Sternum and Ribs Flashcards
Primary centers for ossification for the sternum first appear at what age?
Fifth fetal month
Synchondroses of the corpus sterni will fuse together beginning with which sternabrae?
The lower sterna brae fuse first; they ossify in a caudal to cranial direction
What vertebral levels correspond to the position of the manubrium sterni?
T3-T4
What vertebral levels correspond to the position of the corpus sterni?
T5-T9
How many sternabrae for the corpus sterni?
4 Sternabrae
What surface features on the corpus sterni identifies the location of the synchondroses?
Transverse Lines
What articular sites for the costal cartilage of the ribs will be identified on the corpus sterni?
Costal notches II-VII
What feature of the corpus sterni is present in 4-7% of the population
A Sternal Foramen
What causes the appearance of the sternal foramen?
Failure of the ossification centers of the sternum to fuse together normally
In what part of the rib will primary centers of ossification appear?
The body (corpus, shaft)
In what parts of the rib will secondary centers of ossification appear?
The head, articular surface of the tubercle and non-articular surface of the tubercle
When do primary centers of ossification appear in the rib?
During the second fetal month
When do secondary centers of ossification appear in the rib?
During puberty
Which ribs will demonstrate primary centers of ossification for the body? (corpus or shaft)
All ribs; ribs 1-12
Which ribs will demonstrate secondary centers of ossification?
Ribs 1-10
Which ribs lack secondary centers of ossification?
Ribs 11-12
How does rib 1 differ in ossification centers from typical ribs?
Rib 1 has two secondary centers of ossification:
One for the head
One for the tubercle
Typical ribs have three secondary centers of ossification
How does rib 10 differ in ossification centers from typical ribs?
Rib 10 has two secondary centers of ossification:
One for the head
One for the tubercle
Typical ribs have three secondary centers of ossification
How do ribs 11 and 12 differ in ossification centers from typical ribs?
Ribs 11 and 12 do NOT have secondary centers of ossification
What are the primary parts of the vertebral end of a typical rib?
Head, Neck, Tubercle
What is unique about the body (corpus or shaft) of the first rib?
The body (corpus or shaft) of the first rib is flattened and has a scalene tubercle flanked by the groove for the subclavian artery and the groove for the subclavian vein
What unique feature is present on the body (corpus or shaft) of the second rib?
Tuberosity for Serratus Anterior
What distinguishes the vertebral end of rib 11 from typical ribs?
(3)
The single articular surface
Absence of a well-developed crest on the neck
Tubercle may be absent or present, if present, only consists of a non-articular surface
What are the classifications of ribs 3-7 in the typical adult skeleton?
(4)
Typical ribs, true ribs, costa verae, and vertebrosternal ribs
What are the classifications of ribs 1 and 2 in the typical adult skeleton?
(4)
Atypical ribs, true ribs, costa verae, and vertebrosternal ribs
What are the classifications of ribs 8 and 9 in the typical adult skeleton?
(4)
Typical ribs, false ribs, costa spuriae, vertebrochondral ribs
What are the classifications of rib 10 in the typical adult skeleton?
(4)
Atypical rib, false rib, costa spuriae, vertebrochondral rib
What are the classifications of ribs 11 and 12 in the typical adult skeleton?
(4)
Atypical ribs, false ribs, costa spuriae, vertebral ribs
What is the joint classification of the costochondral joint?
Cartilaginous (amphiarthrosis) synchondrosis
What is the classification of the 5th-6th or 9th-10th interchondral joint?
Fibrous (amphiarthrosis) syndesmosis
What accessory ligaments are present at interchondral joints?
Anterior and posterior interchondral ligaments
Which costal cartilages fail to form a joint at their sternal end?
The 11th and 12th Costal Cartilages
In the developing sternum, what joint classification is present between the manubrium, gladiolus and xiphoid process?
Cartilaginous (amphiarthrosis) symphysis
