Chapter One - Lungs Flashcards
What anatomical parts does the thorax include?
Thorax (chest) includes the thoracic wall and the thoracic cavity. It contains internal organs such as heart and lungs and various other structures (esophagus, trachea, large vessels).
What composes the skeletal part of the thoracic wall? What else is there? What is the role of the wall?
The skeletal part consists of the rib cage, thoracic vertebrae and sternum. The rest of the wall is made of muscles, skin and fascia. The wall protects the thoracic cavity and the structures within it.
What are the intrinsic muscles of the thoracic cage?
INTERCOSTAL MUSCLES
- External intercostal
- Internal intercostal
- Innermost intercostal
DIAPHRAGM (primary muscle of respiration)
What are the three intercostal muscles?
- External intercostal muscle
- Internal intercostal muscle
- Innermost intercostal muscle
What does VAN mean? How are they oriented?
Intercostal vein, artery and nerve (VAN)
What is the pleura and what does it include?
Pleura is a serous membrane covering the inner walls of the thoracic cavity (parietal pleura) and the surface of the lungs (visceral pleura).
The parietal pleura is subdivided into regions… what are they?
Parietal pleura is subdivided into regions:
- Costal pleura covers ribs and intercostal muscles.
- Diaphragmatic pleuracovers diaphragm.
- Mediastinal pleuracovers the mediastinal surface.
- Cervical pleura (or cupola) extends into the neck.
Where is the pleural cavity found? What does it contain, and what is its role (what it contains)?
In the living, the pleural cavities are small, found between visceral and parietal pleura. They contain a small amount of serous pleural fluid to lubricate the surfaces of the lungs to allow movement of the lungs against the parietal surfaces during inspiration and expiration.
What is a pleural reflexion?
Pleural reflection is the point where parietal pleura changes its position from one area to another, such as from the diaphragm to the costal surface.
How are the pleural reflections named?
Pleural reflections are:
1. Costodiaphragmatic reflection: where the costal and diaphragmatic pleurae meet.
- Costomediastinal reflection: where the costal and mediastinal pleurae meet.
What is a pleural recess?
Pleural recesses are parts of the pleural cavity into which the lungs can expand on full inspiration. On full expiration, or during shallow normal breathing, the recesses do not contain lungs.
How are the two pleural recesses named?
- The costodiaphragmatic recess (L and R) is about two rib spaces deep.
- The costomediastinal recess is very small.
What is pleural effusion?
Pleural effusion: excess fluid that accumulates in the pleural cavity. The excess fluid can impair breathing by limiting the expansion of the lungs.
What are the lobes and fissures of both lungs? Which lung is bigger and why?
The right lung is larger than the left lung because the heart occupies more space in the thorax on the left side.
Right lung is divided into upper, middle and lower lobes(or superior, middle and inferior lobe) by an oblique fissure and a horizontal fissure.
Left lung is divided into upperand lower lobes by an oblique fissure.
What are the surfaces of each lung? They match with the pleura’s surfaces.
The surfaces of the lungs match the surfaces of the parietal pleura. Each lung has:
- diaphragmatic
- costal and
- mediastinal surfaces.
What is the hilum of the lung? What is the root of the lung? What is the difference between these two?
Hilum is the area on the medial aspect of the lung where vessels and other structures comprising the root of the lung either enter (bronchus, pulmonary artery) or leave (pulmonary veins) the lung.
The difference between these two is that the hilum is the region where the root is situated, and the root contains all the structures.
Where does the trachea bifurcate into the left and right bronchus? Where does the trachea deviate and why? What is the difference between the left and right bronchus? What does this imply, clinically? What are the two reasons behind the bronchus’ differences?
The trachea bifurcates into the left and right bronchus (main bronchus) at the level of the sternal angle. Because of the heart, the trachea deviates to the right. This fact, plus the size difference of the lungs, means that the right bronchus is bigger in diameter, more vertical and shorter than the left bronchus (i.e., the left bronchus is narrower, more horizontal and longer). Thus, inhaled peanuts and other foods tend to end up in the right bronchus.
How many segments do the upper and lower lobe of the left lung have? How many segments do the lobes of the right lung have? Each segment has a functional unit that consists of…?
The upper and lower lobe of the left lung have 5 segments each.
The upper lobe of the right lung has 3 segments, the middle lobe has 2 segments and the lower lobe has 5 segments.
Each segment of the lung is a functional unit with its own tertiary bronchus, artery and vein.
What are the accessory muscles of respiration? In what regions are they usually situated?
Accessory muscles of respiration
Any muscle attaching to the ribs can potentially move the ribs and act as accessory respiratory muscle. Muscles in the neck and the abdomen can alter the positions of upper and lower ribs.
Scalene muscles
Sternocleidomastoid (SCM)
Pectoralis major
Pectoralis minor
Transversus thoracis
Abdominal muscles
What is the phrenic nerve? What spinal nerves forms it?
Phrenic nerve
Motor innervation to diaphragm! It is formed by the spinal nerves C3, C4, C5.
C3, 4, and 5, keep the diaphragm alive!
If one is damaged, there can be a partial loss of function but not total.
What is the “bucket handle” movement and the “pump handle” movement? Which anatomical structure are responsible for them?
The lower ribs move laterally when they are elevated (“bucket handle” movement). When the upper ribs are elevated the anteroposterior (AP) diameter of thorax is increased (“pump handle” movement) with a greater increase occurring inferiorly.
Pump handle movement of sternum and ribs = superior and anterior movement of sternum
Bucket handle movement of ribs = elevation of lateral shaft of ribs
Thorax widens during inspiration as the ribs are elevated.
The combination of movements that occur during inspiration increase the AP and transverse diameters of the thoracic cage.
What is the structure of an adult female’s breast?
Structure in adult female: made up of many lobules of glandular tissue adipose tissue fibrous tissue - attaches glandular tissue to overlying skin
What is the main clinical concern regarding breasts?
D. Clinical concerns: Lymphatic drainage (pathways for metastasis of breast carcinoma). Most lymph from the breast drains:
a. laterally to pectoral (or anterior axillary) lymph nodes in the axilla, then to the central axillary nodes, then to the apical axillary nodes, and finally by lymphatic ducts into the venous system.
b. to apical nodes directly (i.e., superiorly)
c. to internal thoracic nodes (i.e., deeply)
d. to opposite breast (i.e., medially)
e. to rectus sheath (i.e., inferiorly) then into abdominal cavity
** Enlarged lymph nodes during cancer, simple palpation = first step to diagnosis
