thorax Flashcards
where is the thorax?
the superior part of the trunk, lying between the neck and the abdomen.
what are the 3 divisions of the thorax?
- mediastinum- contains all contents of thorax except lungs
2 and 3. paired lateral pulmonary cavities- occupied but the lungs
what makes up the thoracic cage?
the bones of the thorax which includes 12 pairs of ribs and their associated costal cartilages, 12 thoracic vertebrae and their intervening intervertebral discs and the sternum
what is the primary function of the thoracic cage?
protect the thorax and some abdominal contents
what are the 3 parts of the sternum?
the manubrium, body, and xiphoid process
what can be found on the superior surface of the manubrium?
the jugular notch and paired clavicular notches
what does the first rib articulate with?
the lateral borders of the sternum to form a synchondrosis
what is the junction between the manubrium and body called?
manubiosternal joint or sternal angle (angle of Louis)
where does the second rib articulate?
manubiosternal joint
what does the body articulate with?
ribs 3-6 with the 7th rib attaching at the junction of the body and the xiphoid joint= xiphisternal joint
where does the xiphoid process lie?
around the level of T10 vertebral body
what does the xiphoid process represent?
the inferior limit of the thoracic cavity (projected onto the anterior wall of the thorax)
describe the ribs
curved, flat bones that form most of the cage typical ribs (3-9) exhibit head, neck, tubercle, angle, and body. the facets on the heads articulate with the vertebrae of the same numerical level and the one superior (except 1st rib only articulates with T1 and ribs 10-12 with their respective vertebrae)
what are the true ribs?
1-7 attach directly to the sternum via their costal cartilage
what are the false ribs?
8-10 articulate via their costal cartilage to the next superior rib
what are the floating ribs?
11-12 end in the abdominal musculature
what are costal grooves?
concavities on the inferior, internal borders of the ribs for the intercostal nerves and vessels
where are intercostal spaces seen?
between each successive rib and are named for each superior rib
where are costovertebral joints?
between heads of ribs and vertebral bodies
where are costotransverse joints?
between tubercles of ribs and transverse processes (facets) of thoracic vertebrae
where are costochondral joints?
between ribs and costal cartilage
where are sternocostal joints?
between costal cartilages and the sternum
which joints are synchondroses?
all costochondral joints, 1st sternocostal joint, and xiphisternal joint
where do symphyses occur?
posteriorly between thoracic vertebral bodies and anteriorly at the manubriosternal joint
what is the superior thoracic aperture?
the communicating passageway between the thorax and neck/upper extremity. aka thoracic inlet
what is the posterior boundary of the thoracic inlet?
vertebra T1
what is the lateral boundary of the thoracic inlet?
1st ribs and their costal cartilage
what is the anterior boundary of the thoracic inlet?
the superior border of the manubrium
what structures pass through the thoracic inlet?
trachea, esophagus, nerves and vessels that supply/drain the head, neck and upper extremity
what is the inferior thoracic aperature also known as?
anatomical thoracic outlet
what is the posterior boundary of the thoracic outlet?
T12 vertebrae
what is the posterolateral boundary of the thoracic outlet?
the 11th and 12th ribs
what is the anterolateral boundary of the thoracic outlet?
the costal margins (made up of costa cartilages 7-10)
what is the anterior boundary of the thoracic outlet?
the xiphisternal joint
what is thoracic outlet syndrome?
compression of vessels and nerves emerging from the thorax and heading toward the neck and upper extremity. obstructions/compressions usually occur outside of the thorax, and the manifestations are in the upper limbs
when are the external intercostals most active?
during inspiration