Respiratory Pathology I Flashcards
How are particles usually cleared from the airway?
Via coughing and mucocilliary clearance
the deeper the airway the slower the clearance
What are the four classes of pulmonary macrophage?
- Alveolar
- Interstitial
- Pulmonary intravascular
- Pleural
What are alveolar pulmonary macrophages?
- resident self-renewing pool
- Homeostasis and they prevent inflammation
- not very good at recognising inert substances
What are interstitial pulmonary macrophages?
least characterised type, function is incompletely described
What are pulmonary intravascular macrophages?
phagocytic and proinflammatory
* involved in acute lung injury
* only present in some species
What is mucocilliary clearance?
The self-cleaning mechanism of the airways
What type of mammals have cartilage in their bronchioles?
Marine mammals
What are type I pneumocytes?
large surface area and low antioxidant levels, mainly involved in gas exchange
What are the three general considerations surrounding the removal of pathogens from alveoli?
- generally inefficient
- relies on macrophages rather than cilliary clearance
- they can get into the interstitium if they accumulate
- macrophages with debris often gather around bronchioles and vessels
What is choanal atresia?
The back of the nasal passage is blocked by soft tissue
no communication between nasal pharynx and nasal cavity
In what type of animal does choanal atresia occur?
Mostly in camelids, they are forced to mouth breathe
What is nasal amyloidosis?
rare condition connected to the build up of amyloid in nasal passages
What is epistaxis also known as?
a nose bleed
What is waldeyers ring?
a ring of lymphoid tissue circling the oro and nasopharynx
What is pseudomembranous rhinitis?
fibrin on surface with no underlying ulceration
What is fibrinonecrotic rhinitis?
fibrin is firmly adhered to the ulcerated surface
What is acute rhinitis?
loss of cillia, epithelial attenuation, goblet cell hyperplasia, inflammatory cells
What is chronic rhinitis?
epithelial attenuation or metaplasia, it is classified based on the inflammatory infiltrate
What is idiopathic lymphoplasmacytic rhinitis?
Inflammatory disorder of the nasal cavity in dogs
causes increased mucus and turbinate destruction
What is allergic/ atopic rhinitis?
seen sporadically in most species, probably type I hypersensitivity
most likely related to pollen allergies
can progress to nasal granulomas in cattle
What is atrophic rhinitis?
characterised by the progressive thinning and shrinking of mucus membranes lining the nasal passages
most common in pigs
What are some of the clinical signs of atrophic rhinitis?
- Signs may appear in pigs as young as one week old but more often appear after weaning
- sneezing, snorting and discharge are all signs of AR
When may sinusitis occur?
- after dehorning, fractures, peridontitis
In what animal species is sinusitis most important?
It is most important in horses
What does chronic sinusitis cause?
polyploid mucousal thickening
What is a nasopharyngeal polyp?
inflammatory mass that arises in the middle ear
Who is most likely to get nasopharyngeal polyps?
Young cats 1-3 years old, the clinical signs depend on location
What can the guttural pouch develop after upper respiratory tract infection?
empyema or pockets of pus
What is guttural pouch tympany?
air buildup in the pouch
it is less common than inflammation
What is laryngeal oedema?
local or systemic inflammation of the larynx
swelling/ fluid accumulation in the tissues of the larynx
What is laryngitis?
Inflammation of the larynx
What is laryngeal paralysis in horses?
idiopathic degeneration of the recurrent laryngeal nerve
almost always affects the left side
may cause ‘roaring’ and poor performance
What is laryngeal paralysis in horses?
Usually occurs in older males, large to giant breeds,
unknown cause but may be due to a systemic muscle disease
has a predisposition to aspiration pneumonia
What is laryngeal chondritis?
ulceration at the rostral margin of arytenoid cartilage
it deforms the laryngeal cartilage, causes inflammation and necrosis
pathogenesis is unknown
What does vitamin A toxicosis cause in the trachea?
squamous metaplasia
How does brachycephalic airway syndrome occur?
- tracheal rings overlap
- the dorsal tracheal ligament is therefore impaired
- increased pressure in the airways causes aversion of laryngeal saccules
What can tracheal collapse cause?
dorsoventral narrowing, coughing and exercise intolerance
What is tracheal oedema and haemorrhagic syndrome also known as?
honker syndrome in feedlot cattle
What is honker syndrome?
Partial obstruction by haemorrhage and oedema of the dorsal trachea
What is pneumothorax of the pleura?
Air or gas in the pleura, causes atelactsis due to the loss of negative pressure
What is hydrothorax?
- Clear, watery transudate, colourless or light yellow
- is low protein/ low cells
- due to increased venous pressure and lymphatic obstruction
What is chylothorax?
accumulation of ‘milky’ high triglyceride lymph fluid, usually idiopathic
What is haemothorax?
Blood in the pleura, ususally traumatic
What is pleuritis in dogs usually due to?
inhaled or migrating grass awns
may also occur with bite wounds
What is the most common way that cats can get pleuritis?
FIP
* pyothorax is also relatively common
What is pulmonary hypoplasia?
reduced lung weight, also reduced numbers of alveoli
What is bronchial atresia?
accumulation of mucus in the lung
What is partial bronchial obstruction?
air trapping after birth
What is atelectasis?
- Incomplete expansion of the lungs- they usually look darker than they actually are
What is alveolar emphysema?
abnormal permanent enlargement of alveoli
due to destruction of septa
What is interstitial emphysema?
air in the connective tissues and lymphatics
When is interstitial emphysema serious?
in cases of 3-methylindole toxicity (fog fever),
What are blebs?
air-filled spaces in the connective tissue of the pleura
What are bullae?
air-filled spaces in the parenchyma that bulges into
the pleura
What usually causes overinflation of alveoli?
Usually due to airway obstruction or spasm
often seen at the margins of lobes in animals with respiratory distress
What species has very thick tunica muscularis?
Cats
