Thorax Review 2
Transcript of Thorax Review 2
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
Lungs - Surface Anatomy
R6
R4
Lateral View - Rt
R6
R4
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