Thorax 04: Anatomy of Lungs and Pleural Sacs Flashcards
Mechanical system of the respiratory system
Musculoskeletal elements for changing size of thorax and alveoli
Upper respiratory tract
Nasal cavity to larynx
Lower respiratory tract
Trachea to alveoli
Conducting zone
Runs from the nasal cavity to the terminal bronchioles; cleans, warms, and humidifies air
Respiratory zone
Parenchyma of the lungs; site of gas exchange. Involves the respiratory bronchioles, alveolar ducts, to alveoli
Pump Handle Model of Thoracic Movement
Sternum moves up and out to expand the thoracic cavity; expands the AP diameter
Bucket Handle Model of Thoracic Movement
Elevation of the lateral shaft of the rib to expand thoracic cavity; expands the M-L diameter
How does the thoracic cavity expand during quite inspiration?
diaphragm contracts (i.e., flattens) to increase the vertical dimensions, pushing abdominal cavities out
How does the thoracic cavity contract during quite exhalation?
Diaphragm relaxes and elastic recoil of the lungs forces air out
How does the thoracic cavity expand during vigorous inspiration?
external intercostal muscles contract to increase the mediolateral and anteroposterior diameters of the thorax; first rib is stabilized by scalenes
How does the thoracic cavity expand during very vigorous inspiration?
Alongside vigorous inspiration, the scalenes and sternocleidomastoid both help elevate the thorax
What nerves innervate the diaphragm?
C3, C4, C5 (keep the diaphragm alive)
What nerves innervate the innercostal muscles?
T1-T11 on the intercostal nerves
What nerves innervate the scalenes?
C3-C8
What nerves innervate the sternocleidomastoid
Cranial nerve XI and C3,C4
What are the two sides of the lungs and how many lobes do they have?
Right and left. Right has three lobes, left has two
Upper lobe
The upper lobe of the lungs found in both sides
Bottom lobe
The bottom lobe of the lungs found in both sides
Middle lobe
The lobe between the upper and lower lobes found in the anterior side of the right lung only
Oblique fissure
Separates the upper and lower lobes
Horizontal fissure
Separates the upper and middle lobes of the right lung
Bronchopulmonary segment
A segment of the lung supplied by tertiary-segmental bronchus and is supplied by a pulmonary artery. It is the largest independent unit of the lung
How many bronchopulmonary segments are in each side of the lung?
10
Trachea
The windpipe; consists of c-shaped cartilaginous rings, closed off posteriorly by smooth muscle that runs from C6 to T4/5 that bifurcates into bronchi
Primary bronchi
The two branches of the bifurcation of the trachea; one goes to each side of the lung
Lobular Bronchi
Also known as secondary bronchi; the results of the bifurication of the primary bronchi into one segment for each lobe (there are 5 lobular bronchi in total)
Segmental tertiary bronchi
The results of the bifuricaition of each of the lobular bronchi; each lung has 10 tertiary bronchi in total
Bronchus intermedius
The common stem for right-side lower and middle lobes
Eparterial bronchus
Specifically the upper lobular bronchus of the right lung
Superior lobar bronchus
Lingular segments in left lung
Respiratory epithelium
Pseudostratified ciliated columnar epithelium of the mechanical respiratory tract (not found in the respiratory zone)
What is the function of blood vessels in the lamina?
Warms the air
What is the function of serous secretions from seromucinous glands?
Moistens the air
Carina
The point in the trachea where bifurication into primary bronchi occurs
Bronchiole
A small airway than a bronchus with smooth muscle and an epithelium with less goblet cells and more cuboidal cells.
Asthma
Chronic disorder of airway constriction due to immunological response. There are enlarged smooth muscles, bronchoconstriction, inflammation of bronchial wall, and increased mucus secretion
Alveoli
The small bulbs branching from segmental bronchi that are the site of gas exchange
Pneumocytes
Specialized cells of the lungs divided into Type 1 and Type 2
Type 1 pneumocyte
Located in the alveolar endothelium, they are the site of gas exchange. Super thin
Type 2 pneumocyte
Secretes surfactin
Surfactin
A fluid secreted by type 2 pneumocytes to increase surface tension of the alveoli
Emphysema
A disease of the lower respiratory tract involving the destruction of alveolar walls and enlargement of the alveoli. Weakens gas exchange
Diffuse neuroendocrine system
Secretes peptide hormones to regulate muscle tone in bronchial and vessel walls
What are the two hormones secreted by the neuroendocrine system with relation to the lungs?
Serotonin and bombesin
In a chest xray, where is the heart’s level relative to the right lung?
Right by the middle lobe; behind the lower lobe. Sometimes at the level of the upper lobe
In a chest xray, where is the heart’s level relative to the left lung?
Behind the lower lobe and in front of the upper lobe
Where is the right lung middle lobe located in a chest x-ray cross section?
Anterior to the heart
Where is the left lung lower lobe located in a chest x-ray cross section?
Prosterior IF the heart is in the cross section
Where is the left lung lower lobe located in a chest x-ray?
Above heart in AP and lateral; related to left pulmonary cavity
Lung hitum
The doorway of the lung; the location of the lung where structures enter and exit
Lung root
The structures that go into and out of the lung at the hilum
What are the three surfaces of the lung?
Mediastinal, costal, diaphragmic
Mediastinal surface
The surface at the center of the lung, where the root is located
Costal surface
The surface at the edges of the lung, sticking out more than the mediastinal
Diaphragmic surface
The bottom surface of the lung, which is in contact with the diaphragm
What are the three borders of the lungs?
Anterior, posterior, inferior
Lung apex
The top tip of the lung
How are the two lungs asymmetric?
RALS: Right anterior, Left Superior
In the R lung, the pulmonary artery is Anterior to the bronchus. In the L lung, the artery is Superior to the bronchus.
What structure in the left lung pushes down the bronchus?
The esophagus
What structures are associated with the right lung?
Ribs, diaphragm, vertebrae, vena cava, brachiocephalic veins, azygous veins, middle lobe
What structures are associated with the left lung?
Ribs, diaphragm, vertebrae, esophagus, arch of aorta, descending aorta, left brachiocephalic vein, lingula of upper lobe
Pulmonary arteries
Intrasegmental; run alongside bronchial tree into each bronchopulmonary segment
Pulmonary veins
Intersegmental; drain newly oxygenated blood from adjacent bronchopulmonary segments
Where does the parenchyma blood supply come from?
Pulmonary system
Where does the bronchial blood supply come from?
Bronchial arteries
What are the pulmonary cavities
Regions on either side of the mediastinum filled with lungs, pleural sacs, and pleural cavities
Are the lungs located in the pleural sacs?
No. The pleural sacs are closed bags that surround the lungs. The lungs are located in the pulmonary cavities
Endothoracic fascia
Loose connective tissue that separates the parietal pleura from the intercostal muscles
Pleural cavity
A cavity filled with some fluid that is between the parietal and visceral pleura. This fluid reduces friction but increases surface tension to hold the two linings together
Where does the pleural sacs derive from?
Parietal lining comes from somatopleur, visceral lining comes from splanchnopleur. Both are in the form of mesothelia
Pneumothorax
When air fills the pleural cavity and air pressure is equalized, resulting in a collapsed lung
What are the four sections of the parietal pleura?
Mediastinal, Diaphragmic, Costal, and Cervial
What nerves innervate the parietal pleura?
Phrenic nerve innervates mediastinal and diaphragmic; intercostal nerves innervate costal and cervical
Recess
A location where two kinds of parietal pleura touch during expiration. They are midclavical, medaxillary, and posterior
Pleural effusion
Collection of fluid in pleural sac
What nerves innervate the lungs?
Parasympathetics leave and return to CNS on the Vagus nerve (CN X); Sympathetics leave CNS in T1-5. No afferent sympathetics
Trachealis muscle
Q band of smooth muscle that connects the ends of the C-shaped tracheal cartilages posteriorly, constricting the trachea to increase expiratory velocity
Club cells
Cells that protect the epithelium of the bronchioles by secreting some surfactant components, degrading toxins, and replenishing lost cells
What is the route along which the lymphatics drain from the lung parenchyma?
Segmental–> lobar–> interlobar–> hilar–> mediastinal–> supraclavicular and sternal notch
What effects do beta1-adrenergic and beta2-adrenergic receptor stimulation by epinephrine have on the lung?
beta1: constricts muscles
beta2: relaxes muscles
What are the layers traversed by the needle in a pleural tap performed at the 9th intercostal space at the midaxillary line?
Skin -> Subcutaneous fat and fascia -> Intercostal muscles -> Endothoracic fascia -> parietal pleura
