Question

Ventilation VS Perfusion

(A) Present a brief discussion of how asthma is diagnosed

(B) Present a brief discussion of the difference between bronchitis and pneumonia

(C) Present a brief discussion of the mechanisms of ventilation versus perfusion

(D) Present a brief discussion of the role of the thoracic cage and associated musculature in breathing

Answer 1

A. Asthma Diagnosis:

Chronic inflammatory disease of air ways is called Asthma. It is associated with mucus edema,hyper responsiveness of air way,mucus production.

To diagnose a patient we need to know some criteria about asthma. There will be night time awakening due to asthma because of breathlessness,cough, tight chest,wheezing,airway obstruction also at some times.

After checking the symptoms,we need to check for blood test. Which shows increased count of eosinophils. Asthma is usually associated with mast cells,T lymphocytes, eosinophils. Eosinophils are type of white blood cells associated with allergic disease. Mast cells which are alergy causing cells release histamine which is a chemical causes nasal stiffness,constriction of air ways in asthma. T lymphocytes are associated with allergy and inflammation. These cells along with other inflammatory cells cause airway inflammation in asthma along with airway inflammation which causes airway hyperresponsiveness,airflow limitation, respiratory symptoms and chronic disease. Sometimes this inflammation causes tightness of chest, breathlessness which occurs mostly at might or early morning hours.

During acute episodes, as already mentioned blood and sputum shows eosinophilia, IG E levels will be elevated if there is any energy,pulse oximetry and blood gas analysis shows hypoxemia.

B. Bronchitis and pneumonia.

Bronchitis is inflammation of bronchioles and tracheal pathway which causes difficulty in breathing, Pneumonia oocure as inflammatory response of within alveoli of the lung.

Bronchitis is caused by smoking or immunity weakness.Pneumonia is caused by viruses, bacteria,fungi or parasites.

Symptoms of bronchitis include chest pain, fever,ankle edema,cyanosis and crackling sounds can be heard,shortness of breath,sputum production. Symptoms of pneumonia include cough,fever, tiredness, nausea, breathing difficulty, chest pain.

There is only symptomatic treatment for bronchitis whereas related antibiotics can be given for Pneumonia depending on which tyoe of pneumonia it is.

C.VENTILATION vs PERFUSION:

Ventilation means the total airflow into alveoli and out of the alveoli. Perfusion is the amount of blood flow through the alveolar capillaries.

In our body through the respiratory system,ratio of ventilation and perfusion is maintained and adjusted. When air in form of oxygen goes into alveoli then through the process of Perfusion oxygen goes into blood and at same time carbon dioxide comes out from blood to Lungs which we exhale.

Ventilation is calculated by multiplying tidal volume and respiratory rate.

Count of total volume of blood reaching the capillaries in a given time.

D. THORACIC CAGE AND MUSCULATURE IN BREATHING.

Main function of thoracic cage is to support and protect heart and lungs.

Thoracic cage consists of 12 pairs of ribs,sternum,costal cartilage and thoracic vertebrae.

Thoracic cavity has slightly negative pressure which helps in keeping airways of lungs open. During inhalation lung volume increases due to contraction of diaphragm and intercostal muscles this expanding the thoracic cavity.

Intercostal muscles are muscle group between ribs which enable movement of chest wall. These muscles accompany in mechanical aspect of respiration and assist in pressure changes in respiration. Diaphragm is the muscle which separates thoracic cavity from abdominal cavity. Contraction of diaphragm expands lungs and pass air into lungs. During relaxation of diaphragm lungs contract releasing air out of the lungs. Scalenes are the accessory muscles of expiration which are muscles of first and second ribs which extend upto the lateral neck and are innervated by cervical spinal nerves.external intercostal muscles help in contraction during inspiration. During expiration anterior abdominal wall muscles help in contraction. Internal intercostal muscles also help in expiration. Adductor muscles of vocal cord act as accessory muscles during expiration.