Avp Respiratory

Front 1

What are the 4 defences of the respiratory system?

Back 1

1. Coughing/sneezing
2. Mucoiliary escalator
3. Phagocytosis
4. Immune mediated - IgA URT, IgG LRT

Front 2

What are the divisions of the respiratory system?

Back 2

URT = nasal cavity, paranasal sinuses, nasopharynx
LRT = larynx, trachea, bronchi, bronchioles, alveoli

Front 3

Describe the histology of the respiratory tract

Back 3

Begins with pseudostratified columnar ciliated epithelium. Goblet cells are intersperced, trachea ++ but not in bronchioles. Goes into transition zone with simple cuboidal non ciliated. BALT - secretory IgA

Front 4

What are causes of irritation to the URT?

Back 4

Physical (dust,heat)
Chemical
Viral
Bacterial
Fungal
Parasitic

Front 5

What changes occur as a result of irritation to URT?

Back 5

- Reduced number cilia
Increased number and activity of goblet cells
- acute inflammation of lamina propria
- Get abnormal mucous flow patterns

Front 6

What happens with continued irritation of respiratory tract?

Back 6

With continued irritation get metaplasia = columnated cells become more cuboidal and less cilia
- Increased adhesiveness of mucous
- Ciliostasis

Front 7

What are the 5 causes of problems in the larynx?

Back 7

1. Anomalies (brachycephalic syndrome, equine DDSP, subepiglottic cysts)
2. Inflamatory
3. Neoplasia
4. Circulatory (latyngeal oedema)
5. Degenerative (equine laryngeal hemiplegia)

Front 8

What are the 5 causes of problems to the trachea?

Back 8

1. Anomalies (tracheal collapse, tracheal hypoplasia, tracheo-oesophageal fistula, ciliary dyskinesia)
2. Inflammatory (necrotic laryngitis, kennel cough, herpes)
3. Neoplasia
4. Circulatory (tracheal oedema)
5. Parasitic (filaroised oseleri in dogs)

Front 9

Describe VA
What affects/changes VA?

Back 9

VA inversely proprtional to PaCO2.
- Decreased pH of CSF = increased VA
- Increased PaCO2 = increased VA

Front 10

What are the VA control centers?

Back 10

1. Central control - medullary respiratory center responds to changes in CSF pH
2. Peripheral contro - chemoreceptors on aortic and carotid bodies respond to fall in blood pH and increased PaCO2

Front 11

What are the major clinical signs of respiratory failure?

Back 11

1. Changes in rate and depth of respiratoin
2. Cyanosis

Front 12

What is respiratory failure defined as?

Back 12

1. PaO2 falls from 90-100mm Hg to 60-70 mm Hg
2. PaCO2 rises from 40mm Hg to 50 mm Hg

Front 13

What are the two types of respiratory failure?

Back 13

1. Restrictive = a pulmonary or thoracic process restricting inflation of the lungs
2. Obstructive - a pulmonary process obstructing the airways of reducing elastic recoil

Front 14

What are the clinical signs of restrictive respiratory failure?

Back 14

Inspiratory dyspnoea
Hypoxia
Rapid shallow breaths
Eucapnia/hypocapnia

Front 15

What are the 2 types of restrictive respiratory failure?

Back 15

1. Intrapulmonary
- Predominantly affects the inerstital tissues (alveolar and interlobar septa)
2. Extrapulmonary
- In pleural cavity, mediastinum, thorcic wall

Front 16

What are examples of the 2 types of restrictive respiratory failure?

Back 16

1. Intrapulmonary
- pulmonary oedema
- Pneumonia
- Alveolar fibrosis
2. Extrapulmonary
- haemothorax
-hydrothorax
-SOL
-deformities of thoracic wall

Front 17

Describe what happens with Inrapulmonary restrictive respiratory failure

Back 17

The septa are thickened by accumulation of fluid, inflammatory cells or fibrous tissue. There is type II hyperplasia where type II cells predominate. This causes reduced compliance and thicker diffusion barrier.

Front 18

What are the types of obstructive respiratory failure?

Back 18

1. Airway obstruction
- bronchitis, bronchiolitis
2. Reduced elasticity
- Emphysema

Front 19

What are the clinical signs of obstructive respiratory failure?

Back 19

- Inspiratory and expiratory dyspnoea
- hypoxia
- rapid deep breaths
- eucapnia/hypocapnia

Front 20

What are the 3 types of pulmonary oedema?

Back 20

1. Hydrostatic
- happens with increased pulmonary venous pressure
- common in L heart failure
-Fluid overload
2. Permeability oedema
- Inflammation
-bacterial enotoxins
-drugs
3. Lymphatic oedema
- obstruction of lymphatic drainage i.e. neoplasm

Front 21

What are the events in pulmonary edema?

Back 21

1. Fluid accumulates in interstitium around bronchi and larger vessels
2. Extends to septa adjacent to thick sectors of capillary wall - this restricts lung expansion as reduced compliance alveolar walls
3. Fluid accumulates in alveoli = rapid, late, abrupt - get obstructive failure

Front 22

What are the clinical signs of pulmonary oedema?

Back 22

- Incaresed rate and depth breathing
- soft moist cough
- may have foam at nares

Front 23

What is alectasis? What type of respiratory failure is it?

Back 23

Atelectasis is collapse or incomplete inflation of the lung. It is restrictive intrapulmonary respiratory failure.

Front 24

What are the 3 types of atelectasis?

Back 24

1. Aquired compressive - where contents such as air, fluid, intestinal contenst are introduced into the pleural cavity.
2. Aquired obstructive - obstruction of bronchi or bronchioles - lung distal to obstruction fills with fluid and then collapses
3. Congential

Front 25

What is the end result of atelctasis?

Back 25

End up with a VA/Q mismatch so that blood going through the lungs is not properly perfused so blood shunted from R) to L) of the heart.

Front 26

What is emphysema? What type of respiratory failure?

Back 26

Part or all of the lung is overdistended with air. Usually co-exists with bronchitis or bronchiolitis. It is obstructive respiratory failure.

Front 27

What are the 3 types of emphysema?

Back 27

1. Interstitial
- air forced from overdistended alveoli into interstitial CT. Caused by bronchiolar inflammation - enzymatic lysis of elastin fibers in alveolar walls
2. Vesicular
- Overdistention confined to alveoli and alveolar ducts - get stretching of CT and loss of elsatic recoil.
3. Blubous
-large scale rupture of alveoli produce air filled cavities w/i lung or beneath pleura

Front 28

What are the clinical signs of emphysema?

Back 28

Forced expiration
Soft breath sounds
Expiratory wheeze

Front 29

What are the 2 types of pneumonia?

Back 29

1. Exudative
- Usually infectious and aerogenous in origin
- Alveolar lumen is filled with fluid and inflammatory cells
2. Proliferative
- Alveolar lumen remains relatively clear
-alveolar walls are thickened by hyperplatic epithelial cells and inflammatory cells

Front 30

What are the 2 patterns of exudative pneumonia?

Back 30

1. Bronchopneumonia
- subacute to chronic
- usually bacterial
- inflammatoin from bronchioles spreads down to involve alveolar ducts and alveoli
- lesions spread in defined lobular pattern
2. Lobular pneumonia
(fibrinous pneumonia)
- acute-peracute
- rapid spread of inflammation
- extensive vascular damage - haemorrhage
- may also get abscess formation

Front 31

What is proliferative pneumonia?

Back 31

Inflammatory process centered on alveolar septa. Also called interstitial pneumonitis, alveolistis

Front 32

What are the clinical signs of proliferative pneumonia?

Back 32

- Restricyive
- exercise intolerance
- incaresed respiratory effort
- Increased breath sounds
- late inspiratory crackles

Front 33

What are the causes of proliferative pneumonia?

Back 33

- bacterial (mycoplasma ovipnemonidae)
- Toxic - paraquat, pyrrolizidine alkaloids
- Allergic - mouldy hay

Front 34

What types of neoplasm are there?

Back 34

1. Primary
2. Secondary