Respiratory System

Conduction portion

Conduct air to the lungs; nasal cavity, trachea, bronchi, bronchioles

Function of Conduction Portion

Clearn, humidify, warm/cool the air; olfaction, phonation

Respiratory Portion

Site of gas exchange; Respiratory bronchile, alveolar duct, alveoli

Function of Respiratory Portion

Gaseous exchange, surfactant production, excretion of volatile gases, alcohol & water

Vestibular (cutaneous) Zone

Similar to skin, but has alar cartilage present for support

Vestibular cavity

CT becomes vascular & glandular

What type of epithelium covers Vestibular portion?

Simple Squamous Keratinized epithelium

Turbinate Bone

Site where heavy dust particles are retained

What type of epithelium lines the Respiratory Portion

Psuedostratified columnar epithelium w/ cilia & goblet cells

Function of serous glands within R.Z

Humidification of air

Respiratory venous sinus function

Warming/cooling of air

The nasal cavity is lined with?

Psuedostratified columnar epithelium + specialized sensory cells

Cilia in the Olfactory zone

are non-motile and serve as dendrites of olfactory neurons

The olfactory nerve is formed via

Axons of bipolar neurons in the lamina propria

Bowman Glands

Serous glands in the lamina propria, that secretes an odor dissolving compound

Feline and K9 Oropharynx

Lined with stratified squamous non-keratinized epithelium

Ruminant Oropharynx

Lined with stratified squamos keratinized epithelium

Nasopharynx

Lined with psuedostratified columnar epithelium w/ cilia & goblet cells

Larynx

Psuedostratified squamous keratinized, non-keratinized @ level of vocal cords

Larynx cartilage

Mainly hyaline; some elastic

Epiglottis

Lingual - stratified squamous

Phayngeal - psuedostratified columnar in K9 & feline; stratified squamous in ruminants

What happens to the elastic cartilage in the Epiglottis

Replaced by fat with age

Cartilage rings take on

C-shape; dorsally incomplete and covered with smooth muscle

How are bronchi similar to the trachea?

Cartilage ring replaced with cartilage plaees & smooth muscle cells present beneath epithelium

Layers of the Bronchus

Tunica Mucosa (TM)

Tunica Submucosa (TS)

Tunica Adventitia (TA)

Tunica mucosa

Psuedostratified columnar w goblet cells & cilia

LICT

Muscularis mucosa - smooth muscle

Tunica submucosa

Serous glands within LICT

Tunica adventitia

Hyaline plates

Terminal Bronchiole

Goblet cells absent; Clara cells present to produce surfactant

Smooth muscle contraction

leads to dyspnea in cases of allergy, anaphylactic shock, and asthma

Smooth muscle dialation

leads to the widening of the airways

3 cell types of the alveolus

Type I - gaseous exchange

Type II - produce surfactant

Alveolar macrophage - phagocytose foreign material

Interalveolar Septa

Capillaries, CT cells, type I collagen & elastic fibers

How much of the alveolar surface is Type I cells?

~95%Whe

Where are Type II cells typically found?

Corners of alveoli

Blood Air Barrier

Thin portion of the interalveolar septum where gas exchange occurs

Heart Failure Cells

Increased number of alveolar macrophages seen in congestive heart failture

Respiratory Distress Syndrome

Insufficient surfactant production due to lack of Type II cell differentiation

How is RDS treated?

Corticosteroids increase Type II differentiation

Lavage from mature lung

Functional blood supply to lungs

Via pulmonary artery; low oxygen, high pressure

Nutritional blood supply to lungs

Via bronchial artery; high oxygen, high pressure