M103 T1 L1 Flashcards
What are the three cavities of the thorax?
the left pleural cavity
the right pleural cavity
the mediastinum
What is the function of the visceral pleura?
Adheres to lungs
creates smooth and slippery surface
connects parietal pleura to the hilum
What are the four parts of the parietal pleura?
costal
mediastinal
diaphragmatic
cervical
What six structures are contained in the hilum of the lung?
main bronchus (posterior) pulmonary artery (superior) pulmonary veins (inferior) bronchial arteries and veins pulmonary plexus of nerves lymph vessels and nodes
What is the mechanism of pleural and pulmonary development?
the lungs grow in out pouches these form lung and bronchial buds Rapid division of airways occurs Lungs push their way into primitive thoracic cavity they take the visceral pleura with them
When do the lungs and pleura start to develop and from which germ layer?
4-6 week old embryo
endoderm layer
What does the pleuropericardial membrane form?
the parietal pleura
the visceral pleura
What do the pericardioperitoneal canals form?
the pleural cavity
From what week is ventilation possible from?
26 weeks
When does formation of new alveoli stop?
10 years old
How does the initial lung look like and what does it change to look like?
glandular, becomes canalised - gc
What effect does surface tension, generated by serous fluid, have on the pleural cavity?
provides cohesion
helps lungs be held against thoracic wall
so the lung expands as the thoracic cavity expands
What are two examples of pleural cavity recesses?
costomediastinal recess
costodiaphragmatic recesses
What are the four different parts of the parietal pleura innvervated by?
cervical - 1st intercostal nerve
costal - intercostal nerves
mediastinal - phrenic nerve
diaphragmatic - lower intercostals and phrenic nerves
What is the type of innervation received by visceral pleura?
autonomic from pulmonary plexuses
What are the key features of the right lung?
3 lobes: superior, middle, inferior
2 fissures: horizontal and oblique
Larger and heavier
Shorter and wider
What are the key features of the left lung?
2 lobes: superior and inferior
1 fissure: oblique
has a cardiac notch and lingula
Which structures do the bronchial arteries supply?
the lungs
the visceral pleura
What are the structures of the respiratory tree in order?
Trachea Primary bronchi (main) Secondary bronchi (lobar) Tertiary bronchi (segmental) Bronchioles Alveolus
What three things line the trachea?
mucous membrane
cilia
trachealis muscle
What are the differences between the right and left primary bronchi?
the right bronchus is wider, shorter and more vertical
How many bronchopulmonary segments on each lung?
right - 10
left - 8-10
What are the key features of bronchopulmonary segments?
Separated by connective tissue
Surgically resectable/removable in isolation
What are the key features of the bronchioles?
20-25 generations of conducting bronchioles
no cartilage in walls
terminal bronchiole gives rise to several generations of respiratory bronchioles
respiratory bronchioles characterized by out pockets of alveoli
What are the two cell types of alveoli?
Type 1 pneumocytes (95%)
Type 2 pneumocytes (5%) - they secrete pulmonary surfactant
What are the effects of the innervation on the lungs via sympathetic supply?
from the sympathetic trunk, bronchial musculature dilation and pulmonary vasculature constriction
How is lymph drained from the lungs?
Drains towards the hilum via a series of nodes;
bronchopulmonary - tracheobronchial - paratracheal
What are the three surfaces of the lungs?
costal
mediastinal
diaphragmatic
What are the three borders of the lungs?
anterior (around the costal surface)
posterior
inferior
Where does the trachea run from relative to the spine?
C5 to T4/5
Where are foreign objects that have been aspirated more likely to go and why?
Right pulmonary bronchus as it is more vertical and wider than the left
Why are premature babies at risk of their alveoli collapsing?
Don’t produce (enough) pulmonary surfactant to keep alveoli inflated
Where do the left arteries branch from?
the descending aorta
Where do the right arteries branch from?
the intercostal arteries
Where do the bronchial veins terminate?
in the azygos veins
What structures do the lung pouches form in embryology?
lung buds
bronchial buds
Which cavity do the lungs push their way into during embryology?
the primitive thoracic cavity
Where is the costal parietal pleura?
the internal rib cage
Where is the mediastinal parietal pleura?
the lateral wall of mediastinum
Where is the diaphragmatic parietal pleura?
superior diaphragm
Where is the cervical parietal pleura?
in the cervical region
What are the effects of irritation to the costal parietal pleura’s nerves?
very sensitive, can produce local or referred pain to dermatome supplied by same spinal ganglia
What are the effects of irritation to the diaphragmatic parietal pleura’s nerves?
may refer pain to abdominal walls
What are the effects of irritation to the mediastinal parietal pleura’s nerves?
refers to c3-5 root of neck and over shoulder
What are the effects of parasympathetic supply on the lungs?
bronchial musculature constriction
pulmonary vasculature dilation
via the vagus nerve
