Bounded by the chest wall and below by the diaphragm, it extends upward into the root of the neckabout one fingerbreadth above the clavicle on each side
Chest cavity
the only structure (apart from the pleura and the peritoneum)that separates the chest from the abdominal viscera
Diaphragm
a median partition
mediastinum
a movable partition that extends superiorly to the thoracic outlet and the root of the neck and inferiorly to the diaphragm
mediastinum
The mediastinum is divided into
superior and inferior mediastinum
The inferior mediastinum is further subdivided into the ________,which consists of the pericardium and heart; the ________, which is a space between the pericardium and the sternum; and the ________, which lies between the pericardium and the vertebral column
middle mediastinum
anterior mediastinum
posterior mediastinum
Consist the superior mediastinum
Thymus
large veins
large arteries
trachea
esophagus and thoracic duct
sympathetic trunks.
composes the inferior mediastinum
Thymus
Heart within the pericardium with the phrenic nerves on each side
esophagus and thoracic duct
descending aorta
sympathetic trunks
bounded in front by the manubrium sterni and behind by the first four thoracic vertebrae
superior mediastinum
bounded in front by the body of the sternum and behind by the lower eight thoracic vertebrae
inferior mediastinum
2 parts of a pleura
parietal layer
mediastinal layer
lines the thoracic wall, covers the thoracic surface of the diaphragm and the lateral aspect of the mediastinum
parietal layer
covers the outer surfaces of the lungs and extends into the depths of the interlobar fissures
visceral layer
a loose fold that allow for movement of the pulmonary vessels and large bronchi during respiration
pulmonary ligament
a slit like space that separate he parietal and visceral layers of pleura are from one another
pleural cavity/ pleural space
covers the surfaces of the pleura as a thin film and permits the two layers to move on each other with the minimum of friction
pleural fluid
extends up into the neck, lining the under surface of the suprapleural membrane (see Fig. 2.13). It reaches a level 1 to 1.5 in. (2.5 to 4 cm) above the medial third of the clavicle.
cervical pleura
lines the inner surfaces of the ribs, thecostal cartilages, the intercostal spaces, the sides of the vertebralbodies, and the back of the sternum
costal pleura
covers the thoracic surface ofthe diaphragm
diaphragmatic pleura
This lower area of the pleural cavity into which the lung expands on inspiration is referred to as the ________
costodiaphragmatic recess
covers and forms the lateral boundary of the mediastinum
mediastinal pleura
where the mediastinal pleura is attached to the blood vessels and bronchi that constitute the lung root
hilum
are slitlike spaces between the costal and diaphragmatic parietal pleurae that are separated only by a capillary layer of pleural fluid
Costodiaphragmatic Recesses
are situated along the anterior
margins of the pleura
Costomediastinal Recesses
They are slitlike spaces between the costal and mediastinal parietal pleurae, which are separated by a capillary layer of pleural fluid
Costomediastinal Recesses
The costal pleura is segmentally supplied by what nerve
Intercostal nerve
The mediastinal pleura is supplied by the
Phrenic Nerve
The diaphragmatic pleura is supplied over the domes by the _____ and around the periphery by the _____
Phrenic Nerve & Lower intercostal nerves
It is insensitive to common sensations such as pain and touch and it receives an autonomic nerve supply from the pulmonary plexus
Visceral Pleura
It is a mobile cartilaginous and membranous tube and It begins in the neck as a continuation of the larynx at the lower border of the cricoid cartilage at the level of the 6th cervical vertebra
trachea
In the thorax, the trachea ends below at the _____ by dividing into right and left principal bronchi at the level of the sternal angle
carina
In adults, the trachea is about _____long and _____ in diameter
4 1/2 in. (11.25cm) & 1 in. (2.5 cm
Is kept patent by the presence of U-shaped bars (rings) of hyaline cartilage embedded in its wall
Fibroelastic tube
The posterior free ends of the cartilage are connected by smooth muscle
trachealis muscle
The relations of the trachea in the superior mediastinum of the thorax anteriorly:
The sternum, the thymus, the left brachiocephalic vein, the origins of the brachiocephalic, left common carotid arteries, the arch of the aorta
The relations of the trachea in the superior mediastinum of the thorax posteriorly:
The esophagus, the left recurrent laryngeal nerve
The relations of the trachea in the superior mediastinum of the thorax right side;
The azygos vein, the right vagus nerve, the pleura
The relations of the trachea in the superior mediastinum of the
thorax left side:
The arch of the aorta, the left common carotid, left subclavian arteries,the left vagus and left phrenic nerves, and the pleura
The upper two thirds of the trachea are supplied by the
inferior thyroid arteries
the lower third of the trachea is supplied by the
bronchial arteries
The sensory nerve supply is from the
Vagi and Recurrent laryngeal nerves
Sympathetic nerves supply the
trachealis muscle
The trachea bifurcates behind the arch of the aorta into the
right and left principal (primary or main) bronchi
Each respiratory bronchiole divides into ______ alveolar ducts that enter the alveolar sacs
2 to 11
The right principal (main) bronchus is
wider, shorter, and more vertical and is about 1 in (2.5 cm) long
The left principal (main) bronchus is
narrower, longer, and more horizontal than the right and is about 2 in. (5 cm) long
During life, the right and left lungs are:
soft, spongy,\very elastic
If the thoracic cavity were opened, the lungs would immediately shrink to
one third or less in volume
Each lung has a ________, which projects upward into the neck for about 1 in. (2.5 cm) above the clavicle
blunt apex
Concave base of the lungs sits on the
diaphragm
Part of the lungs which corresponds to the concave chest wall
convex costal surface
Part of the lungs which is molded to the pericardium and other mediastinal
structures
concave mediastinal surface
depression in which the bronchi, vessels, and nerves that form the root enter and leave the lung
hilum
The _______ runs from the inferior border upward and backward across the medial and costal surfaces until it cuts the posterior
border about 2.5 in. (6.25 cm)below the apex
oblique fissure
Runs horizontally across the costal surface at the level of the 4th costal cartilage to meet the oblique fissure in the mid axillary line
Horizontal Fissure
the anatomic, functional,and surgical units of the lungs
Bronchopulmonary segment
structurally and functionally independent unit of a lung lobe
bronchopulmonary segment
smallest bronchi, <1 mm in diameter
Bronchioles
possess no cartilage in their walls and are lined with columnar ciliated epithelium. The submucosa possesses a complete layer of circularly arranged smooth muscle fibers
Bronchioles
bronchioles then divide and give rise to
terminal bronchioles
Gaseous exchange between blood and air takes place in the walls of these outpouchings
Respiratory bronchioles
main characteristics of a bronchopulmonary segment
It is a subdivision of a lung lobe
It is pyramid shaped, with its apex toward the lung root
It is surrounded by connective tissue
It has a segmental bronchus, a segmental artery, lymph vessels, and autonomic nerves
The segmental vein lies in the connective tissue between adjacent bronchopulmonary segments
Because it is a structural unit, a diseased segment can beremoved surgically
formed of structures that are entering or leaving the lung (made up of the bronchi,pulmonary artery and veins, lymph vessels, bronchial vessels, and nerves)
root of the lung
The bronchi, the connective tissue of the lung, and the visceral pleura receive their blood supply from the bronchial arteries, which are branches of the ________
descending aorta
The bronchial veins (which communicate with the pulmonary veins) drain into the ________
azygos and hemiazygos veins
lies beneath the visceral pleura and drains over the surface of the lung toward the hilum, where the lymph vessels enter the bronchopulmonary nodes
superficial (subpleural) plexus
All the lymph from the lung leaves the hilum and drains into the ______ and then into the ______
tracheobronchial nodes & bronchomediastinal lymph trunks
Nerve Supply of the Lungs
pulmonary plexus