Thorax Study Tables

Ribs 1-7 articulate directly with their
thoracic vertebrae posteriorly and with their
costal cartilage anteriorly. They are the true ribs.

Ribs 8-10 articulate directly with their
thoracic vertebrae posteriorly and share a
costal cartilage anteriorly. They are the False Ribs

Ribs 11-12 articulate directly with their
thoracic vertebrae posteriorly and do not
articulate anteriorly
They are the floating Ribs

Ribs 1, 2, 10, 11, 12
○ Referred to as Atypical Ribs
*** any rib with a “1” or “2” = atypical

Posteriorly – T1 vertebral body
Anteriorly – superior border of manubrium
Laterally – first rib and costal cartilages

• Trachea
• Esophagus
• Vagus (CN X) and Phrenic (C3-C5) nerves
• Apex of Lungs (cupula)

The inlet is also called the clinical outlet

• Posteriorly – T12 vertebral body
• Posterolaterally – 12th ribs
• Anterolaterally – costal margin (costal cartilages 7-10)
• Anteriorly – Xiphoid Process

• Aortic Opening (T12)
• Esophageal Opening (T10)
• Caval Opening (T8)

The angle of louis is formed between the maubrium and body of the sternum

The angle of louis marks the level of the second costal cartilage

T4 (T4-T5)

RAT PLANT

Rib 2
Aortic arch
Tracheal bifurcation (AKA carina)
Pulmonary trunk
Ligamentum arteriosum
Azygos vein into SVC
Nerves (recurrent laryngeal)
Thoracic duct

The costal groove is located on the
INFERIOR aspect of the ribs and
shelters the neurovascular bundle

Passage of instruments through an
intercostal space is done in the lower
part of the ICS on the superior aspect of
the lower rib

Neurovascular bundle is found between
the internal intercostal muscle and
innermost intercostal muscle

1. Serratus anterior
2. External intercostals
3. Internal intercostals
4. Innermost intercostals

External intercostals
○ muscle of INSPIRATION
○ fibers run downward and forward

Internal intercostals
○ muscle of EXPIRATION
○ fibers run downward and backward

Innermost intercostals
○ muscles of EXPIRATION
○ fibers run downward and backward

-Innermost proper – between ribs
-Subcostalis – rib angle
- Sternocostalis (AKA transversus thoracis) –
near sternum

Caval opening (T8)
Esophageal Opening (T10)
Aortic Opening (T12)

I Ate 10 Eggs at 12

1. IVC
2. Phrenic Nerves (C3-C5)
3. Lymphatic Vessels

1. Esophagus
2. L and R vagus nerves
3. Esophageal branch of left gastric artery and vein

1. Thoracic aorta
2. Thoracic duct
3. Greater splanchnic nerves (T5-T9)
4. Azygos vein

ICS 1-6 – anterior intercostal arteries from internal
thoracic artery
ICS 7-9 – anterior intercostal arteries from
musculophrenic artery (branch of internal thoracic)
ICS 10-11 – no anterior intercostal arteries

internal thoracic artery

ICS 1 – highest intercostal artery (AKA 1st posterior intercostal artery)
from costocervical trunk
ICS 2-11 – posterior intercostal arteries from thoracic aorta
ICS 12 – subcostal artery from thoracic aorta

thoracic aorta EXCEPT ICS 1
-> costocervical trunk

The ANTERIOR thoracic wall is
drained by the internal thoracic
vein into the brachiocephalic vein

ICS 1 - highest intercostal vein → brachiocephalic vein
ICS 2-3 - highER intercostal vein → azygos
ICS 4-11 - azygos
ICS 12 - (subcostal vein) → azygos

ICS 1 - highest → brachiocephalic vein
ICS 2-4 - accessory hemiazygos → azygos vein
ICS 5-12 - hemiazygos vein → azygos vein

Thoracic duct starts inferiorly at cisterna chyli (L1-L2) and travels
superiorly

The thoracic duct drains into the left brachiocephalic vein between left subclavian
and left internal jugular vein

Thoracic duct drains the whole body except:
• Right UE
• Right thoracic cavity
• Right side of head and neck

The right upper structures go to the right lymphatic duct which drains into the right internal jugular vein

1. Skin
2. Superficial fascia
3. Deep fascia
4. Serratus anterior muscle
5. External intercostal muscle
6. Internal intercostal muscle
7. Innermost intercostal muscle
8. Endothoracic fascia *
9. Parietal pleura
10. Pleural cavity (space) →
11. Visceral pleura
12. Lungs

Endothoracic fascia = connective tissue layer that functions to
prevent the parietal pleura from rubbing against the innermost
intercostal muscles.
This fascia is thickened over the apex of the lungs: SIBSON’s fascia

Ribs 1-7 articulate directly with their
thoracic vertebrae posteriorly and with their
costal cartilage anteriorly. They are the true ribs.

Rib dislocations - costal cartilage displaces from the sternum
(costosternal problem) → Most common for ribs 2-7

Rib separations - displacement of the costochondral joint

Pectus excavatum: “funnel chest”- body of the sternum
projects inferiorly and posteriorly pressing on the heart, which
widens it so looks large on AP radiographs

Pectus carinatum: “pigeon chest” - sternum projects anteriorly

Thoracotomy = surgical incision over ICS 4 or ICS 5, extending from the
lateral margin of the sternum to the anterior axillary line; used for
lobectomy in lung cancer

Thoracostomy:
1) needle
2) tube (ICS 4 or ICS 5 at the anterior axillary line)

Thoracentesis - surgical procedure to remove fluid from around the
lungs. Can be done in ICS 9 at mid-axillary line or in ICS 10 at scapula
line. Must be done on the superior border of lower rib to avoid
neurovascular bundle

Pleurae = membranes covering the lungs and
each lung is surrounded by a pleural sac

Ribs 1-7 articulate directly with their
thoracic vertebrae posteriorly and with their
costal cartilage anteriorly. They are the true ribs.

Visceral pleura = on the lungs

Visceral and Parietal meet to form the hilum
which surrounds the lung root

Pleural cavity = slit like space that separates the
visceral and parietal plerua

Cupula = area of parietal pleura that is reflected
over the apex of the lung

Plerual recess = potential pleural space that is not
occupied by the lungs in quiet respiration

Costodiaphragmatic recess = where the costal and
diaphragmatic recesses meet

Costal parietal pleura extends:
- Anterior ICS 8
- Mid axillary ICS 9
- Posterior ICS 10

Pneumothorax
Breach of the pleura and negative pressure is lost

Parietal pleura:
- Internal thoracic artery and
intercostal arteries
- VERY SENSITIVE TO PAIN

Visceral pleura:
- Bronchial arteries
- INSENSITIVE TO PAIN

Indention in the left lung for the heart in
ICS 3/4/5

The right lung
- has 3 lobes (Superior/ Middle/
Inferior)
- Horizontal fissure (ICS 4) and a
oblique fissure (ICS 6)

The left lung
- Has 2 lobes (Superior/ Inferior) and
no middle lobe just a lingula
- Only a oblique fissure (ICS 6)

Continuation of the larynx at lower border of the
cricoid cartilage (C6)

Trachea continues slightly right of midline and
ANTERIOR to the esophagus

Trachea bifurcates at the carina at the level of
T4-T5 (sternal angle)
- When it bifurcates the angle should be 90
degrees if wider mass present

Vagus nerve

Superior and Inferior thyroid artery and Internal
thoracic artery

The right bronchus is wider and shorter than the left. More prone to aspiration. Objects get stuck in the right lower lobe. It gives off superior lobe before entering the hilum. Two bronchial arteries come from the thoracic aorta.

The left bronchus is more narrow and longer than the rught. Gives off both lobes as it enters the hilum. Passes below the aortic arch and in front of esophagus. One artery from the third intercostal artery.

The mediastinum extends
superiorly to superior thoracic aperture
and inferiorly to diaphragm

The mediastinum extends anteriorly to the sternum
and posteriorly to vertebral
column

Lungs, pleural membrane, pleural cavities

-Anterior to the first four thoracic vertebrae
-Inferior to superior thoracic aperature
-Superior to transverse plane at sternal angle

PVT Left Battle

Phrenic nerve
Vagus Nerve
Thoracic Duct

Left Recurrent Larygeal (not right)

Brachiocephalic vein (SVC)
Aortic Arch
Thymus
Trachea
Lymph Node
Esophagus

Arterial: Right common carotid and right subclavian come
off the brachiocephalic trunk

Venous: Internal jugular + subclavian →brachiocephalics → SVC

C3-C5

-Supplies the RV and RA
- Sinoatrial nodal artery = supplies SA node
- Atrioventricular nodal artery = interatrial septum and
AV node
- Posterior descending artery = supply LV and RV and
posterior 1/3 of the interventricular septum

-Right of SVC and RA
- Anterior to root of right lung**

• Lateral to left vagus and aortic arch
• Anterior to root of left lung***

Left recurrent laryngeal
• Branches at and hooks under the arch of
the aorta distal to ligamentum arteriosum
• May be damaged by pathology
(aortic aneurysm, malignancy)
• Part of superior mediastinum

Right recurrent laryngeal
• Branches at and hooks under the right
subclavian artery
• NOT part of superior mediastinum

The current laryngeals are damged during thyroid surgery

Trachea will shift towards pathology
• Atelectasis
• Pneumonectomy
• Large pleural fibrosis
• Pulmonary agenesis

Trachea will shift away from pathology
• Tension pneumothorax
• Pleural effusions
• Hemothorax
• Large Masses

1. Fatty tissue
2. Thymus gland
3. Lymph nodes

1. Heart
2. Pericardium
3. Main bronchi
4. Great vessel and phrenic
nerves

-Posterior to the percardial sac and diaphram
-Anterior to T5-T12

Vauge Dates

Vagus Nerve
Decending aorta
Azygos venous system
Thoracic Duct
Esophagus
Splanchnic nerves

C6-T10

Lies posterior to
the trachea and left atrium

Esophagus

Deviates to the left, posterior to left main
bronchus and enters diaphragm at T10
anterior to aorta

Anteriorly – left vagus
• Posteriorly – right vagus
• Sympathetic fibers (pain)

Begins at L2 as the cisterna chyli

T12

Found superior to crista terminalis at junction of SVC and right
auricle

T5-T6

Enters the left jugular vein or the
left jugular and left subclavian

-Posterolateral to brachipchephallic
-Lateral to trachea
-Posterior to root of right lung ****
-Medial to right phrenic

-Between the left common corotid and left subclavian
-Crosses the left side of aortic arge
-Posterior to root of left lung ***
-Crossed by phrenic nerve below arch

-Located in middle mediastinum
-Posterior to sternum and 6th ICS
-Anterior to T8

pericardiophrenic ligament

Parietal pericardium = outer fibrous layer

Visceral pericardium = layer reflected
over the heart

Pericardial cavity = potential space
between the pericardial layers

Fibrous pericardium =>Serous sac => Parietal
layer => pericardial cavity => Visceral layer

Epicardium => Myocardium => Endocardium =>
Chambers of the Heart

Transverse sinus: behind the aorta and pulmonary
trunk and in front of the left atrium and superior
vena cava

Oblique sinus: between the pulmonary veins and
IVC

Phrenic nerve ( between the parietal
pleura an fibrous pericardium) and vagus
nerve

Pericardium receives blood from the
internal thoracic/ thoracic aorta/
ascending aorta

Pericardiocentesis = needle goes in the
INFRASTERNAL ANGLE of the left lung.
Can enter through left sternal margin at
ICS 4 too

Heart
- Base = posterior and Apex = inferolateral
- Related to the ribs 3-5 on the left
- Extends from T6-T9 posteriorly

-Right boarder = right atrium
- Left boarder = Left ventricle
- Apex = ICS 5 midclavicular line
- Superior = right and left auricles
- Inferior = diaphragm by right ventricle

What are the surface projections of the heart?
Upper right = 3 R ICS
Lower right = 6 R ICS
Upper left = 2 L ICS
Lower left = 5 L ICS Midclavicular

-Supplies the RV and RA
- Sinoatrial nodal artery = supplies SA node
- Atrioventricular nodal artery = interatrial septum and
AV node
- Posterior descending artery = supply LV and RV and
posterior 1/3 of the interventricular septum

- Left anterior descending = Anterior Left ventricular
wall/ anterior 2/3 of interventricular septum/ Apex
- Circumflex artery = left boarder via MARGINAL
ARTERY & supplies posterior-inferior left ventricular
wall

- Anterior cardiac veins = drain RA
- Small cardiac veins = drains RV and drains into
coronary sinus
- Great cardiac veins = tributary of coronary sinus

- Middle cardiac vein = drains into coronary sinus
- Oblique vein = drains coronary sinus
- Coronary sinus = drains into right atrium

Venae cordis minimae (thebesian veins)
open right into the atria
- DO NOT DRAIN INTO CORONARY
SINUS

All veins of the heart drain into the coronary
sinus except the anterior cardiac veins and
the thebesian veins

right marginal artery

posterior interventricular artery

Anterior interventricular artery

Circumflex artery

A vestigial duct that communcicates the acortic arch with the pulmonary trunk

Left recurrent laryngeal nerve hooks under
the ligamentum arteriosus at angle of louis

The right recurrent laryngeal passes under the right subclavian

https://www.youtube.com/watch?v=1b4V09HzhBw

-Fossa ovalis - site of foramen ovale. Blood RA -> LA before birth
- Pectinate muscle - aid in contraction/ reservation; **only RA, R&L auricles
-Crista terminalis - ridge btwn SVC and IVC; origin of pectinate muscles
-Thebesian valve - opening from coronary sinus
- Openings from SVC/IVC and anterior cardiac veins

-Papillary muscles
-Moderator band/Septomarginal trabecula - prevents overdistention
and carries AV conduction fibers
-Chordae tendinae - prevent valvular backflow and eversion. Attached
to the papillary muscles which extend out from the trabeculae carneae
(“the inner wall of the ventricle”)
- Pulmonary trunk

Auricles = appendages
that act like “storage”
areas for blood absorbing
and increasing blood
capacity in atria

Right atrium to tricuspid to right ventricle to pulmonary valve to pulmonary arteries to pulmondary veins to left artium to mitral valve to left ventricle (papillary muscles, chordae tendinae) to aortic valave to ascending aorta

Trabeculae carneae of both ventricles
= all structures except the cusps,
chordae tendineae, and septomarginal
trabecula

Left pulmonary artery arches superior to the
left main bronchus

Right pulmonary artery runs posterior to
ascending aorta and SVC

Pulmonary trunk or left pulmonary artery -
attached to aortic arch via ligamentum arteriosum

Pulmonary valve = left costal cartilage 3
Aortic valve = left ICS 3
Bicuspid valve = left costal cartilage 4
Tricuspid valve = right ICS 4

Aortic: Right ICS 2 (R Upper Sternal Border)
Pulmonary: Left ICS 2 (LUSB)
(Erb’s Point “secondary pulmonic”: Left ICS 3)
Tricuspid: Left ICS 4
Mitral: Apex (left ICS 5)

(APE to Man)

Heart Sounds
Lub = S1 → tricuspid and mitral valves close
Dub = S2 → pulmonary and aortic valves close

Left side

Subepicardial

Found superior to crista terminalis at junction of SVC and right
auricle

right coronary artery

Submyocardial

Found within the inferior interatrial septum close to opening of
coronary sinus

Supplied by a branch of the right coronary artery

Vagus (parasympathetic) and sympathetics (T1-T5) share their fibers
to form the cardiac plexus

parasympathetics = slow HR, decrease force of contraction

sympathetics = increase HR, increase force of contraction

pain fibers travel through sympathetics

The cardiac plexus is found anterior to the carina, superior to the pulmonary bifurcation, and posterior to aortic arch