Chapter 6 // Thoracic Cage (Axial)

Which part of the axial skeleton protects the heart, lungs, and thoracic organs?

The thoracic cage

What four parts make up the thoracic cage?

Thoracic vertebrae (posterior), ribs (lateral), sternum, and costal cartilages (anterior, medial)

What is the anatomical name for the breastbone?

Sternum

Which part of the sternum has clavicular notches that articulate with clavicles; also articulate with the 1st and 2nd ribs

The manubrium

What is the inferior end of the sternum called?

The xiphoid process

What are the 3 important anatomical landmarks of the sternum?

Jugular notch, sternal angle, xiphisternal joint

What is the central indentation in the superior border of the manubrium?

Jugular notch

What is the part of the sternum called where the sternal body and the xiphoid process fuse?

Xiphisternal joint

How many pairs of ribs are there?

12

Which pairs of ribs are considered your “true ribs”? They attach directly to the sternum by what?

1. 1. Superior ribs 1-7

2. 2. Costal cartilages

What ribs progressively grow in length?

True ribs

Which pairs of ribs are considered your “false ribs”?

Inferior ribs (8-12)

Which ribs progressively decrease in length?

False ribs

Which ribs have no anterior attachments to the sternum and what are those ribs called?

1. 1. Ribs 11-12

2. 2. Floating ribs

Describe the costal margin.

Inferior margin of the rib cage formed by costal cartilages of ribs 7-10

What is the typical rib structure?

1st rib is atypical, head, neck, tubercle, shaft, and costal groove

Which part of the rib structure serves as a passageway for nerves and vessels?

Costal Groove

The portion of the sternum that articulates with the clavicles?

The manubrium

What does the prominent groove along the inferior border of the internal rib surface do?

It’s called the costal groove and it marks the path for nerves and blood vessels.

Which part of the rib indicates the site where the tubular body, or shaft, begins curving towards the sternum?

Angle

Rib pairs 2-7 attach to which part of the sternum?

The body

Which portion of ribs 1–10 contacts the transverse process of a thoracic vertebra?

The inferior portion of the tubercle, via an articular facet