Anatomy Exam 2: Respiratory System Flashcards
Describe the general structure and function of the pleura.
The visceral pleura lines the exterior of the lung itself, and is continuous with the parietal pleura, which lines the pleural cavity. They are serous membranes with a potential space between them, which contains a small amount of serous fluid. This fluid allows the pleural surfaces to move against each other without friction.
Describe the segmental structure of the parietal pleura.
There is no histological difference between the areas of parietal pleura, but we assign them different names based on their innervation.
Most superior: cervical pleura.
Most medial: mediastinal pleura.
Most inferior: diaphragmatic pleura (this can be described as having a medial, dome portion and a peripheral portion).
Most lateral: costal pleura.
Explain the structure and function of the diaphragm.
The diaphragm is a dome-shaped muscle, with a centrally located tendon.
It is the primary muscle of respiration. When it contracts, it flattens, increasing the volume of the thoracic cavity and reducing pressure.
Hiatuses at T8, T10, and T12 allow structures to pass through the diaphragm.
Describe the innervation and blood supply of the diaphragm.
Somatic motor and sensory innervation is via the phrenic nerve (C3-5), though some peripheral parts are innervated by the intercostal nerves.
It is supplied by the pericardiacophrenic, musculophrenic, and inferior phrenic arteries. It is drained by the superior and inferior phrenic veins.
What structures pass through the diaphragm, and where?
T8: Inferior vena cava.
T10: Esophagus and vagus nerve.
T12: Aorta.
Describe the structure of the lungs. How does the left compare to the right?
The right lung (usually) has three lobes.
The left lung (usually) has two lobes. It also has a cardiac notch and a lingula, which is an outgrowth analogous to a third lobe.
The root of the lung is the collection of structures that are covered by the pulmonary sleeve as they meet the lung. The structures in the root include the pulmonary arteries, the main bronchi, and the two pulmonary veins. In most cases, the veins are inferior to the arteries and the bronchi.
The hilum is where these structures contact lung tissue.
Describe the pulmonary ligament.
The mediastinal parietal pleura of the lung reflects on itself and becomes visceral pleura here.
Concerning the vessels in the root of the long, what carries oxygenated blood? What carries deoxygenated blood?
Pulmonary arteries carry de-oxygenated blood from the heart to be oxygenated at the lungs.
Pulmonary veins carry oxygenated blood out of the lungs to the heart.
Describe the fissures of the lungs.
On the typical right lung there are two fissures separating three lobes. The horizontal fissure separates the superior lobe from the bottom two lobes. The oblique fissure separates the inferior lobe from the other two lobes.
The typical left lung has only one oblique fissure.
Describe the blood supply of the visceral pleura.
Arterial: from bronchial and pulmonary arteries (remember that the pulmonary artery has low O2 content).
Venous: drains to the pulmonary vein.
What is a bronchopulmonary segment and why is it significant?
Lungs are segmented into multiple bronchopulmonary segements, each containing segmental/tertiary bronchus, pulmonary artery, and lung tissue. They are enclosed in thin layers of connective tissue, which helps limit the spread of infection. Segmentation also allows surgeons to resect the lung without significant loss of other segments.
Describe the bronchial tree.
The primary bronchus is supported by C-shaped hyaline rings. It is roughly Y shaped, with the right main bronchus being more vertical than the left (implications in aspiration).
The main bronchi split into lobar/secondary bronchi: 3 right and 2 left. These are supported by crescent-shaped cartilage rings.
The secondary bronchi split into segmental/tertiary bronchi: ~10 right, ~8 left. These feed each independent bronchopulmonary segment.
A woman with pneumonia is experiencing pain in her lungs. What nerve is carrying this pain?
Pain is only experienced in the parietal pleura, not the visceral pleura.
Either the intercostal nerves or phrenic nerve (if mediastinal/dome of diaghrampatic parietal pleura) will be involved.
Compare visceral pain from the bronchi to pain originating in the pleura.
Visceral pain from the bronchi would be carried by the cardiosplanchnic nerve, which pleural pain would be carried by an intercostal nerve.
Describe the path of lymphphatic drainage of the lungs.
Pulmonary nodes in lung > bronchopulmonary nodes (in hilum) > tracheobronchial nodes > Left or right bronchomediastinal trunks > lymphatic duct > thoracic duct > systemic lymphatic circulation.
