change in acidity can alter drug absorption

    • Weakly acidic reactions: decreased absorption

    • Weakly basic reactions: increased absorption

What is Zollinger Ellison Syndrome?

  • A tumor [gastroma] of the pancreatic islets causeing secretion of massive amounts of GASTRIN

    • Too much acid life threatening

Which enzyme converts testosterone to DHT?

5α reductase

What is the consequence of inhibition of DHT binding to its receptor?

Impotence and decreased libido

What happens to the absorption of weakly acidic reactions when the gastric pH goes UP?

  • Acids become ionized

  • Decreased absorption!

What happens to the absorption of weakly basic reactions when the gastric pH goes UP?

  • Bases become non-ionized

  • Increased absorption!

MOA of nasal decongestants:

  • α1 agonists!

  • Constrict vessels.

  • Except… oxymetazolone

    • α2 agonist!!!!!!!

What is phenylephrine used for?

  • Nasal decongestant

  • IV for shock or supraventricular tachy

    • Systemic vasoconstriction maintains BP

  • Mydriatic [pupil dilation]

    • Contracts dilator muscle

      Sometimes added to local anesthetics to prevent systemic effects.

List the nasal decongestants

  • Phenylephrine

  • Psedoephedrine [sudafed]

  • Oxymetazoline [afrin]: ocular decongestant

Which nasal decongestant is an α2 agonist?

  • Oxymetazoline


    • SE: hypOtesnsion and pounding HR

      • Why? Centrally acting, decreased sympathetic outflow vasodilation

What is the best expectorant?


What is the MOA of expectorants?

  • Irritate the lining of the airway

  • increase secretions

  • dilute, break up phlegm, decrease viscosity

  • Decrease surface tension

What is Guaifenesin?

  • Robitussin

  • Expectorant

    Robitussin DM= dextromethorphan (antitussive) + guaifenesin



What is the conducting portion of the respiratory system?

  • Nasal cavity, nasopharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles

  • Function:

    • Provides a conduit for the passage of air to and from the lungs

    • “conditions” the inspired air

What is the respiratory portion of the respiratory system?

  • Respiratory bronchioles, alveolar ducts, alveoli

  • Function: sites for the exchange of oxygen and carbon dioxide between the inspired air and blood

What are specialized hairs at the entrance to the nasal cavity called?

  • Vibrissae

    • Removes coarse particles of dust

What is involved in the conditioning of the air?

  • Filtration: vibrissae

  • Moistening: goblet cells and glands in lamina propria

  • Warming: richly vascular lamina propria

What moistens the inhaled air?

  • Goblet cells

  • Glands in lamina propria

What is the function of the mucous?

  • Trap particulate and gaseous impurities

What warms the air?

Lamina propria

  • Richly vascular

What two parts make up the nasal cavity?

  • Vestibule

    • Dilated anteroom supported by cartilage of the external nose

    • The keratinized stratified squamous epithelium is continuous with the skin of the face and contains coarse hairs [vibrissae], sebaceaous glands, sweat glands

  • Nasal cavity proper

    • Divided by the nasal septum

    • Septal wall= smooth

    • Lateral wall= superior, middle, inferior conchae which increase the surface area to 160 cm2

    • Epithelium divided into olfactory and respiratory zones

What type of epithelium is found in the vestibule of the nasal cavity?

Keratinized stratified squamous epithelium

Olfactory cells

  • Modified bipolar neurons

    • Dendrite ends at olfactory knob

    • 6-12 non motile olfactory cilia arise from olfactory knob

    • Axon pierces the basal lamina and joins the other axons to form the olfactory nn [CNI] that penetrate the cribiform plate of the ethmoid bone

    • Synapse in the olfactory bulb

    • While passing thru the lamina propria, the axons acquire a schwann cell sheath

Sustentacular cells of olfactory epithelium

Tall, columnar cells with a microvillus border

Basal cells of olfactory epithelium

  • Undifferentiated

  • Believed to be able to differentiate into the other cell types

Brush cells of olfactory epithelium

  • Long microvilli

  • Synapses with CN V

  • May be involved in the sneeze reflex or in modifying the activity of the olfactory bulb

What is found in the lamina propria of the olfactory zone?

  • Seromucous olfactory [bowman’s] glands

    • Secretions provide a solvent for the olfactory stimulus nd washes the olfactory receptors to prevent stagnation of the odor

  • Branches of ethmoid arteries

  • Lymphatics that are in communication with the subarachnoid space inside the cranial cavity

Secretory cells are found in the epithelial lining of:

  • Alveoli

  • Terminal bronchioles

  • Primary bronchi

  • Trachea

Olfactory epithelium lines:

  • Roof and superior concha

Surface active agent “surfactant” is secreted by:

Type II alveolar cells

Bronchopulmonary segments are supplied by:

  • Bronchioles?

Clara cells secrete a substance similar in action to the secretory product of:

  • Type II pneumocyte

Olfactory epithelium is classified as:

  • Tall pseudostratified columnar

  • Contains olfactory, sustentacular, basal, and brush cells

The larynx is lined by which type of epithelium?

  • Respiratory epithelium

  • Except vocal cords: stratified squamous epithelium

What is respiratory epithelium made of?

  • Pseudostratified, ciliated columnar with goblet cells

5 cell types commonly found in respiratory epithelium:

  • Goblet cell

  • Ciliated cell

  • Basal cell

  • Granule cell

  • Brush cell

Goblet cell of respiratory epithelium

  • unicellular mucous gland

  • Large membrane-bound mucous droplets in the atypical cytoplasm

Ciliated cell of respiratory epithelium

  • 300 cilia on its luminal surface

  • Concentration of mitochondria at the apical part of the cell

Basal cell of respiratory epithelium

  • lies along the basal lamina

  • Fxn as a reserve cell to repopulate the epithelium

Granule cell of respiratory epithelium

  • unicellular endocrine gland

  • Numerous dense-core granules in the basal cytoplasm

  • Granules contain seratonin and dopamine & are released downward into the luminal propria via paracrine secretion

  • Concentrated at bronchial divisions and bronchioalveolar portals

  • Believed to be involved in the local regulation of airway diameter

Brush cell of respiratory epithelium

  • Long microvilli and epitheliodendritic synapses

  • Involved in the sampling of the airway environment

What is the olfactory zone composed of?

  • Roof and superior concha

What is the respiratory zone composed of?

  • Nasal septum and lateral wall below the superior concha

What is the plexus cavernosum concharum?

  • AKA: swell bodies

  • Erectile tissue found over the lower turbinates

  • Smooth muscle is found in the walls, not in the speta

  • Supplied by veins, not arteries

  • Swell bodies on each side of the nasal cavity become engorged on an alternating schedule [20-30 mins]

    • Cuts the flow of air so that the epithelium can rehydrate

  • Regulation by the autonomic nervous system

    • Adrenergic fibers from the superior cervical ganglion cause vasoconstriction

    • Cholinergic fibers from the pterygopalatine ganglion cause vasodilation

    • Arterial flow in the branches of the sphenopalatine artery is in the opposite direction to the air flow countercurrent heat exchanger to warm or cool and humidify inspired air

Paranasal sinuses

  • Frontal, Ethmoidal, Sphenoidal, Maxillary

  • Connected to the nasal cavity by ostia or ducts

  • Lined by typical respiratory epithelium

  • Cilia of ciliated cells beat TOWARD the nasal cavity

  • Few goblet cells

  • FXN:

    • lighten the bones in which they are found

    • Warm and humidify the inspired air

    • Act as resonating chambers for the voice

What are the 3 parts of the pharynx?

  • Nasopharynx: continuous with the NASAL cavity at the posterior nares and extends from the base of the skull to the level of the soft palate

  • Oropharynx: continuous with the ORAL cavity at the palatoglossal arch and extends from the level of the soft palate to the hyoid.

  • Laryngopharynx: extends from the level of the hyoid to the lower border of the cricoid cartilage [C6]. Includes the epiglottis and larynx.

What cells line the nasopharynx?

  • Respiratory epithelium

    • Pseudostratified, ciliated columnar with goblet cells

What cells line the oropharynx?

Stratified squamous epithelium

What cells line the epiglottis?

  • Lingual surface & the apical portion of the laryngeal side:

    • stratified squamous epithelium

  • Toward the base of the epiglottis on the laryngeal side:

    • Transition to respiratory epithelium

      • Pseudostratified, ciliated columnar with goblet cells

What cells line the larynx?

  • Respiratory epithelium

    • Pseudostratified, ciliated columnar with goblet cells

  • Except over the vocal cords

    • stratified squamous epithelium

What connects the pharynx to the trachea?

  • Larynx

    • Lamina propria contains several irregularly shaped cartilages that help to maintain an open airway and also to participate in producing sounds for phonation

What parts of the larynx are made of hyaline cartilage?

  • Thyroid cartilage

  • Cricoid cartilage

  • Arytenoid cartilage

What parts of the larynx are made of elastic cartilage?

  • Cuneiform cartilage

  • Corniculate cartilage

At what level does the trachea bifurcate?

  • Sternal angle/T4-6

  • Divides into left and right primary bronchi

What are the 4 layers of the tracheal wall?

  • Mucosa

    • Respiratory epithelium and elastic fiber rich lamina propria

  • Submucosa

    • Slightly more dense CT

  • Cartilaginous layer

    • C shaped hyaline cartilages

  • Adventitia

    • CT which binds the trachea to the surrounding tissue

Trachealis muscle

  • Smooth muscle fibers that bridge the gap between the free ends of the C shaped cartilage at the posterior border of the trachea adjacent to the esophagus

Which primary bronchus is shorter?

  • Right

    • Also, larger diameter, more vertical

Secondary [lobar] bronchi

  • AKA: intrapulmonary bronchi

  • Branch from primary bronchi at hilum of lungs

  • Left lung gets 2

  • Right lung gets 3

  • Continually bifurcates for about 7 more generations

  • Lined by respiratory epithelium

  • C shaped cartilages become cartilaginous plates as the bronchi become intrapulmonary


  • Division of intrapulmonary bronchi that have a diameter of about 1mm

  • Supply pulmonary lobules

  • NO cartilage lplates

  • Thick later of smooth muscle

What cells line bronchioles?

  • Large diameter: pseudostratified ciliated columnar

  • Small diameter: simple ciliated columnar with fewer goblet cells

What cells line the terminal bronchioles?

  • Simple, cuboidal epithelium

  • Containing:

    • Cliliated cells

    • Non-ciliated bronchiolar [clara] cells

    • Brush cells

Clara cells

  • Have a dome shaped luminal surface projection

  • Secretes a surface active agent, a lipoprotein, that functions to prevent luminal adhesion during expiration

Respiratory bronchiole

  • Branches of terminal bronchioles

  • Concerned with conduction of air AND gas exchange

  • Initial portion is lines with both ciliated cuboidal and clara cells

  • Clara cells predominate in the distal portion

  • Alveoli extend from the lumen of these bronchioles

Alveolar ducts

  • Branches of respiratory bronchioles

  • Walls consisting entirely of alveoli

  • Lined by a thin simple squamous epithelium

  • Lamina propria surrounding the rim of the alveoli is a network of smooth muscle cells

    • Sphincter like bundles of smooth muscles appear as knobs between alveoli

  • Terminate as alveolar sacs: spaces surrounded by clusters of alveoli


  • The terminal air spaces of the respiratory system

  • The site of gas exchange between air and the blood

  • 100 million alveoli per lung

  • About 0.2 mm in diameter

  • Separated by a thin CT layer containing numerous blood capillaries

Alveolar septum

  • Tissue between adjacent alveolar air spaces

  • Composed of:

    • Alveolar epithelial cells

    • Basal lamina of alveolar epithelium

    • Basal lamina of capillary endothelium

    • Capillary endothelium

    • Other CT elements

      • fibroblasts, macrophages, collagen & elastic fibers

Interalveolar pores [of Kohn]

  • Openings in the interalveolar septa that allow circulation of air from one alveolus to another

What types of cells line the alveoli?

  • Type I alveolar cells [type I pneumocytes]

  • Type II alveolar cells [septal cells]

Type I alveolar cells

  • Simple squamous cells

  • Line 95% of the alveolar surface

  • Joined to other epithelial cells by TIGHT JUNCTIONS

Type II alveolar cells

  • Cuboidal cells

  • Interspersed among type I cells

  • Line about 5% of the alveolar surface

  • Cytoplasm: contains multilamellar bodies

  • Surface active agent: SURFACTANT

  • Lamellar bodies are released into the alveolar space by exocytosis

  • Surfactant forms a monomolecular layer over the alveolar epithelium

    • Reduces surface tension at the air-epithelium interface

Role of brush cells in the alveoli

  • Receptors that monitor the air quality in the lung

  • Few in numbers

Function of alveolar macrophages

  • Found in:

    • Alveolar septum

    • Alveolar air spaces: scavenge the surface to remove inhaled particulate matter such as bacteria, dust and pollen

      • Become known as DUST CELLS

  • Some pass up the bronchial tree in the mucus and are disposed of by swallowing or expectoration

  • Others return to or remain in the septal CT

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