Overview of the Pulmonary System/Lung Development Flashcards
Are humans negative or positive pressure ventilators?
Negative
What is a pneumothorax?
A pneumothorax is an abnormal collection of air or gas in the pleural space that causes an uncoupling of the lung from the chest wall.
Like pleural effusion (liquid buildup in that space), pneumothorax may interfere with normal breathing. It is often called collapsed lung, although that term may also refer to atelectasis. One or both lungs may be affected.
What is a pleural effusion?
A pleural effusion is excess fluid that accumulates in the pleural cavity, the fluid-filled space that surrounds the lungs.
This excess can impair breathing by limiting the expansion of the lungs. Various kinds of pleural effusion, depending on the nature of the fluid and what caused its entry into the pleural space, are hydrothorax (serous fluid), hemothorax (blood), urinothorax (urine), chylothorax (chyle), or pyothorax (pus).
How many lobes in each lung?
Right - 3
Left - 2
What is the conducting zone of the lungs?
The first 16 branch points (from trachea => bronchi => bronchioles => terminal bronchioles), are the “conducting zone”. These conducting airways are for conducting gas from the atmosphere and do not exchange gas.
What are the transitional and respiratory zones?
Branch points 17-23. This is where gas exchange starts to happen. As you branch further and further, you get less cartilage, more smooth muscle, and more alveoli.
Levels 17-19 have some alveoli.
Levels 20-22 are lined with alveoli.
Level 23 - alveolar sacs
What is the acinus?
Pulmonary acinus: The cluster at the ending of a tiny airway in the lung, where the alveoli (air sacs) are located.
What are Type I Pneumocytes (Type I alveolar cells)?
Type I alveolar cells are squamous (giving more surface area to each cell) and cover approximately 90–95% of the alveolar surface. Type I cells are involved in the process of gas exchange between the alveoli and blood. These cells are extremely thin (sometimes only 25 nm) – the electron microscope was needed to prove that all alveoli are covered with an epithelial lining. These cells need to be so thin to be readily permeable for enabling an easy gas exchange between the alveoli and the blood.
What are Type II Pneumocytes (Type II alveolar cells)?
Type II alveolar cells cover a small fraction of the alveolar surface area. Their function is of major importance in the secretion of pulmonary surfactant, which decreases the surface tension within the alveoli. They are also capable of cellular division, giving rise to more type I alveolar cells when the lung tissue is damaged. These cells are granular and roughly cuboidal. Type II alveolar cells are typically found at the blood-air barrier. Although they only comprise
What is the difference between ventilation and respiration?
Ventilation is the air movement in and out of the lung while respiration is the gas exchange of O2 and CO2 across the alveolar capillary membrane.
Problems with either of these components results in impaired functioning and symptoms of pulmonary insufficiency.
Explain why gas exchange requires integration of several organ systems.
a) the lung, chest wall, and respiratory muscles to provide adequate gas movement
b) the heart and pulmonary circulation to provide adequate blood flow
c) central and peripheral receptors to control and match ventilation and perfusion.
Which embryonic germ layer do the lungs come from?
Embryonic Endoderm
The embryonic endoderm instructs the formation of ______ organs.
Mesodermal.
The embryonic endoderm instructs the formation of the notochord, heart, and blood vessels.
What is the pleural space?
It is the space in between the parietal pleura (inner lining on the chest wall), and the visceral pleura (outer lining on the lung).
List the conducting airways (3)
Trachea, bronchi, bronchioles
