1. Superior opening of thoracic cavity that slopes downward and forward

2. Kidney shaped

3. Apex of lung rises only to the level of the neck of the 1st rib

1. Inferior opening of thoracic cavity  that is large and irregular

2. Bounded by the 12th thoracic vertebra, the lowest ribs, 7th and 12th costal cartilages and the xiphisternal joint

3. Much wider than superior aperature

4. Occupied by diaphragm

1. Sternum (manubrium, the body, and the xiphoid process)

2. Ribs

3. Vertebrae

Marks the upper border of the sternum, between the sternal heads of the two sternocleidomastoid muscles

1. The junction between the manubrius and the body of the sternum

2. At the level where the second rib articulates with the sternum

Locates the:

1. Cartilage of the 2nd rib

2. Division between the superior and inferior mediastina

3. Beginning and end of the arch of the aorta

4. Bifurcation of the trachea

5. Disc between the 4th and 5th thoracic vertebrae

The first 7 pairs of ribs whose cartilages articulate with the sternum

The last 5 ribs whose cartilages do not articulate directly with the sternum

11th and 12th ribs that are free at their extremities

1. 11 external intercostal muscles on each side

2. Extend from tubercles of ribs dorsally to the cartilages of the ribs ventrally

3. Ventrally, they end as thin membranes, the anterior intercostal membranes, that continue forward to the sternum

1. 11 internal intercostal muscles on each side

2. Begin ventrally, at the sternum at the interspaces between the cartilages of the true ribs, and at the ventral extremities of the cartilages of the false ribs

3. Extend downward as far as the angles of the ribs, where they continue to the vertebral column as thin membranes (posterior intercostal membranes)

Are the deepest layer of muscles, subdivided into different muscles depending upon their location:

1. Transversus thoracis muscles

2. The innermost intercostals

3. Subcostalis muscles

1. Innermost intercostal muscles that pass from the lower aspect of the sternum to the ribs anteriorly

2. The lowest fibers are continuous with the transversus abdominis muscle

1. Innermost intercostal muscles that are incomplete and variable

2. Pass from rib to rib, deep to the internal intercostals

3. Fibers of the innermost intercostals pass in the same direction as those of the internal intercostals and are separated from them by only the intercostal nerves and vessels (VAN=vein, artery nerve from superior to inferior)

 Innermost intercostal muscles that are small and variable in number and cross posterior ribs

1. Come from the descending thoracic aorta (except for those  of the first two interspaces)

2. The arteries from the first two interspaces come from the supreme intercostal branch of the costocervical trunk

3. Each posterior intercostal artery gives off a collateral branch in the intercostal space

1. Branches of the internal thoracic artery and one of its terminal branches, the musculophrenic artery

2. Much smaller than posterior intercostal arteries

3. The upper two intercostal spaces also supplied anteriorly by the supreme thoracic artery, the first artery to arise from the axillary artery

System where the posterior intercostal veins drain into

1. Ventral rami T1-T12

2. Supply general sensory innervation to skin on thoracic wall and to pleura

3. Supply motor innervation to intercostal muscles and carry postganglionic sympathetic nerve fibers

4. Intercostal nerves 2-6 confined to thorax

5. Intercostal nerve 1 contributes to the brachial plexus, as well as innervating the region of the first intercostal space

6. Intercostal nerves 7-12 leave the intercostal spaces after innervating them and continue on to innervate muscles, skin, and parietal peritoneum of the anterior abdominal wall

1. The internal investing fascia of the thorax

2. Lines the internal surface of the thorax and is continuous with the internal investing layer of fascia in the abdominal cavity (transversalis fascia)

1. Lungs extend to 6th rib

2. Parietal pleura extends to 8th rib

1. Lungs extend to 8th rib

2. Parietal pleura extends to 10th rib

1. Lung extends to 10th rib

2. Parietal pleura extends to 12th rib

1. Above the first rib on both sides, anteriorly and laterally (not posteriorly)

2. Below 12th rib on both sides, in the angle between the vertebra and rib

3. Below the 7th costal cartilage near the xiphoid process (right side only)

Best heard on the anterior chest wall superior to the 4th rib

Best heard on posterior chest wall, inferolateral to the spinous process of T3 and inferior to the bony mass of the scapula

Best heard on the anterolateral chest wall inferior to 4th rib

Extend superior to 1st ribs, so can best be examined in the supraclavicular space

Closed invaginated sac that contains a small amount of serous fluid

A portion of the pleura that covers the surface of the lung and dips into the fissures between its lobes

The portion of the pleura that lines the inner surface of the chest wall, covers the superior aspect of the diaphragm, and is reflected over the structures occupying the middle of the thorax

The fluid filled space between the parietal pleura and the visceral pleura that is filled with a small amount of serous fluid

Air in the pleuralcavity

Blood in the pleural cavity

When the pleura itself is inflamed

The interval in the middle of the thorax between the two pleural sacs

1. Costal (lines ribs, cartilages, and sternum)

2. Cervical/cupula (lines apex of lung)

3. Diaphragmatic (adherent to the diaphragm)

4. Mediastinal (lies adjacent to mediastinum)

1. The spaces between the lower border of the lungs and the pleural reflections from the chest wall onto the diaphragm

2. Potential spaces where fluid may accumulate

3. Excess fluid may be drained (pleural tap or thoracentesis) from the pleural cavity without penetrating the lungs

4. Only during forced inspiration do these lungs expand into these recesses

1. On the left side

2. Single potential space between the anterior chest wall and pericardial sac

3. At this site, the heart lies close to the anterior thoracic wall and costal pleura is close to the mediastinal pleura

1. Innervated by visceral sensory fibers

2. Insensitive to somatic pain

1. Innervated by somatic sensory nerves

2. Very sensitive to somatic pain

3. Afferent pain fibers are conveyed through the thoracic wall in branches of intercostal nerves

4. This pain is referred to areas of skin on the thoracic and abdominal walls innervated by the same intercostal nerves (therefore, a patient could complain of pain in the skin surrounding the umbilicus-T10-when parietal pleura underlying the T10 intercostal space is irritated; or a patient could complain of pain referred to the shoulder area when parietal pleura on the diaphragm is irritated)

1. Innervated by C3,4,5 via phrenic nerve

2. Shoulder area is innervated by supraclavicular nerves from C3,4

Extends into the root (base) of the neck and is crossed by the subclavian artery

Broad, concave, and rests on the convex surface of the diaphragm

A deep concavity on the mediastinal surfaces of both lungs, which accommodates the pericardium and the heart

A slight depression that is the place where arteries, veins, lymphatics, and bronchi enter or leave the lung

1. Divided into three lobes (superior, middle, inferior) by two interlobar fissures

2. Shorter than the left lung because the diaphragm is higher on the right side (due to the liver)

3. Broader than left lung because of the inclination of the heart to the left side

Divided into two lobes (superior and inferior) by oblique fissure

An indentation on the anterior border of the upper lobe of the left lung

The tongue-like projection of the left upper lobe, below the cardiac notch

Separates the inferior lobe from the middle and superior lobes on the right, and separates the inferior lobe from the superior lobe on the left

1. Separates the superior from the middle lobe on the right

2. Begins in the oblique fissure near the midaxillary line and runs horizontally to the ventral border on a level with the sternal end of the 4th costal cartilage

1. Formed by structures that enter or leave the lung

2. Include the primary bronchus, pulmonary artery, pulmonary veins, bronchial arteries and veins, pulmonary plexuses of nerves, lymphatic vessels, and bronchial lymph nodes

3. These structures are all embedded in connective tissue and the entire mass is encircled by a reflection of the pleura

4. Pulmonary veins (ventral), bronchus (behind), pulmonary arteries (above the other two)

The reflection of the pleura that is prolonged downward, inferior to the root of each lung

Pass posterior to the root of the lung, heading to the esophagus

Pass anterior to the root of the lung, lying along the pericardium with the pericardiacophrenic artery and veins

1. Two primary (main) bronchi-one to each lung

2. Five secondary (lobar) bronchi-one to each lobe

3. 18 tertiary (segmental) bronchi that go to bronchopulmonary segments

1. Two bronchi formed after trachea divides anterior to the intervertebral disc between T4 and T5

2. At the bifurcation of the trachea, the openings of the two main bronchi are separated internally by the carina

3. The main bronchi are asymmetrical (right is wider, shorter, and more vertical than left-foreign bodies more likely to enter right main bronchus)

1. Gives off a secondary bronchus to the right upper lobe (RUL)

2. Continues as primary bronchus

3. Ends by dividing into the secondary bronchus to the right middle lobe (RML) and the secondary bronchus to the right lower lobe (RLL)

1. Apical tertiary bronchus RUL

2. Anterior tertiary bronchus RUL

3. Posterior tertiary bronchus RUL

1. Medial tertiary bronchus RML

2. Lateral tertiary bronchus RML

1. Superior tertiary bronchus RLL

2. Anterior basal tertiary bronchus RLL

3. Medial basal tertiary bronchus RLL

4. Lateral basal tertiary bronchus RLL

5. Posterior basal tertiary bronchus RLL

1. Passes more horizontally to the left and divides into two secondary (or lobar) bronchi-one for each lobe of that long

2. The secondary bronchus to the left upper lobe (LUL) is unusual in that it divides into a superior division (of secondary) and an inferior division (of secondary) bronchus

3. These divisions will then give off segmental (tertiary) bronchi

4. The secondary bronchus to the left lower lobe (LLL) continues into that lobe and gives off segmental (tertiary) bronchi

5. The number of tertiary bronchi in the left lung is reduced from that of the right lung

1. Superior division secondary bronchus:

a. Apicoposterior tertiary bronchus LUL

b. Anterior tertiary bronchus LUL

2. Inferior division secondary bronchus:

a. Superior lingular tertiary bronchus LUL

b. Inferior lingular tertiary bronchus LUL

1. Superior tertiary bronchus LLL

2. Anteromedial basal tertiary bronchus LLL

3. Lateral basal tertiary bronchus LLL

A sac-like structure that encloses the heart and has two components: fibrous and serous

Tough fibrous outer sac

1. A continuous "balloon-like" serous membrane that lines the fibrous sac and also covers the surface of the heart

2. Has two components: parietal layer and visceral layer

Lines the inner surface of the fibrous pericardium

Covers the heart, extends along the great vessels about 3cm, and is reflected onto the inner surface of the fibrous pericardium to become continuous with the parietal serous pericardium

Potential space between parietal and visceral pericardium containing a small amount of serous fluid

The abnormal leakage of blood into the pericardial cavity

1. Hollow muscular pumping organ

2. The heart and its pericardial sac occupy the middle mediastinum of the thorax and rest on the central tendon of the diaphragm

3. Consists of 4 chambers: 2 atria and 2 ventricles

1. Receives blood from most of the body via the superior vena cava (SVC) and inferior vena cava (IVC) as well as the heart itself via the coronary sinus

2. Blood then passes through the right atrioventricular orifice and valve (tricuspid valve) into the right ventricle

1.  On ventricular contraction (systole), blood in the right ventricle is pumped through the pulmonary semilunar valve, through the pulmonary trunk into the right and left pulmonary arteries to pass into the lungs for removal of gaseous waste products and for oxygenation

2. The oxygen-rich blood is collected into 2 pulmonary veins from each lung

3. These four pulmonary veins empty into the left ventricle

Blood then passes through the left atrioventricular orifice and valve (bicuspid or mitral valve) into the left ventricle

Blood is pumped through the aortic semilunar valves and into the aorta for distribution to the rest of the body and to the heart itself via the coronary arteries

1. Formed by the tip of the left ventricle that points anteroinferiorly to the left

2. Lies about 8-9cm lateral to the  midsternal line deep to the fifth intercostal space

1.  Formed by the atria, mainly the left one

2. Located at the opposite end of the heart from the apex

3. The base of the heart is superior, the apex is inferior

1. Place finger on the right and left sides of the sternal angle

2. Place another finger on the right edge of the xiphisternal junction

3. Place a fourth one over the apex (left 5th intercostal space, just medial to midclavicular line)

4. Connect the points

Innermost endothelial lining adjacent to lumen of chamber

Thick cardiac muscular layer

Outermost layer; also known as the visceral layer of serous pericardium

Projections of myocardium in the ventricles

Finger-like projections in the left and right ventricles to which chordae tendinae attach

Elevations in the wall of the atria/auricles

1. Located between the right atrium and right ventricle

2. Three flap-like cusps (anterior, posterior, and septal)

1. Located between the left atrium and left ventricle

2. Two cusps (anterior and posterior)

1. Attach the atrioventricular (AV) cusps to the papillary muscles in the ventricles

2. Helps to maintain tension on the cusps and prevents regurgitation of blood back into atria during contraction of the ventricles

The largest, attached to anterior and posterior cusps of the tricuspid valve

Attached to posterior and septal cusps of the tricuspid valve

Usually multiple, attached to anterior and septal cusps of the tricuspid valve

Attached to anterior and posterior cusps of the bicuspid valve

Attached to anterior and posterior cusps of the bicuspid valve

The dual attachment by two papillary muscles to each AV cusp provides a safety factor in case of myocardial infarction. If one papillary muscle were to become disabled, the AV cusp may still be somewhat functional, due to chordae tendinae from another papillary muscle

1. The pulmonary valve and aortic valve each consist of three cusps shaped like half moons

2. These valves have no papillary muscles or chordae tendinae

3. Open passively when blood pushes past them as the heart contracts and close passively because of the weight of the blood being forced back toward the heart by the elastic recoil of the arteries

4. Small nodules weight the edges of these cusps and provide better closure of the valve

1. Fibrous rings that anchor all of the heart valves

2. Forms the central support of the heart

3. Prevents over-dilation of the heart

4. Provides attachment for cardiac musculature

Heard at the second intercostal space just to the left of the sternum

Heard at the second right intercostal space at the edge of the sternum

Heard over the left half of the inferior end of the body of the sternum

Heard at the fifth left intercostal space, approximately in the mid-clavicular line (MCL)

1. Initiates the impulse for contraction

2. Located in the wall of the right atrium at the superior end of the crista terminalis

1. Collects and distributes impulses to the AV bundle

2. Located just above the opening for the coronary sinus in the interatrial septum

1. Contains specialized cardiac muscle fibers that descend in the interventricular septum deep to the endocardium (lining of the heart)

2. Divide into branches that are distributed throughout the ventricles

(Vagus)-slows the heart

(T1-T4 or T5)-increases the rate and force of contraction

Located just inferior to the arch of the aorta where both parasympathetic and sympathetic fibers unite

Located at the bifurcation of the trachea where both parasympathetic and sympathetic fibers unite and are distributed to the heart

1. Heart pain commonly radiates to the left shoulder and medial aspect of the left arm

2. Visceral sensory fibers from the heart travel through sympathetic nerves to end in the (T1-T4 or T5) cord segment

3.Through "cross-circuiting" pain impulses from the heart are interpreted as arising from the dermatome at the same cord level

4. Some sensation from the heart is also carried through the vagus nerve

5. Pain is occasionally referred to the jaw region, but this cannot be explained on the dermatome principle

Arises from the left aortic sinus and usually divides into anterior interventricular and circumflex arteries

A branch of the LMCA that courses in the anterior interventricular sulcus toward the apex and branches include:

1. Left conal artery

2. Diagonal arteries

3. Septal perforating arteries

Branches from the anterior interventricular artery and is an anatomical landmark located external to the pulmonary valve

Branch from the anterior interventricular artery and supply the anterior aspect of the left ventricle

Branch from the anterior interventricular artery and supply most of the interventricular septum and some of the adjacent ventricular walls

A branch of the LMCA thatourses to the left and posteriorly in the coronary sulcus toward the crux (where it may or may not continue as the posterior interventricular artery). Branches include:

1. Obtuse (left) marginal artery

2. Left ventricular arteries

Branches from the circumflex artery and supplies the lateral aspect of the left ventricular wall

Branch from the circumflex artery and supply the posterior wall of the left ventricle

A branch of the LMCA and occasionally, this third branch arises from the bifurcation of the left main coronary artery to supply the left ventricular wall

Arises from the right aortic sinus, courses to the right in the coronary sulcus toward the crux and then, usually, continues into the posterior interventricular sulcus. Branches include:

1. Right conal artery

2. Sinoatrial node artery

3. Acute (right) marginal artery

4. Atrioventricular node artery

5. Posterior interventricular or posterior descending artery (PDA)

Branch of the RCA that anastomoses with the left conal artery to supply the pulmonary valve

Branch of RCA that supplies the SA node of the anterior right atrial artery (also known as superior vena caval branch)

Branch of the RCA that courses along the right ventricle toward the apex of the heart

Branch of the RCA that is a posterior branch that supplies the AV node

1. The usual continuation of the RCA from the crux down the posterior interventricular sulcus

2. Gives off numerous septal perforating arteries to supply the posterior aspect of the interventricular septum and adjacent ventricular walls

1. The dominant arterial system is the coronary system that reaches the crux (i.e., posterior junction of the atrioventricular and interventricular sulci) and gives off the posterior descending artery

2. About 2/3 of the time, the right coronary artery is dominant

1. Occurs when a coronary artery becomes severely narrowed (stenotic) or closed off (occluded)

2. Causes a region of the heart supplied by that artery to suffer from a lack of oxygen

1. Occurs when ischemia is severe enough and lasts long enough that there is death of muscle tissue

2. If patient survives, this is clinically manifested by changes in the electrocardiogram and teh appearance of myocardial enzymes in the peripheral blood

3. Since the right ventricle and atria do not develop as much pressure as the left ventricle, these areas do not require as much oxygen and are rarely infarcted

1. Located in the posterior aspect of the coronary sulcus

2. Receives most of the large veins of the heart and drains into the right atrium

3. Tributaries to this sinus include:

a. Great cardiac vein

b. Middle cardiac vein

c. Small cardiac vein

d. Posterior vein of left ventricle

e. Oblique vein of left atrium

Ascends in the anterior interventricular sulcus and curves around in the left atrioventricular sulcus to become the coronary sinus

Ascends in the posterior interventricular sulcus to join the coronary sinus

Lies on the right border of the heart and drains into the coronary sinus

Drain from right ventricular wall into right atrium

Drain into all chambers of the heart

The aspiration of pathologic material from the pleural cavity (serous fluid, fluid mixed with tumor cells, blood, pus, etc.) may be done through the intercostal space. The pleural tap is performed in the midaxillary line or slightly posterior to it. Usually intercostal space 6,7, or 8 is selected for the puncture to avoid penetrating abdominal viscera. A large-bore needle is inserted low in the intercostal space to avoid injury to the intercostal nerve and vessels

The space betwen the superior thoracic aperature (first rib) and an imaginary line drawn between the sternal angle and the disc between T4 and T5 vertebrae

Located in front of thoracic vertebrae T5 to T12 and behind the pericardium

1. Passes through the superior and posterior mediastina on its way from the pharynx (where it begins) to the stomach (where it ends)

2. In thorax, lies behind trachea, then behind left atrium

3. Muscular layer is striated above, and smooth below

4. Blood supply from branches of inferior thyroid and direct branches from the descending thoracic aorta (bronchial and phrenic arteries)

5. The left gastric artery supplies the lower part of the esophagus in the abdomen

Divided into three parts:

1. Ascending aorta

2. Arch of the aorta

3. Descending aorta

1. In the middle mediastinum

2.Gives rise to the coronary arteries

1. Located in the superior mediastinum

2. Gives rise to the brachiocephalic, left common carotid, and left subclavian arteries

3. Becomes the descending aorta at the disc between T4 and T5

1. Formed from arch of aorta at the disc between T4 and T5

2. Gradually passes from the left of the vertebral column to the front of the column where it lies behind the esophagus

3. Gives rise to the third to eleventh posterior intercostal arteries and to the subcostal artery as well

4. Also gives off bronchial, esophageal and pericardial arteries

1. Usually ascends in the posterior mediastinum on the right side of the aorta, bewteen it and the azygos vein

2. At T5 vertebral level, it crosses behind the esophagus, passes behind the left subclavian artery, and enters the neck where it drains into the junction of left subclavian and left internal jugular veins

T1-T4

1. Connective tissue and fat

2. Trachea, esophagus, thymus gland

3. Aortic arch, brachiocephalic trunk, L. common carotid artery, L. subclavian artery, internal thoracic arteries, thymic arteries

4. R &L braciocephalic veins, superior vena cava, arch of azygos vein, L. superior intercostal vein, internal thoracic veins, thymic veins

5. Thoracic duct, lymph vessels and nodes

6. Vagus nerves, L. recurrent laryngeal nerve, phrenic nerves, cardiac nerves, cardiac plexus

T5-T12: Area posterior to pericardium

1. Connective tissue and fat

2. Bronhi, esophagus

3. Descending aorta, posterior intercostal arteries, Azygos V., Hemiazygos V., thoracic duct, vagus nerves, splanchnic nerves

T5-T12: Area between mediastinal pleura laterally and between anterior and posterior mediastinum:

1. Pericardium

2. Heart

3. Roots of eight great vessels, pericardiophrenic arteries and veins

4. Lymph vessel and nodes

5. Phrenic nerves

T5-T12: Area in front of pericardium

1. Connective tissue, fat

2. Thymus gland (or remnants)

3. Twigs of internal thoracic arteries

4. Lymph vessels and nodes

1. Crainial nerves X

2. Begin in the brain, descend through the neck and enter the thorax by passing anterior to the larger arteries and posterior to the large veins

3. Left vagus passes in front of the aortic arch and behind left brachiocephalic vein

4. Right vagus passes in front of the right subclavian artery and behind the superior vena cava

5. Both right and left vagus nerves pass posterior to the root of the lung and contribute to pulmonary plexuses of nerves before continuing to the esophageal plexus

6. Fibers from both vagus nerves intermingle with each other and with sympathetic fibers in the esophageal plexus before forming anterior and posterior vagal trunks

1. Branch from right vagus nerve in the superior mediastinum

2. Recurs or passes under the right subclavian artery on its way back up to the larynx

3. Innervates trachea, esophagus, and larynx

1. Branch of left vagus nerve in superior mediastinum

2. Passes under the arch of the aorta (subject to damage or irritation when aortic aneurysm is present in this region)

3. More inferior in thorax than right recurrent nerve (can be affected by tumors of the mediastinum)

4. Innervates trachea, esophagus, and larynx

1. Cardiac branches of vagus nerve given off in the neck and the thorax

2. Allow cardiac branches of vagus nerve to mingle with sympathetic fibers before innervating the heart

1. Anterior and posterior vagal trunks formed by both right and left vagal nerves and sympathetic fibers

2. These trunks pass through the diaphragm on their way to the celiac plexus in the abdomen

3. LARP= Left vagus Anterior, Right vagus Posterior

Four major collateral ways in which blood from the lower part of the body can bypass an obstruction of the inferior vena cava and maintain venous return to the heart through alternate venous routes:

1. Azygos System

2. Vertebral Venous Plexus

3. Anastomoses of Superior and Inferior Epigastric Veins

4. Thoracoepigastric Venous Network

1. Provides a connection between the inferior and superior vena cavae

2. Receives tributaries from the posterior thoracic wall and from the mediastinal structures (esophagus, pericardium, and bronchi)

3. The anatomical pattern of the azygos system is highly variable

1. Intricate plexuses of veins (with no valves) that extend along the length of the vertebral column

2. May be divided into two plexuses (internal and external) according to their positions inside or outside the vertebral canal

3. These plexuses anastomose freely with each other and with intervertebral veins that accompany spinal nerves through intervertebral foramina

4. Also communicate with veins of the spinal cord and with the vertebral, intercostal, lumbar and lateral sacral veins

1. The vertebral venous plexuses are clinically significant because they parallel and have extensive connections with the caval routes

2. This may permit the spread of certain metastases from one part of the body to another

3. This is especially true when pressure in the thorax or abdomen is increased, as when coughing or straining

4. At such times, the blood flow within the valveless vertebral system is greater in the caval system and the direction of flow could be reversed

1. Venous connections exist within rectus sheath between the superior epigastric veins (tributaries of the internal thoracic veins) and inferior epigastric veins (tributaries of external iliac veins)

2. These connections allow venous flow from the lower extremity to bypass the inferior vena cava by draining through the internal thoracic, subclavian and brachiocephalic veins into the superior vena cava, and back to the heart

1. Involves communications on the anterior and lateral thoracic and abdominal walls in the superficial fascia

2. The major anastomosis in this network is between the lateral thoracic tributary of the axillary vein and the superficial epigastric tributaries of the greater saphenous vein of the lower extremity

3. This network is a 4th way of bypassing the inferior vena cava

A dome-shaped straited muscle that separates the thoracic and abdominopelvic cavities

1. Phrenic nerves ("C3,C4, and C5 keep the diaphragm alive")

2. Lower intercostal nerves are also sensory to its peripheral edge

The diaphragm is pierced by a series of aperatures to permit the passage of structures betwen the thorax and abdomen. The larges openings are for the inferior vena cava, esophagus, and aorta:

1. Inferior vena caval foramen

2. Esophageal hiatus

3. Aortic hiatus

At the level of the 8th thoracic vertebra. It passes through parts of the middle and right leaflet of the central tendon and transmits:

1. Inferior vena cava

2. Right phrenic nerve

Situated in the muscular part of the diaphragm at the level of the 10th thoracic vertebra. Structures which pass through it include:

1. Esophagus

2. Vagal trunks

3. Small esophageal blood vessels

Lies at the level of the 12th thoracic vertebra. Situated slightly to the left of the midline and is bounded ventrally and laterally by the crura of the diaphragm and dorsally by the body of the 1st lumbar vertebra. The structures that pass through this aperature are:

1. The aorta

2. The azygos vein

3. The thoracic duct

From anterior to posterior in the thorax:

1. Inferior vena cava passing through at the 8th thoracic vertebral level

2. Esophagus passing through at 10th thoracic vertebral level

3. Aorta passing through 12th thoracic vertebral level

Thus: I,E,A- 8,10,12

1. Contraction causes descent of central tendon

2. This decreases intrathoracic pressure and increases the volume of the thoracic cavity, resulting in air being drawn into lungs

1. Sclaneus muscles

2. Sternocleidomastoid

3. Levator costarum

4. Serratus posterior, inferior, and superior

5. Quadratus lumborum

6. Intercostals-external, internal, and innermost

1. The thoracic duct drains lymph from most of the lymph vessels in the body and conveys it to the blood stream

2. Intestinal lymphatics (lacteals) absorb fat droplets causing the lymph in the thoracic duct to have a milk appearance

3. Arises from cisterna chyli

4. Ascends on the vertebral column between the azygos vein and the descending aorta

5. As it ascends in the thorax, it passes to the left and continues to the neck where it arches laterally to drain into the union of the internal jugular and subclavian veins (has vein-like appearance)

6. Receives lymph from the intercostal spaces

7. Joined by the left jugular trunk, which drains the left side of the head, and the left subclavian trunk, that drains the upper limb

8. The left bronchomediastinal trunk drains into the thoracic duct

1. An elongated lymphatic sac that lies on the 1st and 2nd lumbar vertebrae between the aorta and the right crus of the diaphragm

2. Receives lymph from almost everything below the diaphragm

Collects most of the lymph from the left lung (except the lower segments), left side of the heart, and left side of the mediastinum and drains into the thoracic duct

1. Formed by the union of the right jugular trunk, the right subclavian trunk, and the right bronchomediastinal trunk

2. Empties into the junction of the right internal jugular and subclavian veins (right venous angle)

3. Occasionally, the right jugular trunk, the subclavian trunk, adn the right bronchomediastinal trunk enter the right brachiocephalic vein independently

4. Right lymphatic duct has a much smaller field of drainage than the thoracic duct

5. The right lymphatic duct drains mostly the upper right quadrant  of the body, which the rest of the body is drained by the thoracic duct

Drains the right side of the heart, right lung, lower segments of the left lung, right mediastinum and the right superior aspect of the liver

1. Lateral half of breast drains mostly into pectoral nodes along the lateral chest wall, then into central nodes and apical nodes, then into the larger lymphatic ducts via the subclavian lymphatic trunks

2. Medial half of breast flows into the axillary nodes and parasternal nodes inside the chest cavity on either side of the sternum, which then drain into the bronchomediastinal trunks. There are cross connections here from one side of the chest wall to the other. Some drainage from teh inferior region flows along the anterior abdominal wall to the inguinal nodes in the groin

1. Located in the lateral horns of the gray matter in spinal cord segments T1-L2 (or L3)

2. Also called thoracolumbar division

3. Send postganglionic fibers out through the ventral horn, ventral root, spinal nerve, ventral ramus, and white ramus communicans to reach their corresponding chain ganglion

1. Located in the sympathetic chain ganglia (paravertebral ganglia) or in the prevertebral ganglia

2. Sympathetic chain ganglia are interconnected by ascending and descending limbs

3. They form the sympathetic trunk

1. Bilateral

2. Lie along the lateral aspects of the vertebral bodies from the base of the skull (vertebra C1) to the tip of the coccyx (vertebra Co1)

3. Generally, one ganglion for each spinal nerve

4. In cervical region, ganglia may fuse into 3 larger masses-superior, middle and inferior ganglia

5. In abdomen, postganglionic sympathetic cell bodies located in prevertebral ganglia (in addition to sympathetic chains). These prevertebral ganglia are located on the anterior aspect of the abdominal aorta around the origins of the major arteries coming off the aorta

In the T1 to L2 range, the preganglionic sympathetic fibers come out from the white ramus to enter the sympathetic chain ganglion and have at least 2 routes to follow

1. In the T1 to T4 or T5 sympathetic chain ganglia, incoming preganglionics synapse on postganglionic cell bodies

2. The postganglionic fibers from these leave the ganglia and course anteromedially as the thoracic splanchnic nerves to innervate most of the thoracic viscera and blood vessels

1. Two types of splanchnic nerves-some postganglionic and some preganglionic

2. Some of the incoming preganglionic sympathetic fibers in the white rami reach the ganglia but do not synapse on postganglionic neurons

3. These preganglionics pass through ganglion and leave it as greater splanchnic nerve (T5-T9), lesser splanchnic nerve (T10-T11), and least splanchnic nerve (T12)

(greater, lesser, least splanchnic nerves)

1. Course along the anterolateral aspects of teh lower thoracic vertebral bodies

2. Pierce diaphragm

3. Course onto the abdominal aorta

4. Synapse in prevertebral ganglion (celiac ganglion "complex")

5. From these prevertebral ganglia, postganglionic sympathetic fibers "jump onto" major arteries and get distributed to all of the abdominal organs by following the blood vessels