Pathology of the Respiratory System

upper airway, lower airway, lung

What are the three major divisions of the respiratory system?

nasal cavity, paranasal sinuses, nasopharynx

What does the upper airway consist of?

larynx, trachea, bronchi, bronchioles

what does the lower airway consist of?

bronchi, bronchioles, alveoli

what do the lungs consist of?

thoracic wall, mediastinum

It is important to remember that diseases affecting the _________ and _________ may also impact the respiratory system.

trachea → primary bronchi → lobar (secondary) bronchi → segmental (tertiary) bronchi → bronchioles → respiratory bronchioles → alveolar ducts → alveolar sacs → alveoli

The respiratory tree is the branching system of airways within the lungs. List the pathway in order of largest to smallest.

alveoli

what are the sites of gas exchange?

resistance

With each division in the respiratory tree, there is increased ________, which is important to remember in upper resp. diseases and pneumonia cases.

conductive and transitional system

gas exchange system

vascular system

What are the three practical subdivisions of the respiratory system?

conductive system

Which practical subdivision includes: nasal cavity, turbinates, paranasal sinuses, nasopharynx, larynx, trachea, bronchi

nasal cavity, turbinates, paranasal sinuses, nasopharynx, larynx, trachea, bronchi

What does the conductive system include? (name like 4 of the 7)

humidifies, warms, filters

The conductive system ________, ________ and _______ inspired air.

50-75

______-_________% of total respiratory resistance is from the conductive system

Turbinates

__________: Curved or scroll shaped bony structures protruding from the lateral walls and septum of the nasal cavity

regulating nasal airflow

turbinates aid in warming, humidifying, and filtering inspired air AS WELL AS _____________________

impaction of inhaled particles

Turbinates are also a major site of what?

paranasal sinuses

___________________: Air filled cavities in the facial bones

1. decrease weight of the head

2. auditory (vocal resonance)

3. buffer against facial trauma

4. insulate structures from temperature changes

What are the four functions of the paranasal sinuses that Dr. Joiner gave us?

doesn't drain well

Because there are only small openings that communicate between the paranasal sinuses and the nasal cavity, what does this mean happens when the sinuses are inflamed?

vasodilation

_______________ is the hallmark of inflammation

horse

What species has six pairs of paranasal sinuses—the frontal, sphenopalatine and maxillary sinuses, and the dorsal, middle and ventral conchal sinuses

sinusitis

_____: refers to inflammation or infection of one or more of the paranasal sinuses

primary

[primary/secondary] sinusitis is defined as an infection in the sinus, usually bacterial in origin, which results in a buildup of pus within the sinus

secondary

[primary/secondary] sinusitis is an infection of the paranasal sinuses as a result of another primary cause, such as tooth root infection, bone fracture, or sinus cyst

secondary

Is primary or secondary sinusitis more common?

last four cheek teeth, the roots are within the maxillary sinuses

What are most likely to cause a secondary sinusitis in horses? And why?

nasopharynx

______________:Mediates air passage from the nasal cavity to the larynx

eustacian tubes, middle ear

pressure equilibration

What 2 structures connect in the nasopharynx? What does this allow?

lymphoid nodules

initiator and effector

Respiratory immunity in the nasopharynx is due to a large aggregate of ____________ in the submucosa. It acts as both a ______ and _______ site, and as a primary site for the colonization of pathogens.

larynx

phonation

the __________ separates the intestinal and respiratory tracts, and is an organ of ___________

aspiration of ingesta

increased airway resistance

Dysfunction of the larynx can lead to ____________, and narrowing can lead to _________

c-shaped cartilaginous rings

the trachea is supported by _________ which maintain rigid structure and lumen size

main stem bronchi

the trachea divides into what?

mainstem bronchi, pulmonary parenchyma

__________ are the terminal division of the trachea and entry into the ______________

peribronchial connective tissue and cartilage

bronchi are supported by extensive __________

inversely, increase

diameter of the bronchi and resistance are ______________ related... so as diameter decreases, resistance will [increase/decrease]

alveolar spaces

Where does air delivery transition into gas exchange?

false; they have no cartilage so the diameter can change with lung inflation

true/false: bronchioles are supported by cartilage so that their small size doesn't change with changes in airflow

small, high

large, low

individually, bronchiole diameter is _____ and resistance is ________. But as a functional unit, cross sectional area is ______ with ______ resistance

true

true/false: widespread damage is necessary to increase resistance to airflow in the bronchioles

there is very little peribronchiolar connective tissue (so it doesn't limit the inflammation)

bronchioles are a common site of inflammation.... why?

acini

gas exchange occurs in the _______

respiratory bronchioles, alveolar ducts, alveolar space

the acini consists of branching ______, _______ and _______

fluid accumulation, exudate

damage to the acini will lead to ________ or _______ filling the alveolar spaces or interstitium

ventilation, perfusion, diffusion

Gas exchange happens over thin barriers through ________ (breathing), _________(blood flow), and ________ (moving gases down their pressure gradients)

terminal bronchiole, alveolar ducts, alveoli

The mammalian gas exchange system originates with each _____________, opening into ________ and a collection of __________

capillaries

Alveoli are wrapped in a dense network of ____________, creating an enormous surface area for gas exchange

acinus

______: The fundamental functional unit of gas exchange in the lung

blood gas interface

where oxygen and carbon dioxide transfer occurs between air and blood.

4

It is important to note that the entirety of the alveolar wall is approximately _____ microns thick.

pores of Kohn

Adjacent alveoli have connections via small openings, called _______, that allow for collateral airflow and equalization of pressure between alveoli

1. increased surface area of the membrane

2. increased alveolar pressure difference (PA-Pa)

3. increased solubility of the gas

4. decreased membrane thickness

What four things can increase the diffusion of gas across alveolar membranes?

right ventricle, deoxygenated

Pulmonary arteries originate from the _________ and carry [oxygenated/deoxygenated] blood

oxygenated, left atrium,

Pulmonary veins carry [oxygenated/deoxygenated] blood back from the lungs to the ___________

pulmonary capillaries

___________________: tiny vessels surrounding alveoli where gas exchange occurs

shortness of breath, heart strain

pulmonary hypertension: High blood pressure in the pulmonary arteries, leading to _______ and ________

blockage

pulmonary embolism: a _______ in the pulmonary arteries, often by a blood clot

pressure, congestion

heart failure can cause increased _______ in the pulmonary system, leading to ________

bronchial circulation

Which of the two arterial supplies to the pulmonary system brings OXYGENATED blood to the lung tissue to keep it working?

pulmonary circulation

Which of the two arterial supplies to the pulmonary system brings UNOXYGENATED blood to the lung tissue for gas exchange?

thoracic aorta & intercostal arteries

trachea & bronchi

The bronchial circulation arises from the _________ and ________ and supplies the ______ and __________ to the level of the bronchioles

pulmonary artery

The pulmonary circulation arrives via the _____________

False: PULMONARY circulation is the largest capillary bed in the body

True/false: the bronchial circulation is the largest capillary bed in the body

filter

due to the small diameter of the capillaries, the pulmonary circulation serves as a sort of blood __________

leukocytes, alveoli

in the pulmonary circulation, ________ migrate through the capillary walls into the ________

1. deliver blood for gas exchange

2. filter small thrombi

3. trapping of leukocytes

What are three functions of the pulmonary circulation

pleura

_______: Covers the lungs, thoracic structures and thoracic wall.

fluid, blood or lymphatic supply

The pleural spaces contain small amounts of _________ but no direct _______ or ______________

(kinda a stretch on the wording I know. but whatever)

mediastinum

___________: Anatomic space bordered by the sternum, pleural surfaces of the lungs, diaphragm and vasculature

thoracic cavity

in some species, the mediastinum completely divides what?

guttural pouch

________: A ventral diverticulum of the Eustachian tube.

cooling of blood in the internal carotid, pressure equalization

Allegedly, the guttural pouch is essential for _______________ in the __________ and __________________

right: cranial, middle, caudal, accessory;

left: cranial and caudal

What are the lung lobes in a dog/cat/cow?

right:______________________

left:________________________

right: cranial, middle, accessory;

left: cranial and caudal

What are the lung lobes in a horse?

right:______________________

left:________________________

pulmonary lobule

__________________: Clusters of 3-5 terminal bronchioles with their acini form this

collateral ventilation

________: "the ventilation of alveolar structures through passages or channels that bypass the normal airways"

For our purposes, this would mean that if one lobule of the lung is infected with something, it could spread to other lobules

true

true/false: cattle and pigs have extensive lobulation due to abundant connective tissue... which means that if one lung lobule is infected with something, it's a lot less likely for the infection to spread to other lobules

olfactory neuroepithelium, stratified squamous, ciliated pseudostratified respiratory epithelium

The entire respiratory tract is covered by epithelium... what are the three kinds?

epithelium

submucosal gland

cartilage

smooth muscle

What are the 4 cells types in the conductive and transitional systems?

________: lines the entire tract

_______: secretes layer of mucociliary escalator

_______: for support

_____: support and pliability

olfactory neuroepithelium

___________: present in portions of the nasal cavity that contain specialized cells that bind to odorants to enable sense of smell

true

True/false: the olfactory receptor neurons are some of the only areas where adult neurons are continuously regenerated

cytochrome p450, some metabolites are more toxic than the full inhalant

the olfactory neuroepithelium, contains ______ which aids to metabolize inhalants... why might this be a bad thing?

stratified squamous epithelium

what type of epithelium covers the nares?

injury

stratified squamous epithelium is resistant to ___________

ciliated epithelial cells

what type of epithelium covers 95% of the conductive system and is a vital part of the mucociliary escalator?

metaplasia

____________________: changing from one type of mature tissue to another

squamous epithelium, chronic irritation

metaplasia of the respiratory epithelium to ____________ can occur in instances of ___________

cilia, mucociliary escalator

in chronic irritation, when the epithelium becomes squamous, this results in a loss of ________ and decreased function of the __________

club cells

________: considered the stem cells of the upper and lower respiratory tract. these cells secrete a thin protein rich fluid and are metabolically active

metabolism, detoxification, reduction

Club cells have lots of smooth ER for efficient _________, ____________ and ______ of oxidants

type I and type II pneumocytes

alveolar epithelium contains what two types of cells primarily?

type I (flattened) alveolar cells

__________________: Extremely thin, flattened cells forming the main gas exchange surface, allowing oxygen and carbon dioxide to diffuse easily across the blood-air barrier.

type II (cuboidal) alveolar cells

____________________: Cube-shaped cells found in clusters, responsible for synthesizing and secreting pulmonary surfactant (which reduces surface tension) and for regenerating damaged Type I cells.

type I pneumocytes

Which type of alveolar cell is very thin and lines the alveolar spaces for gas exchange

type II pneumocytes

Which type of alveolar cells are metabolically active?

type II pneumocytes

Which type of alveolar cells can divide to replace BOTH types of pneumocytes?

type I pneumocytes

which type of alveolar cells prevent leakage of fluid and protein from the alveolar interstitium into the airspace?

type II pneumocytes

which type of alveolar cells prevent alveolar collapse and atelectasis?

producing surfactant to to reduce surface tension

HOW do type II pneumocytes prevent alveolar collapse?

pulmonary alveolar macrophages, interstitial macrophages, pulmonary intravascular macrophages

What are the three types of macrophages in the gas exchange system?