pleura and lung Flashcards
what does the intraembryonic mesoderm divides to?
paraxial
intermediate
lateral plate mesoderm
what is the embryological origin of pleura?
lateral part of the INTERMEDIATE MESODERM
it will give raise to peritoneal and pleura
the pleuroperitoneal cavity will divide the peritoneal and pleura from each others
how is the pleura formed?
it is a sac that is invaginated by the lung similar to the pericardium
what cells forms the pleura?
methothelial like pericardium
what is the inner layer of the pleura and what is it attached to?
visceral pleura –> attached to the lungs directly
what is the outer layer of the pleura and what is it attached to?
parietal pleura –> attached the inside of the chest wall
what is the hilum of the lung?
part of the lung where the vessels enter and leave
what is the root of the lung?
the continuation near the mediastinum where the structures are found
whats the extension of the pleura?
it is continuous around the lung and then at the root of the lung it ends
what does the pleura form below the root of the lung?
pulmonary ligament
what is the function of the pulmonary ligament?
provide dead space into which the :
Lung root descends with the descent of the diaphragm
Pulmonary veins and arteries can expand during exercise so this provides space for the enlargement
whats the name of the closed cavity found in between the layers of the pleura?
pleural cavity
describe the pleural cavity?
it is potential space ( its empty cuz lymphatics keeps draining the excessive fluid )
has thin film fluid –> pleural fluid and encloses the lung
what is pleural rub?
friction rub between the 2 layers due to inflammation and it produces a sound heard via stethoscope
where is the visceral pleura absent in?
hilum of the lung
between the two layers of the pulmonary ligament ( pulmonary ligament is the extension of pleura below the root of the lung )
describe the parietal pleura?
layer of pleura that lines chest wall and covers the mediastinum
what does the parietal pleura divide into to?
costal
Cervical
mediastinal
diaphragmatic
what is the costal parietal pleura?
parietal pleura lining:
sternum
ribs
costal cartilage
intercostal space
sides of verterbral column
what is the diaphragmatic pleura?
parietal pleura covering the diaphragm
what is cervical pleura ?
parietal pleura which covers the apex of the lung
what attaches above the cervical pleura?
suprapleural membrane
what is mediastinal pleura?
part of parietal pleura which covers the sides of the mediastinum
what is the relation between the mediastinal pleura and the mediastinum?
in the mediastinum the mediastinal pleura will represent the lungs
what are the narrow extension of the pleural cavity?
pleural recesses
whats the function of pleural recessed?
allow the lungs to expand during deep inspirations
where are the pleural recesses found?
costodiaphragmatic recess :
between costal and diaphragmatic pleura
INFERIOR margin of the pleura –> inferior because diaphragm is inferior
Costomediastinal recess :
between costal and mediastinal pleura
ANTERIOR margin of the pleura ( anterior because mediastinum is anterior )
whats the other name of costodipahragmatic recess?
costophrenic angle
what happens to the costophrenic angle during pleural effusions?
during pleural effusion
hydrothorax –> fluid in the pleural cavity –> the angle gets obliterated because gravity pulls the fluid down to the costophrenic angle
what is the level of insertion of the needle in thoracocentesis?
9th intercostal spaces
describe the thoracocentesis procedure?
it is inserted in the 9th intercostal spaces in the MID AXILLARY LINE to avoid inferior border of the lung
because after 9th theres no lung
whats the ending level of the lung in the mid CLAVICULAR line? (anteriorly)
6th intercostal spaces
whats the ending level of the lung in the mid Axillary line ( laterally )
8th intercostal space
because its 8th when we do thoracocentesis in the mid axillary line we go below 8th to the 9th to avoid the lung
whats the ending level of the lung in the back ( posteriorly )
10th intercostal spaces
whats the ending level of the pleura in the mid CLAVICULAR line? (anteriorly)
the pleura is little bit lower
8th intercostal spaces
whats the ending level of the pleura in the mid AXILLARY line? (laterally )
10th intercostal spaces
here we dont avoid the pleura in thoracocentesis because we are trying to inject the needle in it to drain the fluid so the 9th intercostal space is still within the pleura because it ends at 10th costal cartilage
whats the ending level of the pleura in the back ( posteriorly )
12th intercostal space
describe the costo mediastinal recess
lies along the anterior border of the left lung ( remember mediastinum = anterior )
overlies the heart
during full inspiration it becomes occupied by the LINGULA of the left lung
where does the costo mediastinum recess lie at?
anterior ends of the left 4th and 5th intercostal spaces
whats the normal pressure inside the pleural cavity?
less than atmospheric
whats the normal pressure inside the lungs?
same as atmospheric
what happens when the air enters pleural cavity?
pressure in the pleural cavity becomes similar to the atmospheric –> lung collapse
what could cause lung collapse or pneumothorax?
stab wound
puncture of the visceral layer –> ruputre of bullae in emphysema for example
whats tension pneumothorax?
air enters and cannot leave so it accumulates inside
what does the tension pneumothorax do the mediastinum?
pushes the mediastinum to the other side compressing the opposite lung ( the normal lung ) –> the obstructed lung will inflate and press the other normal lung
whats chest tube procedure?
procedure of removing air or excess fluid from pleural cavity
where is the incision made?
5th or 6th intercostal spaces in the mid AXILLARY LINE ( MEDIALLY)
whats the risk of chest tube?
long thoracic nerve maybe injured resulting in winged scapula
whats the site of the lung?
pleural cavity and it is separated by mediastinum from the lung on the opposite side
describe the shape of the lung?
conical shaped
has apex , base
2 surfaces ( costal and medial –> thick and round )
3 borders : anterior ( SHARP) , posterior ( THICK) m inferior
describe the costal surface of the lung?
it is on the side of the sternum and costal cartilages , ribs ,intercostal muscles and sternocostalis
what does the medial surface divide into to?
vertebral part : lies behind the hilum and related to the sides of vertebrale bodies and intervertebral disks, sympathetic trunk, splanchnic nerves
mediastinal part : anterior part and it differs between the right and left lungs
what are the impressions on the right lung?
Pericardium –> right atrium ( because right atrium forms the right border of the heart )
Inferior vena cava
Superior vena cava ( upper part of the hilum ) : continuous with the groove of right brachiocephalic which is coming from above
Groove of arch of azygous vein
Azygous vein impression
Trachea and right vagus nerve
esophagus impression (its anterior to the azygous vein impression)
what are the impressions on the left lung?
Pericardium impression –> left ventricle and left auricle
Pulmonary trunk and thymus gland
groove for AORTIC ARCH –> Above hilum which is also related to left vagus and left phrenic and left superior intercostal vein
Descending aorta groove
left subclavian artery
left common carotid
Area of relation to ESOPHAGUS ( infront of the descending aorta ) and THORACIC DUCT and LEFT recurrent laryngeal nerve
Esophagus –> in front of descending aorta
what is lingula?
tongue like projection of the upper lobe at cardiac notch
corresponds to the right middle lobe
where is the cardiac notch found?
upper lobe of the left lung and its due to the heart
how many fissures found on each lung?
left lung –> 1 fissure , oblique fissure dividing it into upper and lower
right lung –> 2 fissures , olbique and horizental dividing it into upper and middle and lower
where does the oblique fissure begins?
posterior border
2.5 inches below the apex
1 inch from median plane
follows the medial border of the scapula when the arm is abducted
where does the oblique fissure opposite in relation to the spine?
T3
whats the extension of oblique fissure?
downward and forward
where does the obliqure fissure cut in relation to ribs?
6th costochondral junction
where does the horizontal fissure begin?
anterior border
end at oblique fissure in midaxillary lnine
at what costal level does it extend and end?
4th costal cartilage and extend to the 4th rib
what is the hilum?
site where structures enter or leave the lung
what is the root?
structures passing through the hilum connecting mediastinum to the lung
what is the most superior structure in the hilum?
pulmonary artery
whats the most posterior structure ?
bronchi
what is the most anterior and inferior structure?
pulmonary veins
how many bronchi are found in the right hilum?
2 bronchi because the right bronchi divides before entering hilum
what constitutes the vascular nutritive system of the pulmonary tissue ?
bronchial arteries and veins
what do the bronchial arteries and veins interconnect with?
Pulmonary arteries and veins
from where does the bronchial arteries originate?
thoracic aorta or one of its branches
what bronchial artery normally arises from intercostal artery and which intercostal artery does it arive from?
Single right bronchial artery normally arise from the THIRD intercostal artery
though sometimes it originate from the upper left bronchial artery
from where does other bronchial arteries arise from?
two left bronchial arteries arise form the ANTERIOR SURFACE OF THE AORTA DIRECTLY
describe the bronchopulmonary segments?
-functionally independent unit of lung tissue
largest subdivision of a lobe
pyramid shaped with the apex at the lung root
receives its own segmental bronchus ( tertiary )
has separate arterial supply from the other segments
Surrounded by connective tissue containing intersegmental vein which drain the SEGMENTS
can be removed surgically without affecting the function of other segments.
wheres the apical segment of the lower lobe found?
scapular spine —> where it also can be heard
what is the most dependent part of the lung when lying supine?
lower lobe
specifically the apical segment
whats segmentectomy?
Affected segment may be removed surgically without disrupting the surrounding lung
whats bronchography?
technique used to visualize the outline of the trachea and bronchi
performed after introducing a contrast medium into respiratory tract
