Lungs Flashcards
Lungs
- Organs of respiration
- light soft and elastic
Function of Lungs
Oxygenation of blood
Location of lungs
-In the chest on either side of the mediastinum
Pleural Cavity
- Surrounds each lung
- Formed by the visceral and parietal pleura
Lung Root
- Suspends the lungs from the mediastinum
- Pulmonary Ligament
Left lung medial surface lies close to :
Heart
Arch of aorta
Thoracic aorta
Oesophagus
Right lung medial surface lies close to :
Oesophagus Heart Inferior vena cava Superior vena cava Azygous vein
Apex of lungs
- Superior end of the lung
- Oblique to the thoracic inlet
- projects upwards above the level of the first costal cartilage
Base of lungs
- Inferior surface of the lung
- concave
- rests on the convex surface of the diaphragm
Lobes
Separated b fissures within the lung
Surfaces
- Costal
- medial /mediastinal
- Inferior/ diaphragmatic
Borders
- Anterior
- inferior
- Posterior
Oblique Fissure
- Runs from the inferior border of the lung in a superoposterior direction, until it meets the posterior lung border.
- runs from 2nd thoracic vertebra posteriorly to 6th costal cartilage anteriorly,
Horizontal Fissure
- Runs horizontally from the sternum, at the level of the 4th rib, to meet the oblique fissure.
- runs from oblique fissure at midaxillary line along 4th rib to its costal cartilage anteriorly.
Right Lung
- slightly larger
- 3 lobes (superior, middle & inferior)
- Oblique fissure separates the inferior lobe from the other 2
- horizontal fissure separates the superior fissure from the middle lobe
Contents of lung root
- Maint stem /lobar bronchi
- Pulmonary vessels and bronchi
- Bronchial vessels , Lymphatics , and autonomic nerves
Hilum of lungs
Connects the mediastinal surface to the heart
Structures that enter and leave the Hilum
-Principal/primary bronchus
-Pulmonary artery
-2 Pulmonary veins
-Bronchial arteries
Pulmonary plexus
Lymph vessels & nodes
Pulmonary artery
Carries deoxygenated blood from the right ventricle
Pulmonary vein
Carries oxygenated blood to the left atrium
Bronchial arteries
Carries oxygenated blood from the descending aorta and veins
Mediastinal surface
- posterior part->thoracic vertebrae
- Anterior part -> accommodates heart
Why is the concavity deeper in the right lung?
Due to the higher position of the right dome overlying the liver.
Cardiac impression
Much larger on the left leg than the right because of the position of the heart
Costal surface
- Smooth and convex
- faces the internal surface of chest wall
Diaphragmatic surface
Formed by the base of the lungs
Anterior border
Formed by the convergence of the mediastinal and costal surfaces.
Cardiac notch
A deep notch created by the apex of the heart
Inferior border
Separates the base of the lung from the costal and mediastinal surfaces.
Posterior Border
- Smooth ad rounded
- Formed by the costal and mediastinal surfaces meeting posteriorly
How many lobes does the right lung have?
3
The right lung contains a horizontal fissure. What rib does this fissure follow the course of?
4th
Parasympathetic innervation of the lungs comes from what nerve?
Vagus
Which of the following is a sympathetic response in the lungs?
Relaxation of bronchial smooth muscles
Pulmonary plexuses
Where the nerves of the lungs derive from
Parasympathetic
- Vagus nerve
- stimulate secretion from bronchial glands
- contraction of bronchia smooth muscle
- Vasodilation of pulmonary vessels
Sympathetic
- sympathetic trunks
- relaxation of bronchial smooth muscle
- vasoconstriction of pulmonary vessels
Visceral Afferent
Conducts pain impulses to the sensory ganglion of the vagus nerve
Venous drainage
The right bronchial vein drains into the azygos vein
-The left drains into the accessory hemiazygos vein.
Bronchial tree
Series of passages that supplies air to the alveoli of the lungs
Branches of the Bronchial Tree
Trachea -> Primary bronchi
-> Secondary bronchi -> Tertiary bronchi -> Conducting Bronchioles -> Terminal bronchioles -> Respiratory bronchioles -> Alveoli
Right Bronchus
Has a higher incidence of foreign body inhalation due to its wider shape and more vertical course.
Trachea
- Lower border of circuit cartilage
- continuation of larynx
- level of C6 to T4/5
- Divides into a left and right Bronchus at the level of the sternal angle
Carina
Hook of the lowest ring of cartilage of the trachea
Primary Bronchi
- T4/5
- Right is wider and more vertical than left
Secondary Bronchi
a. k.a Lobar Bronchi
- formed within lungs
- supplies the lobes of the lungs
Tertiary bronchi
a. k.a Segmental bronchi
- Provides air to bronchopulmonary segment
- 10 segments in each lung
Bronchopulmonary segments
- Pyramidal shaped
- Largest functional lobe
- Bronchioles & terminal bronchioles
Alveoli
Site of gaseous exchange
The trachea is a continuation of what upper respiratory tract structure?
Larynx
At what vertebral level does the trachea bifurcate?
T4
The trachea receives sensory innervation from what nerve?
Recurrent laryngeal nerve
How many right lobar bronchi are there?
3
Which part of the tracheobronchial tree contains club cells?
bronchioles
How many alveoli are there, on average, in an adult?
300 million
Parts of parietal pleura
- costal part
- diaphragmatic part
- mediastinal part
- cervical part
Parts of end-thoracic fascia
- Costal Part:
- Diaphragmatic: Phrenico-Pleural Fascia
- Mediastinal Part:
- Cervical Part: Suprapleural Membrane (Sibson’s Fascia) – C7 Transverse Process to Rib 1
Pleural Recesses
Space between lines of parietal pleural reflection and the corresponding margins of lungs
Drainage of the BP segements
Inter-segmental pulmonary veins
Blood Supple to the BP
Supplied by Segmental Bronchi, Tertiary Pulmonary Artery and Bronchial Artery
Conducting Bronchioles
20-25 generations
-Lack cartilage
Terminal Bronchiole
- End of each conducting bronchiole
- only gas exchange
Respiratory bronchioles
Several generations
-Gas Transport + Exchange
Alveolar ducts
-From each respiratory bronchiole 11-12 AD are given off
