Salvador Dali - Anthropomorphic Chest of Drawers, 1936
Kaan Yücel M.D., Ph.D.
12. 12. 2012
the part between the neck and the abdomen
Chest X-ray
1.1. REGIONS/T ERMS
Thoracic cavity
cavity between neck and
abdomen
protected by the thoracic wall.
Thoracic wall
bounds the thoracic cavity.
formed by the skin, bones,
fasciae, and muscles.
Thoracic cage
bony portion of the thoracic
wall
thoracic skeleton
1.2. SURFACES OF THE THORAX
STERNUM & COSTAL CARTILAGES
anteriorly
12 THORACIC VERTEBRAE & POST. RIBS posteriorly
RIBS & INTERCOSTAL SPACES laterally
Posterior surface
12 thoracic vertebræ &
posterior parts of the ribs
Anterior surface
sternum & costal
cartilages
Lateral surfaces
ribs, separated by the
intercostal spaces
1.3. BOUNDARIES OF THE THORAX
Superior
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Jugular notch
Sternoclavicular joint
Superior border of clavicle
Acromion
Spinous processes of C7
Inferior
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Xiphoid process
Costal arch
12th and 11th ribs
Vertebra T12
1.4. CONTENTS OF THE THORAX
Organs of the cardiovascular, respiratory, digestive,
reproductive, immune, and nervous systems
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thoracic cage (skeleton)
muscles between the ribs
skin
subcutaneous tissue
muscles, and fascia covering its anterolateral aspect.
The mammary glands of the breasts lie within the
subcutaneous tissue of the thoracic wall.
2.1. FUNCTIONS OF THE THORACIC WALL
1) Protects vital thoracic and abdominal organs
2) Resists the negative (sub-atmospheric) internal pressures
generated by the elastic recoil of the lungs and inspiratory
movements.
3) Provides attachment for and support the weight of the
upper limbs.
4) Provides the origins of many of the muscles that move
and maintain the position of the upper limbs relative to
the trunk.
5) Provides attachments for muscles of the abdomen, neck,
back, and respiration.
3. SKELETON OF THE THORACIC WALL
1) 12 pairs of ribs and associated costal cartilages
2) 12 thoracic vertebrae and the intervertebral (IV) discs
interposed between them
3) Sternum
4. THORACIC APERTURES
‘Thoracic inlet’
‘Thoracic outlet’
4.1. Superior thoracic aperture
“doorway” between the thoracic cavity and the neck and upper limb
bounded:
Posteriorly vertebra T1
Laterally 1st pair of ribs and their costal cartilages
Anteriorly superior border of the manubrium
 Trachea
 Esophagus
 nerves, and vessels that supply
and drain the head, neck, and
upper limbs.
4.2. Inferior thoracic aperture
By closing the inferior thoracic aperture, the diaphragm separates the thoracic and
abdominal cavities almost completely.
bounded:
Posteriorly 12th thoracic vertebra
Posterolaterally 11th and 12th pairs of ribs
Anterolaterally joined costal cartilages of ribs 7-10 costal margins
Anteriorly xiphisternal joint
5. JOINTS OF THE THORACIC WALL
1. Costotransverse joints
between tubercle of a rib & transverse
process of its own vertebra
2. Sternocostal joint
between the sternum and costal
cartilages
3. Costachondralis joint
between the rib and costal cartilage
4. Intercondral joints
Synovial joints between the costal
cartilages of 6th and 7th, 7th and 8th,
& 8th and 9th ribs.
5. Sternal Joints
between the manubrium, body, xiphoid
process of the sternum.
6. MUSCLES OF THE THORACIC WALL
Serratus posterior
Levator costarum
Intercostal muscles(External, internal and innermost)
Subcostal
Transverse thoracic
6. MUSCLES OF THE THORACIC WALL
intercostal muscles
three flat muscles found in each intercostal space
external intercostal muscles
most superficial
internal intercostal muscles
between external &
innermost muscles
6. MUSCLES OF THE THORACIC WALL
external intercostal muscles
extend from the inferior margins of the ribs above
to the superior margins of the ribs below
pass obliquely anteroinferiorly
6. MUSCLES OF THE THORACIC WALL
internal intercostal muscles
most active during expiration
between most inferior lateral edge of costal grooves of the ribs above,
to the superior margins of ribs below
in the opposite direction to
those of the external
intercostal muscles
obliquely posteroinferiorly
Attachment to interosseus
parts move down
during expiration!
6. MUSCLES OF THE THORACIC WALL
innermost intercostal muscles
least distinct of the intercostal muscles
same orientation as the internal intercostals
neurovascular bundles (V.A.N.) in
the costal grooves
in a plane between
innermost & internal intercostal
muscles.
6. MUSCLES OF THE THORACIC WALL
transversus thoracis muscles
on the deep surface of the anterior thoracic wall & @ same plane as innermost intercostals
lie deep to the internal thoracic vessels
secure these vessels to the wall.
6. MUSCLES OF THE THORACIC WALL
subcostales
@ same plane as innermost intercostals
Fibers parallel the course of the internal intercostal muscles.
Extend from the angle of the ribs
to more medial positions on the ribs below.
6.1. Accessory muscles of respiration
 upper accessory muscles assist with inspiration.
 upper chest, and abdominal muscles assist with expiration.
6.1. Accessory muscles of respiration
Scalene muscles
elevate, fix & expanding the upper chest during inspiration.
Sternocleidomasteoid muscles
raise the sternum
expand the chest’s A-P & longitudinal dimensions.
6.1. Accessory muscles of respiration
Axioappendicular muscles act primarily on the upper limbs.
pectoralis major Attachment to first seven costal cartilages
pectoralis minor Attachment to anterior surfaces of the 3rd-5th ribs
inferior part of the serratus anteriorAttachment to lateral surfaces of upper 8-9
ribs & deep fascia overlying related intercostal spaces
help elevate the ribs to expand the thoracic cavity.
6.1. Accessory muscles of respiration
Trapezius raises the thoracic cage.
Attachment to spinous processes of the thoracal vertebrae
6.1. Accessory muscles of respiration
Expiration
Abdominal muscles
pull the lower chest down
depress the lower limbs
compress the abdominal content & exerts pressure on chest.
7. MOVEMENTS OF THE THORACIC WALL
One of the principal functions of the thoracic wall and the diaphragm is to alter the
volume of the thorax and thereby move air in and out of the lungs.
During breathing, the dimensions of the thorax change in
vertical, lateral, and A-P directions.
Diaphragm contracts Depression
Diaphragm relaxes  Elevation (during passive expiration)
Elevation &depression of the ribs
inspiration
Diaphragm conracts; thoracic cavity descends, compressing the abdominal viscera
expiration (back to neutral position)
Lungs produces sub-atmospheric pressure
As a result, the diaphragm ascends, diminishing the vertical dimension.
intercostal muscles contract
pump-handle movement
Movement of the ribs (primarily 2nd-6th) at the costovertebral joints
causes the anterior ends of the ribs to rise
+ Slight elevation in A-P of the sternum
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intercostal muscles contract, raising the middle (lateralmost parts) of the ribs (especially the lower ones)
bucket-handle movement
9. VASCULATURE OF
THE THORACIC WALL
Mainly posterior and anterior intercostal arteries
pass between adjacent ribs in intercostal spaces.
9.1. ARTERIES OF THE THORACIC WALL
Arterial supply to the thoracic
wall derives from
Thoracic aorta
[posterior intercostal & subcostal
arteries]
Subclavian artery
[internal thoracic & supreme
intercostal arteries]
Axillary artery
[superior & lateral thoracic arteries]
intercostal arteries
course through the thoracic wall between the
ribs.
Each intercostal space is supplied by
• a large posterior intercostal artery
• small pair of anterior intercostal
arteries
Exception last two intercostal spaces
Anterior intercostal arteries
(paired)
directly or indirectly from internal
thoracic artery
1st-6th (from internal thoracic
artery)
7th-9th (from musculophrenicbranch of internal thoracic)
Posterior intercostal arteries
(large, unpaired)
1st-2nd (from supreme intercostal
artery- branch of costocervical
trunk)
3rd-11th (from thoracic aorta)
Subcostal artery (from thoracic
aorta)
internal thoracic artery
•Very first branch of the
subclavian artery
•Passes vertically through the
superior thoracic aperture
•Lies posterior to the costal
cartilages of the upper 6 ribs
•Lies 1 cm lateral to the
sternum.
@ level of 6th intercostal space,
divides into 2 terminal branches
superior epigastric artery &
musculophrenic artery
9.2. VEINS OF THE THORACIC WALL
Most posterior intercostal veins
(4-11) end @
azygos/hemiazygos
venous system
conveys venous blood to SVC.
1st posterior intercostal veins
right & left brachiocephalic veins
2nd & 3rd (sometimes 4th)
form superior intercostal vein.
Right superior intercostal vein
final tributary of azygos vein
Left superior intercostal vein
empties into left brachiocephalic vein.
Veins
Artery
Nerve
V.A.N.
10. NERVES OF THE THORACIC WALL
12 pairs of intercostal nerves
anterior rami of spinal nerves T1 to T11
lie in the intercostal spaces between adjacent ribs.
Anterior ramus of spinal nerve T12 (subcostal nerve) inferior to rib XII.
• Near the angles of the ribs, the nerves pass between
internal intercostal & innermost intercostal muscles.
V.A.N.
• Neurovascular bundles sheltered by the inferior margins
of the overlying rib.
10.3. DERMATOMES
Skin area supplied by a segment of the spinal cord
Through its posterior ramus and the lateral and anterior cutaneous
branches of its anterior ramus, most thoracic spinal nerves (T2-T12)
supply a strip-like dermatome of the trunk extending from the
posterior median line to the anterior median line.
T2- Sternal angle
T4- Nipple
T6- Xiphoid process
T8- Costal arch
T10-Umbliculus
T12-Midpoint between umbilicus and
symphysis pubis
11. BREASTS
Reproduction, back pain
Aesthetics, and breast cancer
Mammary glands & associated skin -connective tissues.
modified sweat glands in the superficial fascia anterior to the
pectoral muscles and the anterior thoracic wall.
11. BREASTS
Mammary glands:
Series of ducts and associated secretory lobules.
Form 15 to 20 lactiferous ducts open
nipple.
Nipple is surrounded by a circular pigmented area of skin
areola (L. small area).
11.1. FEMALE BREASTS
NON-LACTING WOMEN – PREDOMINANT COMPONENT: FAT
LACTING WOMEN- PREDOMINANT COMPONENT: GLANDULAR TISSUE
The breast rests on a bed
extends transversely from
lateral border of the sternum
mid-axillary line
vertically from the 2nd through 6th ribs
75% (lateral
breast quadrants)
Axillary lymph
nodes
Most of the
remaining
(medial breast
quadrants)
parasternal lymph
nodes or to the
opposite breast
Lymph from inferior quadrants may pass deeply to
abdominal lymph nodes.
1. MEDIASTINUM
(Interpleaural space)
central compartment of the thoracic cavity
Thoracic cavity is divided into 3 major spaces
1) mediastinum
2) right pulmonary cavity
3) left pulmonary cavity
Looseness of the connective tissue
Elasticity of the lungs & parietal pleura on each side of the mediastinum
 movements of the diaphragm, thoracic wall, & tracheobronchial tree
 contraction (beating) of the heart
 pulsations of the great arteries
 passage of ingested substances through the esophagus
Mediastinum extends from
superior thoracic aperture
superiorly
to
diaphragm
inferiorly
from sternum & costal cartilages
anteriorly
to
bodies of thoracic vertebrae
posteriorly
transverse
thoracic
plane
Superior
mediastinum
trachea, esophagus,
thymus, vagus nerve,
phrenic nerve and
great vessels such as
arch of aorta,
brachiocephalic vein
sternal angle
intervertebral disc between T4 - T5
Inferior
mediastinum
Inferior mediastinum further divided into three parts
Anterior mediastinum
Between anterior surface of pericardium & sternum
Middle mediastinum
Pericardium, heart and beginnings of the great vessels
Posterior mediastinum
posterior to the pericardium & diaphragm [T5-T12]
thoracic aorta,
esophagus
1.HEART
Trapezoidal in A-P dimensions
Tipped-over pyramid in 3-D
crucial organ of the human body
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Right heart (Suction)
poorly- oxygenated(venous) blood
from the body
superior vena cava & inferior vena cava
right atrium
right ventricle
pulmonary arteries
lungs
Left heart (Pumping)
well- oxygenated (arterial) blood
from the lungs
pulmonary veins
left atrium
left ventricle
aorta
the body
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right and left atria & right and left ventricles
Atrium – plural atria
Ventricles
Receiving chambers
Discharging chambers
cardiac cycle
1. Ventricular filling (diastole)
2. Ventricular emptying (systole)
Blood pressure
120-80 mm/Hg
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The fibrous skeleton of the heart
Keeps the orifices of the AV & semilunar valves patent
prevents them from being overly distended by an increased volume of blood.
Provides attachments for the valves & myocardium.
Forms an electrical «insulator»
separating impulses of the atria & ventricles  they contract independently
surrounding and providing passage for the initial part of the AV bundle
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coronary sulcus (atrioventricular groove)
between atrium & ventricles
anterior & posterior interventricular (IV) sulci (grooves)
between right and left ventricles
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apex located inferiorly & base located superiorly
Apex projects forward, downward and to the left
Base faces in a posterior direction
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Anterior (sternocostal) surface
o mostly of right ventricle
o some of the right atrium on the right
o some of the left ventricle on the left
Diaphragmatic (inferior) surface
o formed mainly by the left ventricle
o partly by the right ventricle
o related to central tendon of diaphragm.
Right pulmonary surface
o formed by the right atrium.
Left pulmonary surface
o left ventricle & a portion of left atrium.
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2.RIGHT ATRIUM
forms the right border of the heart
Receives venous blood from the SVC, IVC, and coronary sinus.
Through the right atrioventricular orifice,
discharges the poorly oxygenated blood it has received
into the right ventricle.
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3.RIGHT VENTRICLE
forms
largest part of the anterior surface of the heart
a small part of the diaphragmatic surface
almost the entire inferior border of the heart.
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interventricular septum (IVS)
obliquely placed partition between the right and left ventricles, forming part of the walls of each
muscular and membranous parts
Bulges into the cavity of the right ventricle.
Superiorly and posteriorly, a thin membrane, forms the much
smaller membranous part of the IVS.
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4.LEFT ATRIUM
forms most of the base of the heart
right and left pulmonary veins enter here.
Tubular, muscular left auricle,
Its wall trabeculated with pectinate muscles.
A semilunar depression in
the interatrial septum
Floor of the oval fossa
surrounding ridge
Valve of the oval fossa
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5.LEFT VENTRICLE
forms the apex of the heart, left (pulmonary) surface & border, most of the diaphragmatic surface.
Compared to the right ventricle
Walls 2-3 times thicker
Trabeculae carneae finer and more numerous
Cavity longer
Anterior & posterior papillary muscles larger
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aortic valve
semilunar valve
between the left ventricle & ascending aorta
obliquely placed.
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mitral valve
double-leaflet mitral valve
Guards the left AV orifice.
Has two cusps, anterior and posterior.
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6. SEMILUNAR VALVES
Semilunar cusps of the pulmonary valve anterior-right-left
Seminular cusps of the aortic valve posterior-right-left
concave when viewed superiorly
no tendinous cords to support
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7. VASCULATURE OF THE HEART
coronary arteries & cardiac veins
embedded in fat
course across the surface of the heart just deep to the epicardium.
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first branches of the aorta
supply the myocardium and epicardium
Anastomoses between the branches of the
coronary arteries exist, which enables the
development of the collateral circulation.
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8. STIMULATING, CONDUCTING, &
REGULATING SYSTEMS OF HEART
1. sinuatrial (SA) node
initiates the heartbeat & coordinates contractions of the four heart chambers
2.atrioventricular (AV) node
3.bundles
highly specialized conducting fibers for conducting impulses rapidly to different areas of the heart
o Propagation of the impluse
o Simultaneous contraction of the cardiac striated muscle cells
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pacemaker of the heart
@junction of the SVC & right atrium
near to the superior end of the sulcus terminalis
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pacemaker of the heart
stimulated by sympathetic division of the autonomic nervous system to
accelerate the heart rate
inhibited by parasympathetic division
to return to or approach its basal rate.
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a smaller collection of nodal tissue than the SA node
in the posteroinferior region of the interatrial septum
near the opening of the coronary sinus
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JOURNEY OF THE SIGNAL
Generated @ SA node
Passed through the walls of the right atrium
Propageted by the cardiac muscle
Signal passed from SA node to AV node
Distributed to the ventricles through the AV bundle
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AV bundle
the only bridge between the atrial and ventricular myocardium
passes from the AV node
through the fibrous skeleton of the heart and along the
membranous part of the IVS.
@ junction of membranous & muscular parts of the IVS
divides into : right bundle & left bundle.
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right and left bundles
proceed on each side of the muscular IVS deep to the endocardium
then ramify into
subendocardial branches (Purkinje fibers)
extend into the walls of the respective ventricles.
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autonomic nervous system, cardiac plexus
Cardiac plexus
posterior to the ascending aorta and bifurcation of the pulmonary trunk
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autonomic nervous system, cardiac plexus
Parasympathetic supply
presynaptic fibers of the vagus nerves
Slows the heart rate
Reduces the force of the contraction
Constricts the coronary arteries saving energy
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sympathetic supply
presynaptic fibers
cell bodies in the intermediolateral cell columns
(IMLs) of the superior 5 or 6 thoracic segments
postsynaptic sympathetic fibers
cell bodies in the cervical and superior thoracic
paravertebral ganglia of the sympathetic trunks.
causes increased heart rate
increased impulse conduction,
increased force of contraction,
increased blood flow through
the coronary vessels increased
activity.
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11. PERICARDIUM
fibroserous membrane, covers the heart & beginning of its great vessels
a closed sac with two layers
fibrous pericardium
serous pericardium
parietal layer
visceral layer –heart & great vessels
.
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fibrous pericardium
continuous superiorly w/ tunica adventitia of the great vessels & w/pretracheal layer of deep cervical fascia
Continuous inferiorly w/ central tendon of the diaphragm
Attached anteriorly to the sternum by sternopericardial ligaments
Site of continuity pericardiacophrenic ligament
Inner surface lined by parietal layer of the serous pericardium
Protects the heart against sudden overfilling.
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pericardial cavity
potential space between opposing layers of the
parietal & visceral layers of serous pericardium
contains a thin film of fluid : pericardial fluid
enables the heart to move and beat in a frictionless environment.
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12. GREAT VESSELS
formed by the union of
internal jugular & subclavian veins
posterior to the sternoclavicular (SC) joints.
brachiocephalic veins unite
to form the SVC.
@ inferior border of the 1st right costal
cartilage
shunt blood from the head,
neck, & upper limbs
right atrium.
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Returns blood from all structures superior to the diaphragm
except the lungs & heart.
Passes inferiorly and ends by entering right atrium of the heart.
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begins at the aortic orifice.
only branches coronary arteries, arising from the aortic sinuses.
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curved continuation of the ascending aorta
begins posterior to the 2nd right sternocostal (SC) joint at the level
of the sternal angle.
ligamentum arteriosum remnant of the fetal ductus arteriosus
root of the left pulmonary artery
inferior surface of the arch of the aorta
The usual branches of the arch
1) brachiocephalic trunk
2) left common carotid artery
3) left subclavian artery.
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first and largest branch of the arch of the aorta
arises posterior to the manubrium.
ascends superolaterally
divides into right common carotid & right subclavian arteries.
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second branch of the arch of the aorta
arises
o posterior to the manubrium,
o slightly posterior and to the left of the brachiocephalic trunk.
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third branch of the arch of the aorta
arises from the posterior part of the
arch
posterior to left common carotid artery.
ascends lateral to trachea & left
common carotid artery.
Leaves the thorax and enters the
root of the neck.
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Abdominal aorta