thoracic cage Flashcards
what are the main components of the thoracic cage?
- thoracic spine (posterior)
- sternum (anterior)
- ribs (I-XII)
what are the names of the apertures found on the thoracic cage?
- superior thoracic Aperture (inlet)
- inferior thoracic aperture (outlet)
what are the 3 types of ribs?
- true ribs
- false ribs
- floating ribs
what are true ribs?
what rib section do they range from?
these are the ribs that have a direct insertion to the sternum via the costal cartilage
ranges from ribs I-VII
What are false ribs?
what rib section do they range from?
these ribs have an indirect insertion to the sternum via the costal margin (infrasternal angle)
range from ribs VIII-X
What are floating ribs?
what rib section do they range from?
ribs that have no inseion on sternum
ribs XI-XII`
what components are observed on typical ribs?
- posterior: Head, neck, tubercule
- body, costal angle, costal groove
anterior: costal cartilage
what are the 3 articulation surfaces found on ribs?
- costal cartilage (anterior)
- head of the rib (posterior)
- tubercule of the rib (posterior)
where are the demi-facets located on the thoracic vertebrae?
they are located directly on the vertebral body.
where are the costal facets located on the thoracic vertebrae?
on the TP
what type of joint is the costovertebral/ costotransverse joint?
synovial joint
how does the costovertbral joint articulate?
two articular facets on the head of the rib articulate with the demi facets located on the rib’s numerical vertebral counterpart and the vertebrae above it.
how does the costotransverse joint articulate?
the tubercule of the rib articulates with the costal facet on the TPs of the vertebral bone on its own level.
which ribs are considered to be atypical?
rib I rib II rib X rib XI rib XII
what are the properties that make rib I atypical?
short, flat and horizontally oriented
lacks costal groove, instead have anterior and posterior groves for subclavian vein and artery
articulates with vertebral bone on its own level
what are the properties that make rib II atypical?
-smaller size (2x bigger than rib I)
rest is typical
what are the properties that make rib X atypical?
-only articulates with vertebral bone on its levels
what are the properties that make rib XI and XII atypical?
- articulate with vertebral bone on its own level
- lack neck and tubercule
- short
are costovertebral and costotransverse posterior or anterior joints?
what do they articulate with?
posterior
they artiuculate between ribs and vertebrae
what do anterior thoracic joints articulate with?
between ribs and sternum
what is being articulated in the costochondral joint?
what type of joint is that?
between the costal cartilage and the rib body
its a solid, synchondrosis joint
what is being articulated in the sternoclostal joint?
what type of joint is that?
is there and exception to the type of joint it is for particular ribs?
between the costal cartilage and the sternum
it is a synovial join exhibiting plane/gliding
yes rib I is a solid, synchrondrosis joint
what is being articulated in the interchondral joint?
what type of joint is that?
between the costal cartilages of the false ribs
uniquely synovial joints
what components form the sternum
Manubrium
Body
Xiphoid Process
what created the infrasteral angle?
manubriosternal joint
what are the junctions present in the sternum and where are they present (range)
manubriosternal joint (TIV/TV)
Xiphisternal joint (TIX)
what is the fiber direction of the external intercostal muscles?
they are located on the anterior side and pointing downwards (inferior)
what is the fiber direction of the internal intercostal muscles?
they are located on the anterior side and pointing upwards (superior)
what is the fiber direction of the innermost intercostal muscles?
they are located on the anterior side and pointing upwards (superior)
where are the transversus thoracis muscles located?
located between the body of the sternum and the xiphoid process to ribs II-VI
why is the right dome of the diaphragm more elevated than its left side?
at what rib does this elevation/deleveling occur?
because on the right side, is where the liver is located causing for a elevation of the diaphragm
what is the mneumonic to recall diaphragm innervation?
C3-C4-C5 keeps the neck alive
what are the nerves that innervate the diaphragm?
why is it not just one nerve?
- right phrenic nerve
- left phrenic nerve
- the reason that their are 2 nerves is to allow that if one of them is damaged the diaphragm can continue to fonction partly, as it is a crucial part of respiration
what is the primary muscle that partakes in resting respiration?
the diaphragm
what happens during inhalation?
-the contraction causes for an increase in the volume of the thoracic cavity in the superior to inferior axis
what does the diaphragm consist of?
it consists of a right and left dome that joins centrally by the central tendon.
what happens during forced breathing?
during forced inspiration: movement of external intercostal causes an increase in volume
forced expiration moves internal intercostals and decreases volume of the diaphragm
forced respiration will also recruit innermost intercostal muscles and transversus thoracis
in cases of dyspnea what other muscles may be recruited for respiration?
- scalenes,
- serratus posterior superior
- serratus posterior inferior
how is a test tube placement executed?
when proceding, must go to the rib inferior to the nerve and on the superior rige of that rib insert chest tube to avoir dammage of main intercostal nerve
in what order are the nerve, vein and artery positioned relative to the rib? why?
the vein is the most superficial, followed by the artery and lastly the nerve is the deepest.
its a matter of survival and functions of the respective components . a damaged nerve is much more severe than a damaged vein generally speaking.
what are the main thoracic arteries
- internal thoracic artery
- subclavian artery
- anterior intercostal artery
- internal thoracic mamary artery
- posterior intercostal arteries
- musculophrenic artery
- superior epigastric artery
- thoracic aorta
how many pairs of intercostal arteries are there?
11 pairs
where do the anterior intercostal artery arise from?
they arise from the internal Thoracic Artery (first 6-7 intercostal spaces)
and the musculophrenic artery (remaining inferior intercostal space)
what is the terminal branch of the internal thoracic artery?
the musculophrenic artery
what arteries arise from the thoracic aorta?
posterior intercostal arteries
where do the subcostal arteries arise from?
from the aorta
where do the subcostal arteries travel along?
they travel along the inferior border of rib XII
what is an anastomoses?
where does such occur?
it is the junction between 2 blood vessels.
such junction occurs between the anterior and posterior intercostal arteries
how many pairs of intercostal veins are there?
11 pairs
which vein drains into the internal thoracic vein from the frist 6-7 intercostal spaces & in the muscolphrenic veins?
the anterior intercostal veins
what vein drains into the internal thoracic vein (continuously)
musculophrenic vein
what vein drains into the brachiocephalic veins and into the SVC and the
the internal thoracic vein
where does the left posterior intercostal vein drain off?
it drains into the hemiazygos vein then to the azygos vein which drains to the svc and then the heart
where does the right posterior intercostal vein drain off?
drains into the azygos vein then the svc and then the heart
where does the subcostal vein travel and where does it drain off?
it travels along rib 12, drains into the azygos vein on the right side of the body and the hemiazygos vein on the left side of the body
