VMED 02610: Pathobiology II Systemic Pathology – Respiratory System Lecture 1

The nasl cavity extends from what to what ?

from nares to nasopharynx

The nasal cavity is divided by what

the nasal septum

The nasal conchae consist of what

dorsal, ventral, and ethmoidal

Describe the conchae coils

• turbulence

• large surface area

What is the function for “conditioning” in the nasal cavity/paranasal sinuses

•Warms & humidifies inspired air

• Rich mucosal venous plexus

• Heat loss by panting (dogs)

What is the function for “filitration” for the nasal cavity and paranasal sinuses

• Conchal turbulence traps large particles

•Mucus captures dust & microbes

What is the function for “Olfaction” for the nasal cavity and paranasal

• Olfactory

• epithelium in ethmoid region

• Neurons exposed to inhaled agents

What is the function “defense” in the nasal cavity and paranasal sinuses

•First barrier to inhaled pathogens

• NALT, IgA, antimicrobial secretions

Paranasal Sinuses are air filled cavities in the ?

skull bones

What are the sites of the paranasal sinuses

 Frontal, maxillary, sphenoid, palatine (species specific)

 Large, complex sinuses in horses and cattle

Where does the frontal sinuse extend in horned cattle

 Frontal sinus extends into horn core (horned cattle)

How does paranasal sinuses communicate with the nasal cavity

 Communicate with the nasal cavity via small openings

What can poor drainage lead to in the paranasal cavity

Poor drainage → exudates accumulate easily

What is the function of mucociliary clearance

 Cilia move mucus toward the pharynx → swallowed

 Clears trapped material

What is sol layer

watery; cilia beat within it

What is Gel layer:

viscous; traps particles and microbes

What is the function for the humoral (secretions)

• there role is defensins complement

What is the function for secretory IgA

• blocks adherance

What is the function for lysozyme

• lyses bacterial walls

What is the function for lactoferrin

binds iron

What is the function for interferons

antiviral

What are the structure and functions for “cellular” in the nasal/paranasal cavities

• Nasal-associated lymphoid tissue (NALT)

•Dendritic cells & intraepithelial lymphocytes

• Neutrophils recruited in acute injury

• Rapid epithelial regeneration

What leads to the cleft palate

• Palatoschisis

 Can involve the hard and/or soft palate

 Can lead to aspiration pneumonia

Brachiocephalic Airway Syndrome are predisposed to what breeds

bulldogs, pugs, Boston terriers; Persian cats

What are the components for Brachiocephalic Airway Syndrome

 Stenotic nares

 Elongated soft palate

 Eversion of laryngeal saccules

 +/- hypoplastic trachea

Hyperemia/Congestion/Edema is seen when

Frequently seen with acute inflammation

Where does epistaxis occur

Originates from the upper respiratory tract or lung

What are the causes of Epistaxis (hemorrhage)

 Inflammation

 Neoplasia

 Trauma

 Clotting defect

 Exertion

What are the characteristics of Ethmoid Hematoma

 Idiopathic lesion of horses

 Causes unilateral epistaxis

 Mass composed of clotted blood and fibrovascular proliferation

 Progressive and locally destruction

What is the duration for rhinits

•Peracute

• acute

• subacute

• chronic

What are the factors for exudates in the nasal cavity

•Serous

• Catarrhal (mucous)

•Purulent (suppurative)

•Fibrinous / fibrinonecrotic

What are the causes of rhinitis

• Viral

• Bacterial

• Fungal

• Parasitic

• Allergic

• Chemical irritants

Acute Rhinitis – Serous what is the duration stage

Earliest stage

What causes acute rhinits?

 Involved swelling of mucosa and lamina propria from hyperemia and edema

 Increased secretion by goblet cells and submucosal glands

What kind of exudate is Acute Rhinitis – Serous

Exudate is seromucin

Acute rhinitis can cause what kind of inflammatory ?

 Mild inflammatory cell infiltrate (mostly neutrophils)

What kind of exudate is Acute Rhinitis – Catarrhal

Exudate is mucous + Often with purulent (mucopurulent)

How do acute rhinitis - catarrhal look like cellularly

Goblet cells become hyperplastic

Acute Rhinitis – Catarrhal Follows

serous inflammation

Acute Rhinitis – Purulent involves what

Involves exudation of a large numbers of neutrophils and desquamation of epithelial cells

Acute Rhinitis – Purulent may include what

May include ulceration

Acute Rhinitis –Fibrinous is what

Altered vascular permeability leads to fibrin deposition on mucosal surface

Acute Rhinitis –Fibrinous is associated with

Usually associated with purulent exudate (fibrinopurulent) or necrosis (fibrinonecrotizing)

Acute Rhinitis -Fibrinonecrotizing also known as

AKA pseudomembranous

Acute Rhinitis -Fibrinonecrotizing involves what

 Involves severe injury to the epithelium

Acute Rhinitis -Fibrinonecrotizing can lead to what

 Leads to surface accumulation of fibrin, degenerate neutrophils, and necrotic cellular debris (pseudomembrane)

When Acute Rhinitis -Fibrinonecrotizing is removed what happens

When removed, leaves ulcerated/raw surface

Chronic Rhinitis is a result of

 Usually results in fibrovascular proliferation within the lamina propria

What can form in chronic rhinitis

 Polyps may form

 Epithelium may proliferate and become squamous (squamous metaplasia)

What are the Causes of Rhinitis

 Viruses

 Bacteria

 Fungi

 Parasites

 Allergens

 Chemical irritants

Examples of Rhinitis in Cats

 Feline upper respiratory complex

 Feline rhinotracheitis virus (FHV-1)

 Feline calicivirus

 Chlamydia felis

What is the mortality rate for Rhinitis in Cats

Low mortality

Rhinitis in Cats Often associated with

conjunctivitis

Atrophic Rhinitis is caused by what

 Caused by toxin produced by:

 Bordetella bronchiseptica

 Pasterurella multocida

What animal does Atrophic Rhinitis affect

Disease of young pigs

Atrophic Rhinitis toxins causes what

Toxin causes bone resorption in nasal turbinate, leading to facial distortion

Strangles is caused by what

Caused by Streptococcus equi

Strangles can lead to what

Can lead to respiratory difficulty

 Sequelae include purpura hemorrhagica (an immune-mediated vasculitis) and abscesses in other organs (“bastard strangles”)

Example of Mycotic Rhinitis: Aspergillus is most common in

dogs

Example of Mycotic Rhinitis: Cryptococcus is most common in

is most common in cats (can also affect dogs)

What animals may have Mycotic Rhinitis

 Rhinosporidium in horses and dogs

• Aquatic protozoan (acts like a fungus)

Sinusitis is what

 Often difficult to detect clinically unless there’s facial deformity or fistula develops

Sinusitis is secondary to what

 Rhinitis

 Parasites (Oestrus ovis)

 Dehorning in cattle

 Fractures

 Severe dental disease

What are the two examples of

• Chondroma

• Osteoma

What is Chondroma

occurs in a variety of species

What is Osteoma

occasionally occurs in horses and cattle

Malignant neoplasms: are?

 Epithelial

 Squamous cell carcinoma – anterior

 Adenocarcinoma – posterior

What are examples of Mesenchymal Neoplasms

 Fibrosarcoma – most common

 Osteosarcoma

 Chondrosarcoma

 Lymphoma