Thorax Flashcards
The thorax is composed of what four parts
- Thoracic Vertebrae
- 12 pairs of ribs (costae)
- Sternum
- Costal Cartilages
What are the functions of the thorax
- Protection of vital organs within
- attachment point for the shoulder girdle and upper limb
- Expandable/ collapsible container which facilitates respiration
- Maintain hemopoiesis
How does the thorax facilitate respiration
By changing the ration between intrathoracic pressure and volume
What type of bones is the thorax composed of
Flat
What is hemopoiesis
production of blood elements
What are the bones of the Sternum
Manubrium
Body
Xiphoid process
What are the features of the manubrium
clavicular notch
jugular notch
notch for 1st rib
1/2 notch for 2nd rib
What are the features of the sternum body
notches for ribs 2-7
composed of bony fragments called sternebrae
What are the features of the xiphoid process
- Cartilaginous attachment to sternum
- xiphoid process is the tip of the infrasternal angle (costal cartilages of ribs 7-10)
Where is the sternal angle
between the manubrium and the sternal body
What is the sternal angle a good landmark of
an excellent palpable landmark for orientation on the anterior surface of the chest
What is the xiphoid process a good landmark for?
a good landmark for the inferior boundary of thoracic cavity
inferior border of the heart
superior boundary of the liver
What ribs are ‘true ribs’
ribs 1-7
Why are true ribs called that?
because of their direct attachment to sternum
What are ribs 8-12 called
False ribs
What ribs are floating ribs
11 & 12
Why are floating ribs called that?
because they do not attach to the sternum at all
Which ribs are typical ribs
3-10
What are the features of a typical rib
head crest neck angle tubercle flat body costal sulcus
What is the crest on the rib
divides head into 2 articular surfaces to accommodate the head of a rib to articulate with two vertebrae
What are the features of the tubercle of the rib
an additional facet- joint between rib and transverse process of vertebra
What is the shape of a typical body of a rib
flat and exhibit anterior and posterior surfaces
Where is the costal sulcus
inferior margin of typical rib
What is the costal sulcus
a linear groove that provides extra space and protection for intercostal arteries, veins and nerves
What ribs are Atypical
1, 2, 11, 12
What are the features of Rib 1
tubercle of anterior scalenus muscle
grooves for subclavian artery and vein
Which atypical rib has a tuberosity of serratus anterior muscle
rib 2
What are the features of ribs 11 and 12
shorter than other ribs
their heads posses only a single whole facet
these ribs dont have necks or tubercles
Why do ribs 11 and 12 only display a single whole facet
because they articulate with corresponding number vertebrae
2 types of thoracic aperatures
superior and inferior
What parts of the thorax are involved in the superior thoracic aperature
T1 vertebra
1st pair of ribs
their cartilages
superior border of sternum
What parts of the thorax are involved in the inferior thoracic aperature
T12 vertebra
ribs 11 and 12
cartilage of ribs 7, 8, 9, 10
xiphisternal joint
What two acts is the respiratory cycle composed of
Inspiration (inhale) and expiration (exhale)
Is inspiration active or passive
active (requires muscle)
is expiration active or passive
passive (tissues recoil)
During inspiration is the chest expanding or contracting
expanding
During expiration if the thorax collapsing or expanding
collapsing
What happens to the volume and intrathroacic pressure on inspiration
volume is increasing, pressure is decreasing
what is happening to the volume and intrathoracic pressure during expiration
volume is decreasing and pressure is increasing
Define Eupnea
Normal breathing (12-16 cycles/min)
Define Dyspnea
aggravated breathing
Define Tachypnea
accelerated breathing >16 cycles/min
Define Bradypnea
slowed breathing <12 cycles/min
Joints are mostly what type
synovial
When observing the thorax from lateral what would one notice about the ribs
they slope to anterior and inferior direction
Where are ribs attached
vertebrae and sternum
what is the type of movement decribed in joints
‘bucket-handle’
What do costovertebral joints involve
head of rib and body of vetebrae
what reinforces the costovertebral joint
intra-articular and radiate ligaments
What is involved in the costotransverse ligament?
tubercle of rib ad the TP of vertebra
What ligaments are involved in the costotransverse joint?
lateral, medial and superior costotransverse ligaments
What does the constochondral joint entail
attachment of rib to its own cartilage
How is the costochrondral joint reinforced
through the periosteum/perichondrium
What is involved in the sternocostal joint?
attachment of the rib to sternum
How is the 1st rib of the sternocostal joint attached to the sterum
syncgridrisus
How are ribs 2-7 attached to the sternum
synovial joints
How is the sternocostal joint reinforced
anterior and posterior sternocostal ligament
Where are interchondral joints?
between cartilages of ribs 6, 7, 8, and 9 (10)
Is the joint between 9 and 10 fibrous?
yes
Which joints are sternal joints?
manubriosternal and xiphosternal
What are some common pathologies of the ribs
rib dislocation and rib separation
What happens in rib dislocation
separation of costal cartilage from sternum
what happens in rib separation
separation of rib from its cartilage
What is the diaphragm attached to
lumbar vertebrae ribs (7-12) costal cartilage distal sternum xiphoid process
What does the median acruate ligament create?
an opening to allow passage of the aorta from thoracic into abdominal cavity
What is the purpose of the medial and lateral arcuate ligaments
allow fibers of psoas major and quadratus lumbordum muscles to reach their proximal attachments to skeleton
what is the shape of the central tendon
clover leaf
is the central tendon contractile?
no
What runs through the central tendon?
opening for inferior vena cava
Where is the psoas major located?
medial
Where is the quadratus lumborum located
lateral
