Exam 3- Embryology of the Anterior Thorax

Question 1

How many primary centers of ossification appear in the manubrium?

Answer 1

1-3 centers have been identified

Question 2

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

Answer 2

typically 6

Question 3

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

Answer 3

the xiphoid process

Question 4

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

Answer 4

sometimes during or after 3 years old

Question 5

When will synchondroses between sternabrae begin to ossify?

Answer 5

during puberty

Question 6

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

Answer 6

the lower sternabrae fuse first; they ossify in a caudal to cranial direction

Question 7

In what part of the rib will primary centers of ossification appear?

Answer 7

the body (corpus, shaft)

Question 8

In what parts of the rib will secondary centers of ossification appear?

Answer 8

the head, articular surface of the tubercle and the non-articular surface of the tubercle

Question 9

Which ribs will demonstrate primary centers of ossification for the body (corpus or shaft)?

Answer 9

all ribs; ribs 1-12

Question 10

Which ribs lack secondary centers of ossification?

Answer 10

ribs 11 and 12

Question 11

Which ribs demonstrate three secondary centers of ossification?

Answer 11

ribs 2-9

Question 12

Which ribs have only two secondary centers of ossification?

Answer 12

ribs 1 and 10