Lungs Flashcards
Trachea begins at
C6, at the end of cricoid cartilage
Trachea ends at
the sternal angle
Trachea sits in front of
the esophagus, otherwise it is the most posterior
Right Primary Bronchus
wider, shorter, and more vertical than left
Azygous vein arches over it into SC
Left Primary Bronchus
Passes inferolaterally, inferior to aortic artch
Anterior to esophagus and descending aorta
What are you more likely to get something stuck in?
Right Primary Bronchus
Carina
keel-like ridge between orifices of primary bronchi
Apex of lungs comes to
thoracic inlet - near neck - cervical surface of lung
Primary fissure
Also called Oblique fissure
in both lungs, divides superior and inferior lobes
Secondary fissure
Also called transverse/Horizontal fissure
Found in right lung only
divides upper and middle lobes
Right lung
3 lobes, upper, middle, and lower
Oblique and Horizontal fissures
Left lung
2 lobes, upper and lower
Oblique fissure only
Lingula
projection of upper lobe in left lung
right above it sits the heart in the cardiac notch
Cervical surface
Apex of lung
Costal surface
faces ribs
Mediastinal surface
Side with vessels
faces midline organs
Diaphragmatic surface
base, sits on diaphragm
Anterior border
fine edge on outside
Posterior border
rounded ridge near vertebral column
Inferior border
edge around diaphragm surface
Roots of lungs
structures that go into hilum
Pulmonary ligament
formed by reflection of parietal pleura as it becomes visceral pleura
Surrounds structures of root in lungs
Pulmonary arteries
come from heart, thicker, usually more superior than veins
Pulmonary veins
thinner than arteries
return blood to heart
Bronchus
thick tube that carries air
made of cartilage
Bronchia arteries and veins
come off aorta and enter lungs through tiny openings in bronchus cartilage
Oxygenated arteries - right bronchial artery has one that branches inside
left bronchial artery splits into two (superior and inferior) before entering bronchus
Nerves
afferent, stretch and irritant receptors
Hilum of lung
depression or pit at the part of the organ where vessels and nerves enter
Secondary (Lobar Bronchus)
3 branches right - Superior, Middle, Inferior
2 branches left - Superior and Inferior
Segmental Bronchi
specific Bronchopulmonary segment - separated by avascular septa (wall incase of disease) and each have own artery, bronchus, and vein
10 in right lung and 8 in left
Each can be surgically removed with out affecting function of other segments
Terminal Bronchioles
most distal segment - divide to form respiratory bronchioles that contain alveoli
Serous fluid
pleural fluid, reduces friction between pleural layers
Visceral pleura
inner layer of membrane, shiny
remains closely attached to the lung and can’t be separated
Parietal pleura
outer layer of membrane
lines wall on thoracic body wall - does not move
endothoracic fascia
attaches Parietal pleura to thoracic wall
Cervical pleura
emerges through thoracic inlet
costal pleura
in contact with ribs
mediastinal pleura
in contact with mediastinal structures
diaphragmatic pleura
in contact with domes of diaphragm
Pleural cavity
space between two pleural membranes
lung fills up entire space
Pleural reflections
becomes visceral on lungs
specific pleural surface that becomes another pleural surface
form recesses that are potential spaces, within pleural cavity, which can fill with fluid
Costodiaphragmatic recess
between lung and diaphragm
sharp edge
normally don’t see unless fluid filled
Pulmonary Plexus
Nerve innervation to lungs
anterior and posterior plexi, related to carnia
heavy intervation by both sympathetics and parasympathetics
Sympathetics
vasoconstrictors and bronchodilators
Parasympathetics
Vagus nerve - causes bronchials to constrict
Vasodilators, bronchoconstrictors, secretomotor, and afferents
Cough reflex
located around carina - irritant receptor
Respiratory control
stretch receptors located in bronchial tree
Touch and pain receptors are located in
respiratory epithelium
Nerve innervation to costal and cervical pleura
local intercostal nerves
Nerve innervation to mediastinal pleura
phrenic nerve
Diaphragmatic pleura
central - phrenic nerve
Peripheral - local intercostal nerves
Superficial lymphatic plexus
right underneath visceral pleura
drains lung and visceral pleura into superior and inferior tracheobronchial lymph nodes
Deep lymphatic plexus
within lamina propria of bronchi
There are no lymph vessels in alveoli
Flow to pulmonary lymph nodes
Pulmonary lymph nodes
located along large branches of main bronchi
Flow to bronchopulmonary lymph nodes
Bronchopulmonary lymph nodes
Hilar nodes
Flow to superior and inferior tracheobronchial lymph nodes
Superior and inferior tracheobronchial lymph nodes
Carinal nodes - connect two lungs - can spread lung cancer
Flow to bronchomediastinal lymph trunks
Bronchomediastinal lymph nodes
formed by vessels from parasternal, tracheobronchial, and anterior mediastinal lymph nodes
Empty into Thoracic duct on left side and Right lymphatic duct on right side
Respiratory primordium begins at
28 days
Laryngotracheal groove
outgrowth from caudal end of ventral wall of the primordial pharynx, caudal to the 4th pair of pharyngeal puches
Laryngotracheal diverticulum
forms at end of 4th week
ventral to caudal part of foregut
elongates and is invested with splanchnic mesenchyme
Formin end enlarges to form globular respiratory bud - trachea and bronchial buds
Primordial laryngeal inlet
opening of laryngotracheal tube into pharynx
Maintains communication with laryngotracheal diverticulum and pharynx
Tracheoesophageal folds
develop in the posteroinferior aspect of the laryngotracheal diverticulum
Approach each other and fuse to become the tracheoesophageal septum
Tracheoesophageal septum
divides ventrally into the laryngotracheal tube and dorsally into the oropharynx and esophagus
Tracheoesophageal fistula
would occur if tracheoesophageal septum didn’t fuse
Laryngotracheal tube
distal end - tracheal portion
differentiates into trachea - respiratory bud
Endodermal lining of laryngotracheal tube gives rise to
epithelium and glands of the trachea
Overlying splanchnic mesenchyme (mesoderm) of the laryngotracheal tube becomes
cartilage, connective tissue, and muscles of trachea
Primary bronchial buds
form as the tracheal bud continues to grow inferiorly - two outpouchings
Bronchial buds grow in what direction
laterally into the mesenchyme surrounding the pleuroperitoneal canals
Parietal pleura is formed from
Somatic mesoderm
Pseudoglandular Period
6-16 weeks
resembles exocrine gland
forms all major elements of lung except those involved in gas exchange - no respiration, so fetus can’t survive
Canalicular Period
16-26 weeks
Lumina of bronchi and terminal bronchioles become larger and lung tissue becomes highly vascular
Respiratory bronchioles (2 or more) form from each terminal bronchiole
Alveolar ducts (3 to 6) - tubular passages form
Terminal saccules (primordial alveoli) - ends of resp. bronchioles, well vascularized
Terminal Sac Period
26 weeks - birth
Capillaries start to bulge into terminal sacs - allows for gas exchange
Develop blood-air barrier
Type I alveolar cells - pneumocytes, air exchange occurs
Type II alveolar cells - surfacant producing cells - facilitates expansion of terminal sacs
Alveolar Period
32 weeks to 8 years
Development of alveoli - mostly complete by 3 but new alveoli may be added until 8 years
After birth primordial alveoli increase in size forming mature alveoli (can’t form additional primordial alveoli)
