in this presentation the complete anatomy of the lungs is explained, which is very easy to understand. it is very useful for the students of medical field and other students who are appearing in the competitive exams like neet, cet etc.
2. Objectives
Introduction
Features
Fissures and lobes of the lung
Roots and contents of the roots
Bronchopulmonary segments
Arterial supply
Venous drainage
Nerve supply
3. Introduction
lungs a pair of respiratory organs in the
thoracic cavity
Each lung innervates the pleural cavity
correspondent.
In young individuals, the lungs are
brown and gradually become
mottled with black due to the
deposition of inhaled carbon particles.
The right lung weighs about 700 g and
is therefore 50 g to 100 g heavier
than the left lung.
4. Features
Each lung is conical in shape
It has
Apex at the upper end
Base resting on the diaphragm
Three borders – anterior, posterior and inferior
Two surfaces – costal and medial
5. The apex is above the level of the 1st rib.
It extends 2.5 cm above the middle third
of the clavicle, just medial
to the supraclavicular fossa
The base rests on the diaphragm, the
right one Side separates the lung from the
right lobe of the liver and the left lung
from the left lobe of the liver, the fundus
of the stomach and the spleen.
The anterior border of the left lung
shows a broad cardiac notch below the
level of the fourth costal cartilage. In the
area of this indentation, the heart and
pericardium are exposed from the lungs.
6. The posterior border corresponds to the medial margins of
the heads of the ribs. It extends from the level of 7th
cervical spine to the 10th thoracic spine.
Inferior border separates the base from costal and medial
surfaces.
The costal surfaces is a large and convex. It is in contact
with the costal pleura and the overlying thoracic wall.
The medial surface is divided into a vertebral part and
mediastinal part. The mediastinal part shows a cardiac
impression, the hilum
7. Fissures and lobes of the lungs
The right lung is divided into
three lobes by two fissures,
namely
oblique and horizontal
The left lung is divided into
two lobes by oblique
8. The oblique fissure cuts into whole thickness of the lung,
except at the hilum
Due to the oblique plane of the fissure, the lower lobe is
more posterior and the upper and lower lobe is more
anterior
In the right lung, the horizontal fissure passes from the
anterior border upto the oblique fissure and separates a
wedge shaped middle lobe from the upper lobe.
9. The tongue shaped projection of the left lung below the
cardiac notch is called lingual. It corresponds to middle lobe
of the right lung
The lungs expand maximally in the inferior direction because
movements of the thoracic wall and diaphragm are maximal
towards the base of the lung
The presence of the oblique fissure of the each lung allows a
more uniform expansion of the whole lung
10. Root of the lung
The medial surface of the lung is connected to the
mediastinum by a short, wide pedicle called the root of the
lung.
It is created by the structures at the hilum that either enter
or exit the lung.
The bodies of the fifth, sixth, and seventh thoracic
vertebrae are located across from the lungs' roots.
11. Contents of Roots of the lungs
The main bronchus i.e. principal bronchus is on the left, while
the eparterial and hyparterial bronchi are on the right.
One pulmonary artery
Two pulmonary veins, superior and inferior
Bronchial arteries, one on the right side and two on the left
side
Bronchial veins
Anterior and posterior pulmonary plexuses of nerves
Lymphatics of lung
Bronchopulmonary lymph nodes
Areolar tissues
12. Bronchopulmonary segments
Each of these clearly defined lung sectors is aerated by
a tertiary or segmental bronchus.
Each segment has a pyramidal form, with the apex
pointing in the direction of the root of the lung.
They are separate respiratory units that make up the
bronchopulmonary segments.
13. Arterial supply
One bronchial artery on the right side arises from the
upper left bronchial artery or the third posterior
intercostal artery.
Two bronchial arteries on the left side each originate
from the descending thoracic aorta.
The bronchial and pulmonary arteries have pre capillary
anastomoses. When one of these connections is blocked
by illness, the others grow.
14. Venous drainage
Typically, each side has two bronchial veins; the right
one empties into the azygous vein.
Either the left superior intercostal vein or the hemi
azygous vein receives the left bronchial vein's drainage.
The pulmonary veins remove the majority of the venous
blood from the lung.
15. Nerve supply
PARA SYMPATHETIC : Nerves are generated from the vagus
these fibres include:
(a) A bronchial muscle motor that, when stimulated, induces
bronchospasm
(b) A secretomotor to the bronchial tree's mucous glands
(c) The sensory fibres are in charge of the cough reflex and the
lung stretch response.
16. THE SYMPATHETIC :
Nerves come from the second to fifth vertebral segments.
They restrict the bronchial tree's smooth muscles and
glands.
This is how sympathomimetic medications, such as
adrenaline, produce bronchodilation and lessen
bronchial asthma symptoms.