SFP: trachea, bronchi, lungs, pleura Flashcards
Where does the trachea begin?
Lower border of larynx at the cricoid cartilage at C6
Where does the trachea bifurcate?
At the sternal angle
The trachea bifurcates into ___
The right and left primary bronchi
Describe the general structure of the trachea
About ¾ of the diameter is composed of U-shaped bars of hyaline cartilage. The area not composed of cartilage is closed by the trachealis muscle.
What structures are anterior to the trachea?
Arch of aorta, brachiocephalic trunk, common carotid, left brachiocephalic vein, thymus
What structures are posterior to the trachea?
Right and left recurrent laryngeal nerves, esophagus, and vertebral column.
What is on the right side of the trachea?
Azygous vein, right vagus nerve, and pleura
What is on the left of the trachea?
Arch of aorta, left common carotid, left subclavian artery, left vagus nerve, left phrenic nerve, pleura
Compare the right and left primary bronchi
The right is wider, shorter, and more vertical; foreign objects are often aspirated into the right bronchus.
What is the carina?
Keel-shaped cartilage at tracheal bifurcation
The right primary bronchus divides ___ entering the hilum, while the left primary bronchus divides ___ entering the hilum
Before; after
The right primary bronchus branches into…
Superior secondary bronchus and intermediate bronchus
The left primary bronchus branches into…
The superior and inferior secondary bronchi
The intermediate bronchus divides into…
Middle and inferior secondary bronchus
Bronchi ultimately divide into ___
Terminal bronchioles
The lungs are separated by ___
The mediastinum
What are the lobes of the left lung?
Superior and inferior
The hilum of the lung allows for passage of…
Left pulmonary artery, left primary bronchus, and left pulmonary veins
What is the lingula?
Structure at lower tip of the superior lobe of the left lung
What are the lobes of the right lung?
Superior, middle, and inferior
What fissures are present in the right lung?
Oblique and horizontal
What is the difference between structures in the right and left lung in the hilum?
In the right lung, the pulmonary artery is anterior to the bronchus, while it is superior to the bronchus in the left lung. The primary bronchus divides before entering the hilum in the right lung and after entering the hilum in the left.
What makes bronchopulmonary segments anatomical units of the lung?
They each receive a branch of pulmonary artery, lymphatic vessels, and autonomic nerve supply.
What is the functional and surgical unit of the lung?
Bronchopulmonary segments
Bronchopulmonary segments are ventilated by ___
Tertiary bronchi
As we move along bronchi, what happens to cartilage rings?
They become cartilage plates
Describe cartilage in the bronchioles
It’s absent
What kind of epithelium is in the bronchioles?
Ciliated epithelium
What are the levels of bronchioles from most proximal to most distal?
- Terminal bronchiole 2. Respiratory bronchiole 3. Alveolar ducts
Where do alveoli first appear?
Respiratory bronchioles
Describe the flow of blood through the lungs
- Lungs receive deoxygenated blood from the right side of the heart through pulmonary artery
- Deoxygenated blood makes it to capillary beds at alveolar walls and gas exchange occurs
- Oxygenated blood enters pulmonary veins to be delivered to the left heart
What supplies blood to the lung tissue itself?
Bronchial arteries that branch from the descending aorta
What drains the lungs?
Bronchial veins
Bronchial veins drain to ___ on the right and ___ on the left
Azygous vein; hemiazygos vein
The superficial plexus in the lungs drains to ___ nodes
Bronchopulmonary
Deep plexus lymphatic vessels in the lungs drain to __ nodes
Pulmonary then bronchopulmonary nodes
After the hilar nodes, describe the drainage of lymph in the lungs
- Tracheobronchial nodes 2. Paratracheal nodes 3. Broncho mediastinal trunks 4. Brachiocephalic veins directly or indirectly
How does the pleura come to be during development?
The lungs grow into a structure that will eventually have a visceral and parietal layer
Where do the visceral and parietal pleura meet?
The hilum (root)
Describe the visceral pleura
It covers the outer surfaces of the lung and extends into the interlobar fissures
Describe the parietal pleura
Covers the thoracic wall, surface of mediastinum, and into the root of the lung
What is the pleural reflection?
The point at the hilum of the lung where a pleural cuff forms (visceral and parietal pleura join)
What is the pulmonary ligament?
Loose fold that hangs below the cuff and allows for movement of pulmonary vessels and bronchi during inspiration
Describe the cervical pleura
Portion of parietal pleura that covers the apex and extends up into the neck
Describe the costal pleura
Portion of the parietal pleura that lines the inner surface of the ribs, costal cartilages, intercostal spaces, sides of vertebral bodies, and back of the sternum
Describe the diaphragmatic pleura
Portion of the parietal pleura that covers the thoracic surface of the diaphragm
Describe the mediastinal pleura
Portion of the parietal pleura that covers the lateral border of the mediastinum
What are recesses?
Portions where the pleura/lung extend into during inspiration; there is a Costodiaphragmatic recess and costomediastinal recess
The pleura extends ___ rib levels lower than the lung
2
At the mid-clavicular line, the lungs extend to the __ rib, and the pleura extends to the __ rib
6; 8
At the mid-axillary line, the lung extends to the __ rib while the pleura extends to the __ rib
8; 10
At the mid scapular line, the lung extends to the __ rib while the pleura extends to the __ rib
10; 12
Where does the pulmonary nerve plexus distribute?
Trachealis muscle, mucous membrane of trachea and airways, and blood vessels
What is the function of afferent fibers in the lungs?
They carry information from mucous membranes and alveolar stretch receptors to the CNS
The parietal pleura is sensitive to…
Pain, temperature, touch, pressure
The visceral pleura is sensitive to…
Stretch
What are the main innervation methods of the parietal pleura?
Phrenic nerve and intercostal nerves
Describe the phrenic nerve in relation to the pleura
Innervates the mediastinal pleura as well as the dome of the diaphragmatic pleura
Describe the intercostal nerves in relation to the pleura
Segmental intercostal nerves innervate the costal pleura segmentally and the lower 6 intercostal nerves innervate the periphery of the diaphragm
Describe the innervation of the visceral pleura
Autonomic innervation from pulmonary plexuses at the tracheal bifurcation and main bronchi
Describe the phrenic nerves
They descend anterior to the root of the lungs between the pericardium and pleura. They’re distributed to the mediastinal pleura and dome of diaphragm
Which nerves provide motor innervation to the diaphragm?
Phrenic nerve
The right phrenic nerve descends to the right side of…
R brachiocephalic vein, SVC, R atrium, IVC
The left phrenic nerve descends to the left side of…
The aortic arch
The right vagus nerve is between ____
Brachiocephalic vein and brachiocephalic trunk
The left vagus nerve runs across the ___
Left side of the aortic arch
The vagus nerve runs ___ to the root of the lung, while the phrenic nerve runs ___ to the root of the lung
Posterior; anterior
How do we increase thoracic volume during inspiration?
Raising the sternal ends of the ribs to increase anteroposterior diameter and raising the ribs at the costo-vertebral joints to increase the transverse diameter
What happens to the diaphragm during inspiration?
It contracts, causing it to flatten
What happens to the trachea during inspiration?
The bifurcation can move downward by 2 levels
What is used during quiet inspiration?
Diaphragm and external intercostals
What is used during forced inspiration?
SCM, scalene, muscles that stabilize the scapula
What muscles are used in quiet expiration?
Passive; the muscles relax
What muscles are used in forced expiration?
Internal intercostals, abdominal muscles, and quadratus lumborum
When the patient holds their arms with their hands behind their heads, how does this show surface projections?
The scapula rotates superiorly, causing its medial border to be parallel to the oblique fissure from T4
When the patients hold their arm straight up, how does this show surface projections?
The horizontal fissure will cross the 5th rib at the mid axillary line and cross the 4th intercostal space. The oblique fissure will be at the spine of 4th thoracic vertebra. As it descends toward the anterior portion of the body, it crosses the 4th rib, 4th intercostal, 5th intercostal and midaxillary line, and follows the 6th rib anteriorly
