Thoracic Wall Flashcards
what forms the sternal angle?
intersection of manibrium and sternum
where is the sternal angle?
rib 2, T4/5 vertebrae
where is the most common site for a rib fracture
angle of middle ribs
where is the most common site for a sternal fracture
sternal angle
how many ribs are articulated to 1 thoracic vertebra?
1.5
how many costal facets are on a thoracic vertebra?
3
where in the intercostal space is a needle inserted for a nerve block
superior to the rib edge to avoid the structures in the costal groove (VAN complex) while avoiding the collateral branches that run superior to rib
between the paravertebral line and the location anesthetic is needed
do multiple levels because of overlap
what portion of the mesoderm contributes to the parietal and visceral layers of a cavity
lateral mesoderm- forms the body cavities
name 3 parts of a somite differentiates and segregates into during development of the body wall
sclerotome
myotome
dermatome
what are true ribs
ribs 1-7, attach directly to the sternum via costal cartilage
what are false ribs
ribs 8-10, attach indirectly to the sternum via costal cartilage of the rib superior
what are floating ribs
ribs 11-12, end in abdominal musculature, no sternal attachment
what is the rib head
where it interacts with thoracic vertebra, has 2 costal facets
what is the rib neck
between the head and the tuberacle
where is the rib tubercle
on the inferior aspect, down from the head and neck
has a costal facet
where are costal facets located on a rib
2 on head
1 on tubercle
where is the rib angle
where rib turns anterolaterally (curved part
where is the costal groove
inferior edge of the rib
what is in the costal groove
neurovascular bundle
which ribs are typical
3-9
which ribs are atypical
1, 2, 10-12
describe rib 1
short and broad
1 articular facet- articulates with T1
scalene tubercle for attachment of scalene muscles
grooves for subclavian vessels
how are intercostal spaces numbered
rib superior to it
where is the subcostal space?
below rib 12
which rib is rarely fractured and why
rib 1- protected by clavical
what are supernumerary ribs and where are they found
extra ribs
can be in cervical area (rare)
more commonly in lumbar region
which articular facet is larger on the rib?
infeiror
what joint is formed between the rib and sternum
sternal costal interchondral joint
what joint is formed between the rib and thoracic vertebra?
costovertebral joint
what might bifid ribs be mistaken for
supernumerary ribs
what is thoracic outlet syndrome
compression of subclavian artery or brachial plexus (or any structure in the superior thoracic outlet)
what happens to costal cartilage with age?
cartilage becomes calcified and loses its elasticity, making it more likely to be fractured
what is the effect of an extra cervical rib?
thoracic outlet syndrome- extra rib compresses subclavian artery
what are the 3 parts of the sternum?
manibrium
body
xiphoid process
what does the location of the sternum make it good for?
getting bone marrow samples to detect blood diseases (leukemia)
what is the sternal cleft
fusion of bilateral pre-cartilage tissue at the midline during development
what are the 3 defects are related to sternal cleft
complete sternal cleft
partial cleft
sternal foramen
describe complete sternal cleft
the pre-cartilagenous tissue fails to fuse at all- rare
the heart may stick be on the outside of the body
describe partial cleft
manibrium/upper aspect of the sternum do not fuse
describe sternal foramen
small hole in the sternum that is not clinically significant
what happens if the sternal angle is fractured?
dislocation of the manibriosternal joint that may cause damage to underlying organs
how common are sternal fractures
rare
what anatomical structures are at the sternal angle
bifurcation of the trachea start of aortic arch superior limit of pericardium superior/inferior mediastinal boarder arch of azygous vein
what is the joint between the manibrium and sternum?
manibriosternal joint
how many joints are in the costovertebral joint? what are they
2- thoracic vertebra with head of rib and thoracic vertebra with tubercle of rib
what is the joint between the thoracic vertebra and the tubercle of the rib
costotransverse joint
what does the superior rib facet articulate with
the inferior facet of the superior vertebra
what does the inferior rib facet articulate with
the superior articular facet of the vertebra at the same level
what does the tubercle rib facet articulate with
transverse articular facet of the vertebra at the same level
which ribs only have 1 articular facet
1, 10-12
what is the function of the thoracic wall and diaphragm
change the volume of the thorax to move air in and out