Tests Flashcards
What is a normal value for breathing rate?
12-20 berths per minute
What is a normal value for breathing rate?
12-20 breaths per minute
What is a normal value for tidal volume?
500ml
After what age does FEV1 decrease?
30 years. This is accelerated with COPD.
What is lung capacity?
In the healthy state, the amount of gas (or air) that can be accommodated will depend of the size of the lungs and thorax, which is related to the age, sex, height and ethnicity of the individual. This is referred to as lung capacity.
What is the difference between reversibility in COPD and asthma?
In COPD, the airways constriction is irreversible, or nearly irreversible. There would be <15%, or <200 mL/s, improvement in FEV1 and PEFR after salbutamol.
In asthma, the airways constriction is reversible so that the FEV1 and PEFR would be restored to normal after salbutamol.
What is a normal value for tidal volume?
500ml
After what age does FEV1 decrease?
30 years. This is accelerated with COPD.
What is lung capacity?
In the healthy state, the amount of gas (or air) that can be accommodated will depend of the size of the lungs and thorax, which is related to the age, sex, height and ethnicity of the individual. This is referred to as lung capacity.
What is the difference between reversibility in COPD and asthma?
In COPD, the airways constriction is irreversible, or nearly irreversible. There would be <15%, or <200 mL/s, improvement in FEV1 and PEFR after salbutamol.
In asthma, the airways constriction is reversible so that the FEV1 and PEFR would be restored to normal after salbutamol.
What is the work performed by the muscles in respiration at rest in healthy individuals?
2-5% of rating oxygen consumption
What is the work performed by the muscles in respiration at maximum hyperventilating?
30% of rating oxygen consumption
What does Poiseuille’s equation tell us?
The resistance for laminar airflow (without turbulence).
When does airway resistance increase?
- Structures outside ether conducting airways such as tumours, mediastinal masses or hilarity lymph nodes
- Laryngeal spasm
- Blockage of the airways with gastric content or blood
- Relaxation of the genioglossus muscle during anaesthesia, causing the tongue to fall backwards
- Aspirated objects, such as peanuts and pretzels.
What traid is used when considering the principles for appropriate treatment?
Bronchoconstriction, inflammation and secretion
How are mast cells activated? What is the effect?
Mast cells are activated by the attachment of the Fc portion of immunoglobulin IgE and other complement fractions.
What is the effect of activation of Mast cells?
Activation of mast cells leads to synthesis of arachidonic acid derivatives such as the leukotriene C4 that cause a slow but sustained contraction of bronchial smooth muscle. This leads to a rise in intracellular calcium ions as calcium channels open, and the release of range of mediators, primarily histamine that is stored within granules inside the mast cells.
At what pressure do the lungs start to inflate?
During inspiration, there is only a small volume change until a pressure of more than 5-6 mmHg is reached.
In what pattern do the lungs inflation until 15mmHg?
Non-linearly
What is the cause of hysteresis?
During deflation, the curve is displaced to the left, so that the pressure at any volume is less on expiration than inspiration. This phenomenon, known as hysteresis, is attributed to the presence of surface tension at the interface of air and fluid lining the alveolar walls and the effect of surfactant.
What is compliance?
Compliance is a measure of how easily the lungs can be distended.
What is the result of the elastic properties of the lung?
The elastic properties of the lungs tend to pull them away from the thoracic walls, giving rise to a negative intrapleural pressure.
How does the abdominal aorta divide?
Below this the abdominal aorta , as it is now known, descends to the level of L4 where it divides into the left and right common iliac arteries . These are the vessels which supply the pelvic organs ( bladder , rectum and reproductive organs, excluding gonads) and the lower limbs. The abdominal organs are supplied by branches of the abdominal aorta. After giving off the paired phrenic arteries , which supply blood to the inferior diaphragm, the abdominal aorta gives off a major branch, the coeliac trunk , which divides into the common hepatic, splenic and left gastric arteries . These arteries supply the stomach, duodenum, pancreas, liver and spleen. Just below the paired suprarenal arteries, which supply the adrenal glands, the superior mesenteric artery supplies the small and large intestines and part of the colon. Two subsequent pairs of branches are the arteries that supply the kidneys - the renal arteries - and the gonadal arteries (ovarian arteries in females and testicular arteries in males). The last major branch of the aorta, before it divides into the left and right common iliac arteries to supply the lower limbs, is the inferior mesenteric artery - which provides blood to the lower parts of the intestinal tract, the colon and rectum.
What is the gold standard for diagnosing a pulmonary embolism?:
CT-pulmonary angiogram
