Respiratory System in a Breath
June 21, 2012Anna Spirkina, B.Sc.Pharm, ACPR
Objectives
By the end of this presentation the participants should be able to…
Name the different anatomical structures that make up the respiratory system
Describe the primary and secondary functions of the respiratory system
Identify the main causes, symptoms, and mechanisms of disease for COPD and Asthma
Anatomy
Respiratory System
Respiratory airways – tubes carrying air between the atmosphere and lungs
Lungs
Structures of the chest involved in producing air movement
Anatomy
http://www2.estrellamountain.edu/faculty/farabee/biobk/biobookrespsys.html
Anatomy
Nasal Passages
Pharynx
“Throat”
Tonsils – lymphoid tissue (part of immune system)
Passage for respiratory and digestive systems
Trachea and esophagus
Larynx
Cartilage structure connecting pharynx and trachea
Protects air passages
Contains vocal folds
Produce sound through vibration
Prevent air entry when fully closed
Anatomy
Trachea and Bronchi
Rigid, non-muscular tubes
Cartilage-like rings
Keep airways open
Subdivide into smaller bronchioles
Alveoli
Thin-walled, inflatable air sacs
Smallest working unitshttp://www.nlm.nih.gov/medlineplus/ency/imagepages/8675.htm
Anatomy
Lungs
Branched airways, alveoli, blood vessels, elastic connective tissue
Volume – mostly air, weight – mostly blood
No muscle to inflate/deflate during breathing
Done through dimension changes of the chest cavity
Diaphragm
Separates chest cavity from abdominal cavity
Main muscle involved in breathing
Downward movement=inhalation, upward movement=exhalation
Physiology
Respiration
Exchange of oxygen (O2 ) and carbon dioxide (CO2 ) between the external environment and the cells of the body
Four steps
Breathing – moving air in and out of lungs
Exchange of O2 and CO2 between air in the alveoli and blood in the lung blood vessels
Blood transport or O2 and CO2 between lungs and body
Exchange of O2 and CO2 between body tissues and blood
Respiratory System – first 2 steps
Physiology
Primary Function of Respiratory System
Brings O2 -rich air and O2 -poor blood into close proximity
Gas exchange by passive movement of O2 and CO2
Move from higher to lower concentrations
Carried to and from lungs by red blood cells
Contain haemoglobin
Easily reversible bond to O2 and CO2
http://www.goldiesroom.org/Note%20Packets/13%20Human%20Other/00%20Human%20Other%20Systems--WHOLE.htm
Physiology
Non-respiratory Functions of Respiratory System
Water loss and heat elimination
Acid-base balance maintenance
Speech, signing, vocalization
Defence against inhaled foreign material
Sense of smell
Removal, modification or activation of materials added to blood by body tissues
Common Disease States
Chronic Obstructive Pulmonary Disease (COPD)
Chronic bronchitis
Emphysema
Asthma
COPD
Chronic and recurrent obstruction of airflow
Progressive disease
Mostly preventable
Most common cause – smoking
Also chronic irritation by polluted air, allergens
Some people – genetic component
Lack of pronounced symptoms until advanced disease
Increasing mortality (deaths) over past three decades
Fourth leading cause of death – U.S.
Combination of asthma, COPD and sleep apnea – 4th
leading cause of death in Canada
COPD
Two types
Emphysema
destruction of walls between alveoli
Bronchitis
obstruction of small airways by mucus and changes in lining
Both types usually overlapping
Diagnostic tests
Spirometry – measures the amount of air entering and leaving lungs
http://www.nhlbi.nih.gov/health/health-topics/topics/copd/
COPD
Symptoms
Chronic cough
Sputum production
Difficulty breathing – shallow, more frequent breaths
Barrel chest, pursed lips during expiration
Symptoms of rapidly worsening COPD (x 48 hours)
Increase in sputum production; change in colour of sputum
Chest tightness
Increasing difficulty breathing
Decreased exercise tolerance
Fever
Requires timely medical attention
COPD
Treatment
No cure, only symptom management
Smoking cessation – the only strategy to slow progression of COPD
Treatment approaches depend on disease severity
COPD Severity Symptoms Treatment
Mild Shortness of breath when hurrying on the level or walking up a slight hill
Short-acting bronchodilators (eg.
Ventolin® ± Atrovent® )
Moderate Shortness of breath causing the patient to stop
walking after ~100m on the level
Short-acting bronchodilators (eg.
Ventolin®) + Long-acting bronchodilators (eg.
Serevent® or Spiriva®)
Severe and Very Severe Patient too breathless to leave the house,
breathless after dressing; heart failure due to COPD
Short-acting bronchodilators (eg.
Ventolin®) + Combination steroid/bronchodilator (eg. Advair® or Symbicort®) ±
Theophylline ± Oxygen
Asthma
Reversible episodic airway inflammation and obstruction
Triggered by variety of stimuli
Allergens
Cold air, exercise, drugs, air pollution, respiratory infections
Genetic component
Childhood asthma
The number of people diagnosed with asthma have been increasing over several decades
Over 2 million Canadians reported history of asthma in 2010
No proportional increase in mortality (deaths) or hospitalizations over the past years
Asthma
Pathogenesis (how it happens)
Thickening of airway walls due to inflammation
Excessive secretion of thick mucus
Constriction of the smaller airways
Diagnostic tests
Spirometry - measures the amount of air entering and leaving lungs
http://www.asthmacuretoday.com/wp-includes/images/522asthma.jpg
Asthma
Symptoms
Episodes of dry hacking coughing, chest tightness, wheezing, whistling sound when breathing
Often associated with exercise or known allergens, but may be spontaneous
Severe asthma attack
Progresses over days or hours
Severe presentation of the usual symptoms
Can only speak few words at a time
Non-responsive to rescue inhaler
Pale or ash-coloured skin
Increased heart rate
Requires immediate medical attention
Asthma
Treatment
Varies depending on how well symptoms are controlled
Asthma education
Action plans
Characteristic Frequency or Value
Daytime symptoms <4 days/week
Night-time symptoms
<1 night/week
Physical activity Normal
Asthma attacks Mild, infrequent
Absence from school or work
None
Need for rescue inhaler
<4 doses/week
Asthma
Dispensing Medications for Asthma and COPDClass of Medication Examples Mechanism of
ActionThings to Remember
Short-acting Bronchodilators
Ventolin®Bricanyl®
Relax muscle lining of bronchi quickly but short term
Ventolin® - Shake inhaler before use
Long-acting Bronchodilators
Serevent®Oxeze®
Relax muscle lining of bronchi long term
Inhaled steroids Flovent®Pulmicort®
Decrease inflammatory response
Rinse mouth after use to prevent thrush
Combination products Symbicort®Advair®
Relax bronchi, decrease inflammation
Rinse mouth after use to prevent thrush
Anticholinergics Atrovent®Spiriva®
Inhibit chemical receptors responsible for bronchocostriction and mucus production
Spiriva® - capsules not for oral ingestion; expire 5 days after foil openedAtrovent® - Shake inhaler before use
Summary
Respiratory system consists of respiratory airways, lungs, and structures of the chest cavity that are involved in air movement
The primary function of the respiratory system is to facilitate gas exchange between oxygen-rich atmosphere and oxygen-poor blood
Asthma and COPD are two of the common disease states of the respiratory system
References
“Asthma, by age group and sex”. Summary Tables. 11 June 2011. Statistics Canada. 18 December 2011. http://www40.statcan.gc.ca/l01/cst01/health49a-eng.htm
“Centre for Chronic Disease Prevention and Control”. Chronic Disease. 25 October 2011. Public Health Agency of Canada. 18 December 201. http://www.phac-aspc.gc.ca/ccdpc- cpcmc/index-eng.php
Kelly, William., Sorkness, Christine. “Asthma” Pharmacotherapy: A Pathophysiologic Approach. 7th Ed. Ed.Joseph Dipiro et al. China: The McGraw-Hill Companies, Inc., 2008. 463-95. Print.
Moore, Keith L., Agur, Anne M.R. “Thorax” Essential Clinical Anatomy. 3rd Ed. Baltimore, MD:Lippincott Williams and Wilkins, 2007. 70-80. Print.
Moore, Keith L., Agur, Anne M.R. “Neck” Essential Clinical Anatomy. 3rd Ed. Baltimore, MD:Lippincott Williams and Wilkins, 2007. 611-20. Print.
Porth, Carol. “Disorders of Ventilation and Gas Exchange” Essentials of Pathophysiology: Concepts of Altered Health States. 2nd Ed. Philadelphia, PA: Lippincott Williams & Wilkins, 2007. 491-505. Print.
Sherwood, Lauralee. “The Respiratory System” Human Physiology: From Cells to Systems. 6th Ed. Ed. Peter Adams. Belmont,CA: Thomson Brooks/Cole, 2007. 451-99. Print.
Williams, Dennis., Bourdet, Sharya. “Chronic Obstructive Pulmonary Disease” Pharmacotherapy: A Pathophysiologic Approach. 7th Ed. Ed.Joseph Dipiro et al. China: The McGraw-Hill Companies, Inc., 2008. 495-518. Print.