The Chest Wall, Breast and Thoracic Cavity Flashcards
List the 7 major components of the bony thorax.
1 - Manubrium.
2 - Sternum.
3 - Xiphoid process.
4 - Costal cartilages.
5 - Clavicles.
6 - Ribs.
7 - Thoracic vertebrae.
List the boundaries of the thorax.
- Superiorly: Thoracic inlet.
- Inferiorly: Thoracic diaphragm.
- Antero-latero-posteriorly: Ribs.
- Posteriorly: Thoracic vertebrae and scapulae.
How many ribs are there?
12.
Which ribs are have no cartilaginous connection to the manubrium or sternum?
What is the name given to these ribs?
- Ribs 11 and 12.
- Floating ribs.
At which vertebral level is the manubriosternal joint?
T4/5.
At which vertebral level is the xiphisternal joint?
- T9.
What are the other names for the manubriosternal joint?
List 3 important anatomical structures that occur at this level.
- The sternal angle / angle of Louis.
1 - It overlies the aortic arch on the left and the superior vena cava on the right.
2 - It marks the bifurcation of the trachea.
3 - The second pair of costal cartilages.
Which of the ribs are true ribs?
Ribs 1-7.
Define false ribs, and explain why the false ribs of the body are false.
- Ribs that do not connect directly to the sternum (ribs 8-12).
- The upper three false ribs connect to the costal cartilages of the ribs just above them. The last two false ribs are floating ribs.
List the margins of the thoracic inlet.
- The body of the first thoracic vertebra.
- The first ribs and their cartilages.
- The manubrium of the sternum.
What types of joints are found in ribs 1-7?
- Rib 1 has a fibrous joint.
- Ribs 2-7 have gliding synovial joints.
Where does the first rib articulate anteriorly?
On the superolateral surfaces of the manubrium.
Where do ribs 2-7 articulate anteriorly?
- Rib 2 articulates at the manubriosternal joint.
- Ribs 3-6 articulate with the lateral surfaces of the body of the sternum.
- Rib 7 articulates at the xiphisternal joint.
Describe the posterior joints formed by ribs.
- Each rib has two articulations with two vertebrae on each side of the vertebral column.
- One articulation is made the inferior surface of the superior vertebra, and another articulation is made at the superior surface of the inferior vertebra.
- The rib therefore traverses the discs between the bodies of the vertebrae.
What is the median septum?
A membrane that separates the lungs.
List the 6 major structures contained within the thorax.
1 - Lungs.
2 - Great vessels.
3 - The heart.
4 - Mediastinum.
5 - The trachea.
6 - The oesophagus.
Which dermatome covers the nipples?
T4.
Which dermatomes cover the area between the nipples and the umbilicus?
T5-T9.
Which dermatome covers the umbilicus?
T10.
Which dermatomes cover the area between the umbilicus and the genitalia?
T11 and T12.
Which dermatomes cover the genitalia?
S2 and S3.
List the thoracic structures at vertebral level T2.
The superior border of the scapula.
List the thoracic structures at vertebral level T2/3.
The suprasternal notch.
List the thoracic structures at vertebral level T3.
- The medial end of the spine of the scapula.
- The posterior end of the oblique fissure of the lung.
List the thoracic structures at vertebral level T4.
- The end of the arch of the aorta.
- The azygous vein enters the superior vena cava.
List the thoracic structures at vertebral level T4/5.
- The manubriosternal junction (the angle of louis).
- The start and end of the arch of the aorta.
List the thoracic structures at vertebral level T5.
The thoracic duct crosses the midline.
List the thoracic structures at vertebral level T7.
The inferior angle of the scapula.
List the thoracic structures at vertebral level T8.
- The caval opening in the diaphragm.
- The left phrenic nerve pierces the diaphragm.
- The hemi-azygous vein crosses to the left.
List the thoracic structures at vertebral level T10.
The oesophageal opening in the diaphragm.
List the thoracic structures at vertebral level T12.
- The aortic opening in the diaphragm.
- The coeliac trunk.
- The splanchnic nerve pierces the crura.
- The sympathetic trunk passes behind the median arcuate ligament.
- The subcostal bundle passes behind the lateral arcuate ligament.
Which structures pass through the caval opening in the diaphragm?
The inferior vena cava and the right phrenic nerve.
Which structures pass though the oesophageal opening in the diaphragm?
- The oesophagus.
- Branches of left gastric vessels.
- The vagus nerve.
Which structures pass through the aortic opening in the diaphragm?
- The aorta.
- The azygos vein.
- The hemi-azygos vein.
- The thoracic duct.
List the cavities of the thorax.
- The left pleural cavity.
- The right pleural cavity.
- The mediastinum.
What is contained in the mediastinum?
The heart and great vessels of the heart.
What are the anterior and posterior attachments of the mediastinum?
- Anteriorly: The sternum.
- Posteriorly: The vertebral column.
What penetrates the mediastinum at the lateral borders?
The hilum of the lung.
Where is McBurney’s point and what is its significance?
The point over the right side of the abdomen that is one-third of the distance from the anterior superior iliac spine to the umbilicus where the appendix attaches to the caecum.
What separates the mediastinum into superior and inferior cavities?
The sternal angle / angle of louis.
What is contained within the inferior mediastinum?
The pericardial sac and its contents (the heart is not located within the superior mediastinum).
List the divisions of the inferior mediastinum and their locations relative to the pericardial sac.
- Anterior to the pericardial sac is the anterior inferior mediastinum.
- Within the pericardial sac is the middle inferior mediastinum.
- Posterior to the pericardial sac is the posterior inferior mediastinum.
Which structure only exists in the mediastinum in children?
The thymus gland.
Describe the layers of the pericardium.
- The outermost layer is the fibrous pericardium.
- The innermost layer is the serous pericardium.
Describe the layers of the serous pericardium.
- Parietal pericardium.
- Visceral pericardium.
List the boundaries of the heart.
Anteriorly:
- The sternum, which is slightly shifted to the right of the heart.
- The thymus in children.
Posteriorly:
- The trachea.
- The oesophagus.
- The descending aorta.
Inferiorly:
The central tendon of the diaphragm.
Which of the lungs is narrower than the other?
The left lung is narrower.
List superior and inferior boundaries of the lungs.
- Superiorly: The apices extend 1-2cm above the clavicles.
- Inferiorly: Rises and falls between the 9th and 12th ribs.
Describe the segmentation of the lungs.
- Lobes are major divisions of the lungs and are separated by fissures.
- Segments are minor divisons of the lungs.
- Secondary lobules are minor divisions of segments.
How are the left and right lungs segmented into lobes?
- The right lung has 3 lobes (upper, middle and lower).
- The left lung has 2 lobes (upper and lower).
- The right lung has 2 fissures (oblique and horizontal).
- The left lung has 1 fissure (oblique).
How many broncho-pulmonary segments supply the right and left lungs?
- 10 segments supply the right lung.
- 8 segments supply the left lung.
List the muscles associated with the ribs.
- Intercostals (external, internal and innermost).
- Transversus thoracis.
- Levatores costarum.
