The thorax Flashcards
List the boundaries of the thoracic cage:
Posteriorly: the thoracic vertebrae
Laterally: All 12 pairs of ribs (along with fascia/muscles, VAN, skin)
Anteriorly: The manubrium, sternum, and costal cartilages of ribs 7-10 and the xiphisternal joint
Inferior: This space is closed off by the diaphragm in the living.
What are the boundaries of the superior thoracic aperture?
T1- posteriorly
First pair of ribs and their costal cartilages- laterally
Manubrium and medial end of clavicle- anteriorly
What are the boundaries of the inferior thoracic aperture?
- 12th thoracic vertebra posteriorly
- 11th & 12th pairs of ribs laterally
- Costal cartilage of ribs 7-10 anteriorly
- Xiphisternal joint anteriorly
Which ribs are considered “true ribs” and why?
The first 7 pairs of ribs, because they have a direct attachment to the sternum. (Also called “vertebrosternal ribs”)
Which ribs are considered “false ribs?”
Ribs 8, 9, and 10 are considered false ribs because they are attached to the sternum via COSTAL CARTILAGE
Which ribs are considered “floating ribs?”
11th and 12th ribs are considered floating because they only have a vertebral attachment. They are not attached to the sternum, or to other ribs via cartilage.
Which ribs are considered “vetebrosternal?”
Ribs 1-7
How many spaces are there in the thoracic cage?
11
Name three structures that pass through the superior thoracic aperture
The trachea, the oesophagus, and the LCC
What is the relation of the suprasternal notch with the trachea?
The trachea lies posterior to the suprasternal notch
Which rib forms a joint with the sternum at the level of the manubriosternal joint?
2nd pair of ribs
What is the structural and functional significance of the manubriosternal joint?
Located between the manubrium and body of the sternum. The movement between the two bones increases the anterioposterior diameter of the thoracic cage, thus facilitating inspiration
What is the functional significance of the sternoclaviclar joint?
This is the only connection between the axial and appendicular parts of the skeleton. The weight of the limb cannot be supported unless this joint is intact. Arm must be supported in a sling if the clavicle is fractured, or the joint is dislocated.
Which ribs form costal-sternal joints?
Ribs 1-7
What is the functional sigificance of the sternocostal joints?
Assist in respiration
Name the ribs that form the costal margin
The cartilage of ribs 7, 8, 9, and 10, along with the 11th and 12th ribs
Ribs 3-9 are “typical” as they have the following major landmarks:
Head, neck, body, tubercle
Which ribs are considered atypical?
1st, 2nd, 10th, 11th, and 12th ribs are atypical
What makes the first pair of ribs atypical?
Wide and flat, has superior and inferior surface. Has only one articulatory surface where it connects with T1
What do the 10th, 11th, and 12th ribs have in common?
They all only have one facet on their heads, and as such only articulate with a single vertebra
What features are lacking in ribs 11 and 12?
A second facet, as well as the neck and tubercles
How many floating ribs do we have?
Four- two pairs of floating ribs
What are the names of the intercostal muscles?
Innermost, interior intercostals and exterior intercostals
The articulation of the rib tubercles with the transverse process of the vertebrae are called the
Costotransverse joints
What is an accessory rib, and where might they be found?
Accessory ribs are an additional pair of ribs attached to the vertebra of C7
