Ch. 10 Bony Thorax - Sternum and Ribs Flashcards
main function is to serve as an expandable bellows-like chamber, wherein the interior capacity expands during inspiration and contracts during expiration
bony thorax
what does the bony thorax consists of
- sternum anteriorly
- thoracic vertebrae posteriorly
- 12 pairs of ribs connecting the sternum to the vertebral column
a thin, narrow, flat bone with 3 divisions
sternum
what are the 3 divisions of the sternum
- manubrium
- body
- xiphoid process
total length of the adult sternum
about 7” (18 cm)
what type of bone does the sternum consists of
highly vascular cancellous tissue covered by a thin layer of compact bone
this allows for the sternum to be a common site for marrow biopsy
vascular cancellous tissue
under local anesthesia, a needle is inserted into the medullary cavity of the sternum to withdraw a sample of red bone marrow
marrow biopsy
upper portion of the sternum
manubrium
how long is the adult manubrium
2” (5cm)
longest part of the sternum
body
how long is the body of the sternum
4” (10cm)
at birth, the body of the sternum is in how many separate segments
4
when does the union of the segments of the body of the sternum take place
starting at puberty and complete possibly at age 25
most inferior portion of the sternum
xiphoid process
what is the xiphoid process composed of during infancy and youth
cartilage
when does the xiphoid process become totally ossified
40 years
these are the true ribs
1-7
these are ribs that connect directly to the sternum with a short piece of carilage
true ribs
what is the short piece of cartilage that connects the ribs to the sternum called
costocartilage
these are the false ribs
8-12
these have costalcartilage that joint together at the costocartilage of rib 7
false ribs - 8-10
these are floating ribs because they do not connect to the sternum
11 and 12
these ribs do not possess costocartilage
11 and 12
what is the posterior end of a rib called
vertebral end
what is the anterior end of a rib called
sternal end
what does the vertebral end of a rib consists of
head and flattened neck
lateral to the neck of the rib is this which articulates with the transverse process of a vertebra and allows for attachment of a ligament
elevated tubercle
how does the body of the rib extend from the tubercle
laterally and then angles forward and downward
what is the area of forward angulation termed
angle of the rib