Thoracic Cavity and Viscera Flashcards
How many compartments in the thoracic cavity? and name them
3
2 x pulmonary cavities
1 x mediastinum
What is in the mediastinum?
heart, great vessels, trachea, esophagus, thymus and lymph nodes
What goes between the internal aspect of the thoracic wall and the lining on the pleural cavities aka parietal pleura?
endothoracic fascia
Describe the endothoracic fascia
a thin fibro-aveolar layer
between the internal aspect of the thoracic wall, and the parietal pleura
What;s the clinical significance of the endothoracic fascia
provides a cleavage plane for the surgeon
what is the visceral pleura adherent to
all surfaces incl. INSIDE the horizontal and oblique fissures
what happens to the pleura at the root of the lungs
Together, they form the pleura sac. At the root of the lungs, it’s forming/called the ‘pleural sleeve’.
4 parts of the parietal pleura
cervical pleura
costal part
diaphragmatic part
mediastinum part
what does the parietal pleura line
The pulmonary cavities, adhering to thoracic wall, mediastinum and the diaphragm.
Purpose of the pleural sleeve continuing inferior to the root of the lung?
The continuity between the parietal and visceral pleura i.e. pleural sac forms the pulmonary ligament
Where does the pulmonary ligament extend between?
The lung and the mediastinum
Which lung do you find the cardiac notch?
left lung
Which lung has the horizontal fissure- which is superior to the oblique fissure?
right lung
What’s in the pleural cavity? And why?
pleural fluid, it acts as a lubrricant for pleural surfaces and allows layers of pleura to slide smoothly DURING RESP.
What does the pleural surface tension of the pleural cavity help with?
Of the pleural cavity, provide cohesion that helps the lung surface in contact with the thoracic wall.
What does the thoracic wall enclose?
The left and right pleural cavities (containing the lungs).
Does the thoracic wall enclose the mediastinum?
Yes.
Where is the mediastinum located?
In between the pleural cavities. Part of the mediastinum includes the heart within the pericardial cavity.
The mediastinum incl. heart, great vessels, trachea, esophagus, thymus and lymph nodes
Are the pleural cavities and the pericardial cavity closed off?
Yes. They’re basically closed sacs.
Purpose of the thoracic wall?
To protect all the cavities. And permit the movements associated with respiration
Does the thoracic wall incl. the sternum?
yes
What vertebrae in the thoracic wall
T1-12
What ribs in the thoracic wall
1-12
Manubrium is part of
part of sternum
Manubrium articulates with what
clavicle, 1st rib, upper part of second costal cartilage
What is the name given to the joint between manubrium of the sternum and everything else, and what type of joint is it
sternocostal joints of 1st and 2nd rib, 1st rib = primary cartilaginous, 2nd rib = synovial plane joints
and sternoclavicular, saddle synovial joint
list all the 6 joints of the the thoracic wall
sternoclavicular
sternocostal joints
manubriosternal joint
costochondral joint
xiphisternal joint
interchondral joints
where is the manubriosternal joint
between manubrium and body of the sternum
what is the manubriosternal joint type
secondary cartilaginous (symphysis)
what makes the xiphoid process, at what level, special
T10
smallest and most variable part of the sternum.
cartilaginous in young people, ossified in adults. could fuse in elderly
where is the xiphisternal joint
T9
The xiphisternal joint is a marker for what three things
superior level of the liver,
central tendon of the diaphragm,
inferior border of the heart
level of sternal angle/manubriosternal joint
T5
Importance of sternal angle as a surface landmark
where trachea bifurcates aka carina, and overlies the aortic arch
typical rib numbers?
1-9
true rib numbers?
1-7th
false rib numbers?
8-10
floating free ribs numbers
11-12th
head of true rib has two articulations
superior articular facet to superior vertebrae
inferior articular facet to numerically corresponding facet
Purpose of the tubercle on a true rib?
for articulating with the transverse process of the vertebra via synovial joint, and non articular part for fibrous attachment to the same process via
What part of a vertebra articulates with the rib tubercle?
transverse process
what is the ‘scalene’ tubercle for
for attachment of the anterior scalene muscle of the neck, an accessory respiratory muscle in forced inspiration
which rib has the scalene tubercle
the first rib
which rib has two shallow horizontal grooves crossing it’s superior surface for the subclavian artery and vein
the first rib
where on the first rib is the scalene tubercle located
between the grooves for the subclavian artery, and the groove for the subclavian vein
which is closest to the head, (and therefore the vertebrae): the groove for the subclavian artery, or for the subclavian vein
the subclavian artery is closer to the head
Which part of a rib articulates with these demi-facets on a vertebral body?
The head.
there are two demi-facets.
Which part of the rib articulates with the demi-facet of the transverse process?
the tubercle
What is the most common chest injury
Fractures of the ribs are the most common chest injuries.
Which ribs are most commonly fractured and why
Ribs 5-10 are most commonly fractured as they are relatively more exposed and fixed.
How could a fractured rib lead to pneumothorax?
The ends of a fractured rib may then perforate the pleura resulting in a pneumothorax.
How would a broken rib present?
It is accompanied by severe localised pain mediated through the intercostal nerves located above and below and concomitant dyspnoea (difficulty in breathing).
How many layers of intercostal muscles in the thoracic wall are there?
3
How many layers of muscles are in the abdominal wall?
3
What are the three intercostal muscles?
external, internal, innermost
What muscles do we have to ‘take away’ to see the intercostal muscles
the pectoralis major and the pectoralis minor
The external intercostal muscles run from the vertebrae to just about where
where the bone meets the cartilage
In what direction do the external intercostal muscles run
hands in pockets direction
How do the internal intercostal muscles run
inferior-posteriorly, opposite to hands in pocket, from the sternum to the angle of the rib
where do the internal intercostal muscles end
Angle of the rib, as in: the place all the ribs turn anterlaterally
Where do the innermost intercostal muscles run?
They’re deep to the internal ones, but follow the same path from sternum to angle of the ribs.
When are the external intercostal muscles most active?
during inspiration (upwards and outwards)
What moves the ribs?
the intercostal muscles- but different movements each
When are the internal intercostal muscles most active? (innermost does the same job)
during inspiration, PULLING the ribs IN
Important job of the intercostal muscles that isn’t just ‘moving the ribs’?
Form a pressure barrel, basically forming the wall of the thorax with the ribs that resist that pressure changes
Which nerves innervate the intercostal muscles?
The intercostal nerves, running from spinal cord to in between the ribs
How can you damage the intercostal nerves?
cervical spinal cord injury
Which muscle is the parietal pleura stuck up against?
Innermost intercostal ( or really the endothoracic fascia)
Patients being treated for TB with ethambutol should have their vision monitored as it can cause optic neuritis.
True – this is a recognized side effect of ethambutol, so patients will routinely have their vision monitored during treatment.
“Pneumonia” is infection within the pleural cavity.
False – pneumonia is infection within the alveolar air spaces. You will often hear the term “consolidation” used in this context, usually to describe an X-ray or pathology finding. Consolidation simply means that the air in the alveoli has been replaced by solid material – in the case of pneumonia, it is bacteria and inflammatory cellular debris.
What pneumonia is commonly associated with alcoholism.
Klebsiella pneumoniae infection
Moraxella catarrhalis is a typical cause of what in COPD
Moraxella catarrhalis is a typical cause of LRTIs in COPD.
Bacterial bronchitis leads to decreased mucociliary clearance.
False – it is the other way around. Viral respiratory infections infiltrate the mucosa and impair the mucociliary escalator, resulting in stagnation of secretions and bacteria and leading to infection.
Croup is treated with oral steroid.
yes
Why is cystic fibrosis is a cause of bronchiectasis.
Cystic Fibrosis is a multi-system disease affecting multiple organs. It causes impaired ciliary motility, and in the lungs this results in pooled secretions and bronchiectasis.
What’s the common reason of secondary bacterial infection after flu?
Secondary bacterial infection after flu is usually due to damage to the mucociliary escalator, which results in bacteria and mucus accumulating in the lower respiratory tract.
Pseudomonas aeruginosa pneumonia is typically associated with cystic fibrosis.
True – pseudomonas infection is typically seen in cystic fibrosis and other bronchiectatic disease. It causes copious, green, foul-smelling sputum.
Lung consolidation results in a decrease in vocal resonance on examination.
false, increase
Rusty brown sputum is a symptom of what pneumonia
Streptococcus pneumoniae.
Where do structures passing to or from the thorax and abdomen pass through?
Through openings in the diaphragm, e.g. inferior vena cava (IVC) and esophagus, or posterior to it e.g. aorta
inlet vs outlet for anatomists vs clinicians
Anatomists refer to the superior opening of the thorax as the thoracic INLET and the inferior opening as the OUTLET. However, clinicians refer to the superior opening as the thoracic OUTLET. Therefore, in Thoracic Outlet Syndrome, the brachial plexus (C5-T1), the subclavian artery and vein become compressed by structures such as tumours of the lung between the first rib and clavicle, as they enter the upper limb, with resultant limb clinical signs.
not much volume increases in the thoracic cavity results from contraction of the intercostal muscles in a newborn during inspiration.
why
cuz ribs in a newborn don’t lie obliquely in an anteroinferior plane
what muscle is primarily used for breathing in a newborn
the diaphragm
does being attached to a rib automatically mean that it’s an accessory muscle?
yes
Are there are accessory muscles I could use from the appendicular skeleton?
yes, e.g. when you stand over a table, lean and plant your hands, they’re pulling on the ribs to help draw air in
