Thorax Review

Two types of classification True ribs (1-7) False ribs (8-10) Floating ribs (11-12)

Typical ribs (3-9) Atypical ribs

(1,2,10,11,12)

Ribs

Thoracic Outlet Syndrome

A misnomer, actually it is thoracic inlet syndrome!! Types/Classification: Costoclavicular syndrome,

scalenus anticus syndrome or cervical rib syndrome S/S-

Pallor and coldness of skin of upper limb, Diminished radial pulse [Vascular Symptoms]

Tingling, numbness or pain in limb [neurogenic symptoms]

Results from compression of subclavian artery between clavicle and 1st rib and/or Lower trunk of brachial plexus

Sc. Ant

Cervical ribRib arising from

anterior tubercle of transverse process of C7

0.5-1% of personsCan causes pressure

onLower trunk of BPSubclavian artery

Sternal Angle (Angle of Louis)

Sternal Angle (Angle of Louis)

Connects 2nd CC laterally & corresponds with Lower border of 4th thoracic vertebra Count ribs from this angle Bifurcation of trachea Ascending aorta ends Descending thoracic aorta begins at this level Beginning of aortic arch which ends posteriorly at

same level Border between superior and inferior

mediastinum Thoracic duct changes course [from right to

left] at this level Esophagus is crossed by left main bronchus

If a bone marrow needle passes thru the manubrium....

It can hit aorta

CLINICAL CASE

A 25 year old male is brought into the emergency room following a motorcycle accident in which he struck an object in the road and was thrown over the handlebars striking his left lateral chest against a telephone pole.

He is conscious, in considerable pain, his lips are blue, his respiratory rate is 40/minute, BP is 90/60mmHG, Pulse is 120

Once his shirt is removed you notice an 8x8 cm portion of the left lateral chest wall mid axillary line caves in when he takes a breath in.

Clinical Anatomy of Thoracic wall Flail chest-

Portion of rib cage is separated from rest of chest wall (multiple rib fractures)

Due to severe blunt trauma Serious fall Car accident

Injured region of chest wall moves paradoxically

In on inspiration Out on expiration

Common site of fracture- Middle ribs Weakest part of ribs- just anterior to ANGLE

Vasculature of Breast

o Anterior intercostal A. (from internal thoracic artery)

o Lateral thoracic A. (from axillary artery)o Branches of thoracoacromial A.o Posterior intercostal A.

o Branch of thoracic aorta 2nd, 3rd, & 4th P.I.C.

o Venous drainage- o Axillary vein (main) [lateral thoracic]o Internal thoracic vein [anterior intercostal]o Azygous vein [posterior intercostal]

Lymphatic Drainage of Breast

Lymph from nipple, areola, and lobules of mammary glands- subareolar lymphatic plexus From there, a system of interconnecting

lymphatic channels drains lymph to various lymph nodes

Majority (75%) of lymph, especially from lateral quadrants→ pectoral nodes→ axillary nodes

Remaining lymph, especially from medial quadrants→ parasternal lymph nodes along internal thoracic vessels

Some lymph from lower quadrants→ inferior phrenic nodes

Lymph from medial quadrants can cross to opposite breast Secondary metastases of breast

carcinoma can spread to opposite breast in this way

Lymphatic Pathway

From Supraclavicular Nodes

Subclavian Lymphatic trunk

Right Lymphatic

DuctThoracic Duct

Superior Vena Cava

(venous system)

On Rt sideOn Lt side

From parasternal Nodes

Costo-Mediastinal Trunk

Right Lymphatic Duct

Thoracic Duct

Superior Vena Cava

(venous system)

On Rt side On Lt

side

Breast cancer in the medial quadrants can cross the midline to the opposite breast!

Spread of Cancer from Breast

Lymphatic spread From Lateral Quadrant >> Axillary lymphnodes From Medial side >> Parasternal lymphnode and potentially to

opposite side and opposite breast.

After that by major lymphatic channels into Superior vena Cava

Hematogenous spread By venous routes From lateral Portion >> Axillary vein, to Subclavian to Superior

Vena cava From (Infero-)lateral Portion>> Posterior Intercostal, to Azygous

system to Superior Vena cava or Vertebral Venous Plexus [Vertebrae]

From Medial portion >> Internal Thoracic to subclavian to Superior Vena Cava

SVC >>> Right Side of Heart >>> LUNGS >>> Left side of Heart >>> all over body

3 diameter of respiration

1-Vertical diameter Above suprapleural membrane below mobile diaphragm Can be increases by descent of diaphragm

2-Anteroposterior diameter Can be increased by raising ribs and sternum

(pump handle movement) [more in upper ribs]

3-Transverse diameter Can be inccreased by raising out lower ribs (bucket

handle movement) [more in lower ribs]

Respiratory movements

Inspiration Diaphragm contract & go down First rib is fixed by contraction of

scaleni muscle in root of neck 2nd-12th rib raised toward first rib by

contraction of ICM [pump handle and bucket handle movement]

ICM = Inter Costal Muscles

ExpirationActually a passive movement by

elastic recoil of lungsBut when we need, 12th rib is

fixed by quadradratus lumborum muscle and oblique m. of abd.

1st-11th rib will be lowered by contraction of ICM

Structure involved in Quit/Forced respiration Quiet inspiration Diaphragm ICM [ribs go up and out]

Forced inspiration in addition to above Scalenus anterior Trapezius, Levator scapulae, rhomboid

muscles Pec.minor, pec. major

Quiet Expiration Passive movement Elastic recoil of lung

Forced Expiration Active process Anterior abdominal muscle contraction Quadratus lumborum with Inter Costal

Muscles [ribs go down and in] Latissimus dorsi

Structure involved in Quit/Forced respiration

Inspiration: Diaphragm descend, >>>

intrathoracic volume increase >>> result in drop in intrathoracic pressure [negative pressure] >>> air sucked in lung >>> inspiration happens

This drop in intrathoracic pressure cause Increase Venous return

during inspiration Inward movement of

broken chest piece in flial chest

Expiration Lung recoil and diaphragm

relaxes and go up >> reduction in intrathoracic volume >> increase in intrathoracic pressure

This increase intrathoracic pressure causes Decrease venous return on

right side of heart during expiration

Downward movement of paralyzed diaphragm on expiration

Outward movement of broken chest piece in flial chest

Paralysis of Diaphragm

Cause- injury to phrenic nerve Paralysis of one half does not affect other half

because each dome has a separate nerve supply

On X-ray- note its paradoxical movement Instead of descending on inspiration, paralyzed

dome is pushed superiorly by abdominal viscera that are being compressed by active side

Paralyzed dome descends during expiration as it is pushed down by positive pressure in lungs

Intercostal Nerve Block

Local anesthesia of an intercostal space is produced by injecting a LA agent around intercostal nerves

Involves infiltration of anesthetic around intercostal nerve and its collateral branches

Because any particular area of skin usually receives innervation from two adjacent nerves, considerable overlapping of contiguous dermatomes occursTherefore, complete loss of sensation usually

does not occur, unless two or more intercostal nerves in adjacent intercostal spaces are anesthetized

Lungs - Surface Anatomy

Anterior View

3 lobes on Right

2 lobes on Left

Posterior View

Lateral View - Rt

Lateral View - Lt

Pleura

Each lung is enclosed in a serous sac (pleura)

Visceral Pleura invests the lungs

Parietal Pleura lines thoracic cavity (adherent to thoracic wall, diaphragm & mediastinum)

Visceral and parietal pleura are continuous at hilum of lung

Pleural space is a potential space between parietal and visceral pleura

Contains pleural fluid Lubrication Cohesion

Parietal pleura Lines the pleural cavities Very sensitive to pain

Intercostal and phrenic nerves [somatic nerves] Has 4 parts

Costal pleura- Lining internal surface of thoracic wall

Mediastinal pleura- Covering sides of mediastinum

Diaphragmatic pleura- Covering superior surface of dome of each hemidiaphragm

Cervical pleura- A dome of pleura extending superiorly into superior thoracic aperture

IMP

Pleural Nomenclature

Cervical pleura

Mediasinal pleura

Costal pleura

Diaphragmatic pleura

Visceral pleura

Visceral pleura

Covers the lungs Cannot be dissected from lungInsensitive to pain

Does not have any somatic sensory innervation but may be supplied by autonomic nerves which also supply lung substance

IMP

Pleural cavity

Potential space between parietal and visceral pleura Contains a thin layer of serous pleural fluid

Lubricates and allows pleurae to move smoothly over each other during respiration

Surface tension keeps lung surface in contact with thoracic wall

Due to continuous drainage of lymphatic fluid out of the pleural cavity there is slight suction effect resulting in negative pressure in pleural cavity.

IMP

Lines of Pleural ReflectionLines of pleural reflection are lines along which parietal pleura changes directions from one wall to another

Apex of lung at neck or 1st rib Inferior margin of lung

6th rib MCL 8th rib MAL 10th rib MSL

Inferior pleural reflection 8th rib MCL 10th rib MAL Neck of 12th rib on either side

of the vertebral column

IMP

Lines of Pleural Reflection

Lines of Pleural Reflection

Pleural effusion

= Fluid in Costodiaphragmatic recess

IMP

Pleural Effusion

Obliteration of costodiaphragmatic recess

IMP

Left Pleural Effusion Lateral Chest Film

Lung root contains Main stem or lobar

bronchi Pulmonary vessels and

bronchi. Bronchial vessels,

lymphatics, and autonomic nerves

Lung root is surrounded by a pleural sleeve, from which extends pulmonary ligament

ROOT OF LUNGIMP

IMP

IMP

Must be able to Identify Hilar Structures

• Pulmonary Veins Anateriorly and Inferiroly

• From Above Downwards: Artery, Bronchus, Vein

• Pulmonary Veins Anateriorly and Inferiroly

• From Anetior to Posterior: Bronchus Artery, Vein

LEFT RIGHT

IMP

Know these impressions

Trachiobronchial Tree

Trachea Bronchi

Right and left [primary] Lobar [secondary] [3 or 2] Segmental [Tertiary] [10] Large & Small Intra-segmental

Bronchiole Terminal Respiratory

Alveoli Alveolar duct Alveolar Sac Alveoli

IMP

IMP

A bronchopulmonary segment Is a pyramidally shaped section of lung with its

base covered by visceral pleura Is separated from adjacent segments by

connective tissue septa Is aerated by segmental bronchus Has its own segmental bronchus and

segmental branch of pulmonary artery and segmental branch of bronchial artery but not pulmonary vein

IMP

THERE ARE 10 BRONCHOPULMONARY SEGMENTS ON EACH SIDE

IMP Q – Which is the most dependent area/segment in both lungs?

Aspiration of Foreign Bodies

More likely to enter in right bronchus Because right bronchus is wider and shorter

and runs more vertically than left bronchus Encountered by dentists

Aspiration of piece of tooth, filling material, or a small instrument

Location with Aspiration

1. Standing or Sitting Posterobasal segment of Rt. Lower Lobe

2. Lying Down on back Superior segment of Rt. Lower Lobe

MC site of lung abscess

3. Lying on Right side Rt. Middle Lobe Posterior segment of Rt. Upper Lobe

4. Lying on Left side Lingual

IMPORTANT

ANTERIOR VIEW

MEDIAL VIEW

Broncho – Pulmonary Segments

IMP

Aspiration Pneumonia

Post Surgery or Drunk alcoholic found unconscious

Which lobe & segment? Which position on chest wall for abnormal

sound?

Bronchogram

Vasculature of lungs

Pulmonary artery Carries unoxygenated blood

from heart to lungs Each artery gives lobar and

segmental arteries

Pulmonary veins Intrasegmental veins drain to

intersegmental veins in pulmonary septa, which drain to two pulmonary veins for each lung

Carry oxygenated blood from lungs to heart

IMP

2 sets of Blood Supply

1.Pulmonary Vessels: for Gas Exchange

2. Bronchial Vessels: for blood supply to lung substance like any other organ

Bronchial arteries Basically supply lung substance From thoracic aorta Carry oxygenated blood to tissue of lungs,

traveling along posterior surface of bronchi

Left bronchial arteries- arise from thoracic aorta Right bronchial artery- arise from posterior

intercostal A.

Bronchial veins drain to azygos and accessory hemiazygos veins

IMP

Lymphatic drainage

Lymph from lungs drains to Pulmonary lymph nodes (along lobar bronchi) Bronchopulmonary lymph nodes (along

main stem bronchi) Superior and inferior tracheobronchial lymph

nodes (superior and inferior to bifurcation of trachea)

Deep Cervical Lymphnodes Costomediastinal Trunk Thoracic duct [left side] and Right lymphatic

duct [right side]

IMP

Lymphatic Drainage of Lung

Inferior deep cervical (Scalene) lymph nodes

Paratracheal nodes Aortic node Subcarinal nodes Hilar nodes intrapulmonary nodes

Once cancer spreads beyond hilar nodes it cannot be removed surgically

IMP

Vagus & Phrenic Nerves

Vagus nerve Phrenic nerve Left Recurrent

laryngeal nerve Hilum of left lung

IMP

Lung cancer spreads to regional lymphnodes Once cancer spreads beyond hilar nodes it cannot be removed surgically

Special case of Left Upper Lobe: cancer can spread to aortic lymphnodes, which can enlarge to compress the recurrent laryngeal nerve. Since this nerve supplies vocal cords, compression of the nerve can lead to paralysis of vocal cord and hoarseness.

Interestingly left lower lobe cancer are likely to skip this aortic lymph node as lymphatics from LLL cross to opposite side & therefore can not cause hoarseness.

Obviously right lung cancer do not cause hoarseness...

IMP

Left Vocal Cord Paralysis Secondary metastatic involvement of the left recurrent laryngeal nerve near the ligamentum arteriosum by lung CA

epiglottisaryepiglottic fold

Vestibular fold

Vocal fold Vocal Fold

midline Paralyzed

Normal Chest Xray {Lungs}

• Air filled lungs

• Normal Pulmonary Vascular Marking

• Hilum area

• Clear Costodiaphragmatic Recess

IMP

Pneumonia

A bacterial or viral infection of lung Can lead to widespread systemic infection

and lung collapse Lobar pneumonia

Confined to a single lobe of one lung Broncho pneumonia

Patches in lung

IMP

Lobar Pneumonia: which lobe of lung?

Right Upper Lobe

Is this Right Lower Lobe pneumonia?

No Actually in right middle lobe – look at the lateral view!

IMP

Pulmonary Collapse

If a sufficient amount of air enters pleural cavity [=pneumothorax], the surface tension adhering visceral to parietal pleura is broken, and lung collapses

It can be partial or total One lung may be collapsed

without collapsing other because pleural sacs are separate

Other Causes- a growing tumor, an infection, or even an inhaled foreign object blocking a major airway

IMP

Pneumothorax

Entry of air into pleural cavity S/S- Chest pain, short breath Uncomplicated pneumothorax may heal on its

own in a week or two

IMP

Pneumothorax - Differentiation

Spontaneous Mild to moderate Leads to partial lung collapse Decreased breath sounds, trachea in midline or

shifted [pulled] to same side, diaphragm normal or elevated on affected side

Tension Quite severe/emergency Leads to partial or total lung collapse Decreased breath sounds, trachea shift/pushed to

opposite side, diaphragm pushed down on affected side

Pleural effusion

Excess fluid that accumulates in pleural cavity

Can impair breathing by limiting the expansion of lungs during inhalation

Types Serous fluid (hydrothorax) Blood (hemothorax) Chyle (chylothorax) Pus (pyothorax or empyema)

IMP

IMP

Pleuritis Pleurisy Inflammation of pleurae Makes the lung surfaces rough Plural rub is heard with a stethoscope Acute pleuritis

S/S- sharp, stabbing pain, especially on exertion, such as climbing stairs, when rate and depth of respiration may be increased even slightly, it also increases on cough but is relieved by sleeping on the affected side.

IMP

Thoracocentesis

To obtain a sample of pleural fluid or to remove blood or pus or air

To avoid damage to intercostal nerve and vessels, needle is inserted superior to rib, high enough to avoid collateral branches

IMP

Pulmonary embolism

Blockage of pulmonary artery (or one of its branches)

Cause- DVT (Venous thrombus)- thromboembolism Fat (trauma), air (diving), clumped tumor cells, and

amniotic fluid (affecting mothers during childbirth) S/S-

Difficult breathing, pain in chest, collapse, circulatory instability and sudden death

Treatment- Anticoagulant medication (heparin and warfarin) with

thrombolysis or surgery

IMP

IMP

COMMON SITE OF ORIGIN OF THROMBUS

Thrombus in Deep vein >>> got dislodged >>> thrombo-embolism >>> IVC >>> Rt. Atrium >>> Mitral valve >>> right ventricle >>> Pulmonary Valve >>> Pulmonary trunk and Artery. Stopped the blood flow going to the lungs

Pancoast’s Tumor

Is a malignant neoplasm of the lung apex and causes Pancoast's syndrome,

1) Lower trunk brachial plexus compression - severe pain radiating toward the shoulder and the medial aspect of the arm, and atrophy of the muscles of the forearm and hand)

2) Lesion of cervical sympathetic chain ganglia with Homer's syndrome (ptosis, enophthalmos, miosis, anhydrosis, and vasodilation).

The treatment is radiation therapy followed by surgical resection of tumor and thoracic wall when feasible.

ON LEFT

On RIGHT

Radiographs of Thorax (Heart)

Anteroposterior chest films show the contour of the heart and great vessels—the or cardiac shadow. The silhouette contrasts with the clearer areas occupied by the air-filled lungs because the heart and great vessels are full of blood.

The silhouette becomes longer and narrower during inspiration because the fibrous pericardium is attached to the diaphragm, which descends during inspiration.

IMPNormal Chest X-Ray

IMP

Pericardial Sac

Covering of heart Two Layers: Fibrous and

Serous Serous itself has two layers:

outer – Parietal and inner – Visceral.

Pericardial space [between two layers of serous pericardium] contains a small amount of fluid that allows the heart to function in a frictionless environment.

Pericardial Sinuses

Transverse Sinus Oblique sinus

PA

PVs

AOSVC

Two spaces within pericardial cavity

Transverse Sinus

Lies between

1.Great vessels anteriorly [aorta and pulmonary trunk]

2.SVC posteriorly

During Open heart surgery, clamp is passed here to block the blood flow while patient is put on artificial heart-lung machine.

Pericarditis and Pericardial Effusion

Inflammation of the pericardium (Pericarditis) usually causes chest pain. Normally, the layers of serous pericardium make no detectable sound during auscultation. However, pericarditis makes the surfaces rough and the resulting friction, PERICARDIAL FRICTION RUB, sounds like the rustle of silk when listening with a stethoscope.

Certain inflammatory diseases may also produce pericardial effusion (passage of fluid from the pericardial capillaries into the pericardial cavity). As a result, the heart becomes compressed (unable to expand and fill fully) and ineffectual.

Large Pericardial Effusion (fluid)

Pericardial Effusion = excessive fluid in the pericardial cavity

Hemoparicardium and Cardiac Temponade

CARDIAC TEMPONADE (heart compression) due to sudden accumulation of blood or other fluid in pericardial cavity

is a potentially lethal condition because the fibrous pericardium is tough and inelastic. Consequently, heart volume is increasingly compromised by the fluid outside the heart but inside the pericardial cavity

Stab wounds that pierce the heart causing blood to enter the pericardial cavity (= HEMOPARICARDIUM).

Hemopericardium may also result from perforation of a weakened area of heart muscle after a heart attack. As blood accumulates, the heart is compressed and circulation fails.

If it is quite severe then there is also risk of producing cardiac tamponade.

Pericardiocentesis• Drainage of serous

fluid from pericardial cavity

• Is usually necessary to relieve the cardiac tamponade.

• To remove the excess fluid, a wide-bore needle may be inserted through the left 5th or 6th intercostal space near the sternum.

Left Paraxyphoid

HEART

• Many of the subsequent slides are heavy with Text material. You may read the descriptive text about Anatomy of Heart from either Text book or the PDF document in the folder

You should be able to identify All structures on this picture

Heart lies obliquely between 3rd & 5th ribsMainly on left side of midline of thorax, but 1/3rd

of it slightly to right Base-

Posterior surface (left atrium)Apex-

Most inferior and lateral part of left ventricle Left 5th IC space at mid-clavicular line

Surfaces of the Heart

Roughly shaped like a tipped over three sided pyramid with the apex pointing down and left and the base facing the spine.

Apex

5th ICS

Base

L. Atrium

Diaphragmatic (inferior) surface

Right Ventricle and Left ventricle

[Lt] Pulmonary Surface

Left Ventricle

Sternocostal surface (anterior)

Right ventricle

Surfaces of the Heart

Apex

5th ICS

Base L.Atrium

Diaphragmatic (inferior) surface Right Ventricle and Left ventricle

Pulmonary Surface

Left Ventricle

Sternocostal surface (anterior) Right ventricle

Base

The 4 surfaces of heart

Anterior/Sternocostal, formed mainly by the right ventricle.

Diaphragmatic, formed mainly by the left ventricle and partly by the right ventricle; it is related to the central tendon of the diaphragm.

Left Pulmonary, formed mainly by the left ventricle; it forms the cardiac impression of the left lung.

Right pulmonary, formed mainly by the right atrium [very small surface almost same as right border]

Posterior Surface or Base of Heart: formed by Right Atrium

The 4 borders of the heart

Right: (slightly convex), formed by the right atrium and extending between the SVC and the IVC.

Inferior (nearly horizontal), formed mainly by the right ventricle and only slightly by the left ventricle.

Left(oblique), formed mainly by the left ventricle and slightly by the left auricle.

Superior, formed by the right and left atria and auricles in an anterior view; the ascending aorta and pulmonary trunk emerge from the superior border, and the SVC enters its right side. [If you imagine heart as pyramidal shape then this border is described as base of the heart or posterior surface of heart]

Open Right Atrium

Pectinate muscles Christa terminalis Tricuspid valve Fossa ovalis Coronary sinus [Vein]

opening

Right Atrium

The Right Atrium forms the right border of the heart and receives venous blood from the SVC, IVC, and coronary sinus.

The ear-like Right Auricle is a small, conical muscular pouch that projects from the right atrium. [it is primordial atrium represented in the adult].

Coronary Sinus lies in the posterior part of the coronary groove and receives blood from the cardiac veins.

The part of the embryonic venous sinus incorporated into the primordial atrium becomes the smooth-walled of the adult right atrium.

The separation between the primordial atrium and the sinus venarum is indicated externally by the (terminal groove) and internally by the (terminal crest).

The Interior of Rt Atriumhas A smooth, thin-walled posterior part (the sinus venorum), on

which the SVC, IVC, and coronary sinus open, bringing poorly oxygenated blood into the heart.

A rough, muscular wall composed of Pectinate Muscle. The Opening of SVC is into its superior part, at the level of the

right 3rd costal cartilage. The opening of IVC is into the inferior part, almost in line with

the SVC at approximately the level of the 5th costal cartilage. The Coronary sinus is between the right AV orifice and the IVC

orifice. A Right RV Orifice, through which the right atrium discharges

the poorly oxygenated blood into the right ventricle. The Interatrial Septum, separating the atria, has an oval,

thumbprint-size depression, the (L. ), a remnant of the oval foramen and its valve in the fetus

Course of blood through the Right Atrium

Fossa ovalis: A closed but depressed area

in the Atrial septum In Fetal Circulation this

represents a Foramen Ovale; Most of the blood from IVC

entering the Rt Atrium is diverted towards this Foramen ovale and thereby goes to Left Atrium...

This is a normal course of blood during fetal circulation

Normal flow of blood: from SVC and IVC>>> Rt. Atrium >>> Right Ventricle

IVC

SVC

Atrial Septal Defect

Congenital anomalies of the interatrial septum—usually related to incomplete closure of the oval foramen—are (ASDs).

A probe-size patency (defect) appears in the superior part of the oval fossa in 15–25% of people. [PFO= patent foramen ovale]

These small ASDs, by themselves, are usually of no clinical significance;

however, large ASDs allow oxygenated blood from the lungs to be shunted from the left atrium through the defect into the right atrium, causing enlargement of the right atrium and ventricle and dilation of the pulmonary trunk.

LEFT to RIGHT shunt

Open Right Ventricle

Main pulmonary artery Conus artereosus/Infundibulum

Septal papillary muscle 1. Anterior leaflet TV 2. Septal leaflet TV 3. Posterior leaflet TV Moderator band Trabeculae carne

aorta

Right Ventricle

The right ventricle forms the largest part of the anterior surface of the heart, a small part of the diaphragmatic surface, and almost the entire inferior border of the heart.

Superiorly it tapers into an arterial cone, the Conus Artereosus (infundibulum), which leads into the pulmonary trunk.

The interior of the right ventricle has irregular muscular elevations called Trabeculae Carneae.

A thick muscular ridge, the SupraVentricular Crest, separates the ridged muscular wall of the inflow part of the chamber from the smooth wall of the conus arteriosus or outflow part of the right ventricle.

The inflow part of the right ventricle receives blood from the right atrium through the Tricuspid orifice, located posterior to the body of the sternum at the level of the 4th and 5th intercostal spaces

The Tricuspid Valve guards the right AV orifice. The bases of the valve cusps are attached to the fibrous ring around the orifice.

Tendenous Cords(L. Cordae Tendineae ) attach to the free edges and ventricular surfaces of the anterior, posterior, and septal cusps—much like the cords attached to a parachute.

Because the cords are attached to adjacent sides of two cusps, they prevent separation of the cusps and their inversion when tension is applied to the cords throughout ventricular contraction (systole)—that is, the cusps of the tricuspid valve are prevented from prolapsing (being driven into right atrium) as ventricular pressure rises. Thus regurgitation of blood (backward flow of blood) from the right ventricle into the right atrium is blocked by the valve cusps

The Papillary muscles form conical projections with their bases attached to the ventricular wall and tendinous cords arising from their apices. There are usually three papillary muscles (anterior, posterior, and septal) in the right ventricle that correspond in name to the cusps of the tricuspid valve.

The papillary muscles begin to contract before contraction of the right ventricle, tightening the tendinous cords and drawing the cusps together. Contraction is maintained throughout systole.

The Septomarginal Trabecula (moderator band) is a curved muscular bundle that runs from the inferior part of the interventricular septum to the base of the anterior papillary muscle

Moderator band is important because it carries part of the right bundle branch of AV bundle of the conducting system of the heart to the anterior papillary muscle. This “short cut” across the chamber of the ventricle seems to facilitate conduction time.

When the right atrium contracts, blood is forced through the into the right ventricle, pushing the cusps of the tricuspid valve aside like curtains. The inflow of blood into the right ventricle (inflow tract) enters posteriorly, and the outflow of blood into the pulmonary trunk (outflow tract) leaves superiorly and to the left. Consequently, the blood takes a U-shaped path through the right ventricle. The inflow (AV) orifice and outflow (pulmonary) orifice are approximately 2 cm apart.

The Pulmonary Valve at the apex of the conus artereosus is at the level of the left 3rd costal cartilage. Each of the 3 semilunar cusps of the pulmonary valve (anterior, right, and left) is concave when viewed superiorly.

Membraneous ventricular septum

Muscular ventricular septum

Note: relationship of membraneous septum to aortic valve!

RV

LV

LV

RV

Inter Ventricular Septum

The Interventricular Septum, composed of membranous and muscular parts, is a strong, obliquely placed partition between the right and the left ventricles, forming part of the walls of each.

The superoposterior [Membranous] part is thin and is continuous with the fibrous skeleton of the heart. The Muscular part of IV septum is thick and bulges into the cavity of the right ventricle because of the higher blood pressure in the left ventricle.

Ventricular Septal Defects[VSD]

VSD: VSD most common congenital heart defect The membranous part of the IV septum develops

separately from the muscular part Membranous part is the common site of VSD . A VSD causes a left-to-right shunt of blood

through the defect. A large shunt increases pulmonary blood flow, which causes pulmonary disease (pulmonary hypertension, or increased blood pressure) and may cause cardiac failure.

Left Atrium and Ventricle

L. atrial appendage Left atrium Valve of the fossa

ovalis Pulmonary veins Aortic valve Membranous

ventricular septum

Mitral valve removed

Anterior Surface Posterior Surface

Left Atrium

The left atrium forms most of the base of the heart.

The pairs of valveless right and left pulmonary veins enter the left atrium.

The left auricle forms the superior part of the left border of the heart and overlaps the pulmonary trunk

Interior: A larger smooth-walled part and a

smaller muscular auricle containing pectinate muscles.

Four pulmonary veins (two superior and two inferior) entering its posterior wall.

A slightly thicker wall than that of the right atrium.

An interatrial septum A left AV orifice through which the

left atrium discharges the oxygenated blood it receives from the pulmonary veins into the left ventricle.

IMP: Which chamber of heart is just anterior to esophagus?

Transesophageal echocardiogram illustrating a basal inferior left ventricular aneurysm (An). Arrowheads indicate the connection between the left ventricle and the aneurysm

LEFT ATRIUM

Left Ventricle

A double-leaflet Mitral Valve that guards the left AV orifice. Walls that are two to three times as thick as that of the

right ventricle. A conical cavity that is longer than that of the right

ventricle. Walls that are covered with thick muscular ridges,

trabeculae carnae, that are finer and more numerous than those in the right ventricle.

Anterior and posterior papillary muscles that are larger than those in the right ventricle.

A smooth-walled, non-muscular, superoanterior outflow part the Aortic Vestibule, leading to the aortic orifice and aortic valve

The left ventricle forms the apex of the heart, nearly all of its left (pulmonary) surface and border, and most of the diaphragmatic surface. Because arterial pressure is much higher in the systemic than in the pulmonary circulation, the left ventricle performs more work than the right ventricle and therefore more thick.

Left Ventricle

The Mitral Valve closing the orifice between the left atrium and left ventricle has two cusps, anterior and posterior.

Located posterior to the sternum at the level of the 4th costal cartilage. Each of its cusps receives tendenous cords from more than one papillary muscle.

These muscles and their cords support the mitral valve, allowing the cusps to resist the pressure developed during contractions (pumping) of the left ventricle.

The tendinous cords become taut, just before and during systole, preventing the cusps from being forced into the left atrium.

The ascending aorta , begins at the aortic orifice.

The Aortic Valve, obliquely placed, is located posterior to the left side of the sternum at the level of the 3rd intercostal space.

The Aortic Sinuses are the spaces at the origin of the ascending aorta between the dilated wall of the vessel and each cusp of the aortic (semilunar) valve.

The mouth of the right coronary artery is in the right aortic sinus and the mouth of the left coronary artery is in the left aortic sinus and no artery arises from the posterior [non coronary] aortic sinus

Aortic Valve

Noncoronary cusp = posterior cusp

Aortic-Mitral Continuity

Nomenclature of Aortic and Pulmonary Valve Cusps

Anterior

Posterior

Heart Diastole (Ventricles Relaxed & Filling)

Pulmonary valve

Aortic valve

Mitral valve

Tricuspid valve

P

RL

RL

A

Heart in Systole, Ventricles Contracting

Pulmonary Valve

Aortic Valve

Mitral valve

Tricuspid valve

Normal Heart Sounds

The First Heart Sound = S1 = described as “Lub” Closure of mitral [M1] and Tricuspid valve [T1] At beginning of Systole

Second Heart Sound = S2 = Described as “Dub” Closure of Aortic [A2] and Pulmonic Valves

[P2] At beginning of Diastole

Think- What would be the best places to hear the S1 and S2 respectively?

Auscultation Areas for Heart Valves

2nd ICS, RSB: Aortic valve

2nd ICS, LSB: Pulmonary Valve

5th ICS, LSB: Tricuspid valve

5 ICS, MCL: Mitral valve

Valve Surface Projection Best Heard

Tricuspid (right atrioventricular) valve

Inferior middle sternum

Over inferior middle sternum

Bicuspid (left atrioventricular) valve

Fourth costal cartilage and 4th intercostal space

Over apex of heart (5th intercostal space at midclavicular line)

Pulmonary valve Third left costal cartilage

2nd left intercostal space, just lateral to sternum

Aortic valve Fourth left costal cartilage

2nd right intercostal space, just lateral to sternum

Abnormal Heart Sound

When a valve is stenotic or damaged, there is problem in opening of those valves and as a result the abnormal turbulent flow of blood produces a murmur which can be heard during the normally quiet times of systole or diastole. This murmur may not be audible over all areas of the chest, and it is important to first note where it is heard best.

Think: Murmurs from 4 different damaged valves will be heard at what places?

Murmurs of Valvular Stenosis

Mitral Stenosis Lt. 5th ICS near MCL [midclavicular line]

Tricuspid Stenosis Lt. 5th ICS at LSB [lateral sternal border]

Aortic Stenosis Rt. 2nd ICS at RSB

Pulmonic Stenosis Lt. 2nd ICS at LSB

Diastolic Murmur

Systolic Murmur

For Med 1 Not For Med 1

Identify the pointed structures

Strokes or Cardiovascular Accidents

Thrombi(clots) form on the walls of the left atrium in certain types of heart disease.

If these thrombi detach or pieces break off, they pass into the systemic circulation [=remobilization] and occlude peripheral arteries.

Occlusion of an artery in the brain results in a stroke or Cerebrovascular Accidents(CVA), which may affect, for example, vision, cognition, or sensory or motor function of parts of the body previously controlled by the now-damaged area of the brain.

Endocarditis

Infective or non infective inflammation of endocardium covering the heart valves.

Lead to small vegetations [collection of platelet, fibrin, +/- bacterial colony, fibrin etc] over the heart valves

May lead to defect in closing the valves and therefore murmurs.

Conduction System

• SA node

• AV node

• AV bundle

• Right and Left Bundle branches

• Purkinje fibers

Where?

Rt. Coronary artery in the Atrioventricular grooveRt. [Acute] Marginal Br.

SA nodal br.

Post. Interventricular Br.

AV nodal br.

Be able to label the arteries!

Lt. Coronary artery in the Atrioventricular groove & divides into 2 branches.:

1. Circumflex branch turns around the right border in AV grooveLeft marginal [Obtuse Marginal]

is imp br. of circumflex art

2. Lt. anterior descending or Ant. Interventricular runs in interventricular groove to meet with post. Interventricular br. of right coronary

Be able to label the arteries!

Diagonal branch from LAD

Most coronary flow is in diastole.

WHY?

Right coronary

Right atrium, SA and AV nodes, Right ventricle and posterior part of IV septum

SA nodal SA node

Right/Acute marginal

Right ventricle and apex of heart

Posterior IV [in67%] posterior third of septum and Right and left ventricles

AV nodal AV node

Left coronary

Most of left atrium and ventricle, IV septum, and AV bundles; may supply AV node

Anterior IV (LAD) & Diagonal br.

Right and left ventricles; anterior two thirds IV septum

Circumflex Left atrium and left ventricle

Left /Obtuse marginal

Left ventricle

Posterior IV [in33%] posterior third of septum and Right and left ventricles

Area of Distribution

>>> Angina &/or Heart Attack [=Myocardial Infarction]

Blockage of Artery may be due to any one or combination of

• Cholesterol Plaque

• Thrombus

• Vasospasm

Coronary Artery Disease

Coronary Angiograph

yVisualization of Coronary artery by radio opaque dieInjected by catheter in femoral artery reaching up to aorta and coronary openings

TREATMENT OPTIONS of Coronary Blockages

PTCA[=Percutaneous Transluminal Coronary Angioplasty]

• A balloon at the tip of catheter is introduced at the blockage and then inflated to break up the plaque

A balloon Angioplasty can be followed by placement of STENT to prevent reblockage.

CABG: Coronary Artery Bypass Grafting

Two Common Vessels used from patients own body for grafting Internal

Thoracic Artery

Great Saphenous Vein from lower limb

Clinical Case A 45 year old man with a history of

smoking 1 pack of cigarettes per day since age 20 presents with anterior chest pain radiating to his left arm & nausea. His blood pressure is low and an EKG shows injury to the diaphragmatic / inferior surface of the heart.

What coronary is likely to be involved?

Do we need to worry about injury to his conduction system? [which part of conducting system]

RCA/Rt. marginal

AV node [leading to heart block]

Clinical Case A 45 year old man with a history of

smoking 1 pack of cigarettes per day since age 20 presents with anterior chest pain radiating to his left arm & nausea. His blood pressure is low and an EKG shows injury to the Posterior surface of the heart.

What coronary is likely to be involved? Do we need to worry about injury to

his conduction system? [which part of conducting system]

Distal RCA, Cx or PDA

AV node [leading to heart block]

Clinical Case A 45 year old man with a history of

smoking 1 pack of cigarettes per day since age 20 presents with anterior chest pain radiating to his left arm & nausea. His blood pressure is low and an EKG shows injury to the anterior /Sternocostal surface of the heart.

What coronary is likely to be involved? Do we need to worry about injury to

his conduction system?

LAD

Bundle Branches damage lead to Bundle branch Block

Clinical Case A 45 year old man with a history of

smoking 1 pack of cigarettes per day since age 20 presents with anterior chest pain radiating to his left arm & nausea. His blood pressure is low and an EKG shows injury to the Lateral surface of the heart.

What coronary is likely to be involved? Do we need to worry about injury to

his conduction system?

Circumflex/ left marginal

No, not this time!

Which wall infarction

Which artery blocked

comment

Diaphragmatic or inferior surface

Proximal RCA or Rt. marginal

If proximal RCA then - AV node ischemia > heart blockIf Rt. Marginal then – AV node spared, so no rhythm irregularity

True Posterior surface

Distal RCA, PDA, Distal Cx [in case of left dominance]

If Distal RCA or Distal Cx then AV node ischemia > heart blockIf PDA then Mostly AV node is spared – No rhythm irregularity

Anterior wall LAD Bundle branch blocks

Lateral Wall Cx, Lt. marginal or diagonal br of LAD

No rhythm irregularity

Diaphragmatic or Inferior wall infarct

True Posterior wall infarct

Anterior wall infarct

Antero-lateral infract

Coronary Veins (anterior view)

Coronary Veins (posterior view)

Parts of Mediastinum

Green, superior mediastinum;

Purple, anterior mediastinum;

Yellow, middle mediastinum;

Blue, posterior mediastinum.

Purple +Yellow + Blue= Inferior Mediastinum

Superior MediastinumContents

Thymus, a primary lymphoid organ. Great vessels related to the heart and pericardium:

Brachiocephalic veins. Superior part of SVC. Arch of aorta and roots of its major branches:

Brachiocephalic trunk. Left common carotid artery. Left subclavian artery.

Vagus and phrenic nerves. Cardiac plexus of nerves. Left recurrent laryngeal nerve. Trachea. Esophagus. Thoracic duct.

Superior Vena Cava Syndrome

Compression of SVC

Mostly due to malignancy (cancer) Mostly Lung cancer

S/S Dyspnea (difficulty

in breathing) Facial swelling

(swelling of UL/Trunk)

Enlarged neck veins

How many arteries can you label in this arteriogram?

Flow of O2 rich blood [IVC] in Fetus =

Role of Ductus venosus

Flow of CO2 rich blood [SVC] in Fetus

= Role of Ductus artereosus

Patent Ductus Arteriosus

Patent Ductus Arteriosus (What are the two ends connected to?)

Pulmonary Artery Aorta

Normally closes at birth.

In fetal circulation allows blood from SVC>RA>RV>PT to enter Aorta.

In fetal circulation allows blood from SVC>RA>RV>PT to enter Aorta. Hypoxemia keeps this duct open during fetal circulation.

At birth due to restoration of pulmonary circulation O2 content of blood increases and duct closes.

If it does not close at birth, then it will lead to passage of some blood from aorta to pulmonary trunk after birth due to pressure difference between two vessels. This is like a Left to Right shunt seen in ASD and VSD

Some drugs like Indomethacin help close this PDA.

Association with PreMature Birth

Why?

Ligamentum Arteriosum

The remnant of the fetal ductus arteriosus, passes from the root of the left pulmonary artery to the inferior surface of the arch of the aorta.

The left recurrent laryngeal nerve [a branch of Vagus nerve] hooks beneath the arch immediately lateral to the ligamentum arteriosum and then ascends between the trachea and esophagus

Coarctation of the Aorta

Hypertension in children

POSTDUCTAL

Effects of Co-arctation of aorta

• Asymetrical hypertension

• Prestenotic aortic dilatation and regurgitation

• Lt Ventricular Hypertrophy.

Thoracic Aortic Aneurysm aneurysm is a localized or diffuse dilation of an artery

with a diameter at least 50% greater then the normal size of the artery.

abdominal aortic aneurysm are more common than thoracic

Can occur due to connective tissue diseases like Marfan syndrome or Ehler Danlos syndromes OR due to infection like syphilis

symptoms: Mostly asymptomatic or chest pain If compress SVC- SVC syndrome [distended neck veins, red

face, distress, decreased BP etc] If compress Esophagus – Dysphagia = difficulty in swallowing If compress Lt. Recurrent laryngeal nerve – Hoarseness of voice If compress trachea – stridor[=harsh sound of breathing],

wheeze[= sound of laborious or difficult breathing], cough If cause dilatation of aortic valve then – Aortic Regurgitation

murmur

Aortic Dissection tear in the wall of the

aorta that causes blood to flow between the layers of the wall of the aorta and force the layers apart

High degree of mortality

s/s: Sever Tearing Chest Pain which radiates to the back. Syncope or cerebro-vascular stroke, asymmetrical radial pulse etc.

On x ray – widening of aortic arch

Injury to the Recurrent Laryngeal Nerves

The recurrent laryngeal nerves supply all the intrinsic muscles of the larynx, except one.

Consequently, any investigative procedure or disease process in the superior mediastinum may involve these nerves and affect the voice. [=Hoarseness of Voice]

Because the left recurrent laryngeal nerve hooks around the arch of the aorta and ascends between the trachea and the esophagus, it may be involved when there is a bronchial [Lung] cancer esophageal cancer, enlargement of mediastinal lymph nodes, or an aneurysm of the arch of the aorta.

Esophagus has 3 areas of compression or narrowing

Aortic arch

Left main bronchus

Diaphragm T10 (esophageal hiatus)

• These are sites where swallowed foreign bodies may lodge!

Ab N Esophageal Constrictions

Aortic AneurismLeft Atrial Enlagement

Mitral Stenosis

Passing thru’ Diaphragm

T8 – IVCT10- EsophagusT12 - Aorta

Thoracic Duct The thoracic duct conveys most lymph of the body to the venous

system (that from the Both lower limbs, pelvic cavity, abdominal cavity, left side of thorax, left side of head, neck, and left upper limb).

The thoracic duct originates from the Cycterna Chyli in the abdomen and ascends through the aortic hiatus in the diaphragm.

The thoracic duct is usually thin walled and dull white; often, it is beaded because of its numerous valves. It ascends between the thoracic aorta on its left, the azygos vein on its right, the esophagus anteriorly, and the vertebral bodies posteriorly.

At the level of the T4–T6 vertebrae, the thoracic duct crosses to the left, and ascends into the superior mediastinum.

The thoracic duct receives branches from the middle and upper intercostal spaces of both sides through several collecting trunks. It also receives branches from posterior mediastinal structures.

Near its termination, it often receives the jugular, subclavian, and bronchomediastinal lymphatic trunks.

The thoracic duct usually empties into the venous system near the union of the left internal jugular and subclavian veins, the LEFT VENOUS ANGLE or origin of the left brachiocephalic vein.

Right Lymphatic Duct

Receives jugular, subclavian, and bronchomediastinal lymphatic trunks from the right side

drain lymph from right side of thorax, right side of head, neck, and right upper limb

It also drains in Right venous angle

AZYGOUS SYSTEM OF VEINS

The Azygous system, on each side of the vertebral column, drains the back and thoracoabdominal walls as well as the mediastinal viscera.

The azygos system exhibits much variation, not only in its origin but also in its course, tributaries, anastomoses, and termination.

Aygous system veins provide collateral pathway between SVC and IVC, which may open up in case of SVC or IVC obstruction.

Azygous vein arches over the superior aspect of the root of the right lung to join the SVC.

Sympathetic Ganglion

Sympathetic Ganglion

Dorsal root Ganglion

Lateral Horn Spinal Nerve Gray Ramus White Ramus Splanchnic N.Notice the relationship between somatic and autonomic system here…

Please ignore black and green lines at this stage

Autonomic innervation of Heart and Lungs

Innervation of tracheobronchial tree

Sympathetic: Inhibits the

parasympathetic Bronchodilation Decreased

secretion Parasympathetic

Constricts bronchi (conserving energy)

Promotes bronchial secretion

Innervation of the heart Sympathetic

Increases rate and strength of contraction

Inhibits parasympathetic nerves allowing coronary vessels to dilate

Parasympathetic Decreases rate and

strength of contraction (conserving energy)

Constricts coronary vessels in response to reduced demand

Sectional View of Mediastinum and CT scans

http://www.anatomyatlases.org/HumanAnatomy/3Section/Topc.shtml

First look at these sectional images of thorax and then look at the CT scans in subsequent slides.

A

B

C