Primary Function of Respiratory System
gas exchange (in alveoli)
True or False
O2 from air is transferred into blood
True
CO2 is _____________ into atmosphere
eliminated
Respiratory System is divided into 2 parts:
conducting system
respiratory tissues
Conducting System
air passes between atmosphere & lungs
Respiratory Tissues
where gas exchange takes place
Respiration Requires:
ventilation
perfusion
diffusion
Ventilation
movement of gases into & out of lungs
Perfusion
movement of blood through the lungs
Diffusion
diffusion of gases between lungs & blood
True or False
Anatomy of respiratory tract is divided into upper & lower respiratory tract
true
Upper → organs outside thorax
nose
pharynx
larynx
Lower → organs with in thorax
trachea
bronchi
bronchioles
alveolar duct
alveoli
Physiology of Respiratory Tract
gas exchange!
internal, external, cellular respiration
Pneumonia
inflammation of parenchymal structures of the lung in the lower respiratory tract
6th leading cause of death in the U.S
Etiologic Agents of Pneumonia
infectious: S. Pneumonia, Pseudomonas, Staph (bacterial)
Non-Infectious: inhalation of irritating fumes, aspiration of gastric contents (inflammation response)
Classification of Pneumonia
according to setting: community or hospital acquired (Nosocomial)
ex: “I was in the hospital for appendectomy but I also got pneumonia from the pt next door”
according to type of agent causing the infection (typical or atypical)
according to distribution of infection (lobar, bronchopneumonia)
Inflammatory Process of Pneumonia
typical pneumonia → in alveoli
atypical pneumonia → in tissues that surround the alveoli
Who gets Pneumonia?
Immunocompromised Pt:
bone marrow/organ transplant
cancers
pts on corticosteroids
Acute Bacterial Pneumonia:
based on etiologic agent
pneumococcal
legionella
→ assess for loss of cough reflex, damage to ciliary endothelium, diabetes, chronic bronchitis, smoking
Bronchopneumonia
signifies a patchy consolidation involving more than one lobe
Labor Pneumonia
consolidation of a part or all of a lung lobe
Lung Cancer
disease of the lung tissue itself
leading cause of cancer death
True or False
Cigarette smoking cause 80% of cases of lung cancer
True
smokers can benefit at any age from smoking cessation (part of discharging a pt, to encourage a pt to not smoke anymore)
Risk for lung cancer is greater in people exposed to ________ (in old city buildings - tiles have it in ceiling)
asbestos
Tumors arise from ____________ lining of major bronchi
epithelial
Small lesions may form masses that invade ______ _______ or form large/bulky masses that extend into lung tissue
bronchial mucosa
Some masses undergo central ________ or may invade pleural cavity & chest wall
necrosis
Classify lung cancer by it being either ____ _______ or _________ lunch cancer
small cell or non-small cell
Both small cell and non-small cell can….
produce paraneoplastic syndromes
Squamous Cell Carcinoma
25-40% occurence
Adenocarcinoma
20-40% occurence
Small cell Carcinoma
20-25% occurence
Large Cell Carcinoma
10-15% occurence
Lung Cancer Symptoms
weight loss
anorexia
chronic cough
SOB
wheezing
hemoptysis
pain
Diagnosis of Lung Cancer
chest x-ray
history/physical
bronchoscopy
cytological studies
CT scan/MRI
PET (CAT Scan with contrast)
Hypoxemia
reduction in arterial blood O2 levels = PaO2 < 95mmHg (not enough O2)
Causes of Hypoxemia
inadequate O2
dysfunction of neurologic system
alterations in circulatory function
~if PO2 pf the tissues falls below a critical level, aerobic metabolism stops → anaerobic metabolism takes over → lactic acid is released
Symptoms of Hypoxemia
increased heart rate
diaphoresis (cold, clammy, sweaty)
mental status changes
restlessness
confusion
combative/agitated
stuper/coma
hyperventilation
cyanosis
Diagnosis of Hypoxemia
arterial blood gas (PaO2)
pulse ox (good idea if someone is hypoxemia
Hypercapnia
increase in CO2 of arterial blood (PaCO2=too much CO2)
Cause of Hypercapnia
pt not breathing enough
alterations in CO2 production
disturbance in gas exchange in lungs
abnormalities in function of chest wall & respiratory muscles
changes in neural control of respiration
Symptoms of Hypercapnia
respiratory acidosis (decreased pH, elevated CO2)
vasodilation of blood vessels
CNS depression
Diagnosis of Hypercapnia
arterial blood gas (PaCO2)
Obstructive Airway Disorder (asthma)
chronic disorder of airway
Causes of Asthma Episodes
episodic airway obstruction
bronchial hyperresponsiveness
airway inflammation
in some → airway remodeling (repeated inflammation)
Risk factor for development of Asthma
genetic disposition for development of IgE to common allergies
family history
antenatal exposure to tobacco smoke
Triggers for Asthma
tobacco smoke
dust mites
GERD
hormones
cold
emotions
excerise
Pathogenesis of Asthma
airway inflammation manifested by inflammatory cells (eosinophils, most cells) → damage to bronchial epithelium
mediators associated with asthma
cytokines: tumor necrosis, interlukins 1,4,5
histamine
leukotrienes
episodes are reversible either spontaneously or with tx
Symptoms of Asthma
airways narrow due to bronchospasm
edema of bronchial mucosa
FEV1 → decreased ( can’t get air out of alveoli)
accessory muscle use
increased work of breathing
ineffective cough
hypoxemia/hypercapnia
decreased breath sounds
wheezing
chest tightness
fatigue
diaphoresis
severe dyspnea
acute resp. failure (inaudible breath sounds, no wheezing)
Chronic Obstructive Pulmonary Disease (COPD)
characterized by chronic & recurrent obstruction of airflow
obstruction is progressive & accompanied by inflammatory responses
→ leading cause of death/hospitalization
Causes of COPD
smoking
antitrypsin (hereditary)
asthma
airway hyperresponsiveness
Pathogenesis of COPD
inflammation
fibrosis of bronchial wall
hypertrophy of submucosal glands
hypersecretion of mucus
loss of elastic lung fibers & alveolar tissue
destruction of alveolar tissue decreases surface area for gas exchange
loss of elastic fibers impair expiration → oncrease air trapping airway collapse
2 types of COPD
emphysema
bronchitis
Emphysema
destruction of area surface of the alveoli
enlargement of airspaces & destruction of lung tissue
→ loss of lung elasticity
→ abnormal enlargement of airspaces - air trapping
→ destruction of alveolar walls/capillary beds
→ breakdown of elastin by enzymes (protease)
Causes of Emphysema
smoking
antitrypsin deficiency
Symptoms of Emphysema
“pink puffer”
lack of cyanosis
use of accessory muscles
pursed lips breathing “puffer breathing”
airways collapse during expiration → airway trapping in alveoli & lungs = barrel chest
Chronic Bronchitis
destruction of major/small airways
increased mucus production
chronic productive cough (last for 3 months → 2 years)
hypersecretion of mucus in large airways
plugging of airway lumen, inflammation
increase in goblet cells
Causes of Chronic Bronchitis
cigarette smoking
dust/toxic gases
Symptoms of Chronic Bronchitis
“blue bloaters”
cyanosis
fluid retention with right sided heart failure (causes fluid to build up)