Lower Respiratory Tract Flashcards
What are the main components of the lower respiratory tract?
Trachea
Main stem of bronchi
Bronchial tubes
Lungs (alveoli)
What type of epithelium lines the trachea, bronchi, and bronchial tubes?
What are these structures contained in?
Pseudostratified columnar ciliated epithelium
Contained in a mucous membrane
What is the purpose of the cilia on the pseudostratified columnar ciliated epithelium lining the lower respiratory tract?
Cilia move a layer of mucous toward the laryngopharynx where it can be swallowed or coughed up
What midline structure is continuous with the larynx from the neck into the superior mediastinum?
Trachea
The trachea extends from _____ vertebrae to the ______ angle (the junction of the manubrium to the sternal body) at the same level as ______
C6
Sternal
T4
The ________ _________ plane passes through the sternal angle to intersect the intervertebral disc between the T4-T5 verebrae. This plane intersects the trachea in the midline where it bifurcates into 2 main bronchi.
Transverse thoracic
Describe the diameter and length of the trachea in adults
3/4” diameter
3.5-5” long
Describe the composition of the trachea
20 U-shaped hyaline cartilage rings
Smooth muscle - found in elastic posterior wall next to esophagus
Mucous glands - keep surface of epithelium coated
What arteries supply the trachea?
Superior and inferior thyroid aa.
What veins drain the trachea?
Superior, middle, and inferior thyroid veins
Compare/contrast the right main bronchus with the left main bronchus
Right main bronchus:
Larger diameter
More vertical
Shorter length
Left main bronchus:
Smaller diameter
Less vertical
Longer length
The secondary (lobar) bronchi go to the lobes of the lungs. Describe the lobar bronchi in the right vs. left lung
Right lung = 3 lobar bronchi (because 3 lobes)
Left lung = 2 lobar bronchi (because 2 lobes)
The _________ ___________ refer to the largest subdivisions of a lobe of a lung. They are pyramidal shaped segments with their apices facing the lung root and their bases at the pleural surface.
Bronchopulmonary segments
The bronchopulmonary segments refer to the largest subdivisions of a lobe of a lung. They are pyramidal shaped segments with their apices facing the lung root and their bases at the pleural surface.
They are separated from adjacent segments by connective tissue ________.
They are supplied independently by a __________ bronchus and tertiary branch of a _________ artery
Septa
Segmental; pulmonary
Bronchopulmonary segments are named according to segmental bronchi supplying them. They are supplied independently by a segmental bronchus and a tertiary branch of a pulmonary artery. What drains the bronchopulmonary segments?
Intersegmental parts of pulmonary veins that lie in connective tissue between and drain adjacent segments
What do the tertiary (segmental) bronchi supply?
The bronchopulmonary segments - which are the largest subdivisions of a lobe (pyramidal shaped segments of the lung with their apices facing the lung root and their bases at the pleural surface)
How many segments/segmental bronchi are associated with each lung?
Right lung = 10 segments, 10 segmental bronchi
Left lung = 8 segments, 8 segmental bronchi
What is the next level of branching below the tertiary (segmental) bronchi?
Beyond tertiary segmental bonchi, there are 20-25 generations of branching conducting bronchioles that eventually end as terminal bronchioles
What are the overall levels of branching of the lower respiratory tract from the trachea to the alveoli?
Trachea Primary/main bronchi Secondary/lobar bronchi Tertiary/segmental bronchi Terminal bronchioles Respiratory bronchioles Alveoli
What are the smallest conducting bronchioles? Describe their characteristics
Terminal bronchioles
Lack cartilage in their walls
Transport air but lack glands or alveoli
Give rise to respiratory bronchioles
In which division of the lower respiratory tract do alveoli first appear?
Respiratory bronchioles
Respiratory bronchioles are characterized by scattered, thin walled outpocketings called ______ that extend from their lumens.
Alveoli
What are the 2 primary functions of respiratory bronchioles?
Transport air
Gas exchange
Each respiratory bronchiole gives rise to 2-11 _______ _______
Alveolar ducts
Each respiratory bronchiole gives rise to 2-11 alveolar ducts
Each alveolar duct gives rise to 5-6 ______ _______, into which clusters of alveoli open
Alveolar sacs
Alveoli have a ______ ______ thickness
They are organized in ________ and are surrounded by a dense _______ network
Single-celled
Clusters; capillary
What arteries supply the bronchi but not the alveoli?
3 bronchial arteries (2 left, 1 right)
[these supply the bronchial tubes but not the alveoli because they are not part of pulmonary circulation]
The 3 bronchial arteries (2 left and 1 right) are responsible for supplying the bronchial tubes. What do these branch from?
The descending aorta
Describe venous drainage of the bronchi
Bronchial veins drain to the azygous veins, which are tributaries to the superior vena cava
What general structures are associated with the surface anatomy of the lungs?
Fissures Cardiac notch Lingula Apex Base Hilum Visceral pleura
What fissure(s) is/are found in the left lung and what do these divide?
Oblique fissure only - divides the upper and lower lobes
What fissure(s) is/are found in the right lung and what do these divide?
Oblique fissure - divides middle lobe from lower lobe and upper lobe from lower lobe
Horizontal fissure - divides upper lobe from middle lobe
Which of the following is found only in the right lung?
A. Cardiac notch B. Lingula C. Oblique fissure D. Horizontal fissure E. Hilum
D. Horizontal fissure
Where is the cardiac notch located?
In the upper lobe of the left lung, adjacent to the heart
What surface anatomy structure of the lung is found in the upper lobe of the left lung, adjacent to the cardiac notch?
Lingula
What constitutes the apex of the lung? What is another term for apex of the lung?
Apex = area above first ribs
Cupola = apex
What is the term for the area of the lungs adjacent to the respiratory diaphragm?
Base
What is the term for the lung structures containing other structures entering and exiting the lungs like bronchi, pulmonary vessels, pulmonary nerves, lymphatic vessels, and bronchial vessels?
Hilum
What is the difference between pulmonary and systemic circulation?
Pulmonary circulation moves blood between the heart and lungs (deoxygenated blood from heart goes to lungs, then returns to heart as oxygenated blood)
Systemic circulation moves blood between the heart and other body systems (oxygenated blood from heart goes to body, then returns to heart as deoxygenated blood)
Vessels associated with pulmonary circulation include:
Pulmonary trunk
Pulmonary arteries
Alveolar capillary network
Pulmonary veins
What does the pulmonary trunk itself emerge from?
The right ventricle
Vessels associated with pulmonary circulation include:
Pulmonary trunk
Pulmonary arteries
Alveolar capillary network
Pulmonary veins
Which of the above have right and left divisions, and have a branching pattern similar to bronchi?
Pulmonary arteries
Vessels associated with pulmonary circulation include:
Pulmonary trunk
Pulmonary arteries
Alveolar capillary network
Pulmonary veins
Which of the above constitutes the functional part of pulmonary circulation?
Alveolar capillary network - serves function of gas exchange
[note that total surface area must be equal in size to all combined capillaries in all organs in the body]
Vessels associated with pulmonary circulation include:
Pulmonary trunk
Pulmonary arteries
Alveolar capillary network
Pulmonary veins
What is the purpose of the pulmonary veins?
Collect blood from alveoli and return to the left atrium
General visceral afferent fibers supply what type of innervation to the lungs?
Sensory
Sensory (general visceral afferent) fibers supplying the lungs are contained in the ______ nerve
Vagus (CN X)
Sensory (general visceral afferent fibers) supplying the lungs are contained in the vagus nerve. What are the 5 types of receptors are associated with these fibers?
Stretch receptors Irritant receptors Tactile receptors Baroreceptors Chemoreceptors
Sensory (general visceral afferent fibers) supplying the lungs are contained in the vagus nerve. These are associated with 5 types of receptors:
Stretch receptors Irritant receptors Tactile receptors Baroreceptors Chemoreceptors
Which of the above are found in pulmonary arteries?
Baroreceptors
Sensory (general visceral afferent fibers) supplying the lungs are contained in the vagus nerve. These are associated with 5 types of receptors:
Stretch receptors Irritant receptors Tactile receptors Baroreceptors Chemoreceptors
Which of the above are found in respiratory epithelium?
Irritant receptors
Sensory (general visceral afferent fibers) supplying the lungs are contained in the vagus nerve. These are associated with 5 types of receptors:
Stretch receptors Irritant receptors Tactile receptors Baroreceptors Chemoreceptors
Which of the above are found in alveoli and smooth muscle?
Stretch receptors
Sensory (general visceral afferent fibers) supplying the lungs are contained in the vagus nerve. These are associated with 5 types of receptors:
Stretch receptors Irritant receptors Tactile receptors Baroreceptors Chemoreceptors
Which of the above are found in pulmonary veins?
Chemoreceptors (these detect blood gases)
Sensory (general visceral afferent fibers) supplying the lungs are contained in the vagus nerve. These are associated with 5 types of receptors:
Stretch receptors Irritant receptors Tactile receptors Baroreceptors Chemoreceptors
Which of the above are associated with the cough reflex?
Tactile receptors
General visceral efferent fibers are associated with what type of innervation in the lungs?
Motor
Motor (general visceral efferent) fibers supplying the lungs are autonomic fibers that are contained in the _______ _______ plexus
Pulmonary nerve
Motor (general visceral efferent) fibers supplying the lungs are autonomic fibers that are contained in the pulmonary nerve plexus. What are the 2 divisions of these motor fibers and what aspects of the lung do they supply innervation to specifically?
Sympathetic (post-ganglionic) fibers
Parasympathetic nerve fibers
Both supply smooth muscle and glands
Motor (general visceral efferent) fibers supplying the lungs are autonomic fibers that are contained in the pulmonary nerve plexus. Both sympathetic (post-ganglionic) fibers and parasympathetic nerve fibers supply smooth muscle and glands.
What are the functions of the sympathetic division in terms of their effects on glandular secretion, bronchial vessels, and bronchial tubes?
Inhibit glandular secretion
Induce vasoconstriction of bronchial vessels
Dilate bronchial tubes
Motor (general visceral efferent) fibers supplying the lungs are autonomic fibers that are contained in the pulmonary nerve plexus. Both sympathetic (post-ganglionic) fibers and parasympathetic nerve fibers supply smooth muscle and glands.
What are the functions of the parasympathetic division in terms of their effects on glandular secretion, bronchial vessels, and bronchial tubes?
Increase glandular secretion
Induce vasodilation of bronchial vessels
Constrict bronchial tubes
Describe course of parasympathetic fibers in association with the lungs
Pre-ganglionic parasympathetics come to pulmonary nerve plexus by vagal nerves
They synapse with post-ganglionic parasympathetics on surfaces of bronchial tubes and vessels
What are the 2 lymphatic plexuses associated with the lungs? Where are these found?
Superficial plexus - deep to visceral pleura
Deep plexus - located in substance of bronchi
The superficial lymph plexus is found deep to the visceral pleura. Where does this plexus drain FROM and TO?
Drains lymph FROM visceral pleura and lung parenchyma TO bronchopulmonary lymph nodes in the hilum
The deep lymph plexus is located in the substance of the bronchi. Where does this plexus drain lymph FROM and TO?
Drains lymph FROM bronchi TO pulmonary lymph nodes near the hilum, THEN goes to bronchopulmonary nodes in the hilum
Name the 4 groups of lymph nodes associated with the lungs in sequence of their lymphatic drainage
Pulmonary nodes
Bronchopulmonary (hilar) nodes
Tracheobronchial nodes
Tracheal nodes
What group of lymph nodes would you find in the hilum?
Bronchopulmonary (hilar) nodes
What group of lymph nodes would you find in the lungs at the bifurcation of larger bronchi?
Pulmonary nodes
What group of lymph nodes would you find at the bifurcation of the trachea?
Tracheobronchial nodes
What group of lymph nodes would you find on the lateral surfaces of the trachea?
Tracheal nodes
What are the 2 lymph trunks associated with the respiratory tract?
Right bronchomediastinal lymph trunk
Left bronchomediastinal lymph trunk
What does the right bronchomediastinal lymph trunk drain FROM and TO?
Drains lymph from right side of trachea to right lymphatic duct
What does the left bronchomediastinal lymph trunk drain FROM and TO?
Drains from left side of trachea to the thoracic duct
Both the superficial and deep lymph plexuses eventually drain into the bronchopulmonary (hilar) lymph nodes.
The right lung drains primarily through the consecutive sets of nodes on the _____ side. The superior lobe of the left lung drains primarily through corresponding nodes on the ____ side.
Many, but not all, lymphatics from the lower lobe of the left lung drain to the _____ superior tracheobronchial nodes; the lymph then continues to follow the ___ side pathway
Right; left
Right; right
The bronchomediastinal lymph turnks are major lymph conduits draining the thoracic viscera. Where do the right and left bronchomediastinal lymph trunks usually terminate?
On each side at venous angles = junctions of the subclavian and internal jugular veins
[however, the right bronchomediastinal trunk may first merge with other lymphatic trunks converging ehre to form the short right lymphatic duct; and the left bronchomediastinal trunk may terminate in the thoracic duct]
Lymph from parietal pleura drains into what 4 groups of lymph nodes of the thoracic wall?
Intercostal nodes
Parasternal nodes
Mediastinal nodes
Phrenic nodes
[note that a few lymph vessels from the cervical parietal pleura may drain into axillary nodes]
At what spinal level does the trachea bifurcate into primary bronchi?
T4-T5 (midline at the level of the areola)
If a child were to aspirate a foreign body while standing/sitting upright, where are you most likely to see it on an imaging study?
Right lower lobe
If a child were to aspirate a foreign body while laying supine, where are you most likely to see it on an imaging study?
Right upper lobe
Cardiomegaly (enlargement of the heart tissue) may lead to pulmonary complaints such as shortness of breath due to irritation of what structure?
Lingula - located on left lung adjacent to the cardiac notch
Describe the pathway of lymph nodes from pulmonary to tracheal
Pulmonary –> hilar –> tracheobronchial –> tracheal