SM_151: Lung Anatomy, Histology, and Development Flashcards
The vertebrosternal ribs are ribs ____
The vertebrosternal ribs are ribs 1-7
The vertebrocostal ribs are ribs ____
The vertebrocostal ribs are ribs 8-10
The verebtral (floating) ribs are ribs _____
The verebtral (floating) ribs are ribs 11-12
Pivoting around an axis through the head, neck, and tubercle _________ the ribs
Pivoting around an axis through the head, neck, and tubercle elevates/depresses the ribs
Which muscles are used in inspiration (elevators)?
- External oblique
- Accessory: scalenes, pectoralis minor and major, serratus anterior
Diaphragm depression ________ volume for quiet inspiration
Diaphragm depression decreases volume for quiet inspiration
Which muscles are used in expiration (depressors)?
- Internal oblique
- Abdominal muscles
Visceral pleura lines the ______
Visceral pleura lines the lung surface
Parietal pleura lines the ______
Parietal pleura binds the body wall
Parietal pleura extends to the _____ rib laterally, while the lungs extend to the _____ rib laterally
Parietal pleura extends to the 10th rib laterally, while the lungs extend to the 8th rib laterally
Is the costodiaphragmatic recess visible on radiograph?
No, the costodiaphragmatic recess is not visible on radiograph
A pleural effusion ______ the costophrenic angle
A pleural effusion blunts the costophrenic angle
Posteriorly, pleura and lungs extend _______ compared with the sides due to downward sloping of the rib
Posteriorly, pleura and lungs extend two ribs inferiorly compared with the sides due to downward sloping of ribs
Lungs extend to
- ___ rib laterally
- ___ rib posteriorly
- ___ rib anteriorly
Lungs extend to
- 8th rib laterally
- 10th rib posteriorly
- 6th rib anteriorly
The right lung has ___ lobes
The right lung has 3 lobes
The left lung has ___ lobes
The left lung has 2 lobes
What is the Silhouette sign?
Similar densities of pneumonia and heart cause the right margin of the heart to be obscured
The _____ of the left lung is analogous to the middle lobe of the right lung
The lingula of the upper lobe of the left lung is analogous to the middle lobe of the right lung
The ______ and ______ lie against the heart
The right middle lobe and lingula of left upper lobe lie against the heart
The heart margin is still visible if there is a ______ lobe mass
The heart margin is still visible if there is a lower lobe mass
The trachea extends from the _____ to the _____
The trachea extends from the larynx to the carina
Which lung do aspirated objects usually end up in?
Right lung
Primary bronchi go to each _____
Secondary bronchi go to each _____
Primary bronchi go to each lung
Secondary bronchi go to each lobe
Lobes are subdivided into _____, which are supplied by _______ and _______
Lobes are subdivided into bronchopulmonary segments, each supplied by a tertiary bronchus and corresponding artery
Veins are intersegmental
What is the smallest unit of a lung that can be surgically removed?
Bronchopulmonary segment
Root refers to _____, while hilum refers to _____
Root refers to structures, while hilum refers to location
Pulmonary artery is ______ in the root, while the pulmonary veins is ______ in the root
Pulmonary artery is highest in the root, while pulmonary vein is lowest in the root
The left lung has an impression for the ______, while the right lung has an impression for the ______
The left lung has an impression for the aorta, while the right lung has an impression for the azygos vein
In the lung, ________ are bronchoconstrictors and supply glands
In the lung, parasympathetics are bronchoconstrictors and supply glands
What are the parasympathetics for the lungs?
Vagus nerves
In the lung, _______ effects are unclear
In the lung, sympathetic effects are unclear
(B2 receptors are for circulating epinephrine from the arenal gland)
What are the sympathetics for the lungs?
Upper thoracic splanchnic nerves (T1-T5)
______ supply airway walls, while the ______ are for gas exchange
Bronchial arteries supply airway walls, while pulmonary arteries are for gas exchange
________ run with the airway, while the ________ are independent
Pulmonary arteries run with the airway, while pulmonary veins are independent
There are _____ generations of branching from trachea to alveolar sacs
There are 23+ generations of branching from trachea to alveolar sacs
(16th generation is transition from conduction to respiratory zone)
Gas molecules move by _______ in conducting airways and by _______ in the respiratory airways
Gas molecules move by convection in the conducting airways and by diffusion in the respiratory airways
As aggregate cross-sectional area _______, velocity _______
As aggregate cross-sectional area increases, velocity decreases
Cross-sectional area is greatest in the _______ airways, so velocity is the lowest
Cross-sectional area is greatest in the alveolar airways, so velocity is the lowest
Lungs sounds heard during a physical exam are the sounds produced in ______
Lungs sounds heard during a physical exam are the sounds produced in primary bronchi
Bronchi have _______, while bronchioles have _______
Bronchi have cartilage plates (or cartilage rings if smaller), while bronchioles have no cartilage
What indicates that a bronchiole is a respiratory bronchiole?
An alveolus poking out of the wall of the bronchiole
What is the effect of elastic fibers on smaller airways?
Elastic fibers keep smaller airways open during expiration
What effect does loss of elastic fibers have on smaller airways?
Loss of elastic fibers in smaller airways leads to dynamic compression of the airway on expiration in COPD
(emphysema)
What kind of cells are found in bronchi?
What distinguishes this cell type?
Pseudostratified columnar cells
Looks like multiple layers but every cell touches basal lamina
Lobules are defined by _________
Lobules are defined by terminal bronchioles
Pulmonary artery and bronchioles are ______, while pulmonary veins and lymphatics are ______
Pulmonary arteries and bronchioles are intralobular, while pulmonary veins and lymphatics are interlobular
One lobule is supplied by a _______
One lobule is supplied by a terminal bronchiole
What are Kerley B lines?
Dilated interlobular lymphatics and edema in the interlobular septa seen peripherally in X-rays of patients w/ pulmonary edema
Lobule septal walls are defined by ______ in ______
Lobule septal walls are defined by carbon in macrophages
Kerley A lines are _____ and _____ compared to Kerley B lines
Kerley A lines are larger and more central compared to Kerley B lines
Alveolar ducts have a ______ of alveoli along their walls, while respiratory broncholes have _____ alveoli along their walls
Alveolar ducts have a series of alveoli along their walls, while respiratory bronchioles have isolated alveoli along their walls
Bronchioles have a _______ layer and _______
Bronchioles have a continuous smooth muscle layer and respiratory epithelium
Describe the histology of larger bronchioles
Larger bronchioles have pseudostratified columnar epithelium w/ cilia and goblet cells
Describe the histology of smaller bronchioles
Smaller bronchioles have simple cuboidal epithelium of clubs cells that produce a surface-active substance
(no goblet cells b/c do not want mucous to plug up airways)
_______ produce surfactant, which reduces ______
Type II pneumocytes produce surfactant, which reduces surface sentence
Where are macrophages found in alveoli?
Macrophages are found on the lumen side of the inside wall of alveoli
What is the main component responsible for the properties of surfactant?
A choline phospholipid
What are the functions of proteins in alveoli?
- Regulate surfactant secreteion, spreading, and stability
- Important in host defense by binding to microorganisms and regulating immune responses
O2 and CO2 must cross the ______, ______, and ______
O2 and CO2 must cross the capillary endothelium, Type 1 alveolar cells (pneumocytes), and a shared basal lamina
The aveolar septum has _____ and _____ portions
The alveolar septum has thick and thin portions
What comprises the thin portion of the alveolar septum?
What is its function?
Type 1 pneumocytes, capillary endothelium, and shared basal lamina
Facilitates diffusion (0.15-0.50 microns thick)
What comprises the thick portion of the alveolar septum?
Type II pneumocytes, connective tissue stroma, and other cell types
What occurs at 4-5 weeks in embryonic airway development?
Lung buds off foregut
(Ventrsal bud is bud of endoderm w/ its coating of mesoderm from lateral plate, comes from splanchnopleure)
What occurs at 5-6 weeks in embryonic airway development?
Lobes and lobar bronchi
What occurs at 6-7 weeks in embryonic airway development?
Bronchopulmonary segments form
What occurs in the pseudoglandular stage of airway development?
- Simple cuboidal / simple columnar epithelium looks glandular
- Vessels develop but are not closely applied to the airway
When does the canalicular stage of airway development occur?
What occurs in the canalicular stage of airway development?
At 6 months
- Branching to level of respiratory bronchioles
- Type I cells differentiate
- Vessels closely applied to airway
- Gas exchange possible but surfactant not produced yet
What occurs in the saccular and alveolar stages?
Alveolar ducts and sacs form
Do alveoli stop developing after birth?
No, alveoli continue to develop years after birth
Why does airway velocity increase a bit in the upper airways?
The extra flow keeps the airways clear of debris
What is the earliest time at which a baby can be delivered and survive?
6 months
Capillaries are right against epithelium of airway and surfactant is produced shortly after
