Respiratory Anatomy Flashcards
What is the embryological origin of the respiratory tract?
A respiratory diverticulum from the upper end of the foregut
What structure first form in development of the lungs?
Two lung buds
What do lung buds become?
Primary bronchi
Primary bronchi divide into what?
Secondary bronchi
What are secondary bronchi also called?
Lobar bronchi
What do secondary bronchi divide into?
Tertiary bronchi
What are tertiary bronchi also called?
Segmental bronchi
Tertiary bronchi keep dividing to form what?
Terminal bronchioles
What do terminal bronchioles give rise to?
Respiratory bronchioles
Alveoli develop from respiratory bronchioles when?
Third trimester
What is a rare congenital malformation in which the upper esophagus is blind-ending and the lower esophagus is connected to the trachea by a fistula?
Esophageal atresia with tracheo-esophageal fistula
Where does the trachea begin?
Cricoid cartilage (C6)
What type of cartilage is in the trachea?
Fibrocartilage
What type of cell lines the trachea?
Pseudostratified columnar epithelium
What holds the trachea open?
15-20 U-shaped rings
What are the dimensions of the trachea?
5 inches long and 1 inch in diameter
What connects the tracheal rings posteriorly?
Trachealis
Where does the trachea end?
The sternal angle (of Louis) at T4/T5
What marks the bifurcation of the trachea?
Carina (V shaped cartilage)
Where does the esophagus lie in relation to the trachea?
Posterior
What crosses the 2nd-4th tracheal rings?
The isthmus of the thyroid
Which bronchus is shorter, wider, and more vertical?
Right
Which bronchus divides into two secondary bronchi?
Left main bronchus
Which bronchus divides into three secondary bronchi?
Right main bronchus
How much surface area does a lung provide for gas exchange?
40 square meters
What are the different lung surfaces?
Cervical (apex), Diaphragmatic (base), Costovertebral (lateral), Mediastinal (medial)
Which lung is bigger, wider and shorter?
Right
How many bronchopulmonary segments are in each lung?
10 right
8-9 left
Where do the intersegmental veins of the lungs drain into?
The azygos veinous system or the pulmonary veins
What are the segmental arteries of the lungs derived from?
Bronchial branches of the aorta
In the root of the lungs, what is the orientation of the bronchus and veins?
Bronchus - behind
Veins - below
What is the orientation of the pulmonary arteries in the lungs?
The right pulmonary artery is in the lung root anterior to the bronchus; The left pulmonary artery lies superior to the bronchus
What layer of the pleura is sensitive to pain?
Parietal
What is the visceral layer of pleura innervated by?
Vagus nerve
What is the parietal pleura innervated by?
Intercostal and phrenic nerves
What is a sleeve of pleura at the root of the lung and functions as anatomical dead space for pulmonary veins?
Pulmonary ligament
What part of the of the cervical pleura extends above the 1st rib?
Cupola
What limits the extension of the lung into the neck?
Sibson’s fascia
What supplies blood to the pleura?
Anterior and posterior intercostal arteries
What are the upper 6 anterior intercostal arteries derived from?
The internal thoracic artery of the subclavian artery
What are the anterior 7th-9th intercostal arteries derived from?
Musculophrenic branch of the internal thoracic artery
What are the 1st and second intercostal arteries derived from?
The costocervical branch of the subclavian artery
What are the 3rd through 11th posterior intercostal arteries derived from?
Descending thoracic aorta
What is the venous drainage of the pleura?
Azygos venous drainage
What lie on the right side of the lower eight thoracic vertebra?
Azygos vein
What vessels does the azygos vein receive?
2nd through 11th posterior intercostal artery and right subcostal veins
What does the hemiazygos vein drain?
The 3 or 4 lower left intercostal veins and the left subcostal vein
What is the accessory hemiazygos vein formed by?
5th-8th left intercostal vein
What do the 1st and 2nd posterior intercostal veins drain into?
The brachiocephalic vein
What is the fibromuscular septum that separates the thoracic cavity and abdominal cavity?
Diaphragm
What are the embryological origins of the diaphragm?
Central tendon (3-5th cervical somite)
Pleuroperitoneal membranes
Peripheral rim of the body wall
Dorsal mesentery of the esophagus
What are the muscular fiber origins of the diaphragm?
Right crus (from bodies of of L1-3)
Left crus (from bodies of L1-2)
The lower 6 ribs
Sternum (posterior aspect of xiphoid process)
What is the muscular insertion of the diaphragm?
The central tendon
What levels are the openings of the diaphragm at and for what?
T8 - IVC, Right phrenic, pericardiophrenic vessels
T10 - Esophagus and Vagus nerve
T12 - Aorta, Thoracic duct, Azygos vein
What innervates the diaphragm?
The phrenic nerve (C3-5)
What covers the diaphragm?
Superior - Pleura
Inferior - Peritoneum
What is the condensation of fascia over the psoas muscle?
The medial arcuate ligament
What is the condensation of fascia over the quadratus lumborum?
Lateral arcuate ligament
What connects the right and left crura of the diaphragm?
Median arcuate ligament
