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Objectives:
  • Define at least 10 terms referring to the respiratory system.
  • Describe the three functions of the respiratory sstem.
  • Identify at least 10 respiratory system structures and the function of each.
  • Describe at least five disorders of the respiratory system.
  • Describe at least three methods of assessment of the respiratory system.

Intro to HSTE Terms:
Apnea - Cessation of breathing.
Bradypnea - Abnormally slow rate of breathing.
Chronic - Persisting over a long period of time.
Cilia - Hairlike projections fro the surface of a cell.
Dysphagia - Difficulty swallowing.
Dyspnea - Difficult or labored breathing.
Eupnea - Easy or normal breathing.
Expiration - Act of breathing out, exhalation.
Inspiration - Act of drawing air into the lung, inhalation.
Mediastinum - Thoracic space between the two lungs.
Phlegm - Thick mucus secreted by the tissues in the respiratory passages and usually discharged through the mouth,
Pulmonary - Pertaining to the lungs.
Respiration - Exchange of oxygen and carbon dioxide between the atmosphere and the cells of the body, also calld ventilation.
Tachypnea - excessively fast respiration.


Structure and Function of the Respiratory System

  • The Respiratory system brings oxygen into the body through the breathing process.
    • With inspiration (inhaling air) oxygen is brought into the lungs.
    • With expiration (exhailing air) carbon dioxide is removed from the lungs.

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The respiratory system functions in three ways:
  1. It exchanges gases between the blood and the lungs.
  2. It helps regulate body temperature by cooling or warming the blood.
  3. It helps maintain the blood's electrolyte balance.

There are three processes of respiration:
  1. External respiration (ventilation) brings oxygen into the lungs.
  2. Internal respiration exchanges oxygen and carbon dioxide between blood and body cells.
  3. Cellular respiration changes acid produced during metabolism into harmless chemicals in the cells.

Both voluntary and in voluntary nervous systems control respiration. How fast (rate) and how deep (depth)
the breaths are, is regulated chemically. If the concentration of gases in the blood changes, the brain adjusts
respiratory rate and depth to counteract the changes to maintain homeostasis.

Air enters the respiratory system through the nose. The nasal cavity is lined with hairs called cilia to help
filter out any foreign particles. It also helps to warm and moisten the air. Air also enters through the mouth,
when the nasal cavity is blocked. The tonsils and adenoids at the back of the throat help the body resist
infection.


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The sinuses are hollow spaces in the bones of the skull that open into the nasal cavity. Sinuses help regulate
the temperature of air before it reaches the sensitive lungs. They also humidify and filter the air. The spaces
act as chambers for vibration of the air producing "vocal resonance" or the sound quality of the voice.
The air from the nose or mouth is funneled through the throat (pharynx) and into the windpie (trachea). The throat
is divided into three portions, the nasopharynx (nose), oropharynx (mouth), and laryngopharynx (larynx). The Trachea
is lined with rigid cartilage to keep the passageway open. Sometimes an opening is made into the trachea as an
alternative method for the exchange of gases (tracheotomy).


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The voice box (larynx) is located below the pharynx. Voice sounds are made when air moves through it. A flap of tissue
called the epiglottis covers the voice box or larynx during swallowing to prevent food and liquid from entering the bronchi
and lungs. The pharynx also contains the opening for tubes through which air reaches the middle ear to adjust for pressure
changes (eustachian tubes).

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The trachea branches into two tubes called bronchi. Each bronchus enters one of the lungs and then branches into smaller
tubes called bronchioles. The bronchi and bronchioles are lined with tiny hairs called cilia and sticky mucus called phlegm to
catch dust and germs. The respiratory system produces approximately 125 mL of mucus each day that is removed by the
movement of the cilia. The bronchioles have small sacs at their ends called alveoli. Capillaries in the walls of the alveoli exhange
oxygen and carbon dioxide by the process of diffusion. Each alveolus is lined with a liquid called surfactant through which the
diffusion occurs.The large number of alveoli, nerves, lymph tissues, and capillaries give the lungs a spongelike texture. The lungs are divided into sections called lobes. The space separating the lungs (mediastinum) contains the esophagus, heart, and bronchi.

Each lung is surrounded by a double membrane called pleura. The pleurae separate and lubricate the delicate lung tissues. They
are slippery, allowing a gliding motion of the lungs during respiration. The ribs support and protect the chest cavity (thorax). During
breathing, muscles lift and seperate the ribs to help the lungs expand. The diaphragm is a large flat muscle that separates the thoracic cavity from the abdominal cavity. The diaphragm contracts and moves downward during inhalation. This creates suction, and air is pulled
in from outside the body. Exhalation occurs when the diaphragm relaxes.

Rate:
The normal rate of respiraton varies with age, gender, posture, exercise, temperature, and other factors. Children breathe more than 20 times a minute, adults breathe 16 to 20 times, and the elderly often breathe less than 16 times. Normal respiration is called eupnea. Painful or difficult respiration is dyspnea. Tachypnea is abnormal respiratory rate greater than 24, and bradypnea is less than 10.

Character:
Respirations should have a regular rhythm, occurring at regular intervals. Irregular rhythms of respirations may occur in different patterns, such as a rapid series followed by a pause or by no respiration, called apnea. Respirations may also be dry, which is normal, or wet. They can also be characterized as deep or shallow.

Sounds:
Breath sounds can be heard by using a stethoscope. The quality of the sound varies with the location of the stethoscope over the bronchial tree but should all be dry and clear. Wheezing or other abnormal or misplaced (adventitious) sounds in the upper respiratory tract may indicate an abnormal condition.

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Lung Volume:
The amount of air that can be brought into the lungs is called respiratory capacity. It is measured with a spirometer. Lung capacity depends on age and physical condition. The measurement of respiratory capacity is called lung volume. The vital capacity includes the tidal volume, inspiratory reserve, and expiratory reserve. The tidal volume is the amount of air normally exchanged with each cycle of inspiration and expiration. Inspiratory reserve is an additional amount of air that can be inhaled with conscious effort. The sum of these three values is called the vital capacity. This is the total amount of air that can be exchanged by that person. A certian amount of air is always in the lungs to maintain their shape. This is called the residual volume.

Blood Gases:
Blood gas studies measure the amount of gases such as oxygen (O2) and carbon dioxide (CO2) are in the blood and the blood's pH. These tests provide an accurate assessment of respiratory fuction.

Disorders of the Respiratory System:

Antrax
(AN-thraks) is caused by spores of the bacteria bacillus anthracis. The spores may be present in the soil for years and occasionally infect grazing animals. In humans, anthrax may appear as an infection of the skin, digestive system, or respiratory system. Inhalation anthrax has a death rate of more than 80%. In 2001 anthrax spores were sent through the U.S. postal system as a type of biological terrorism, which resulted in the death of five people. A vaccine for anthrax has been developed. After exposure, treatment with antibiotics may prevent infection.

Asthma (AZ-muh) affects 26 million people, 5 million of whom are 17 years of younger. The conventional belief is that asthma is an allergic reaction. However, recent studies indicate that cells in the airway may trigger the attack, not the immune system. It is known that asthma attacks may result from exposure to an allergen, cold temperature, exercise, or emotion. The bronchi narrow and contract in spasms, and the person may experience wheezing and difficulty exhaling. Treatment includes relaxation and medication to clear air passages. If the cause is determined to be the airway cells, treatment includes relaxation and medication to clear passages. If the cause is determined to be the airway cells, treatment might include inhalation of genes that stop the reaction. There is no known cure for asthma, but half of all children outgrow the condition by their teens.

Atelectasis (at-uh-LEK-tus-sis) is collapse of part or all of a lung, caused by a tumor in the thoracic cavity, pneumonia, or injury. The person feels sevre pain and shorness of breath, or dyspnea. Treatment corrects the cause and reexpands the lung with pulmonary suction.

Bronchitis (bron-KIE-tis) is an infection of the bronchi. Inflammation causes the bronchial walls to thicken, and less air can be echanged. Bronchitis often results in a heavy cough and much mucus eliminated as sputum. Treatment may include the use of expectorant medications and postural drainage.

Carbon monoxide poisoning occurs from breathing carbon monoxide, usually from automobile exhaust fumes. Breathing too much carbon monoxide can be life treatening because the body cells are deprived of oxygen. Carbon monoxide poisoning first causes nausea and drowsiness. Ther person should be removed from the area of the gas, and oxygen should be administered.

Chronic obstructive pulmonary disease (COPD) is a group of chronic respiratory disorders including asthma, chronic bronchitis, and pulmonary emphysema. These conditions have similar symptoms and treatments. The symptoms include shourness of breath (dyspnea) and tissue overgrowth called hyperplasia (hi-per-PLAY-zhee-uh). Treatments includes giving oxygen, an antidiuretic (an-tie-die-uh-RET-ik), a medication used to increase the amount of fluids excreted by the body, and a bronchodilator (brong-ko-die-LAY-ter), a medication used to dilate the bronchi and bronchioles for easier breathing.

A Cold is a respiratory infection, caused by 1 of more than 200 viruses. It lasts from 1 to 2 weeks. It may cause a sore throat, sneezing, aches, pains, a runny nose, and fever. Cold medications may relieve the symptoms, but there is no cure.

Cystic fibrosis (SIS-tik-fie-BRO-sis) is a genetic disorder of the exocrine (EK-so-krin) glands, usually diagnosed before the age of 6 months.The mucus in the respiratory system becomes thicker (more viscous), and excess salt appears on the skin. The condition requires intensive pulmonary care to prevent chronic disorders.

Emphysema (em-fuh-SEE-ma) results when the alveoli lose elasticity, usually after 50 years of age. The alveoli become dilated and do not exchange gases well. Emphysema can result from smoking or several disorders of the respiratory system. Treatment includes use of "pursed lip breathing," the very slow exhalation of air to allow alveoli to respond.

Hanta virus is a respiratory condition spread by breathing in materials contaminated by urine or saliva of infected rodents such as deer mice and chipmunks. The symptoms appear like influenza including fever, cough, a muscle ache, and enflamed, reddened eyes. This virus has a rapid onset and is often fatal. Treatments is supportive to assist the infected person with respiratory function.
Medical Termonology Respiratory System Vocabulary