9.1 Disorders of the Respiratory Function pt. 1 Flashcards
What is Pleuritis or pleurisy?
inflammation of the parietal pleura
Caused by viral infections, cancer, lung infections, and surgery.
What is a pleural effusion? How does fluid normally enter and exit the pleural cavity?
abnormal collection of fluid in the pleural cavity. Normally fluid enters via capillaries in parietal pleural and exits via lymphatics.
What does pleural effusion cause
compromises ones ability to expand their lungs-> shortness of breath
Describe transudate (hydrothorax) and recall what can cause this
changes forces involved in capillary exchange. Moves fluid out of capillary and into interstitial space. Caused by heart failure, malignancy, kidney failure or liver failure.
Describe exudate and what can cause this. How do we test for exudate?
found most often with pathological process that has caused inflammation. Unhealthy tissue dies and releases contents (LDH) (intracellular). A thoracentesis tests the pleural effusion for LDH and other proteins.
Describe a hemothorax and what can cause it
collection of blood in the pleural space
Causes: cancer, blood clotting disorders, and trauma near lungs
Describe a pyothorax (empyema) and what can cause it.
infection in tissues that are near the pleural cavity. infections can causes abscesses and those can pop. The pus that goes into pleural space is called empyema.
Causes: invasion by bacteria by the lungs
Describe a chylothorax and what can cause it
contains a milky fluid consisting of lymph. Lymph will contain fat
droplets (chylomicrons).
Causes: trauma and cancer
Describe a urinothorax and what can cause it
movement of actual urine into the pleural space. If urine cannot get out, then it can sometimes seep into pleural cavity.
Causes: obstruction or trauma that involves ureters
What is the most common cause of a primary spontaneous pneumothorax?
Blister on the surface of the lung. If it pops, air from the lung alveoli will flow to the pleural space causing the lung to collapse.
More common in smokers and tall, slender men.
Secondary pneumothorax is more common in those with lung diseases such as COPD. What are causes that
may lead to this in children?
effects of measles, foreign body aspiration and certain congenital malformations of the lung (such as Marfan syndrome, Ehlers-Danlos syndrome, and alpha 1-antitrypsin deficiency)
What is the difference between an open and a tension pneumothorax?
Open: opening in pleural space that’s unsealed. Expiration=volume decreased equals positive pressure. Inspiration=volume increased equals negative pressure.
Tension: injury that allows air to enter the pleural space but not with exhalation
Tension pneumothorax
Pressure increased in the chest. Shifts mediastinum to the opposite side of chest and compresses vena cava. This leads to decreased cardiac output and venous return.
Tx: needle or chest tube into affected area to release drainage
What is atelectasis?
incomplete expansion of the lung. Alveoli is deflated
What is the difference between primary and secondary (acquired) atelectasis?
- Primary: lungs of newborn do not fully expand due to lack of surfactant.
- Secondary: partial or complete collapse of lungs that have once been fully expanded. Sometimes due to lack of surfactant or airway obstruction
- anesthesia could cause this-
Asthma
Obstructive airway disorder caused by an immunological reaction.
-Causes: bronchoconstriction, inflammation of bronchioles, and increased mucus
Asthma symptoms
wheezing, shortness of breath, chest tightness, and a cough
Extrinsic (allergic or atopic) Asthma
Type 1 hypersensitivity that begins in childhood.
Causes: Family history, airborne allergens, overproduction of IgE
Explain the pathophysiology of atopic asthma
- Antigen presenting cell (APC) presents allergen to naïve helper T-cells. Helper T-cells secretes IL-4 which triggers more naïve cells to differentiate into T helper 2 cell (TH2).
- TH2 interacts with B cells and release IL-4 to cause B cells to produce IgE antibodies.
- IgE binds to mast cells.
- TH2 cells also release IL-5 which activates eosinophils and IL-13 which causes mucus secretion.
- Allergen binds to IgE on mast cells. This causes cytokines and histamine to be released.
What does histamine, IL-13, cytokines, and leukotrienes do?
- Histamine: vasodilator and increase vascular permeability
- IL-13: increased mucus production by goblet cells
- Cytokines: trigger intrapulmonary parasympathetic nerves to release ACH = increase in bronchoconstriction and mucus secretion
- Leukotrienes: contribute to bronchoconstriction and vascular permeability
Late response in extrinsic Asthma
Due to damage done by recruited leukocytes (eosinophils, neutrophils, basophils)
-Eosinophils release toxic substances that cause further damage and inflammation
What happens with airway remodeling?
Repeated asthmatic episodes brings lasting changes to the airway. Immune cells like mast cells, macrophages, eosinophils, and neutrophils accumulate underneath a thickened basement membrane.
Underlying smooth muscle cells undergo hypertrophy and hyperplasia.
This causes excess mucus
Risks for atopic asthma
- polymorphisms in genes that code for cytokines and cytokines receptor.
- exposure to second hand smoke in fetuses and young children
- growing up in industrialized areas
Intrinsic (Non-Atopic Asthma) triggers
Not caused by allergies
Triggers: respiratory viral infections, air pollutants (smog), occupational exposure, and harmless actions (exercise, the cold)
