Which six structures make up the conducting zone of the respiratory tree?
The nose, the pharynx, the trachea, the bronchi, the bronchioles, and the terminal bronchioles
Name the four functions of the conducting zone of the respiratory tree.
The conducting zone brings air in and out, warms, humidifies, and filters air
What type of muscle is found in the walls of the conducting airways?
Smooth muscle
What anatomic area does the respiratory zone encompass and what is the major function?
The respiratory bronchioles, the alveolar ducts, and the alveoli all function in gas exchange
Cartilage is present only in what two components of the respiratory tree?
Trachea and bronchi
Which zone of the respiratory tree includes the anatomic dead space?
The conducting zone; by definition, dead space does not participate in gas exchange
Goblet cells extend to the _____ (respiratory/terminal) bronchioles, whereas pseudostratified ciliated cells extend to the _____ (respiratory/terminal) bronchioles.
Terminal; respiratory
What type of pneumocyte makes up 97% of alveolar surfaces?
Type I pneumocytes
What type of pneumocyte makes up just 3% of pneumocytes?
Type II pneumocytes
What are two important functions of type II pneumocytes?
To secrete surfactant and to serve as precursors to pneumocytes (both types I and II)
What is dipalmitoyl phosphatidylcholine and what is its function?
Surfactant, to decrease alveolar surface tension
Which cells proliferate to repair the lungs after they have been damaged?
Type II pneumocytes; they are the precursors of both types of pneumocytes
What feature of the pseudostratified columnar cells of the respiratory tract allow them to move mucus toward the mouth?
Their cilia
What ratio of concentrations of which two molecules in amniotic fluid can be used as a marker of fetal lung maturity?
The lecithin/sphingomyelin ratio
A lecithin/sphingomyelin ratio with what value is indicative of fetal lung maturity?
>2.0
Histologically, while type I pneumocytes are _____ (cuboidal/squamous), type II pneumocytes are _____ (cuboidal/squamous).
Squamous; cuboidal
What is the advantage of having thin squamous cells that line the alveoli?
Maximum gas exchange is permitted by thin cells
Describe clara cells and their three functions.
Nonciliated columnar pneumocytes with granules that secrete a component of surfactant and degrade toxins and act as reserve cells
Which cells are responsible for clearing debris that accumulates in the alveoli?
Macrophages
In pulmonary gas exchange, _____ (carbon dioxide/oxygen) diffuses from the capillary lumen to the alveolar space, while _____ (carbon dioxide/oxygen) diffuses from the alveolar space to the capillary lumen.
Carbon dioxide; oxygen
Surfactant is secreted from the lamellar bodies of ____ (type I/type II/clara cell) pneumocytes.
Type II
An oxygen molecule is in the alveolus. In order, what cells will it cross to be able to bind to heme in the red blood cells?
To pass through the alveolar space to the capillary lumen, oxygen diffuses across the type I pneumocyte and then the endothelial cell
A carbon dioxide molecule is in the red blood cell within the capillary lumen. In order, what cells will it cross before it is exhaled?
The majority of carbon dioxide will exit red blood cells as bicarbonate (in exchange for chloride), cross the endothelial cell, then the type I pneumocyte to enter the alveolar space
Along with pneumocytes, which phagocytic cells can be found in the alveolar space?
Macrophages
Each bronchopulmonary segment has what three structures in the center?
A tertiary bronchus and two arteries (remember: Arteries run with Airways)
What two arteries are found in the center of each bronchopulmonary segment?
A bronchial artery and a pulmonary artery
What two structures are found along the borders of each bronchopulmonary segment?
Veins and lymphatics
Pulmonary _____ (arteries/veins) carry _____ (deoxygenated/oxygenated) blood from the right side of the heart to the lungs.
Arteries; deoxygenated
How does pulmonary arterial pressure fluctuate depending on the stage of the cardiac cycle?
It does not fluctuate; elastic walls maintain relatively constant pulmonary arterial pressure during the cardiac cycle
- How many lobes does the right lung have?
- How many does the left lung have?
- Three
- Two
What structure does the left lung have that the right lung does not?
A lingula (remember: Left has the Lingula)
In what lung is it more common to find an inhaled foreign body and why?
The right lung because the right main stem bronchus is wider and more vertical than the left
Instead of a middle lobe, the left lung has a space that is occupied by what?
The heart
Where is the pulmonary artery in relation to the bronchus within the right lung hilus?
Anterior (remember: RALS = Right Anterior; Left Superior)
Where is the pulmonary artery in relation to the bronchus within the left lung hilus?
Superior (remember: RALS = Right Anterior; Left Superior)
The oblique fissure divides which two lobes in the right lung? Left lung?
The middle and the inferior lobes; the superior and the inferior lobes
The horizontal fissure of the right lung is at the level of the _____ rib.
Fourth
In the posterior aspect of both the right and left lungs, the _____ (horizontal/oblique) fissure divides the superior and inferior lobes.
Oblique
In the posterior aspect of the right and left lungs, the medial aspect of the oblique fissure is at the level of which vertebra?
T2
While both the right and left lungs have a(n) _____ (oblique/horizontal) fissure, only the right lung has a(n) _____ (oblique/horizontal) fissure.
Oblique; horizontal
A 5-year-old male presents after having aspirated a peanut while lying in bed. The peanut has most likely lodged in what portion of the lung?
The superior portion of right inferior lobe
A 33-year-old male presents after having aspirated a steak tip while sitting at the dinner table. The steak tip has most likely lodged where?
The lower portion of right inferior lobe
At what level does the inferior vena cava perforate the diaphragm?
T8 (remember: T8: vena cava [8 letters in vena cava])
What two structures perforate the diaphragm at the level of T10?
The esophagus and the vagus
At what level does the esophagus perforate the diaphragm?
T10 (remember: T10: (o)esophagus [10 letters in (o)esophagus])
What three structures perforate the diaphragm at the level of T12?
The aorta, thoracic duct, and azygos vein; (remember: T12: aortic hiatus [12 letters in aortic hiatus])
Neurons from vertebral levels _____, _____, and _____ come together to form the phrenic nerve, which innervates the diaphragm.
C3, C4, and C5 (remember: “C3, 4, 5 keeps the diaphragm alive.”)
Pain from the diaphragm can be referred to which anatomic region?
The shoulder
Which tendon can be found on the inferior aspect of the diaphragm surrounding the caval and esophageal hiatuses?
The central tendon
What mnemonic can be used to recall the levels at which certain anatomic structures perforate the diaphragm relates?
“I (IVC) ate (8) ten (10) eggs (esophagus) at (aorta) twelve (12).”
During quiet breathing, what muscle is used for inspiration?
The diaphragm
During quiet breathing, what muscle is used for expiration?
No muscles are used; the expiration of quiet breathing is passive
During exercise, what three muscle groups are used for inspiration?
The external intercostals, the scalene muscles, and the sternomastoids
Name the four abdominal wall muscle groups and the chest wall muscles used for expiration during exercise.
The rectus abdominus, the internal obliques, the external obliques, and the transversus abdominus; the internal intercostals
While expiration during quiet breathing is _____ (active/passive), expiration during exercise is _____ (active/passive).
Passive; active
