Lecture 22 and 23 Flashcards
Normal pig lung
Normal rats lung
What do the black dots represnet
Inhaled particles trapped in mucous
What are the 3 types of lining in the alvioli
- Type I aveolar
- Type II aveolar
- Macrophages
Why is the respiratory system vulnerable to injury
- Constant exposure to - microes, particles, fibres, toxicgases a vapours in the air
- Large surface area in the alveoli
- Large volume of air passing continuously into the lungs
- Lungs are also susceptible to haematogenous microbes,toxins and emboli
5.
What is the conducting defense mechanism of the lungs
- Sneezing, coughing
- Mucociliary clearance, mucous
- Antibodies
What is the transitional system of the lungs
- Clara cells (detoxify foregin substances)
- Antioxidants, antibodies
What is the exchange system of the lungs
- Alveolar macrophages
- Intravascular monocytes
- Antibodies, surfactant, antioxidants
When is the defensce mechanism of the lungs altered
- Injured epithelium
- Enhances bacterial attachment
- Impaired mucociliary clearance
- Reduction in antibacterial secretory products
- Dysfunction of alveolar macrophages and lymphocytes
- Immunosupressive effects of some virsues
What viruses predispose to bacterial pneumonia
- Influenzia
- Bovine herpesvirus 1, parainfluenza-3, bovine syncytial virus
- Canine distemper
- Bacterial infections may result from normal flora of the respiratory tract
Blue: large macropahage that has ingested bacteria
Red: small cluster of neutrophils
R. Equui
What are the effects of gases on the respiratory system
- Render respiratory tract susceptible to secondary bacterial infections - impaired defense mechanisms
- Hydrogen sulphide and ammonia in housed animals: overcrowding of animals increases the problem
- Pollutants in cities
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What is epistaxis
Blood flow from the nose - either from the nasal cavity or lungs
What is haemoptysis
Coughing up blood in septum or saliva - commonly from lung lesions
What is ethmoidal haematomas
Important in horses
- Chronic, progressive, often unilateral nasal bleeding
- Appears as soft, tumour-like, dark mass arising from the mucosa of the ethmoidal conchae
What is hyposmia
Reduction of olfactory function secondary to chronic injurt to olfactory epithelium
What is anosmia
Loss of olfactory function
Ethmoidal haematoma - horses
What is serous Rhinitis
Clear fluid
What is catrrhal rhinitis
Thick mucus with some leukocytes and cellular debris
Progressto mucopurulent with neutrophils present
What is mucopurulent rhinitis
- Heavy neutrophil content plus mucous and cellular debris
- More severe damage to mucosa, necrosis
- Indicates secondary bacterial infections
Suppurative Rhinitis: calf
What is fibrinous rhinitis
- Inflammation with increased vascular permeability
- Large amount of fibrinogen coagulates into fibrirn
- Yelow, tan or grey rubbery mat on the mucosa
- May form a pseudomemrane that is difficult to remove and has underlying necrotic tissue
Fibrinous rhinitis: calf
What is granulomatous rhinitis
- Chronic allergic inflammation
- Fungal infections
- Foreign bodies
- Granulomatous masses may obstruct nasal cavity
- May lead to destruction of the turbunates or erosion into sinuses
Granulomatous rhinitis: cow with fungal infection on nasal septum