Definition: Mucus is a thick liquid produced by mucous glands and goblet cells. It prevents lung damage by keeping breathing passages moist. The function of mucus is to trap foreign particles so that they may be carried up the respiratory tract and expelled.
Source: Living with Lung Cancer by Cox, Carr, and Lee
Pronunciation: mew’ kus
Examples: In chronic bronchitis, mucus is overproduced, causing obstruction to the airways.
Definition: The medulla is one of the main structures of the hindbrain. The medulla is the enlarged tip of the spinal cord. Nerve impulses from the medulla stimulate the intercostal muscles and diaphragm. The medulla also regulates the heartbeat and adjusts the blood flow by regulating the diameter of the arterioles.
Also Known As: medulla oblongata
Definition: The mediastinum is the area between the lungs where the following structures are located:
# Heart and its vessels
# Trachea
# Esophagus
# Thymus
# Lymph nodes
Source: University of Maryland Medical Center
Definition: A cancerous mass of cells that have formed due to excessive cell division. Malignant tumor cells are abnormal and divide uncontrollably and without order.
Patients diagnosed with lung cancer have malignant tumors in their lungs. However, malignant tumors can be found anywhere within the body.
The opposite of a malignant, or cancerous, tumor is a non-cancerous, or benign tumor.
Also Known As: Cancer
Definition: The lungs are part of the respiratory system. The lungs are large, conical-shaped, lobed organs located in the chest behind the ribcage. The lungs are composed of a spongy, porous, elastic tissue. The right lung has three lobes, while the left lung only has two. Each lung is between 10 to 12 inches long, and are separated by the mediastinum.
The lungs are where respiration takes place. The alveoli, located within the lungs, exchange oxygen with the blood for carbon dioxide. The diaphragm and intercostal muscles, which surround the lungs, contract and relax to draw in and expel air from the lungs.
The lungs are lined with pleura, which produces surfactant to facilitate smooth movement of the lungs within the chest cavity.
The lungs have three important roles:
# Supply oxygen to the blood
# Remove wastes and toxins from the body
# Defend against hostile intruders
There are three dozen distinct cells types within the lungs, all with different responsibilities.
Lung diffusion testing is used to determine how well oxygen passes from the air sacs of the lungs into the blood.
Alternative Names:
Diffusing capacity; Diffusion capacity; DLCO test
How the test is performed:
You inhale a single breath from a volume of gas containing a known small quantity of carbon monoxide, hold your breath for 10 seconds, then rapidly exhale. The exhaled gas is then analyzed to determine the amount of carbon monoxide that was absorbed during the breath.
How to prepare for the test:
Do not eat a heavy meal before the test. Do not smoke for at least 4 to 6 hours prior to the test. Specific instructions will be given if bronchodilators or inhaler medications should not be used before the test.
For infants and children:
The preparation you can provide for this test depends on your child’s age and experience. For specific information regarding how you can prepare your child, see the following topics:
* infant test or procedure preparation (birth to 1 year)
* toddler test or procedure preparation (1 to 3 years)
* preschooler test or procedure preparation (3 to 6 years)
* schoolage test or procedure preparation (6 to 12 years)
* adolescent test or procedure preparation (12 to 18 years)
How the test will feel:
There is a tight fitting mouth piece to breathe through, and nose clips are applied.
Why the test is performed:
The test is performed to determine the presence and extent of certain lung diseases that affect how well gases cross from the air sacs into the bloodstream.
The layrnx is more commonly known as the voice box or glottis. The larynx extends from the pharynx to the trachea. The larynx is divided into three sections:
# Sublarynx
# Larynx
# Supralarynx
The larynx plays an important role in speech. During speech, the vocal cords close and vibrate as air is passed through the larynx. The epiglottis serves to keep food and liquid from entering the larynx
The intercostal muscles are located between the ribs. There are two kinds of intercotal muscles: internal and external. The intercostal muscles are controlled by the medulla.
The internal intercostal muscles are located on the inside of the ribs and extend from the front of the ribs, around back and past the bend in the ribs.
The external intercostal muscles are located on the outside of the ribs, and wraparound the back of the ribs.
Hypoxia / hypoxemia is a condition in which there is an inadequate supply of oxygen in the blood. Hypoxia is caused by:
# A reduction in partial pressure of oxygen
# Inadequate oxygen transport
# The inability of the tissues to use oxygen
1)Hypoxic Hypoxia
Hypoxic Hypoxia is a reduction of oxygen entering the blood. This condition occurs when:
# There is a reduction in oxygen pressure in the lungs
# Reduced gas exchange area
# Lung disease
2) Hypemic Hypoxia
Hypemic hypoxia is a reduction in the capacity of the blood to carry oxygen. This condition is caused by:
# A reduction of hemoglobin in the blood
This may be caused by blood donation, hemorrhage, or anemia.
# A reduction in the number of red blood cells
This may be caused by drugs, chemicals, smoking, or carbon monoxide exposure.
3) Stagnant hypoxia is a deficiency in oxygen due to poor blood circulation.
This condition occurs when a person sits or hangs, or is exposed to cold temperatures for prolonged periods of time.
4) Histotoxic Hypoxia
Histotoxic hypoxia is an inability of the tissues to use oxygen. This condition occurs during carbon monoxide or cyanide poisoning, or from the use of certain narcotics, chewing tobacco, and alcohol
