Physiology 1.2

Question 1

Describe the main anatomical features of the airways and the gross anatomical features of the lung.

Answer 1

The main anatomical features of the airways and the gross anatomical features of the lung can be observed with the naked eye.

Question 2

Identify the different classes of airways and the two different types of alveolar cells.

Answer 2

There are different classes of airways and two types of alveolar cells within the respiratory system.

Question 3

Explain why and how resistance to air flow varies across the respiratory tract.

Answer 3

Resistance to air flow varies across the respiratory tract, and it is important to understand the reasons behind this variation.

Question 4

Describe the functions of the nose in the respiratory system.

Answer 4

The nose plays a crucial role in warming, moistening, and filtering the air we breathe, making it more comfortable for inhalation.

Question 5

Discuss the role of the pharynx in the respiratory system.

Answer 5

The pharynx, also known as the throat, serves as a common conduit shared with the digestive system and plays a key role in the respiratory tract.

Question 6

Explain the significance of breathing through the nose versus the mouth.

Answer 6

Breathing through the nose is more comfortable as it effectively warms, moistens, and filters the air, while breathing through the mouth is less comfortable due to its inefficiency in these functions.

Question 7

Describe the structure and function of the ciliated epithelium in the nose.

Answer 7

The ciliated epithelium in the nose is responsible for trapping mucus and aiding in the removal of particles from the respiratory system.

Question 8

Discuss the relationship between the nose’s surface area to volume ratio and its function in the respiratory system.

Answer 8

The nose’s large surface area to volume ratio is essential for its effectiveness in warming and moistening the inhaled air.

Question 9

Explain the connection between the pharynx and the larynx in the respiratory system.

Answer 9

The pharynx connects the back of the nose and mouth to the larynx, which is a critical part of the respiratory system.

Question 10

Describe the function of the epiglottis in the respiratory system.

Answer 10

The epiglottis acts as a gate to the respiratory system, closing when swallowing to prevent food or liquid from entering the lungs.

Question 11

What is the role of the larynx in speech production?

Answer 11

The larynx houses the vocal cords and allows us to change the tension in them, controlling the way air travels across them to produce speech sounds.

Question 12

Define the trachea and its location in the body.

Answer 12

The trachea is the main airway of the respiratory system, located below the larynx and running down to the sternal angle at the top of the sternum.

Question 13

How do the bronchi divide in the respiratory system?

Answer 13

The trachea splits underneath the sternal angle to give the two primary bronchi, one going to each lung, which then continue to divide about 24 times into smaller airways.

Question 14

Describe the structure and function of the alveoli in the lungs.

Answer 14

The alveoli are microscopic air sacs where gas exchange occurs, allowing for the exchange of oxygen and carbon dioxide, forming the functional level of the lungs.

Question 15

What is the boundary between the upper and lower respiratory tract?

Answer 15

The larynx serves as the boundary, with everything above it belonging to the upper respiratory tract and everything below it belonging to the lower respiratory tract.

Question 16

Describe the significance of theaveric image of respiratory system shown in the content.

Answer 16

The cadaveric image displays real lungs a deceased individual, providing a rare opportunity for students to observe the anatomy.

Question 17

What is the role of the diaphragm in respiration?

Answer 17

The diaphragm is a crucial muscle for inspiration, allowing air to enter the lungs.

Question 18

Define the pleural cavity and its importance.

Answer 18

The pleural cavity is a space inside the thoracic cavity that becomes significant in understanding lung inflation and deflation.

Question 19

How are the lobes of the lungs distributed?

Answer 19

The right lung has three lobes (superior, middle, and inferior) separated by two fissures, while the left lung has two lobes (superior and inferior) separated by one fissure.

Question 20

Describe the appearance of the lungs in the cadaveric image.

Answer 20

The lungs appear dark, possibly indicating smoking or exposure to pollution, and exhibit a larger pleural cavity due to deflation after death.

Question 21

What separates the thoracic cavity from the abdominal cavity?

Answer 21

The diaphragm, a sheet of muscle, separates the thoracic cavity from the abdominal cavity.

Question 22

Do the lungs in the cadaveric image fill the entire thoracic cavity in life?

Answer 22

Yes, in life, the lungs would fill the entire thoracic cavity, but after death and deflation, they separate from the chest wall, enlarging the pleural cavity.

Question 23

Describe the difference in lobe distribution between the right and left lungs.

Answer 23

The right lung has three lobes and two fissures, while the left lung has two lobes and one fissure, with some space occupied by the heart.

Question 24

What is the fibrous pericardium, and where is it located?

Answer 24

The fibrous pericardium is a fibrous tissue surrounding the heart and is located underneath the chest wall, above the heart.

Question 25

Describe the thoracic cavity.

Answer 25

The thoracic cavity is defined by the ribs, with the inferior border being the diaphragm, and it contains the pleural cavity that surrounds the lungs.

Question 26

What is the function of the pleural cavity?

Answer 26

The pleural cavity is important for the mechanics of breathing and allows air to move in and out of the lungs.

Question 27

Define primary bronchi.

Answer 27

The trachea branches at the level of the sternal angle to give us the left and right primary bronchi, with one primary bronchus going to each lung.

Question 28

How are the lungs further divided beyond lobes?

Answer 28

The lung tissue is further split into segments, with one tertiary bronchi going to each segment of the lung.

Question 29

Describe the structure of the airways beyond the bronchi.

Answer 29

Beyond the bronchi, the airways continue to branch, eventually losing cartilaginous rings and becoming bronchioles, which terminate in alveoli.

Question 30

What is the function of alveoli in the respiratory system?

Answer 30

Alveoli are tiny, blind-ended sacs filled with air where gas exchange takes place, as their walls are thin enough for oxygen and carbon dioxide to be exchanged.

Question 31

Describe the process of creating resin cast of a of lungs.

Answer 31

Pumping the lungs full of resin, allowing it to, and then dissolving the lung tissue with acid to obtain a cast of the respiratory tree.

Question 32

What is the difference between the right and left primary bronchi?

Answer 32

The right primary bronchi is slightly wider and has a more vertical trajectory compared to the left primary bronchi.

Question 33

How does the diameter of the airways change as we move down the respiratory tree?

Answer 33

The diameter of the airways gets smaller as we move down the respiratory tree, with the trachea having the largest diameter and the smallest bronchioles having the smallest diameter.

Question 34

Define broncho-pulmonary segments.

Answer 34

They are the segments of the lung supplied by tertiary bronchi.

Question 35

Do the laws of physics regarding resistance to airflow apply to the respiratory system?

Answer 35

No, the greatest amount of resistance to airflow occurs in the largest airways, contrary to what physics would predict based on vessel diameter.

Question 36

Describe the cross-sectional area of the trachea compared to the bronchioles.

Answer 36

The cross-sectional area of the trachea is about 2.5 centimeters squared, while the cross-sectional area of the bronchioles is about five thousand centimeters squared, making the total area available for airflow much greater in the smaller airways.

Question 37

How does the number of air particles in the airways change as we move up the respiratory tree?

Answer 37

As we move up the respiratory tree, more and more air particles are jostling for a proportionally smaller part of the airway.

Question 38

What is the significance of the difference in diameter and cross-sectional area between the trachea and bronchioles?

Answer 38

The difference in diameter and cross-sectional area explains why the greatest amount of resistance to airflow occurs in the largest airways, despite the laws of physics predicting otherwise based on vessel diameter.

Question 39

Describe the relationship between airway diameter and resistance in the system.

Answer 39

As airway diameter increases in the respiratory system, the increase in diameter is not proportional to the number of air molecules trying to move through it, resulting in an increase in resistance.

Question 40

Define dead space in the context of the respiratory system.

Answer 40

Dead space in the respiratory system refers to the conducting zone, where upper airways have walls too thick for gas exchange to occur, resulting in air that cannot participate in gas exchange.

Question 41

How does the resistance to airflow vary in the respiratory system?

Answer 41

The resistance to airflow is greatest in the upper airways and trachea, and lowest in the lower airways, with the ability to be dynamically altered by changing the diameter of the airways.

Question 42

Describe the role of bronchial smooth muscle in altering airway diameter and resistance in the respiratory system.

Answer 42

Bronchial smooth muscle can contract to decrease airway diameter and increase resistance to airflow, or relax to increase airway diameter and decrease resistance.

Question 43

How does the sympathetic nervous system impact bronchial smooth muscles in the respiratory system?

Answer 43

The sympathetic nervous system can act on bronchial smooth muscles to cause contraction, leading to a decrease in airway diameter and an increase in resistance to airflow.

Question 44

Describe the role of the nervous system on beta two receptors in the lungs.

Answer 44

The sympathetic nervous system acts on beta two receptors in the lungs, causing bronchial smooth muscle relaxation, increasing the diameter of airways, and reducing resistance to airflow.

Question 45

What is the function of adrenaline or noradrenaline binding to beta two receptors in the lungs?

Answer 45

Adrenaline or noradrenaline binding to beta two receptors in the lungs brings about relaxation of the bronchial smooth muscle, increasing the diameter of airways and reducing resistance to airflow.

Question 46

Define the relationship between the sympathetic nervous system and the fight-flight response in relation to the respiratory system.

Answer 46

The sympathetic nervous system triggers the fight-flight response, leading to bronchial smooth muscle relaxation, increased airway diameter, and reduced resistance to airflow, facilitating increased ventilation and oxygen delivery to the muscles.

Question 47

Describe the structure and function of the bronchiole smooth muscle in the respiratory system.

Answer 47

The bronchiole smooth muscle can contract or relax, changing the diameter of the bronchiole and therefore the resistance to airflow, ultimately affecting gas exchange in the alveoli.

Question 48

How does gas exchange occur in the respiratory system and the cardiovascular system?

Answer 48

Gas exchange occurs in the alveoli of the respiratory system, in direct contact with the capillary network of the cardiovascular system, allowing for the exchange of oxygen and carbon dioxide.

Question 49

Describe the role of elastic fibers in the alveoli during inspiration and expiration.

Answer 49

Elastic fibers in the alveoli allow for inflation during inspiration and store energy, which is released during expiration to force air out of the respiratory system. This process is essential for normal physiological function.

Question 50

What is the function of the pulmonary artery in the gas exchange process?

Answer 50

The pulmonary artery carries deoxygenated blood full of carbon dioxide from the right side of the heart to the lungs, where gas exchange occurs in the capillary beds, allowing for the exchange of carbon dioxide and oxygen.

Question 51

Define the relationship between the alveoli and the capillary network in the respiratory and cardiovascular systems.

Answer 51

The alveoli are surrounded by a dense capillary network, allowing for direct contact between the respiratory and cardiovascular systems, facilitating gas exchange between the alveoli and the blood vessels.

Question 52

Describe the process of expiration in the respiratory system.

Answer 52

Expiration at rest is passive, as the energy stored in the elastic fibers of the alveoli during inspiration is released to squeeze the alveoli and force air out of the respiratory system, without the use of additional energy.

Question 53

Describe the process of expiration at rest.

Answer 53

Expiration at rest is passive, involving the cessation of contraction in the muscles involved in inspiration and the release of energy stored in elastic fibers during inspiration.

Question 54

Define the role of type one alveolar cells in gas exchange.

Answer 54

Type one alveolar cells make up the bulk of the alveolar wall and are responsible for facilitating gas exchange due to their thin walls.

Question 55

How do type two alveolar cells contribute to respiratory function?

Answer 55

Type two alveolar cells secrete surfactant, which makes the work of breathing easier and aids in inspiration.

Question 56

Describe the relationship between type one cells and capillaries in the respiratory system.

Answer 56

Type one cells are directly abutted to capillaries, as they are the sites where efficient gas exchange takes place.

Question 57

What is the function of elastic fibers in the respiratory system?

Answer 57

Elastic fibers allow the alveoli to inflate during inspiration and squeeze during expiration to push air out of the respiratory system.

Question 58

Do macrophages play a role in the respiratory system?

Answer 58

Yes, macrophages are important for immune function in the respiratory system, helping to protect against infections entering the body through the respiratory route.

Question 59

Describe the structure of the alveoli.

Answer 59

The alveoli are small air sacs in the lungs responsible for gas exchange. They have an enormous surface area, about 80 square meters, and are extremely thin to facilitate gas exchange.

Question 60

Define anatomical dead space in the respiratory system.

Answer 60

Anatomical dead space refers to the air in the trachea and bronchi, which does not participate in gas exchange due to the thick walls of the airways.

Question 61

How does airway resistance affect lung function?

Answer 61

Airway resistance determines how much air flows into the lungs at any given pressure difference between the atmosphere and the alveoli. It is a major determinant of lung function.

Question 62

Describe the impact of diseases like emphysema on the respiratory system.

Answer 62

Diseases like emphysema result in a destruction of the alveoli, leading to a loss of surface area available for gas exchange. This has a massive impact on respiratory function.

Question 63

Do the walls of the upper airways allow for gas exchange?

Answer 63

No, the walls of the upper airways are too thick to allow gases to cross, and their function is purely the conduction of air to and from the alveoli.

Question 64

What is the function of the conducting zone in the respiratory system?

Answer 64

The conducting zone consists of the trachea, bronchi, and bronchioles, and it is responsible for conducting air to and from the alveoli.

Question 65

Describe the size and capacity of the lungs.

Answer 65

Each lung has a capacity of about three liters, totaling to a lung capacity of about six liters. The surface area of the alveoli, about 80 square meters, fits into this volume due to its thinness.

Question 66

How does the surface area of the alveoli contribute to gas exchange?

Answer 66

The large surface area of the alveoli, about 80 square meters, is hugely significant in terms of gas exchange. Gases can only exchange over the very thin membranes found in the type one alveolar cells.