What is the thoracic cavity?
region of the body enclosed by the thoracic wall
What does the thoracic cavity contain?
heart and lungs
What are pleurae?
fascial coverings of the lungs, serous sacs of fluid
What does the visceral pleura line?
the surface of the lung
What does the parietal pleura line?
walls of thoracic cavity, diaphragm, mediastinum
What type of innervation does the visceral pleura have?
Visceral sensory innervation (ischemia, stretch)
What type of innervation does the parietal pleura have?
Somatic sensory innervation (sensitive to pain/temp/touch)
What types of nerves carry sensory information from the parietal pleura to the CNS?
intercostal nerves, phrenic nerves
What is pleuritis/pleurisy and what can it lead to?
inflammation of the pleura; adhesion of the visceral and parietal pleura layers which can cause acute pain
What is inner space between the inner visceral and outer parietal pleurae?
pleural cavity
What is the space within the serous sac?
pleural cavity
Do the R and L pleural cavities depend on each other?
no - they are independent
What is the fluid in the pleural cavity and what does it allow for?
Serous fluid; allows the parietal and visceral layers to slide against each other during respiration
Hydrothorax
fluid in pleural cavity
Hemothorax
blood in pleural cavity
Pneumothorax
air in the pleural cavity
Where are the costodiaphragmatic recesses?
Inferior lateral parts of the pleural cavities
What happens in the costodiaphragmatic recesses during inspiration?
The lungs expand and these recesses decrease in area
What happens in the costodiaphragmatic recesses during expiration?
the recesses enlarge again
What shape should the costodiaphragmatic recess show on an x-ray and what is the shape caused by?
Acute sharp angle; formed by lateral thoracic wall and the lateral aspect of the diaphragm
What is thoracentesis?
A procedure to remove fluid or air from around the lungs. Includes an intercostal nerve block (anesthesia), then a needle is inserted in an intercostal space (typically 7-9th intercostal space)
What type of innervation does the parietal pleura receive?
Somatic sensory
What is the main function of the lungs?
oxygenate blood
What happens to the color of the lungs over time?
darken over time
What characteristics does the lung tissue have?
light, spongy, elastic
What is the root of the lung?
collection of structures that enter and exit the lung
How do the lungs of a donor differ from a living person?
Donor lungs are firm to the touch and exhibit impression from the ribs, heart, great vessels
What is the apex of the lung?
The blunt superior end of the lung
What is the base of the lung?
Concave inferior surface, convex
Where are the apex of the lungs positioned?
In the root of the neck
How many lobes does the right lung have?
3 lobes (superior, middle, inferior)
How many lobes does the left lung have?
2 (superior and inferior)
What are the fissures of the right lung?
horizontal fissure and oblique fissure
what is the fissure of the left lung?
oblique fissure
Which lung is larger?
right
Where is the cardiac notch?
anterior border of left lung
What is the trachea?
Part of the airway that allows air to pass into the lungs
Where can you palpate the trachea?
At the jugular notch (the C-shaped rings of hyaline cartilage)
Where does the trachea bifurcate?
sternal angle
What is the carina?
bifurcation of trachea
What does the bifurcation of the trachea lead to?
The right and left main bronchi
Describe the main bronchi
C-shaped cartilages that are extrapulmonary
How do the right and left bronchi differ in structure?
The right main bronchi is wider, shorter and more vertical
Which of the bronchi are foreign object more likely to end up in?
Right
What do the main bronchi divide into?
lobar bronchi
How many lobar bronchi are there?
3 right, 2 left
Are the lobar bronchi intrapulmonary or extrapulmonary
Intrapulmonary
What do the lobar bronchi divide into?
segmental bronchi
Are the segmental bronchi intrapulmonary or extrapulmonary?
intrapulmonary
What is a bronchopulmonary segment?
subdivision of a lobe
How many bronchopulmonary segments are in each lung?
10
What are the areas of the lung supplied by?
Segmental bronchus, segmental branch of pulmonary artery
What are the areas of the lung separated by?
connective tissue
Can the lungs be surgically resectioned?
Yes
Where do the pulmonary veins lie in relation to the bronchopulmonary segments?
Between the segments in the connective tissue
What is the function of a pulmonary artery?
Carry oxygen rich or oxygen poor blood away from the heart
What is the function of a pulmonary vein?
Carry oxygen rich or oxygen poor blood to the heart
What is the function of bronchial arteries and veins?
Supply/drain bronchi, connective tissue of the lungs
What is the flow of blood through the pulmonary arteries?
Oxygen poor blood is pumped out of the right ventricle and into the pulmonary trunk > R/L pulmonary Arteries > Lungs> Lobar arteries > Segmental arteries
How do the structure of the pulmonary arteries and the bronchial tree compare?
They branch in unison
What is the flow of blood through the pulmonary veins?
oxygen rich blood from the lungs > 2 pulmonary veins on each side (intersegmental of the lungs) > left atrium
What is the function of bronchial arteries?
Carry oxygen right blood to lung tissues
What structure to bronchial arteries typically take?
Branching of the thoracic aorta
What is the function of bronchial arteries?
Return oxygen poor blood from lung tissues to the azygos system or the intercostal veins
What does the diaphragm separate?
thoracic and abdominal cavities
What is the diaphragm composed of?
Skeletal muscle and central tendon
What shape does the diaphragm take?
2 domes
Where is the heart in relation to the diaphgram?
Right on the central tendon in the center
What part of the heart is attached to the central tendon?
Fibrous pericardium
What does the attachment of the fibrous pericardium to the heart result in?
The heart moving with the diaphragm during breathing
What are the attachments of the diaphragm?
Xiphoid process, costal margin, ribs 11-12, lumbar vertebrae (R and L crura)
What are the 3 openings of the diaphragm?
caval opening T8, Esophageal hiatus (T10), aortic hiatus T12
What is the caval opening for?
IVC
What is the esophageal hiatus opening for?
Esophagus and vagus nerve
What is the aortic hiatus opening for?
aorta, thoracic duct, azygos vein
How does the diaphragm receive sensory innervation?
Mainly through phrenic nerves, peripherally through intercostal nerves
How does the diaphragm receive motor innervation?
Phrenic nerves
What do phrenic nerves arise from?
ventral rami of C3, C4, C5 "keep the diaphragm alive
How do the R and L phrenic nerves innervate the R and L domes of the diaphragm?
Independently
What is the primary muscle for inspiration?
diaphragm
What direction are the domes of the diaphragm pulled when the muscle is contracted?
Inferiorly, flattened
What happens if there is a lesion of a phrenic nerve?
Because each dome is independently innervated so the corresponding dome will be paralyzed
During inspiration, how is the thorax cavity volume changed?
increased volume
During expiration, how is the thorax cavity volume changed?
decreased volume
How is the volume of the thoracic cavity changed?
By muscle contraction and relaxation
During inspiration, how does the contraction of muscles that elevate the ribs change the thoracic cavity?
Moves the laterally shaft of the rib mediolaterally, and the sternum superior and anteriorly
When can the pectoralis major be recruited in breathing?
forcefull inspiration
What muscles are recruited during forceful expiration?
oblique muscles, rectus abdominis
What direction does the sternum move during inspiration?
anterior and superiorly