Respiratory Path (1-4) Flashcards
name the 3 key zones of the respiratory system
- conducting (nasal cavity, larynx, pharynx, trachea, bronchi)
- transitional (bronchioles)
- exchange (alveoli)
name the defense mechanisms of the conducting zone of the respiratry system
- musus and mucociliary clearance
- antibodies
- lyzozyme
name the defense mechanisms of the transitional zone of the respiratry system
- clara cells
- antibodies
- lyzozyme
name the defense mechanisms of the exchange zone of the respiratry system
- macrophages
- surfactant
- antibodies
name the 3 main routes of invasion into the repiratory tract
- aerogenous
- hematogenous
- trancoelomic
name the route of invasion into the resp tract
infection reaches lung as inhaled droplets or larger food particles or fluid
aerogenous
particles >10µm will usually be deposited here in the resp tract
above the larynx
irritant/infectious particles that are ~1-2µm in size will deposit mostly here in the resp tract
bronchiolar-alveolar junction
hematogenous lesions tend to localise here in the lungs
caudal lobes
this is blood in nasal discharge - may originate from nose or lower respiratory tract
epistaxis
this is blood in saliva or sputum
hemoptysis
this is inflammation of the nasal cavity
rhinitis
this is inflammation of the sinuses
sinusitis
name the clasification of rhinitis
mildest form; early stages of infectious disease, allergy or irritation
serous rhinitis
name the clasification of rhinitis
goblet cells and mucus glands now contribute to secretion; may contain white blood cells and exfoliated debris
catarrhal rhinitis
name the clasification of rhinitis
thicker exudates with many more cells; dominated by neutrophils
purulent or mucopurulent
name the clasification of rhinitis
increase in vascular permeability allows exudation of fibrinogen which coagulates to fibrin and forms a yellow mat on affected surface; may be associated with severe underlying ulceration
fibrinous
name the clasification of rhinitis
macrophage dominated; wither specific pathogens or chronic allergic reaction
granulomatous
name the feature of chronic rhinitis
polypoid thickening of the inflamed nasal mucosa;
often round, large, multiple protuberances into the nasal meatus
nasal polyps
name the rhinitis
important disease where there is atrophy of nasal turbinates and distortion and shortening of snout;
caused by co-infection of nasal mucosa with Bordatella bronchiseptica and toxin-producing strain of Pasteurella multocida
(pigs)
Atrophic rhinitis
name the rhinitis
caused by S. equi;
characterized by suppurative rhinitis, pharyngitis, and lymphadenitis;
lymph nodes often rupture and discharge pus 2-3 weeks after onset of infection
(horses)
Strangles
name 3 possible complications that can occur as a result of Strangles in horses
- metastatic abscesses
- guttural puch empyema or chondroid formation
- pupura hemorrhagica
name the rhinitis
common cause in dogs by Aspergillus fumigatus; infection causes chronic necrotising inflammation with friable exudate containing necrotic tissue and fungal hyphae
mycotic rhinitis
inflammatory disease involving pharynx, larynx and trachea areas are important because of potential of these 2 consequences
- to obstruct airflow
- to cause aspiration pneumonia
name the larynx/trachea disease
cause uncertain but appears to be genetic predisposition to short-necked breeds (Texels, Southdowns); rams > ewes;
chronic suppuration within the aretynoid cartilages of the larynx result in swelling and occlusion of the lumen
laryngeal chondritis
name the larynx/trachea disease
trachea is flattened dorsoventrally with widened, flaccid dorsal tracheal membrane;
upon inspiration the flaccid membrane is sucked into the tracheal lumen causing obstruction
tracheal collapse
name the larynx/trachea disease
most common cause of abnormal respiratory noise in horses;
usually left-sided hemiplegia in horses due to degeneration of the left recurrent laryngeal nerve;
neurogenic atrophy of the left cricoarytenoid muscle causes the left arytenoid cartilage to sag into laryngeal lumen during inspiration;
condition is usually bilateral in dogs
laryngeal paralysis
name the larynx/trachea disease
dangerous due to potential to cause asphyxiation;
can occur in systemic anaphylaxis, associate with trauma, irritant gases
laryngeal oedema
this is inflammation of the bronchi
bronchitis
what 3 consequences can chronic bronchial irritation/injury result in
- excess production of mucus as a result of goblet cell hyperplasia
- squamous metaplasia
- bronchiectasis
name the type of bronchitis
common condition characterized by persistent tracheobronchial inflammation; tonsils and RPLNs are enlarged; major pathogen is Bordatella bronchiseptica
Kennel cough (infectious tracheobronchitis)
name the type of bronchitis
bronchial irritation and mucus hypersecretion causes chronic intractable cough; underlying bronchial mucosa is thickened, hyperemic and oedematous;
smooth muscle hypertrophy in pulmonary arteries can result in pulmonary hypertension and cor pulmonae
chronic bronchitis
(in dogs)
name the type of bronchi disease
permanent saccular or cylindrical dilation of bronchi as a result of the accumulation of exudate within the lumen and partial rupture of bronchial walls;
sac-like nodules in the lungs which are filled with purulent exudate;
often occurs secondary to chronic bronchitis
bronchiectasis
(in cattle)
what is the name of the lesion
development of organized polyp-like masses within the bronchilar lumen caused by infiltration by fibroblasts when the exudate cannot be cleared
bronchiolitis obliterans
this is when the repair process of alveolar cells is so spectacular in severe diffuse forms of alveolar injury that the affected tissue takes on the appearance of a gland
alveolar epithelialization
these are microscopic eosinophilic bands formed by a combination of pulmonary surfactant and plasma proteins which can leak into the alveoli following injury to type I pneumocytes and alterations in the blood-air barrier
hyaline membranes
this is inflammation that takes place in the alveoli and their walls
pneumonia
this is an altered texture of lung (firmer) due to accumulation of exudates
consolidation
name the type of pneumonia
common; inflammation focused on bronchi, bronchioles and adjacent alveolar lumens;
most common causes are bacterial and mycoplasma infections or aspiration of foreign material
bronchopneumonia
name the type of bronchopneumonia
characterized by neutrophils, cell debris and macrophages within the airway and alveolar lumens
suppurative bronchopneumonia
name the type of bronchopneumonia
more sever and can cause sudden death due to associated toxemia; less likely to resolve completely
fibrinous bronchopneumonia
name the type of pneumonia
inflammation that occurs primarily in alveolar walls rather than alveolar spaces;
lesions usually result from blood-borne insult and damage is often diffuse;
injury to alveoli may cause protein and fluid exudation leading to hyaline membrane formation
interstitial pneumonia
name two examples of interstitial pneumonia
- fog fever
- paraquat poisoning
name the type of interstitial pneumonia
usually seen in adult beef cattle in the autumn and is associated with change in pasture (lush, green)
Fog fever
name the type of interstitial pneumonia
lesions range from acute to chronic;
additional extraplmonary lesions include necrosis of adrenal zona glomerulosa and renal tubular epithelium
Paraquat poisoning
name the type of pneumonia
hybrid of bronchopneumonia and interstitial pneumonia; often caused by viruses damaging both airway and alveolar epithelial cells; cranioventral
bronchointerstitial pneumonia
name the type of pneumonia
lung inflammation caused by hematogenous spread of infections into the lung; has no orientation around airways and can occur in any lung region (caudal lobs most common);
inflammation is oriented around pulmonary arterioles or alveolar capillaries
embolic pneumonia
name the type of pneumonia
reaction dominated by macrophages, +/- giant cells and varying associated lymphocytes and neutrophils
granulomatous pneumonia
name 4 things that pulmonary abscesses can be a consequence of
- septic emboli lodging in pulmonary vessels
- extension from severe focal suppurative bronchopneumonia
- aspiration of foreign material
- direct penetration
name 2 canine viruses that cause pneumonia
- parainfluenza virus type 3 (PI3)
- cnaine distemper virus (CDV)
name the canine agent of pneumonia
paramyxovirus which can induce acute respiratory disease in a range of species;
replicates in airway epithelial cells and results in initial bronchitis leading to bronchiolitis and extension into alveoli
Parainfluenza virus type 3 (PI3)
name the canine agent of pneumonia
syndrome of catarrhal oculonasal discharge, pharyngitis and bronchitis relatively common in intial stages
canine distemper virus (CDV)
name 3 equine agents/diseases that can lead to pneumonia
- equine influenza
- equine viral rhinopneumonitis
- Rhodococcus equi
name 2 bovine agents/diseases that can lead to pneumonia
- Shipping/Transit Fever
- Respiratory Syncytial Virus (RSV)
name an ovine agent/disease that can lead to pneumonia
Maedi visna virus
name the agent of pneumonia
pulmonary lesions develop very slowly (uncommon in sheep under 2 years old);
lungs fail to collapse properly on opening chest and can weigh 2x normal weight and are a mottled grey/tan color; lesions vary from irregular grey speckling to homogenous grey consolidation
Maedi visna virus
name the agent of pneumonia
interstitial atelectasis and consolidation; interstitial emphysema which is more prominent in caudal lung lobes (results from bronchoconstriction);
formation of syncytial giant cells
(bovine)
Respiratory Syncytial Virus (RSV)
when are cattle and sheep most susceptible to Dictyocaulus?
when first exposed to contaminated pasture
name the two ruminant species of Dictyocaulus
- D. viviparus (cattle)
- D. filaria (sheep)
name the 3 phases of the pathogenesis/pathology associated with Dictyocaulus spp.
- penetration phase
- prepatent phase
- patent phase
name the phase of Dictyocaulus pathogenesis
larvae are in transit to lungs - no pulmonary lesions apparent
penetration phase
name the phase of Dictyocaulus pathogenesis
larvae appear in alveoli leading to alveolitis leading to bronchiolitis leading to bronchitis
associated infiltration of neutrophils, eosinophils, and macrophages which can plug airways resulting in collapse distal to lesion
prepatent phase
name the two main types of lesions that occur in the patent phase of Dictyocaulus pathogenesis
- parasitic bronchitis
- parasitic pneumonia
what parasite causes these lesions?
wedge-shaped areas of red/grey consolidation especially at the caudal edge of the diaphragmatic lobes
Dictyocaulus spp.
what is the species of Dictyocaulus affecting horses and donkeys?
D. arnfieldi
what parasite causes these lesions?
firm ‘lead-shot’ nodules scattered throughout parenchyma but most obviously in dorsal regions of the caudal lung lobes
Meullerius capillaris
name the parasite
parasites of bronchi/bronchioles of pigs;
histological lesions similar to those in Dictyocaulus but less extensive
Metastrongyles
name the parasite
causes widespread cat lungworm;
gross lesions are multifocal subpleural firm yellow nodules scattered throughout parenchyma;
eggs and larvae in alveolar spaces cause a foreign body reaction ;
heavy infestation can cause chronic coughing
Aelurostrongylus abstrusus
what parasite causes these lesions?
cause proliferative chronic arteritis and an intersitial eosinophilic pneumonia in the pulmonary arteries and R ventricle of dogs and foxes;
can lead to R sided heart failure
Angiostrongylus vasorum
name the parasite
the intermediate stage of Echinococcus granulosus - found in the lungs;
range in size up to 5-10cm; important as a zoonosis and cause carcas condemnation
Hydatid cysts
Name 2 type I hypersensitivity diseases of the lungs
- Feline asthma (allergic bronchitis)
- pulmonary infiltration with eosinophilia (PIE)
name the type 1 hypersensitivity disease of the lungs
inflammation dominated by eosinophils;
causes recurrent cough/dyspnea associated with bronchoconstiction
cats
Feline asthma / allergic bronchitis
name the type 1 hypersensitivity disease of the lungs
group of small animal diseases where there is a predominance of eosinophils in the airways;
considered that there is underlying hypersensitivity to allergens.
Pulmonary Infiltration with Eosinophilia (PIE)
name 3 type III hypersensitivity disease of the lungs
- Extrinsic Allergic Alveolitis (bovine farmers lung)
- Diffuse Fibrosing Alveolitis
- COPD
name the type III hypersensitivity disease of the lungs
due to repeated inhalation of spores of thermophilic actinomycetes in moldy hay;
affects housed animals in winter;
numerous small grey nodules on lungs representing lymphoid reaction;
can lead to pulmonary hypertension and cor pulmonae in extreme cases
Extrinsic Allergic Alveolitis (bovine farmers lung)
name the type III hypersensitivity disease of the lungs
‘catch all’ for end stage of a number of different diseases including EAA, reinfection syndrome, and fog fever BUT not preferred to be grouped together anymore
Diffuse Fibrosing Alveolitis / Atypical Interstitial Pneumonia
name the type III hypersensitivity disease of the lungs
characterized by chronic coughing and poor performance;
lungs often grossy unremarkable;
lesions consistent with chronic generalized bronchiolitis (plugging of airways with mucus, lymphoplasmacytic infiltration, goblet cell metaplasia, smooth muscle hypertrophy)
COPD (chronic obstructive pulmonary disease)
what 3 factors does the response of lungs to aspirated foreign material depend on?
- nature of the material
- bacterial load
- distribution of the material within the lungs
name the type of pneumonia
caused by: administration of medicines intended for oesophagus or as a sequel to aspiration pneumonia;
dead tissue undergoes liquefactive necrosis forming a cavity which is surrounded by intense hyperemia and inflammation
gangrenous pneumonia
name the type of pneumonia
endogenous: accumulation of surfactant in pulmonary macrophages leading to multifocal white nodules
exogenous: associated with inhalatin of oil & paraffin; results in reaction dominated by macrophages (which fill alveoli) and interstitial thickening
lipid pneumonia
this is the incomplete expansion of the lung at birth (congenital) OR collapse of previously air-filled lung (acquired)
atelectasis
name 4 types of atelectasis
- obstructive
- compression
- massive
- recumbency (hypostatic)
name the type of atelectasis
caused by complete airway obstruction, usually by inflammatory exudate, foreing bodies, parasites or tumors
obstructive atelectasis
what blockage is needed in species with good collateral ventilation (dogs & cats) to cause obstructive atelectasis?
complete blockage of lobular or segmental bronchi
what blockage is needed in species with poor collateral ventilation (ruminants) to cause obstructive atelectasis?
blockage of small bronchi and bronchioles
name the type of atelectasis
caused by pleural, intrathoracic, or intrapulmonary space-occupying lesions (fluid, blood or exudate can cause it)
compression atelectasis
name the type of atelectasis
complete lung collapse which occurs in pneumothorax
massive atelectasis
name 2 types of secondary pulmonary emphysema
- alveolar
- interstitial
name the type of secondary pulmonary emphysema
distension and rupture of these walls leading to formation of air ‘bubbles’ in the parenchyma
alveolar
name the type of secondary pulmonary emphysema
most common in cattle
air enters interlobular connective tissue, forms bullae, and leads to bullous emphysema
interstitial
name 3 mechanisms in place to protect the lung from entry of circulatory fluid into alveolar spaces
- alveolar epithelium highly impermeable to fluid (seal off alveolar space)
- interstitum of alveolar septa at lower pressure than intra-alveolar
- interstitial pressure negative toward fascia surrounding vessels/airways & hilus
what is the net effect of the 3 mechanisms in place to protect the lung from the entry of circulatory fluid into alveolar spaces?
liquid moves from alveolar interstitium towards lymphatics in fascia
this is excessive fluid in the lung characterized by expansion of perivascular/peribronchial/peribronchiolar fascia and distension of interstitial lymphatics
pulmonary oedema
name 3 major causes of pulmonary oedema
- increased capillary or type 1 epithelial permeability
- increased capillary hydrostatic pressure
- decreased plasma oncotic pressure
name 3 things that can cause increased capillary or type 1 epithelial permeability (possibly leading to pulmonary oedema)
- systemic toxins
- shock
- inhaled caustic gases
this is a potential sequel of septicemias, bleeding disorders, disseminated intravasclar coagulation and severe congestion
(lungs)
pulmonary hemorrhage
this type of pulmonary hemorrhage occurs commonly in horses during training or racing - hemorrhage is dorsocaudal
Exercise-Induced Pulmonary Hemorrhage (EIPH)
this is caused by left-to-right vascular shunts or increased resistance of the pulmonary vascular system
-most commonly a sequel of widespread fibrosis in the lung OR chronic bronchitis/bronchiolitis stimulating hypertrophy in walls of small arteries
pulmonary hypertension
name 4 classifications of pulmonary tumors in lower airwasy
- bronchial papilloma
- bronchial adenoma/carcinoma
- bronchioloalveolar adenoma/carcinoma
- carcinoid
name the primary tumor
caused by a retrovirus;
lesions progress from small firm grey/white nodular lesions to extensive confluent areas with replacement by neoplastic tissue;
multiplw neoplastic of cuboidal/columnar cells forming papillary projections into lumen
(lungs)
Sheep Pulmonary Adenomatosis (SPA) (Jaagsiekte)
name the primary tumor
most common in dogs;
solitary nodules at periphery of lung
bronchioalveolar tumors
name two examples of common metastatic tumors in the lungs
- mammary carcinoma
- malignant melanoma
these tumors often manifest in the lungs as multiple nodules scattered throughout the parenchyma; often referred to as ‘cannon-ball’
metastatic tumors
this is the presence of air in the pleural; always accompanied by atelectasis proportional to the amount of air in the cavities;
can be spontaneous or traumatic
pneumothorax
this is the accumulation of oedema fluid and has the same causes as oedema elsewhere
hydrothorax
this is the accumulation of chylomicron-rich lymph, generally through traumatic or inflammatory rupture of the thoracic lymphatic duct
chylothorax
this is the presence of blood in the thorax
hemothorax
this is purulent effusion in the pleural space; most significant in horses, dogs and cats
pyothorax (thoracic empyema)
pyothorax is usually the result of this in horses
secondary to pneumonia or lung abscesses
pyothorax is usually the result of this in dogs
migrating grass awns
this degenerative pleural disease is common in dogs with chronic uremia and vitamin D toxicity
pleural mineralization
