Anatomy of lower respiratory tract II Flashcards
What kind of stimuli are the pleura sensitive to?
Pain, pressure, temperature, and touch
What nerves supply the costal pleura?
Costal pleura is supplied by intercostal nerves (anterior rami of T1 - T11) and sucostal nerve (T12)
What nerves supply the mediastinal pleura?
Mediastinal pleura is supplied by phrenic nerves (C3 - C5 spinal segments)
What nerves supply the diaphragmatic pleura?
Diaphragmatic pleura (phrenic nerves, lower 5 iintercostal nerves and subcostal nerve)
What structures are supplied by the same nerves as parietal pleura?
The muscles and bones of the same area.
What supplies sensory innervation for visceral pleura?
It is sensitive only to stretch and so only has visceral reflexive afferent fibers which follow the parasympathetic fibers.
Not sensitive to pain
How long and wide is the trachea?
12.5cm long and 2.5cm wide
How long is the trachea?
Extends from lower border of cricoid cartilage (C5/C6) to the sternal angle at T4/5
Does trachea descend directly at the middle?
No, it descends through superior mediastinum a little to the right of the median plane.
What is the carina?
A keel-like ridge between at the bifurcation of the trachea into bronchi. It represents a cartilaginous projection of the last tracheal ring.
What is the importance of the carina in clinical practice?
It acts as a landmark for bronchoscopy.
Mucosa that lines carina is rich in sensory nerve endings and if mucous reaches carina it causes cough reflex.
Morphological changes in the carina assists with differential diagnosis of diseases. This is because tumours or growths can modify the shape of the carina.
What are the differences between right and left primary bronchi?
Right bronchus is shorter (2.5cm compared to 5). wider, shorter, and runs more vertically than left main bronchus
Descends more vertically than left lung.
What direction does the right bronchus descend?
Vertically, posterior to the right pulmonary artery and ascending aorta, anterior to the oesophagus and right vagus nerve
What direction does the left main bronchus descend?
Passes inferolaterally inferior to the arch of the aorta, posterior to the pulmonary artery and anterior to the thoracic aorta
What structures is the right main bronchus related to?
Posterior to right pulmonary artery and ascending aorta, anterior to the oesophagus and right vagus nerve
What structures is the left main bronchus related to?
Inferior to the arch of the aorta, posterior to left pulmonary artery and anterior to the thoracic aorta
What is the clinical significance of the morphology of the lungs?
Right main bronchus is more likely to be occluded by foreign body than left main bronchus
What artery runs anterior initially to the trachea then lateral to the trachea?
Carotid artery
What structures run anterolaterally to the trachea?
Brachiocephalic veins and arteries.
Vagus nerve (still runs posterior to hilum)
What are the branches of the right primary bronchus?
Superior lobar bronchus (braches before entering the lung)
Middle lobar bronchus
Inferior lobar bronchus
What are the branches of the left primary bronchus?
Superior lobar bronchus
Inferior lobar bronchus
What do lobar bronchi divide into?
Tertiary/segmental bronchi
How many segmental bronchi does each lung have?
Right lung = 10
Left lung = 8 - 10
What is a bronchopulmonary segment?
The segmental bronchus and surrounding lung parenchyma.
What is the division of segmental bronchi?
Bronchioles
Do bronchioles have cartilage plates?
No they are self supporting and have smooth muscle
What do bronchioles divide bronchopulmonary segments into?
Pulmonary lobules
What is the diameter of bronchioles?
1mm
What do bronchioles further divide into?
Terminal and respiratory bronchioles
What do respiratory bronchioles terminate in that terminal bronchioles don’t?
Alveolar sacs
What is the smallest functional unit of pulmonary system?
Pulmonary acini
What are the parts of the bronchopulmonary segments?
Bronchopulmonary segments are the anatomical, functional, and surgical units of the lungs