Exam 3 | Respiratory

Question 1

What does the respiratory system do?

Answer 1

The respiratory system is responsible for acquiring oxygen (O2) through inhalation, and recycling carbon dioxide (CO2) through exhalation

Question 2

What other things is the respiratory system responsible for?

Answer 2

Maintains a stable internal temperature by providing warm air to the body.

Maintains a stable blood pH through balance of gases (specifically, keeping a relatively low carbon dioxide level in the blood)

Assists in speech production as well as olfaction

Question 3

What are the 2 division of the respiratory system?

Answer 3

upper respiratory tract & lower respiratory tract

Question 4

What does the upper respiratory tract include?

Answer 4

Nose

Pharynx (including nasopharynx)

Larynx

Question 5

What does the lower respiratory tract include?

Answer 5

Trachea

Bronchi/ bronchioles

Lungs (including alveoli)

Question 6

Describe the trachea (windpipe).

Answer 6

It is the starting point for the lower respiratory tract

It is a stiff, roughly 5-inch structure that serves to relay air in and out of the lungs. It is lined with “c-rings” of cartilage that help to maintain an open airway (this is in contrast to the esophagus, which is flaccid and lined with smooth muscle).

Question 7

What is a tracheotomy?

Answer 7

In some cases of injury or disease, a procedure known as a tracheotomy may become necessary, in which an incision is made at the base of the neck to bypass the upper portion of the trachea and provide an outlet for air to enter and exit the respiratory tract.

Question 8

What are bronchi/bronchioles?

Answer 8

The bronchi are the branches that extend from the “trunk” of the trachea, and this branching continues well into the lungs.

Question 9

What is the naming system for bronchi/bronchioles?

Answer 9

The first bronchi are referred to as the primary bronchi, which then branch to give rise to the secondary bronchi, and finally give rise to the tertiary bronchi which terminate with smaller branching structures called bronchioles.

Question 10

Where are the lungs located and how are the right and left lungs different?

Answer 10

The lungs are contained within the entire thoracic cavity, even extending slightly up to the collarbone.

The right and left lungs are not structurally identical, largely due to the presence of the heart between each lobe:

The right lung has three lobes and is situated slightly farther away from the heart.

The left lung has two lobes, and the cardiac notch, a small divot in which the heart is situated.

Question 11

What is the lungs lined with and what purpose does it serve?

Answer 11

The lungs are lined by a thin membranous sac known as the pleural sac. This membrane is moist, and helps to soften and protect the lung tissue so that it does not dry out, or dessicate, which can lead to tears or damage to the lung epithelium.

This damp environment also helps facilitate gas exchange in the tiny, membranous air sacs contained within the lungs, known as the alveoli.

Question 12

What do alveoli do?

Answer 12

The alveoli are the termination points of the bronchioles, and are surrounded by small capillaries that supply oxygenated and deoxygenated blood to the lungs. While these capillaries are tightly wrapped around each individual alveolus, the pulmonary arteries and pulmonary veins supply clusters of alveoli with blood.

It is the site of gas exchange

Question 13

How does gas exchange work in the alveoli?

Answer 13

The process of gas exchange occurs when deoxygenated blood enters the lungs and becomes oxygenated due to the diffusion of oxygen through the alveolar membrane and capillary wall (along its concentration gradient).

Likewise, carbon dioxide is also exchanged for oxygen and moves along its concentration gradient (across the capillary wall and into the alveoli, to be exhaled).

This “assembly line” cycle takes place every time you inhale and exhale.

Question 14

What is the main driving force for gas exchange?

Answer 14

Diffusion

Question 15

How does gas exchange look in other species?

Answer 15

The different variations in this gas exchange process are virtually identical across all vertebrate and invertebrate species, however, the key differences lie in the anatomical structures actually participating in gas exchange.

In invertebrates, the skin functions analogous to the alveoli.

In marine vertebrates, the gills function analogous to the alveoli.

In terrestrial vertebrates, the lungs (alveoli) are the site of gas exchange.

Question 16

How do we inhale/exhale?

Answer 16

The lungs change in size (or volume), which in turn creates a change in the internal pressure within the lungs, ultimately determining the direction of airflow

(either being sucked in to the lungs due to negative pressure, or being forcefully pushed out of the lungs due to positive pressure).

Question 17

What causes the lungs to change in size?

Answer 17

The diaphragm!

Question 18

What is the diaphragm?

Answer 18

It is a thin (but powerful!) muscle that sits at the base of the ribcage.

Without the diaphragm, the lungs wouldn’t be able to change size meaning we wouldn’t be able to breathe

Question 19

Explain how the diaphragm causes air to move into and out of the lungs.

Answer 19

During inhalation, the diaphragm contracts, lowering and creating more space within the rib cage for the lungs to expand. This expansion causes air to be drawn into the lungs.

During exhalation, the diaphragm relaxes, returning to its higher resting position and causing the lungs to shrink in size. This reduced lung volume causes air to be pushed out of the lungs.

Thus, the process of inhalation is (mostly) active, while the process of exhalation is (generally) passive.

Question 20

What is Boyle’s Law?

Answer 20

According to this law, increases in volume will result in decreases in pressure, and vice versa: in other words, these two factors are inversely proportional to each other

Question 21

How is Boyle’s law related to respiration?

Answer 21

This mechanism of volume changes in the lungs leading to internal pressure changes follows a classical Gas Law, known as Boyle’s Law.

Thus, the negative pressure produced during inhalation is responsible for drawing air (oxygen) into the lungs, and the positive pressure produced during exhalation is responsible for pushing air (carbon dioxide) out of the lungs.

Question 22

What are three factors that determine the binding affinity of hemoglobin for oxygen?

Answer 22

Partial pressure, temperature, and pH

Question 23

How does partial pressure impact hemoglobin’s binding affinity?

Answer 23

The partial pressure of oxygen (and of carbon dioxide) determines how likely hemoglobin is to bind oxygen. In the lungs, the partial pressure of oxygen is usually very high, and thus, this increased partial pressure functions in a similar manner to the concentration gradient of oxygen, providing the driving force for oxygen to diffuse from the alveoli into the capillaries to bind to hemoglobin on the RBCs. Likewise, in areas where the partial pressure of oxygen is low, hemoglobin is less likely to bind oxygen (and more likely to release it to the surrounding tissues that are presumably lacking in oxygen).

Question 24

How does temperature impact hemoglobin’s binding affinity?

Answer 24

Hemoglobin has the highest affinity for binding oxygen in low temperature environments (such as the typical environment in the lungs), and is far more likely to release oxygen in high temperature environments (such as in muscle tissue undergoing cellular respiration at high rates).

Question 25

How does pH impact hemoglobin’s binding affinity?

Answer 25

In high pH (basic) environments (such as the internal environment in the lungs, which is usually slightly basic), hemoglobin will bind oxygen more strongly than in low pH (acidic) environments. Low pH extracellular environments are typically the result of carbon dioxide production/release, and when carbon dioxide is concentrated in the blood, it will quickly be converted to carbonic acid and then bicarbonate, which will drive the blood pH lower (potentially to dangerous levels that can lead to anoxia).

Question 26

When there is a low affinity of oxygen for hemoglobin, what can we assume?

Answer 26

The binding affinity for CO2 is higher

Question 27

What happens when CO2 enter the blood?

Answer 27

when carbon dioxide enters the blood, it is immediately converted to carbonic acid (because of the interaction with water in the blood), which drives down the blood pH

Question 28

What does a high concentration of CO2 in the blood lead to?

Answer 28

high concentrations of carbon dioxide can lead to a condition known as hypercapnia, which can be a symptom/ byproduct of more serious respiratory/ cardiovascular diseases.

Question 29

What do RBCs do when there’s an increase concentration of CO2 in the blood?

Answer 29

Enzymes in the RBCs are capable of converting carbonic acid into bicarbonate and water, helping to minimize the effect of carbon dioxide in the blood on the blood pH and serve as a pH buffer. When carbon dioxide is expired via the lungs, it is converted back to its original (gas) form.

Question 30

What is asthma?

Answer 30

Asthma is a mild condition characterized by swelling of the airways, specifically the bronchi and bronchioles, as well as excessive production of mucus lining these airways that can ultimately result in difficulty breathing. There is some evidence to suggest that asthma is a highly heritable disease.

Question 31

What are the symptoms for an asthma attack?

Answer 31

Uncontrolled coughing or wheezing

Breathlessness or feeling short of breath

Chest tightness

Question 32

What is prescribed to those with asthma?

Answer 32

Individuals with moderate to severe asthma are often prescribed a rescue inhaler, which typically contains the drug albuterol.

Question 33

How does albuterol work and what other diseases does it treat?

Answer 33

Albuterol works to relax the smooth muscles of the airways, thus preventing bronchospasms that typically occur during asthma attacks.

Albuterol is also sometimes used to treat other chronic pulmonary conditions, such as COPD and even chronic bronchitis.

Question 34

What is Chronic Obstructive Pulmonary Disease (COPD)?

Answer 34

Typically more serious than asthma, it is a class of disorders that effect someone’s ability to breathe. Individuals are diagnosed with COPD after they are diagnosed with another chronic pulmonary condition, such as emphysema and/or chronic bronchitis: these two conditions together are often considered to be the foundation for COPD progression.

The damage to the lungs (and specifically, the bronchioles and alveoli) caused by COPD cannot be reversed.

Question 35

What are common symptoms for COPD?

Answer 35

Shortness of breath

Wheezing

A persistent cough

Question 36

How is COPD treated?

Answer 36

Like asthma, rescue inhalers (intended to be used during episodes of coughing/ wheezing/ difficulty breathing), as well as inhalers containing steroids are typically prescribed to help control symptoms and prevent further lung damage.

Question 37

Who are more likely to develop COPD?

Answer 37

Individuals who are exposed to harmful chemicals on a routine basis, including those who smoke, are significantly more likely to develop COPD than those who do not participate in these activities.

Question 38

What is pulmonary edema?

Answer 38

Pulmonary edemas are characterized by excess fluid accumulation/ build-up in the lungs, specifically in the alveoli, interfering with the gas exchange process.

Question 39

How do pulmonary edemas occur?

Answer 39

They result from other (potentially non-respiratory) disease/damage.

Question 40

What are symptoms for pulmonary edema?

Answer 40

Mild to severe difficulty breathing

Chest tightness and/ or chest pain

Coughing

Fatigue

Question 41

How can you detect pulmonary edemas?

Answer 41

An initial chest x-ray can detect pulmonary edema, but further diagnostic tests, (including, but not necessarily limited to: blood analysis, CT scans, echocardiograms and EKGs) are often required to isolate the cause of the edema.

Question 42

What disease are pulmonary edemas associated with and how are they treated?

Answer 42

Pulmonary edemas are often associated with cardiovascular diseases (CVDs), and thus, can be treated pharmacologically with drugs that are traditionally used to treat CVDs (specifically high blood pressure), such as:

Diuretics & Beta-blockers

Question 43

Besides CVD, what can pulmonary edema be a symptom of?

Answer 43

Pulmonary edemas can also be a symptom of severe altitude sickness, and this form of pulmonary edema is known as High Altitude Pulmonary Edema (HAPE).

In cases of HAPE, patients must be transported to a lower altitude immediately, stabilize their body temperature and receive pharmacological treatment.

Question 44

What is emphysema?

Answer 44

It is characterized by (permanent) damage to the bronchioles and alveoli, resulting in reduced efficiency in gas exchange and ultimately, chronic difficulty in breathing.

Commonly associated with COPD

Question 45

What are the symptoms of emphysema?

Answer 45

Persistent coughing and wheezing

Rapid breathing

Shortness of breath (which gets worse during physical exertion)

Sputum production (release of phlegm during coughing episodes)

Question 46

How is emphysema treated & who’s more at risk?

Answer 46

While emphysema can be treated pharmacologically, once the disease progresses to a more severe level, patients must often rely on supplemental oxygen to aid in their breathing.

As with COPD, individual who are regularly exposed to harmful chemicals and/ or smoke have an increased risk of developing emphysema.

Question 47

What is bronchitis?

Answer 47

Bronchitis is a disease characterized by mild to severe inflammation of the bronchi, interfering with one’s ability to take in air. As with asthma, mucus build-up in the bronchial tubes also affects one’s ability to breathe.

Question 48

What are the symptoms of bronchitis?

Answer 48

Persistent and aggressive coughing (sometimes a “wet cough”, in which mucus production is observed)

Shortness of breath and/ or difficulty breathing

Question 49

What is the difference between acute and chronic bronchitis?

Answer 49

acute bronchitis is the result of a viral infection, and can resolve on its own without treatment.

However, chronic bronchitis may lead to COPD over time, due to sustained damage of the airways, and requires further treatment and diagnosis.

Antibiotics are almost never recommended to treat bronchitis, as the cause is almost always viral in nature.

Question 50

What is pneumonia?

Answer 50

Pneumonia is a pulmonary disease characterized by swelling/ inflammation of the bronchioles (similar to what is observed in bronchitis), as well as the accumulation of fluid in the alveoli, interfering with normal gas exchange.

This disease tends to be more severe than bronchitis, and mostly affecting older/ more vulnerable populations

Question 51

What is the underlying cause for pneumonia?

Answer 51

Pneumonia can be viral or bacterial in nature, and thus, an early diagnosis is essential for determining the appropriate course of treatment (either with antibiotics or with viral therapies).

Question 52

What are symptoms of pneumonia?

Answer 52

Coughing with phlegm or pus

Fever and/ or chills

Difficulty breathing

Question 53

How is pneumonia treated?

Answer 53

Depending on the nature of the pneumonia, treatments can be pharmacological (including the prescription of certain antibiotics or antivirals), and often imaging (such as a chest x-ray or chest ultrasound) is necessary to confirm the diagnosis and rule out other possible (related) conditions.

Some vaccines can even prevent certain forms of pneumonia, and are thus strongly recommended to patients in vulnerable groups (aged 65 or older).

Question 54

What is Covid-19?

Answer 54

COVID-19 is the disease caused by infection with the Sars-CoV-2 virus. In recent months, this disease has become more mild (for most vaccinated patients who are at low-risk for developing severe disease).

Question 55

What damage does Covid-19 cause?

Answer 55

More severe cases of COVID-19 can cause multi-organ damage and specifically, permanent damage to the internal structures of the lungs.

Early studies suggest that the “locus” of damage caused by COVID-19 are the alveoli, and that this damage may be similar to the damage observed in emphysema/ COPD.

Question 56

What are symptoms for covid-19?

Answer 56

Sore throat and other “head cold” symptoms (stuffy or runny nose, headache, etc.)

Coughing

Shortness of breath/ difficulty breathing

Neurological symptoms (such as “brain fog”, loss of taste and/ or smell, etc.)