[USMLE] Sternum, Mediastinum, Trachea, Lungs, Bronchopulmo, Respiration Flashcards
Is a flat, elongated, dagger-shaped bone and consists of the manubrium, the body, and the xiphoid process.
sternum (broad above, narrow below)
the sternum is relatively _____ and _____ in the female
slopes ________
shorter; thinner
downward and forward
the body of the sternum is more than twice as long as the _____ in the male but is usually less in the female
manubrium
The sternum: is a common site for bone marrow biopsy because
it possesses hematopoietic marrow
throughout life and because of its breadth and subcutaneous position
It may be split in the _____ to allow the surgeon to gain easy access to the lungs, heart, and great
vessels.
median plane (median sternotomy)
It has a superior margin, the jugular notch, which can be readily palpated at the root of the neck.
manubrium
the manubrium aas a clavicular notch on each side for articulation with the
clavicle
the manubrium also articulates with the
cartilage of the first rib, the upper half of the second rib, and the body of the sternum at the manubriosternal joint, or sternal angle
the junction between the manubrium and the body of the sternum; most reliable surface landmark of chest
Sternal angle (angle of Louis)
Is located at the level where:
The ______ ribs articulate with the sternum.
The aortic arch begins and ends.
The trachea bifurcates into the right and left bronchi at the _____.
The inferior border of the superior mediastinum is demarcated.
A transverse plane can pass through the intervertebral disk between ____ and ____.
2nd;
carina;
T4 and T5
Body of the sternum articulates with the
2nd to 7th costal cartilages
the body of the sternum also articulates with the _____ at the xiphisternal joint, which is level with the _____ thoracic vertebra.
xiphoid process;
9th
the Xiphoid process is a ____, __________ at birth that ossifies slowly from the central core and unites with the body of the sternum after middle age. it is _____ shaped
flat, cartilaginous process;
sword
The xiphoid process lies at the level of _____, and the xiphisternal joint lies at the level of the T9 vertebral body,
which marks the lower limit of the thoracic cavity in front, the upper surface of the liver, diaphragm, and
lower border of the heart.
T10 vertebra
the xiphoid process can be palpated in the epigastrium and is attached via its pointed caudal end to the
linea alba
the ribs consists of
12 pairs of bones that form the main part of the thoracic cage, extending from the vertebrae
to or toward the sternum
the ribs _____ the anteroposterior and transverse diameters of the thorax by their movements
increase
Typical ribs characteristics
ribs 3 through 9, each of which has a head, neck, tubercle, and body (shaft)
The _____ of the ribs articulates with the corresponding vertebral bodies and intervertebral disks and supra-adjacent vertebral bodies.
head
The _____ is thin and flat and turns sharply anteriorly at the angle and has a costal groove that follows the inferior and internal surface of a rib and lodges the intercostal vessels and nerves.
body (shaft) of the ribs
The tubercle of the ribs articulates with the _____ of the corresponding vertebrae, with the exception
of _____.
transverse processes;
ribs 11 and 12
true ribs
the first seven ribs (ribs 1 to 7)
true ribs are attached to the sternum by their
costal cartilages
false ribs
the lower five ribs (ribs 8 to 12)
ribs 8 to 10 are connected to the costal cartilages immediately above them to form the _____
anterior costal margin
Are the last two ribs (ribs 11 and 12) , which are connected only to the vertebrae.
floating ribs
bony thorax (skeleton) consists of
TICS
thoracic vertebrae, intervertebral discs, cartilages, sternum
superior thoracic aperture (thoracic inlet)
small, kidney-shaped, oblique
thoracic inlet boundaries
1st pair of ribs and cartilages
front: manubrium
inferior thoracic aperture (thoracic outlet)
large, irregular, oblique
thoracic outlet boundaries
T12 vertebra 12th rib behind sides cartilage of ribs 7-12 front- xiphisternal junction closed by diaphragm
is the compression of neurovascular structures in the thoracic outlet (a space between the clavicle and the first rib), causing a combination of pain, numbness, tingling, or weakness and fatigue in the upper limb caused by pressure on the brachial plexus (lower trunk or C8
and T1 nerve roots) by a cervical rib (mesenchymal or cartilaginous elongation of the transverse
process of the seventh cervical vertebra).
Thoracic outlet syndrome
a loss of stability of the thoracic cage that occurs when a segment of the anterior or lateral thoracic wall moves freely because of multiple rib fractures; an extremely painful injury and impairs ventilation, thereby affecting oxygenation of the blood and causing respiratory failure
Flail chest
Fracture of the first rib may injure the _____ and _____
brachial plexus and subclavian vessels
are most commonly fractured and usually result from direct blows or crushing injuries
middle ribs
broken ends of ribs may cause ______ and lung or spleen injury
pneumothorax
Lower rib fractures may tear
the diaphragm, resulting in a
diaphragmatic hernia
First rib is the
broadest and shortest of the true ribs
first rib has a
single articular facet on its head
first rib articulates with the
first thoracic vertebra
first rib has a _____ and _____
scalene tubercle - for the insertion of the anterior scalene muscle
two grooves - for the subclavian artery and vein
Second rib
Has two articular facets on its head, which articulate with the bodies of the first and second thoracic
vertebrae.
first vs second rib (in length)
second rib is about twice as long as the first rib
Tenth rib
Has a single articular facet on its head, which articulates with the tenth thoracic vertebra
Eleventh and twelfth ribs
Have a single articular facet on their heads; Have no neck or tubercle
the only bony attachment between the appendicular and axial skeletons
Sternoclavicular joint
Sternoclavicular joint has a _____ and contains ______
fibrocartilaginous articular surface;
two separate synovial cavities
The sternoclavicular joint is a saddle-type synovial joint but has the movements of a
ball-and-socket joint
Are synchondroses in which the sternum articulates with the first seven costal cartilages
Sternocostal (sternochondral) joints
Are synchondroses in which the ribs articulate with their respective costal cartilages
Costochondral joints
ext. intercostal
eleven in number; occupy ICS;
from rib tubercle behind to costochondral junction anteriorly
ext. intercostal {origin, insertion, innervation}
origin: lower border of the rib below
insertion: upper border of the rib (below)
innervation: branches of the IC nerve
int. intercostal
eleven in number; occupy ICS; extend medialward
anterior primary rami of the first 11 thoracic spinal nerves.
intercostal nerves
The anterior primary ramus of the twelfth thoracic spinal nerve is the
subcostal nerve - runs beneath the 12th rib
intercostal nerves run between
the internal and innermost layers of muscles, with the intercostal veins and arteries above
(Veins, Arteries, Nerves [VAN ]).
intercostal nerves are lodged
in the costal grooves on the inferior surface of the ribs
Gives rise to two anterior intercostal arteries in each of the upper six intercostal spaces and terminates
at the 6th intercostal space by dividing into the musculophrenic and superior epigastric arteries
Internal thoracic artery
Internal thoracic artery usually arises from the
first part of the subclavian artery
Internal thoracic artery descends directly behind the
first six costal cartilages, just lateral to the sternum
Accompanies the phrenic nerve between the pleura and the pericardium to the diaphragm.
Pericardiophrenic artery
Pericardiophrenic artery supplies the
pleura, pericardium, and diaphragm (upper surface)
Anterior intercostal arteries
12 small arteries
2 in each of the upper six intercostal spaces that run laterally, 1 each at the upper and lower borders of each space
The upper artery in each intercostal space anastomoses
posterior intercostal artery
lower artery in each intercostal space joins the
collateral branch of the posterior intercostal artery
the anterior intercostal arteries provide muscular branches to the
intercostal, serratus anterior, and pectoral muscles
Provide the medial mammary branches (second, third, and fourth branches).
Anterior perforating branches
Anterior perforating branches supply the
pectoralis major muscle and the skin and
subcutaneous tissue over it
Gives rise to two anterior arteries in the seventh, eighth, and ninth spaces; perforates the diaphragm;
and ends in the tenth intercostal space
Musculophrenic artery
the musculophrenic artery anastomoses with the
deep circumflex iliac artery
the musculophrenic artery supplies the
pericardium, diaphragm, and muscles of the abdominal wall
Descends on the deep surface of the rectus abdominis muscle within the rectus sheath; supplies this
muscle
Superior epigastric artery
Superior epigastric artery anastosomes with
inferior epigastric artery
Superior epigastric artery supplies the
diaphragm, peritoneum, and anterior abdominal wall
Is formed by the confluence of the superior epigastric and musculophrenic veins, ascends on the medial
side of the artery, receives the upper six anterior intercostal and pericardiacophrenic veins, and ends in
the brachiocephalic vein.
Internal thoracic vein
Is a venous connection between the lateral thoracic vein and the superficial epigastric vein
Thoracoepigastric vein
Are placed along the internal thoracic artery
Sternal or parasternal (internal thoracic) nodes
Sternal or parasternal (internal thoracic) nodes drain into the junction of the _____ and ______
internal jugular and subclavian veins
Sternal or parasternal (internal thoracic) nodes receive lymph from the _____ portion of the breast, intercostal spaces, diaphragm, and supraumbilical
region of the abdominal wall.
medial
Lie near the heads of the ribs
Intercostal nodes
Intercostal nodes receive lymph from the
intercostal spaces and the pleura
Intercostal nodes drain into the
cisterna chyli or the thoracic duct
Lie on the thoracic surface of the diaphragm.
Phrenic nodes
Phrenic nodes receive lymph from the
pericardium, diaphragm, and liver
Phrenic nodes drain into the
sternal and posterior mediastinal nodes
Mediastinum is an interpleural space (area between the pleural cavities) in the thorax and is bounded:
laterally by the pleural cavities;
anteriorly by the sternum and the transversus thoracis muscles; and
posteriorly by the vertebral column (does not contain the lungs)
Mediastinum consists of the
superior mediastinum above the pericardium and the three lower divisions: anterior,
middle, and posterior
Superior mediastinum boundaries
superiorly by the oblique plane of the 1st rib; and inferiorly by the imaginary line running from
the sternal angle to the intervertebral disk between the 4th and 5th thoracic vertebrae (T3-T4 on the SIM);
laterally by the parietal pleura
Superior mediastinum contains the
superior vena cava (SVC), brachiocephalic veins, arch of the aorta , thoracic duct, trachea, esophagus, vagus nerve, left recurrent laryngeal nerve, and phrenic nerve
is the site at which immature lymphocytes develop
into T lymphocytes; and secretes thymic hormones, which cause T lymphocytes to gain immunocompetence. It begins involution after puberty.
thymus, a lymphoid organ
pericardium is loosely bound to manubrium by fibrous tissue which constitutes the
superior sternopericardial ligament
Lies anterior to the pericardium and posterior to the sternum and the transverse thoracic muscles.
Anterior mediastinum
Anterior mediastinum contains the remnants of the
thymus gland, lymph nodes, fat, and connective tissue
Anterior mediastinum consists largely of
areolar tissue
Lies between the right and left pleural cavities.
Middle mediastinum
Middle mediastinum contains the
pericardium, heart and great vessels, bronchi, comp of root of lungs, arch of azygos vein, phrenic vein
Lies posterior to the pericardium between the mediastinal pleurae.
Posterior mediastinum
Posterior mediastinum contains
esophagus, thoracic aorta, azygos and hemiazygos veins, thoracic duct, vagus nerves,
sympathetic trunk, and splanchnic nerves
trachea pathway
Begins at the inferior border of the cricoid cartilage (C6) as a continuation of the larynx and ends by
bifurcating into the right and left main stem bronchi at the level of the sternal angle (junction of T4 and
T5).
location: sup mediastinum
trachea length
about 9 to 15 cm in length (12 cm long, 2 cm wide according to SIM)
trachea has _____ that open posteriorly toward the esophagus and prevent the trachea from collapsing.
16 to 20 incomplete hyaline cartilaginous rings
carina
a downward and backward projection of the last tracheal cartilage
lies at the level of the sternal angle and forms a keel-like ridge separating the openings of the right and left main
bronchi
carina
may be compressed by an aortic arch aneurysm, a goiter, or thyroid tumors, causing
dyspnea
trachea
may be examined with a bronchoscope and may be distorted, widened posteriorly, and
immobile in the presence of a bronchogenic carcinoma. The mucous membrane over the carina is one
of the most sensitive areas of the tracheobronchial tree and is associated with the cough reflex.
carina
right vs left main bronchus
right main bronchus is shorter, wider , and more vertical than the left main bronchus
right main(primary) bronchus pathway
Runs under the arch of the azygos vein and divides into three lobar or secondary (superior, middle ,
and inferior ) bronchi and finally into 10 segmental bronchi
The right superior lobar (secondary) bronchus is known as the _______ because it passes above the level of the pulmonary artery. All others are the hyparterial bronchi.
eparterial (above the artery) bronchus
Left main (primary) bronchus pathway
Runs inferolaterally inferior to the arch of the aorta , crosses anterior to the esophagus and thoracic
aorta, and divides into two lobar or secondary bronchi , the upper and lower, and finally into 8 to 10
segmental bronchi.
Left main (primary) bronchus is also crossed superiorly by the _______ over its proximal part and by the _______ over its distal part.
arch of the aorta;
left pulmonary artery
Left main (primary) bronchus dilates its lumen by
sympathetic nerves
Left main (primary) bronchus constricts by
parasympathetic stimulation
is a group of lung diseases associated with chronic
obstruction of airflow through the airways and lungs. It includes chronic bronchitis and emphysema ,
which are the most common forms and is caused primarily by cigarette smoking.
COPD
is an inflammation or irritation of the airways, and excessive mucus production
plugs up the airways, causing a cough and breathing difficulty.
chronic bronchitis
is an accumulation of air in the terminal bronchioles and alveolar sacs (air is trapped
in the lungs) due to destruction of the alveolar walls, reducing the surface area available for the
exchange of oxygen and carbon dioxide and thereby reducing oxygen absorption
emphysema
is an airway obstruction and is characterized by dyspnea (difficulty in breathing) and cough
with wheezing because of spasmodic contraction of smooth muscles in the bronchioles, which narrows
the airways particularly during expiration
asthma
is a chronic dilation of bronchi and bronchioles resulting from destruction of
bronchial elastic and muscular elements, which may cause collapse of the bronchioles
Bronchiectasis
pleura
thin serous membrane
pleura consists of
a parietal pleura and a visceral pleura
Lines the inner surface of the thoracic wall and the mediastinum and has costal, diaphragmatic,
mediastinal, and cervical parts
parietal pleura
is the dome of the pleura, projecting into
the neck above the neck of the first rib.
cervical pleura (cupula)
a suprapleural membrane, which is a thickened portion of the endothoracic fascia , and is attached to the first rib and the transverse process of the seventh cervical vertebra
Sibson’s fascia
endothoracic fascia
extrapleural fascial sheet lining the thoracic wall.
parietal pleura is innervated by the
intercostal nerves and the phrenic nervesal pleu
parietal pleura is very sensitive to
pain
parietal pleura is supplied by
branches of the internal thoracic, superior phrenic, posterior intercostal, and superior
intercostal arteries
visceral pleura is supplied by
bronchial arteries
pulmonary ligament
two-layered vertical fold of mediastinal pleura
pulmonary ligament runs along mediastinal surface of each lung from
hilus to the base
Intimately invests the lungs and dips into all of the fissures
visceral pleura
visceral pleura is supplied by
bronchial arteries
visceral pleura’s venous blood is drained by
pulmonary veins
visceral pleura Is insensitive to pain but is sensitive to
stretch
visceral pleura contains
vasomotor fibers and sensory endings of
vagal origin
is an inflammation of the pleura with exudation (escape of fluid from blood vessels) into its cavity, causing the pleural surfaces to be roughened
Pleurisy (pleuritis)
Is a potential space between the parietal and visceral pleurae.
pleural cavity
pleural cavity
Represents a closed sac with no communication between right and left parts
pleural cavity contains
a film of fluid that lubricates the surface of the pleurae and facilitates the movement of the
lungs
Can accumulate fluid when in the erect position.
Allow the lungs to be pulled in and expanded during inspiration.
Costodiaphragmatic recesses
Costodiaphragmatic recesses
Are the pleural recesses formed by the reflection of the costal and diaphragmatic pleurae
Costomediastinal recesses
Are part of the pleural cavity where the costal and mediastinal pleurae meet.
is an accumulation of air in the pleural cavity, and thus, the lung collapses because the negative pressure necessary to keep the lung expanded has been eliminated. It results from an injury to the thoracic wall or the lung.
Pneumothorax
a life-threatening pneumothorax in
which air enters during inspiration and is trapped during expiration
Tension pneumothorax
an abnormal accumulation of excess fluid in the pleural space
Pleural effusion:
(type of pleural effusion) clear watery fluid
transudate
(type of pleural effusion) cloudy viscous fluid
exudate
An accumulation of fluid (water) in the pleural cavity
hydrothorax
An accumulation of fluid (blood) in the pleural cavity
hemothorax
An accumulation of fluid (lymph) in the pleural cavity
chylothorax
An accumulation of fluid (pus) in the pleural cavity
pyothorax
Are the essential organs of respiration
lungs
lungs are attached to the heart and trachea by their roots and the
pulmonary ligaments
lungs contain
nonrespiratory tissues
lungs are are nourished by the
bronchial arteries
drained by the
bronchial veins for the larger subdivisions of the bronchi and by the pulmonary veins for the smaller
subdivisions of the bronchial tree
lungs have bases that rest on the convex surface of the diaphragm, descend during _____, and ascend
during _____.
inspiration;
expiration
Has an apex that projects into the neck and a concave base that sits on the diaphragm
Right lung
right lung vs left lung
right lung is larger and heavier than the left lung, but is shorter and wider because of the higher right dome of the diaphragm and the inclination of the heart to the left
right lung is divided into upper, middle, and lower lobes by the
oblique and horizontal (accessory) fissures
The oblique fissure usually begins at the head of the fifth rib and follows roughly the line of the
6th rib
The horizontal fissure runs from the oblique fissure in the
midaxillary line at the 6th rib level and extends forward to the
4th costal cartilage level
right lung has
3 lobar (secondary) bronchi and 10 segmental (tertiary) bronchi
Has grooves for
SVC, arch of azygos vein, esophagus
left lung is divided into upper and lower lobes by an
oblique fissure
lingula
a tongue-shaped portion of the upper lobe that corresponds to the middle lobe of the right lung. (contained in the left lung)
left lung contains
a cardiac impression , a cardiac notch (a deep indentation of the anterior border of the
superior lobe of the left lung), and grooves for various structures (e.g., aortic arch, descending aorta,
left subclavian artery).
left lung has
has 2 lobar (secondary) bronchi and 8 to 10 segmental bronchi
is an inflammation of the lungs, which is of bacterial, viral, and mycoplasmal origin. Symptoms are usually cough, fever, sputum production, chest pain, and dyspnea. It
can be treated by administering antibiotics and antimicrobial drugs for initial therapy.
Pneumonia (pneumonitis)
is an infectious lung disease caused by the bacterium Mycobacterium tuberculosis and is characterized by the formation of tubercles that can undergo caseous necrosis. Its symptoms are cough, fever, sweats, tiredness, and emaciation. TB is spread by coughing and mainly enters the body
in inhaled air and can be treated with very effective drugs.
Tuberculosis (TB)
causes severe pain radiating toward the shoulder and along the medial aspect of the arm and atrophy of the
muscles of the forearm and hand)
lower trunk brachial plexopathy
is a malignant neoplasm of the lung apex and
causes Pancoast’s syndrome
Pancoast’s or superior pulmonary sulcus tumor:
is a deep vertical groove in the posterior wall of the thoracic cavity on
either side of the vertebral column formed by the posterior curvature of the ribs, lodging the posterior
bulky portion of the lung
Superior pulmonary sulcus
is an inherited multisystem disease that has widespread dysfunction of the exocrine glands.
Cystic fibrosis (CF)
involves fluid accumulation and swelling in the lungs caused by lung toxins (causing altered capillary permeability), mitral stenosis, or left ventricular failure that results in increased pressure in the pulmonary veins.
Pulmonary edema
As pressure in the pulmonary veins rises, fluid is pushed
into the _____ and becomes a barrier to normal oxygen exchange, resulting in _____.
alveoli;
shortness of breath
is a condition of permanent deposition of substantial amounts of particles in the
lungs, usually of occupational or environmental origin.
Pneumoconiosis
is a form of pneumoconiosis caused by accumulation of carbon from inhaled smoke or coal dusts in the lungs
Anthracosis
is caused by inhalation of crystalline silica dusts from rocks and sands, which are collected in terminal airways.
Silicosis
is caused by inhalation of asbestos fibers, and accumulated particles and fibers in the lungs can cause irritation and inflammation, leading to a breathing disorder, cough, chest pains, and a high risk of lung cancer
Asbestosis
Is the anatomic, functional, and surgical unit (subdivision) of the lungs
Bronchopulmonary segment
Bronchopulmonary segment consists of
a segmental (tertiary or lobular) bronchus, a segmental branch of the pulmonary artery, and a segment of the lung tissue, surrounded by a delicate connective tissue septum (intersegmental septum
Bronchopulmonary segment is drained by
intersegmental part of the pulmonary vein
Bronchopulmonary segment refers to the portion of the lung supplied by each segmental bronchus and segmental artery. The pulmonary veins are said to be
intersegmental
Bronchopulmonary segment is clinically important because the intersegmental pulmonary veins form surgical landmarks; thus, a surgeon CAN remove a bronchopulmonary segment without seriously disrupting the surrounding _____
lung tissue and major blood vessels
is the collapse of a lung by blockage of the air passages or by very shallow breathing because of anesthesia or prolonged bedrest. It is caused by mucus secretions that plug the airway, foreign bodies in the airway, and tumors that compress or obstruct the airway.
Atelectasis
Lung cancer has three types:
squamous cell carcinoma , adenocarcinoma , and
small-cell carcinoma
arises in the epithelium of the larger bronchi and tends to form masses
squamous cell carcinoma
originates in the peripheral areas of the
lung as solitary nodules that develop from bronchial mucous glands and alveolar epithelial cells
adenocarcinoma
contains small epithelial cells that originate in the main bronchi and grow
aggressively in cords of grapelike clusters
small-cell carcinoma
is the surgical removal of an entire lung and is usually performed as a treatment for lung cancer. It consists of either a traditional pneumonectomy, in which only the diseased lung is removed, or an extrapleural pneumonectomy, in which the lung, the parietal pleura, and a part of the diaphragm are removed.
Pneumonectomy
Conducting portion (airway) includes the
nasal cavity, nasopharynx, larynx, trachea, bronchi, bronchioles (possess no cartilage), and terminal bronchioles
respiratory portion includes the
respiratory bronchioles, alveolar
ducts, atria, and alveolar sacs
takes place across the wall (blood-air barrier) of lung alveoli and pulmonary capillaries
Oxygen and carbon dioxide exchange
Is the vital exchange of oxygen and carbon dioxide that occurs in the
respiration
the airborne barrier of respiration consists of
alveolar type I cells, basal lamina, and capillary endothelial cells.
The alveolar type II cells secrete
surfactant
Occurs when the ribs and sternum (or thoracic cage) are elevated by the following muscles: the
diaphragm; external, internal (interchondral part), and innermost intercostal muscles;
sternocleidomastoid; levator costarum; serratus anterior; scalenus; pectoralis major and minor; levator
costarum; and serratus posterior superior muscles.
inspiration
inspiration involves the following processes
Contraction of the diaphragm, Enlargement of the pleural cavities and lungs, Forced inspiration
Pulls the dome inferiorly into the abdomen, thereby increasing the vertical diameter of the thorax.
Contraction of the diaphragm
Reduces the intrapulmonary pressure (creates a negative pressure ), thus allowing air to rush into the
lungs passively because of atmospheric pressure.
Enlargement of the pleural cavities and lungs
Involves contraction of the intercostal muscles and elevation of the ribs (superolateral movement),
with the sternum moving anteriorly like a bucket handle . (When the handle is raised, the convexity
moves laterally.)
Forced inspiration
Involves the following muscles: the muscles of the anterior abdominal wall, internal intercostal
(costal part) muscles , and serratus posterior inferior muscles.
expiration
expiration involves the following processes
Overall process,Elastic recoil of the lungs, Forced expiration
Involves relaxation of the diaphragm, the internal intercostal muscles (costal part), and other muscles;
decrease in thoracic volume; and increase in the intrathoracic pressure.
Overall process
what happens to the ribs and abdominal pressure in overall process?
The abdominal pressure is
decreased , and the ribs are depressed.
Elastic recoil of the lungs produces what in the pleural cavities
a subatmospheric pressure
expiration is a
passive process caused by the elastic recoil of the lungs
quiet inspiration results from
contraction of the diaphragm
Requires contraction of the anterior abdominal muscles and the internal intercostals (costal part).
Forced expiration
Lymphatic Vessels of the Lung drain the
bronchial tree, pulmonary vessels, and connective tissue septa
Lymphatic Vessels of the Lung pathway
Run along the bronchiole and bronchi toward the hilus, where they drain to the pulmonary
(intrapulmonary) and then bronchopulmonary nodes, which in turn drain to the inferior (carinal) and
superior tracheobronchial nodes, the tracheal (paratracheal) nodes, bronchomediastinal nodes and
trunks, and eventually to the thoracic duct on the left and right lymphatic duct on the right.
Pulmonary trunk circulation
Extends upward from the conus arteriosus of the right ventricle of the heart and carries poorly
oxygenated blood to the lungs for oxygenation.
Pulmonary trunk pathway
Passes superiorly and posteriorly from the front of the ascending aorta to its left side for about 5 cm and
bifurcates into the right and left pulmonary arteries within the concavity of the aortic arch at the level of
the sternal angle.
pulmonary trunk vs aorta
Has much lower blood pressure than that in the aorta
pulmonary trunk is contained where?
within the fibrous pericardium
left vs right pulmonary artery
left pulmonary artery is shorter and narrower than the right pulmonary artery, and
left pulmonary artery pathway
arches OVER the left primary bronchus.
left pulmonary artery Is connected to the arch of the aorta by the
ligamentum arteriosum , the fibrous remains of the ductus arteriosus.
right pulmonary artery
Runs horizontally toward the hilus of the right lung under the arch of the aorta behind the ascending
aorta and SVC and anterior to the right bronchus.
is an obstruction of the pulmonary artery or
one of its branches by an embolus (air, blood clot, fat, tumor cells, or other foreign material), which
arises in the deep veins of the lower limbs or in the pelvic veins or occurs following an operation or
after a fracture of a long bone with fatty marrow.
Pulmonary embolism (pulmonary thromboembolism)
Pulmonary veins are _____ in drainage
intersegmental (do not accompany the bronchi or the segmental artery within the
parenchyma of the lungs).
pulmonary veins leave the lung as
five pulmonary veins, one from each lobe of the lungs. However, the right upper and
middle veins usually join so that only four veins enter the left atrium.
pulmonary veins circulation
Carry oxygenated blood from the respiratory part (alveoli) of the lung and deoxygenated blood from the
visceral pleura and from a part of the bronchioles to the left atrium of the heart. (Gas exchange occurs
between the walls of alveoli and pulmonary capillaries, and the newly oxygenated blood enters venules
and then pulmonary veins.)
Bronchial arteries arise from the
thoracic aorta; usually there is one artery for the right lung and two for the left lung.
Bronchial arteries supply oxygenated blood to the
nonrespiratory conducting tissues of the lungs and the visceral pleura
Anastomoses of the bronchial arteries occur between the
capillaries of the bronchial and pulmonary systems
bronchial veins receive blood from the and
bronchi
bronchial veins empty into the
azygos vein on the right and into the accessory hemiazygos vein or the superior intercostal vein on the left.
bronchial veins may receive twigs (small vessels) from the
tracheobronchial lymph nodes
Receives afferent and efferent (parasympathetic preganglionic) fibers from the vagus nerve, joined by
branches (sympathetic postganglionic fibers) from the sympathetic trunk and cardiac plexus.
pulmonary plexus
pulmonary plexus is divided into the
anterior pulmonary plexus , which lies in front of the root of the lung, and the
posterior pulmonary plexus , which lies behind the root of the lung
pulmonary plexus has sympathetic nerve fibers that
dilate the lumina of the bronchi and constrict the pulmonary vessels
pulmonary plexus has parasympathetic fibers
constrict the lumina , dilate the pulmonary vessels, and increase glandular secretion
phrenic nerve arises and lies where?
Arises from the third through fifth cervical nerves (C3–C5) and lies in front of the anterior scalene
muscle.
phrenic nerve enters the thorax by passing
deep to the subclavian vein and superficial to the subclavian arteries
phrenic nerve runs
anterior to the root of the lung
vagus nerve runs
posterior to the root of the lung
phrenic nerve is accompanied by the
pericardiophrenic vessels of the internal thoracic vessels
phrenic nerve descends
between the mediastinal pleura and the pericardium
phrenic nerve innervates the
fibrous pericardium, the mediastinal and diaphragmatic pleurae, and the diaphragm for motor and its central tendon for sensory
Lesion of the phrenic nerve: may or may not produce complete paralysis of the corresponding half of
the diaphragm because
the accessory phrenic nerve , derived from the fifth cervical nerve as a branch
of the nerve to the subclavius, usually joins the phrenic nerve in the root of the neck or in the upper
part of the thorax
is an involuntary spasmodic sharp contraction of the diaphragm , accompanied by the
approximation of the vocal folds and closure of the glottis of the larynx. It may occur as a result of the
stimulation of nerve endings in the digestive tract or the diaphragm. When chronic, it can be stopped by
sectioning or crushing the phrenic nerve.
Hiccup
Primordium for the lower respiratory system appears as
a laryngotracheal groove in the floor of the
pharyngeal foregut.
forms from the laryngotracheal groove in the ventral wall of the foregut
.
Laryngotracheal (respiratory) diverticulum
the diverticulum is separated from the foregut proper by the formation of a
tracheoesophageal septum
Tracheoesophageal septum divides the foregut into a
ventral portion, the laryngotracheal tube
(primordium of the larynx, trachea, bronchi, and lungs), and a dorsal portion (primordium of the
oropharynx and esophagus)
develop at the distal end of the laryngotracheal diverticulum
lung buds
Epithelium and glands in the trachea and bronchi are derived from the
endoderm
is derived from visceral mesoderm covering the outside of the bronchi
Visceral pleura
is derived from somatic mesoderm covering the inside of the body wall.
parietal pleura
The conducting (airway) system through the terminal bronchioles develops. Respiration is not possible.
Glandular period (prenatal weeks 5 to 17)
Luminal diameter of the conducting system increases, and respiratory bronchioles , alveolar ducts, and
terminal sacs begin to appear. Premature fetuses born before week 20 rarely survive.
Canalicular period (prenatal weeks 13 to 25)
More terminal sacs form, and alveolar type I cells and surfactant producing alveolar type II cells develop. Respiration is possible, and premature infants can survive with intensive care.
Terminal sac period (prenatal weeks 24 to birth)
Respiratory bronchioles, terminal sacs, alveolar ducts , and alveoli increase in number.
Alveolar period (late fetal stage to 8 years)
