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.