Sternum

Question 1

What is the name given to the segments of the sternum?

Answer 1

sternabrae (for sternal bodies)

Question 2

How many primary centers of ossification appear in the manubrium?

Answer 2

1-3 centers

Question 3

How many primary centers of ossification appear in the corpus sterni?

Answer 3

typically 6

Question 4

What are the locations of the primary centers of ossification in the corpus sterni?

Answer 4

one in each of the first two sternabrae and bilateral centers in the last two sternabrae

Question 5

Primary centers of ossification for the sternum first appear at what age?

Answer 5

fifth fetal month

Question 6

In what part of the sternum will a secondary center of ossification appear?

Answer 6

the xiphoid process

Question 7

When does the xiphoid process first demonstrate a center of ossification?

Answer 7

sometime during or after 3 years old

Question 8

When will the synchondroses between sternabrae begin to ossify?

Answer 8

during puberty

Question 9

Synchondroses of the corpus sterni will fuse together beginning with which sternabrae?

Answer 9

• the lower sternabrae fuse first

- they ossify in a caudal to cranial direction

Question 10

What is the ratio of primary:secondary centers of ossification for the sternum?

Answer 10

6:1