RESPIRATORY PHYSIOLOGYThis unit discusses the respiratory system's function in the allowment of gas exchange throughout different areas of the body. STRUCTURE OF THE RESPIRATORY SYSTEMAir moves through the body as follows:Enters through the nostrils->trachea->left & right bronchi->bronchioles->cluster of trminal bronchioles->alveoli


The air passages of the respiratory system are divided into two functional zones:Respiratory Zone is the region whre gas exchange occurs and includes the bronchioles and the terminal alveolar sacs.Conductioning Zone includes all the anatomical structures (nose, mouth, trachea, pharynx, bronchi) through which air passes before reaching the respiratory zone. The thoracic cavity includes the diaphragm, which is a dome-shaped sheet of muscle which seperates the abdominal and thoracic cavities. The thoracic cavity includes the lungs, heart, trachea, large blood vessels, esophagus and thymus.

This is a 3D Animation of how air moves through the body. Pretty cool!
THE REGULATION OF BREATHINGInspiration and expiration is produced by the contraction and relaxation of sketelal muscles responding to activity from somantic motor neurons located in the spinal cord. These motor neurons are controlled from neurons in the respiratory control centers of the medulla oblongata and also from neurons located in the cerebral cortex. The rhythmicitiy center in the medulla oblongate controls our automatic breathing. Chemoreceptors also influence automatic breathing control. These receptors are sensitive to change sin the pH of brain interstitial fluid,cerebrospinal fluid and the Pco2, pH and Po2 of blood. The two different types are named central and peripheral chemoreceptors. The central chemoreceptors are located in the medulla oblongata and the peripheral are located in the aorta and carotid arteries. PULMONARY FUNCTION TESTSPulmonary function tests are a group of tests that measure how well an individual is able to take in and release air and how well they can circulation air and other gases throughout their body.The most common technique used is called spirometry. In this test, the individual breathes through a mouthpiece into a closed system where air is trapped within a light plastic bell floating in water. The bell moves up upon exhaling and down when the individual inhales. For some of the test, the individual can breath quiet and normally. Some of the areas forced inhalation or exhalation after a deep breath. Lung volumes are th four nonovrlapping components of total lung capacity. Tidal volume (tv) is the volume of gas inspired or expired in an unforced respiratory cycle.Inspiratory reserve volume (irv) is the max volume of gas that can be inspired during forced breathing plus tidal volume. Expiratory reserve volume (erv) is the max volume of gas that gets expired during forced breathing plus tidal volume.Residual volume (rv) is the volume of gas that remains in the lungs after a maximum expiration. Lung capacities are measurements that are the sum of two or more lung capacities.Total lung capacity is the total amount of gas in the lungs after a maximum inspiration.Vital capacity is the max amount of gas that can expired after a max inspiration.Inspiratory capacity is the max amount of gas that can b inspired after a normal tidal expiration.Functional residual capacity is the amount of gas rmaining in th lungs after a normal tidal expiration. APPLICATIONAs a nurse, I often deal with respiratory issues and pulmonary disorders. Upon seeing a client, I prioritize using the ABC's. (airway, breathing and circulation). If the patient doesn't have a patent airway or has impaired gas exchange, those are the priority interventions we as nurses need to do take care of (or prevent) before moving further. I often deal with disorders such as ashma, COPD and emphysema. It's important for me to know at a deeper level how the respiratory system works and the abnormalities that cause these disease processes. CASE STUDY: "INTO THIN AIR"1. What types of physiological problems do humans encounter at high altitudes?Shortness of breath, coughing, mild fever, headaches, and nausea. 2. What symptoms did the climbers exhibit that might be related to altitude? Signs and symptoms include shortness of breath, coughing and fatigue. These could be caused by pulmonary edema, common at altitudes 9,000 ft and greater (The climbers are at 17,660 ft). 3.Compare the air at 18,000 feet (atmospheric pressure 280 mm Hg) to the air at sea level(760 mm Hg). What specific changes in the primary atmospheric gases (nitrogen, oxygen, carbon dioxide) might occur? Are they significant? Oxygen, nitrogen and carbon dioxide levels all go down the higher up into the air you go. This makes proper air circulation and perfusion a lot harder in high elevation.
4. What is the specific pulmonary response to high altitude? [Assume you are considering a subject at rest.] Acute exposure to high altitudes will cause an increase in heart rate, blood pressure and ventilation. (

5. How will this response affect overall blood gases? What about oxygen loading and unloading from hemoglobin? Explain how you arrived at your conclusions. These changes result in increased oxygen transport to the tissue, increased alveolar PO2 with a decrease in carbon dioxide (CO2) and hydrogen ions (H+), increased vascular resistance, and decreased work capacity.