Respiratory System Diseases Pathophysiology Review of Anatomy & Physiology Upper Respiratory Tract

Respiratory System Diseases
Pathophysiology
Review of Anatomy & Physiology
Upper Respiratory Tract
Respiratory Mucosa
lined with ciliated mucus producing cells
125cc/ day
purifies air
is contiguous with all structures
Nose
paranasal sinuses
frontal, maxillary, sphenoid, ethmoid
lighten skull
sound resonant chambers
conchae (3 pairs)
warm & humidify air
lacrimal ducts
olfactory receptors
Pharynx
3 parts: Nasopharynx, Oropharynx, Laryngopharynx
Tonsils(3 pairs)
pharyngeal (adenoids)
palatine
lingual
Eustachian (auditory) tubes open into nasopharynx
equalizes pressure between middle ear & the outside
Larynx
composed of pieces of cartilage
Thyroid cartilage= Adam’s apple
epiglottis & glottis
Lower Respiratory Tract
Trachea
composed of C- shaped cartilaginous rings
called windpipe
Bronchi, Bronchioles, Alveolar Duct, Alveoli
gas exchange occurs in alveoli
occurs via Passive Diffusion
Respiratory Membrane
2 cell layers thick
surfactant = reduces surface tension to keep alveoli distended
lining of alveolus (alveolar epithelium)
lining of capillary ( capillary endothelium)
Lungs & Pleura
right lung = 3 lobes; left lung = 2 lobes
lower part of lung resting on diaphragm = Base of lung
upper part of lung under clavicle = Apex of lung
pleura = serous membrane (i.e. secretes some fluid)
parietal pleura lines thoracic cavity
visceral pleura lines organs (viscera)
Mechanics of Breathing
air moves by differences in air pressure
Inspiration
active process; get contraction of diaphragm & external intercostal muscles
results in increase in size of chest cavity
Expiration
passive process with normal expiration
active process with forced expiration; get contraction of abdominal & internal intercostal muscles
results in decrease in size of chest cavity which increases pressure & forces air out
Manifestations of Pulmonary Disease
Sneezing = reflex response to irritation of upper respiratory tract
Coughing = reflex response to irritation of lower respiratory tract
Sputum production
If yellowish- green ------ infection
If rusty ------- blood + pus = pneumococcal pneumonia
If bloody , called “hemoptysis” ---- usually frothy --- seen in pulm. Edema
Also seen in pulm. TB & cancer
Large amounts & foul = bronchiectasis
Thick & sticky = asthma, cystic fibrosis
Breathing patterns
Eupnia, labored (dyspnea) , wheezing, stridor
Breath sounds
Normal, rales, rhonchi, decreased breath sounds
Dyspnea --- discomfort feeling when can’t get enough air
Orthopnea = dyspnea lying down
Cyanosis --- not a reliable early indicator of hypoxia
Respiratory System Diseases
General Outline
Infectious diseases
Upper
URI
Croup
Epiglottitis
Flu (Influenza)
Lower
Bronchiolitis (RSV)
Pneumonia
SARS
TB
Fungal diseases
Obstructive lung diseases
Cystic fibrosis
Cancer
Aspiration pneumonia
Asthma
COPD (chronic obstr. pulm. dis)
Emphysema
Chronic bronchitis
Restrictive lung diseases
Chest wall abnormalities
Connective tissue abnormalities
Pneumoconioses
Vascular disorders
Pulmonary edema
Pulmonary embolism
Expansion disorders
Atelectasis
Pleural effusion
Pneumothorax
Resp. distress syndrome
Infant
adult
Upper Respiratory Tract Infections
Upper Respiratory Infection (URI)
Def = Acute inflammatory process that affects mucus membrane
of the upper respiratory tract
Includes one or more of the following problems
Rhinitis ------ also called Coryza
Pharyngitis
Laryngitis
Sinusitis
Pathophysiology ------ see next slide
Sx = low-grade fever, malaise, cephalgia, sore throat, & discharge
Incubation period short ----- 2-3 days
As a rule: bacterial diseases = short incubation
viral diseases = long incubation except URI’s
Etiol = over 200 different viruses have been implicated
can get secondary bacterial infection
Tx = symptomatic
Lower Respiratory Tract Infections
Obstructive Lung Diseases
Cystic Fibrosis
Also called mucoviscidosis
Etiol: genetic autosomal recessive
Gene on 7th chromosome
Dx: sweat test

Chronic Obstructive Pulmonary Disease (COPD)
Restrictive lung disorders
2 groups of diseases
1. Abnormalities of chest wall which limits lung expansion
Includes:
Kyphosis
Scoliosis
Polio
ALS
Muscular dystrophy
1. Disease affecting lung tissue that provides supporting framework
Includes:
Occupational diseases (pneumoconioses)
Idiopathic pulmonary fibrosis (autoimmune disease)
Pulmonary edema
Acute respiratory distress syndrome (ARDS)
Vascular disorders
Pulmonary Emboli
def = clot of foreign matter that occludes artery in pulmonary system
Size of embolus & general health of patient determine degree of damage and amount of symptoms
see next slide for pathophysiology
etiol
determined by composition of emboli
thrombus (most common) , air, fat, bacteria, tissue
risk increased by CHF, lung disease, stasis with varicosities
90% originate from deep veins (primarily in leg)
Old age large bone fractures give fat emboli
Sx
generally apprehension, cough, chest pain, fever
if severe ------ dyspnea, tachypnea, hemoptysis
if massive ----- shock & death
Dx = imaging, blood gases
Tx
maintain adequate ventilation via O2 & anticoagulants
? Thrombolytic drugs
Prevention via early ambulation, TED Stockings
Expansion disorders
Pneumothorax
def = collection of air or gas in pleural cavity resulting in collapse ( either partial or full) of lung
Etiol & types
Spontaneous pneumothorax
from blebs,
from too much pressure with ventilation,
from tumor
Open pneumothorax --- usually secondary to trauma
Tension pneumothorax
Both of the above may result in this serious typo
Sx = sudden pain & shock-like symptoms
Tx = thoracentesis with chest tube see next slides
RDS (Respiratory Distress Syndrome)
2 Types:
Infant RDS(also called: hyaline membrane disease)
leading cause of death in premies
etiol = not enough surfactant
First appears in early 3rd trimester & is adequate by 37 weeks
Amount determined by L/S ratio
lecithin-sphingomyelin
Done via amniocentesis
Treatment = synthetic surfactant (Exosurf Neonatal)