Respiratory System Flashcards
What tests are used to diagnose pneumonia?
Chest X-rays, sputum cultures, and blood tests (e.g., CBC).
When a patient is suspected of having pneumonia, we usually start with a chest X-ray to look for any signs of infection or fluid in the lungs. If they’re coughing up mucus, we can do a sputum culture to find out what’s causing the infection, like bacteria, viruses or fungus. We might also run a blood test, like a CBC, to check their white blood cell count and see how their immune system is responding. These tests together give us a clearer picture of what’s going on and help guide treatment.
What is Chest Xray?
A chest X-ray is an imaging test that uses a small amount of radiation to create pictures of the lungs, heart, and chest structures.
What it looks like: On an X-ray image, healthy lungs appear black (because air doesn’t block X-rays), while areas of infection or fluid appear white or gray (indicating consolidation or fluid buildup).
In pneumonia: A chest X-ray can show infiltrates (white patches of infection), fluid in the lungs (pleural effusion), or areas of reduced air exchange.
Consolidation refers to an area of the lung where normal air-filled spaces (alveoli) are replaced by something denser, like fluid, pus, blood, or cells caused by infection or inflammation.
What is the normal WBC range in a CBC test?
The normal range for white blood cell (WBC) count in a complete blood count (CBC) test is typically 4,000 to 11,000 cells per microliter of blood (or 4.0–11.0 x 10⁹/L).
What it means:
High WBC (Leukocytosis): Could indicate infection, inflammation, stress, or certain medical conditions like leukemia.
Low WBC (Leukopenia): May suggest a weakened immune system, viral infections, or issues like bone marrow suppression.
The normal WBC range is 4,000 to 11,000. If it’s higher, it might mean the body is fighting an infection like pneumonia. If it’s lower, it could indicate immune suppression, like in patients undergoing chemotherapy.”
What is pneumonia?
A lung infection that causes inflammation in the lung parenchyma, leading to difficulty breathing and reduced gas exchange.
What are common types of pneumonia?
Why is hospital-acquired pneumonia more severe than community-acquired pneumonia?
Community-acquired pneumonia (CAP)
- Hospital-acquired pneumonia (HAP)
- Ventilator-associated pneumonia (VAP)
- Aspiration pneumonia.
Hospital pathogens are often more resistant to antibiotics and involve stronger organisms like MRSA.
What are the symptoms of pneumonia?
What are common symptoms of the flu?
Fever, cough (productive or non-productive), shortness of breath, chest pain, crackles, and diminished lung sounds.
They might suffer from cough, chills, fatigue, headaches, sore throat, runny nose.
How is the flu typically transmitted?
Through droplet transmission, requiring precautions like wearing surgical masks and practicing hand hygiene.
Is the flu viral or bacterial, and why don’t we use antibiotics for it?
This is viral, right? So antibiotics won’t work on flu.”
What types of influenza viruses are most common?
The most common viruses we see, A and B viruses. 80% of the influenza viruses cover influenza A, and maybe 25% is influenza B.”
Why don’t we vaccinate children under six months old for the flu?
Their immune systems are not fully developed.
What are common complications of the flu in elderly patients?
Why is pneumonia more difficult to diagnose in elderly patients?
What populations are most at risk for severe flu complications?
Pneumonia is the most common and serious complication.
Elderly populations may not present with fever but instead show cognitive problems, confusion, or weight loss.
Our vulnerable populations are elderly population, right? People with chronic diseases like diabetes, hypertension, renal or liver problems, immunocompromised individuals like cancer or HIV patients, and long-term care facility residents.
What do the H and N in H1N1 stand for?
They refer to protein spikes on the virus, hemagglutinin (H) and neuraminidase (N).
Protein spikes are like tools the virus uses to infect us. H1N1 means the virus has one type of hemagglutinin and one type of neuraminidase. These spikes help the virus attach to and spread between our cells.
How does negative pressure in the thoracic cavity contribute to lung expansion and airflow during respiration, and why is it important to maintain the balance of this pressure?
The thoracic cavity helps keep the lungs in shape and functioning by creating negative pressure, which is pressure lower than atmospheric pressure. This negative pressure exists because the lungs naturally recoil inward, while the chest wall expands outward. These opposing forces create a constant pull, keeping the pleural cavity at a sub-atmospheric pressure. This prevents lung collapse and supports their basic structure.
When you breathe in, the diaphragm contracts and your chest expands. This makes the thoracic pressure even more negative (about -8 cmH₂O), which lowers the pressure in the alveoli to just below atmospheric pressure (around -1 cmH₂O). Since air flows from high pressure to low pressure, this creates the perfect gradient for air to flow into the alveoli, which are the only place where gas exchange happens because the pleural cavity is sealed off.
When you breathe out, the diaphragm relaxes and the chest gets smaller. The thoracic pressure becomes less negative (about -5 cmH₂O), and the alveolar pressure increases slightly above atmospheric pressure (around +1 cmH₂O). This pressure gradient pushes air out of the lungs.
The key takeaway here is that thoracic pressure is always more negative than alveolar pressure, which keeps the lungs from collapsing. Airflow is only determined by the pressure gradient between the atmosphere and the alveoli. This negative pressure needs to be just right—too little, and the lungs could collapse (like in pneumothorax); too much, and it could overstretch and damage the lungs. So, the thoracic cavity is not just about helping you breathe; it also plays a big role in keeping your lungs in shape and functional.
