ANT Throrax I Lecture

What are the functions of the thorax

• conduit (passage for things like arteries nerves etc)

• protection of vital organs

• breathing

What are the compartments of the thorax

• mediastinum

• L and R pleural cavities

What are the bony parts of the thoracic cage

1. sternum

• manubrium

• body

• xiphoid process

• sternal angle (T4-T5)

2. Ribs (and costal cartilage)

3. thoracic vertebrae (12)

Label the parts of the sternum

How many true, false and floating ribs do we have

• 7 true ribs

• 5 false ribs (2 of which are also floating)

Where is the tubercle of the ribs and why is it important

• location: bony portrusion on the side of the rib where it posteriorly is (connects to spine)

• function: connects ribs to spine via ligaments at the transverse costal facet on thoracic vertebrae

Identify the blanks and list the articulations of where it would connect

demifacets: articulate with head of the ribs

costal facets: articulate with tubercle of ribs T1-10

What is the name of the ligament that binds the costal facets to the ribs

radiate ligament of head of rib

What are the features of the superior thoracic aperture

• body of T1 posteriorly

• medial margin of rib 1 on each side

• manubrium anteriorly

• open structure

Inferior thoracic aperture features

• body of T12 posteriorly

• rib 12 and distal end of rib 11 posterolaterally

• cartilage of ribs 7-10 anterolaterally

• xiphoid process andterior

• closed off by the diaphragm

What are the boundaries of the thoracic aperture

• body of T1 posteriorly

• medial margin of rib 1 on each side

• manubrium anteriorly

What structures pass through the superior thoracic aperture

1. vessels

• subclavian artery, subclavian vein, brachiocephalic vein

2. nerves

• brachial plexus, vagus nerve, phrenic nerve

3. organs

• trachea, esophagus, thoracic duct

Label each part

What are the three layers of intercostal muscles and their functions

• External intercostal muscle

  • elevates rubs during forced inhalation

• Internal

  • depresses ribs during forced exhalation

• innermost intercostal muscles

  • depresses ribs during forced exhalation

Label

What is the innervation of the intercostal muscles, and what is the arterial supply?

innervation: intercostal nerves

arterial supply: posterior and anterior intercostal arteries

Where is the intercostal nerve located

The costal groove

What is the mediastintum, and what does it hold (organs and arteries)

compartment between two lungs that contains heart, esophagus, trachea, thymus gland

and aorta and SVC

Label

What are the mediastinal divisions

superior: thymus, trachea, esophagus, thoracic duct, aortic arch, veins (SVC, brachiocephalic), nerves (vagus phrenic, left recurrent laryngeal), lympathics

Anterior: remenents of thymus and lymph notes

middle: pericardium, phrenic nerve, heart, pulmonary trunk, svc

posterior: descending thoracic aorta, azygos veins, thoracic duct, esophagus, vagus nerve, splanchnic nerves, lymphatics

What is pleura (and label this diagram)

lines and protects lungs and chest wall (2 layers) on either side of the mediastinum

CHECK WITH NOTES AFTER MONDAY What is the difference between the right lung and the left one?

Left: 2 lobes (bc heart), narrower, has the cardiac notch for the heart, has lingula (google idk if you need to know it)

Right: 3 lobes, bigger, heavier, shorts (bc liver under it)

What does the phrenic nerve pass through

C3, C4, C5 keeps the diaphragm alive

label