NURS 3180 Review Guide Exam 3
Chapter 18 Thorax and Lungs
1. Know the anatomical landmarks of the thorax and lungs
• The right lung has three lobes (RUL, RML, RLL). It is shorter than the left long b
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NURS 3180 Review Guide Exam 3
Chapter 18 Thorax and Lungs
1. Know the anatomical landmarks of the thorax and lungs
• The right lung has three lobes (RUL, RML, RLL). It is shorter than the left long because of the
underlying liver.
• Left lung has two lobes (LUL, LLL). It is narrower than the right lung because the heart bulges the left.
2. Mechanisms of respiration
• Four major functions of the respiratory system
o Supplying oxygen to the body for energy production
o Removing carbon dioxide as a waster product of energy reactions
o Maintaining homeostasis (acid-base balance) of arterial blood
o Maintaining heat exchange (less important in humans)
• Lungs help maintain the pH balance by adjusting the level of carbon dioxide through respiration.
• Hypoventilation (slow, shallow breathing) causes carbon dioxide to build up in the blood.
• Hyperventilation (rapid, deep breathing) causes carbon dioxide to be blown off.
• The normal stimulus to breathe is an increase of carbon dioxide in the blood, or hypercapnia.
• A decrease of oxygen in the blood (hypoxemia) also increases respirations but is less effective than hypercapnia.
• The purpose of breathing is to maintain an adequate oxygen level in the blood to support cellular
life
• Respiration is the physical act of breathing; air rushes into the lungs as the chest size increase (inspiration) and is expelled from the lungs as the chest recoils (expiration)
• Diaphragm is the major muscle responsible for the increase in thoracic size. During inspiration
(negative pressure) contraction of the bell-shaped diaphragm cause it to descend and flatten.
• Expiration (positive pressure) is primarily passive.
3. Terms:
• Hemoptysis: blood in sputum
• Dyspnea: shortness of breath
• Orthopnea: shortness of breath when lying down
• Paroxysmal nocturnal dyspnea (PND): sudden awakening from sleeping, with shortness of breath
• Fremitus: a palpable vibration from the spoken voice felt over the chest wall
• Crepitus: coarse, crackling sensation palpable over the skin when air abnormally escapes from the lung and enters the subcutaneous tissue
• Hyperresonance: a lower-pitched, booming sound found when too much air is present such as in emphysema or pneumothorax.
• Bronchial (tracheal): high-pitched, normal breath sounds over trachea and larynx.
• Bronchovesicular: the normal breath sound heard over major bronchi, characterized by moderate pitch and an equal duration of inspiration and expiration
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