DISORDERS OF THE RESPIRATORY SYSTEM

Effects of SmokingKnown to cause:

CancerCOPDAsthma

Effects of Smoking

3 Problematic Substances: Nicotine – addictive, stimulates

reward pathway in the brainCarbon Monoxide – hemoglobin

has a greater tendency to bind to carbon monoxide than oxygen (200 times stronger bond)

Tar – accumulates in the alveoli = prevents gas exchange

AsthmaA chronic respiratory dieses characterized by inflammation and swelling of the bronchi and bronchioles that obstructs airflow

Asthma

Inflammation is a protective reaction designed to eliminate some foreign substances or infection

Swelling – more blood to the areaProduction of mucusMuscles around the bronchi and bronchioles contractALL this = reduced air flow

Although the causes of asthma are not known, the condition is often associated with allergies. An allergic reaction initiates the swelling of the tissues and the tissues which line the walls of the bronchioles swell.

Also, an allergic reaction causes spasms of the muscles lining the bronchiole walls.

                                                                                                    

Asthma

Medication for AsthmaOpen up or dilate the bronchi and

bronchioles to allow greater airflowPuffers: Corticosteroids suppress

the multiple inflammatory genes that are activated

Chronic Obstructive Pulmonary Disease (COPD)

~90% of COPD caused by smoking a chronic, progressive disease that

involves both:1. Obstructive Bronchitis

inflammation and mucus (similar to asthma)

2. Emphysema Causes permanent damage to the alveoli,

they loose elasticity and shape = decrease surface area for gas exchange

NO CURE – Damage to alveoli is permanent

BronchitisBacterial or viral infections as well as reactions to

environmental chemicals can cause a variety of ailments characterized by a narrowing of air passages.

It is characterized by an inflammation of the mucous lining of the bronchial tubes.

The excess production of mucus leads to inflammation and tissue swelling, a narrowing of the air passages, and decreased air movement through the bronchi.

The condition becomes more serious in the bronchioles which are not supported by rings of cartilage that help keep them open.

Two conditions, bronchial asthma and emphysema, are associated with inflammation of the bronchioles.

In both conditions, greater effort is required to exhale than to inhale.

This occurs because lower pressure is produced in the lungs and bronchioles during inspiration.

Bronchitis

During expiration, increased pressure in the chest cavity compresses the lungs and the bronchioles, decreasing the diameter of the bronchioles and increasing resistance to airflow.

The imbalance between the amount of air entering the lungs and the amount of air leaving the lungs must be met by increasing the exertion of expiration

Bronchitis

EmphysemaEmphysema is

associated with long-term bronchitis. It involves an increased resistance to airflow through the bronchioles.

Although air flows into the alveoli fairly easily, the decreased diameter of the bronchioles creates resistance to the movement of air out of the lungs.

Air pressure builds up in the lungs (emphysema means “over inflated”).

Unable to support the building pressure, the thin walls of the alveoli stretch and eventually rupture.

The fact that there are fewer alveoli means there is less surface area for gas exchange which leads to decreased oxygen levels.

In the body’s attempt to maintain homeostasis, the breathing rate increases and exhalation becomes more laboured .

The circulatory system adjusts by increasing the heart rate.

Emphysema

Another problem is that adjoining pulmonary capillaries and alveoli are both destroyed. Although blood clotting prevents any major internal hemorrhaging, the tissue of the lungs is replaced by scar tissue, the lungs are less able to expand, and therefore they hold less air.

Inhaled steroids. Corticosteroid drugs inhaled as aerosol sprays may relieve symptoms of emphysema associated with asthma and bronchitis. Although inhaled steroids have fewer side effects than oral steroids do, prolonged use can weaken your bones and increase your risk of high blood pressure, cataracts and diabetes.

Protein therapyAntibioticsTransplant

Emphysema

Treatment

Bronchiodilators: These drugs can help relieve coughing, shortness of breath and trouble breathing by opening constricted airways, but they're not as effective in treating emphysema as they are in treating asthma.

Emphysema

Lung Cancer

More Canadian men and women die from lung cancer than from any other form of cancer.

There is uncontrolled growth of cells and the solid mass of cancer cells in the lungs greatly decreases the surface area for diffusion.

Tumours may actually block bronchioles, reducing airflow to the lungs and potentially causing the lungs to collapse.

Treatment

SurgeryRadiation therapyChemotherapyPrevention: no smoking, avoid second-hand

smoke, avoid carcinogens

Cystic FibrosisNormally, mucus is watery. It

keeps the linings of certain organs moist and prevents them from drying out or getting infected. But in CF, an abnormal gene causes mucus to become thick and sticky.

The mucus builds up in your lungs and blocks the airways. This makes it easy for bacteria to grow and leads to repeated serious lung infections. Over time, these infections can cause serious damage to your lungs.

Causes of CF

Mutation on Chromosome 7, deletion of 3 amino acids

Causes abnormal membrane protein to develop which does not allow the passage of chloride ions across the membrane

TreatmentPatient specific depending on

age and severity of disorderpercussion and postural

drainage, to help loosen the mucus to unclog the lungs

pancreatic enzymes, taken with all meals, to aid digestion

nutritional supplements and vitamins to promote good nutritional status

inhalation of aerosol medications, to alleviate congestion and prevent and treat lung infection

exercise