Thorax Anatomy and Clinical Correlations

• These notes cover key aspects of the thorax, including anatomy and clinical correlations.

Tricuspid Valve Location

• Located on the level of the 5th intercostal space, left sternal border.

Lung Cancer Metastasis

• Right lung cancer is likely to metastasize to the right hilar lymph nodes (same as bronchiopulmonary nodes).
• The metastasis then spreads to the right tracheobronchial and bronchomediastinal lymph nodes.

Thoracic Duct Origin and Course

• The thoracic duct originates at the level of T12-L1 posterior to the aorta within the cisterna chyli.
• Ascends through the aortic opening of the diaphragm.
• Lies along the left margin of the esophagus in the superior mediastinum.
• Crosses from the right to the left side at the fourth thoracic vertebra level.
• Empties into the left subclavian vein.

Thoracic Duct Statements

• The thoracic duct may enter the left subclavian vein.
• It starts in the abdominal cavity as a dilation called the cisterna chyli.
• Drains lymph from the entire head and neck, carrying it centrally to the bloodstream.

Phrenic Nerves

• Irritation of phrenic nerves is a source of hiccups.
• They provide sensory innervation to the pericardium.
• Arise from the cervical plexus.
• Provide motor and sensory innervation to the diaphragm.

Bronchopulmonary Segments

• The superior lobe of the right lung contains three bronchopulmonary segments.
• The superior lobe of the left lung contains four bronchopulmonary segments.
• The inferior lobes of both lungs contain five bronchopulmonary segments each.

Mitral Valve Auscultation

• The mitral valve is heard most distinctly on the left side in the midclavicular line in the 5th intercostal space.

Valve Auscultation Areas

• The pulmonary valve area is on the level of the second left intercostal space.
• Left A-V valve area is located on the level of fifth left intercostal space laterally to the left sternal line

Normal Heart Chambers

• The conus arteriosus (infundibulum) is part of the right ventricle.
• The coronary sinus and crista terminalis are located in the right atrium.

Foreign Body Aspiration

• A foreign body is more likely to fall into the right main bronchus as it's wider, shorter, and more vertical than the left.

Thoracocentesis

• During thoracocentesis, a needle is inserted superior to the rib.
• This helps to avoid the neurovascular bundle.

Splanchnic Nerves

• Splanchnic nerves mainly consist of preganglionic sympathetic fibers.
• Only pelvic splanchnic nerves are parasympathetic.

Ductus Arteriosus

• The ductus arteriosus connects the left pulmonary artery to the arch of the aorta.
• Closure begins soon after birth.
• It's a remnant of the left side branchial arch (6th arch).

Thoracodorsal Nerve Injury

• Injury to the thoracodorsal nerve (C6-C8) during surgery affecting scapular lymph nodes will most likely affect the latissimus dorsi muscle.

Sympathetic Trunk

• The sympathetic trunk in the thorax has 11 paravertebral ganglia on either side.
• It lies on each side of the vertebral column.
• Ganglia T1-T4 contribute to thoracic splanchnic nerves.
• Involved in sympathetic innervations that increase heart rate.

Ductus Venosus

• The ductus venosus diverts over one half of the blood around the liver into the inferior vena cava.
• In the fetal period, this blood is charged with oxygen and nutrients from the placenta.

Diaphragm

• The diaphragm assists the anterior abdominal muscles during defecation and parturition.
• Contains the thoracic duct in the aortic hiatus.
• Assists in inspiration.

Papillary Muscles

• The papillary muscles contract to close the atrioventricular (A-V) valves during ventricular systole.
• They prevent eversion of the valve cusps during contraction.

Structures at the T10 Level

• The esophagus passes through the diaphragm via the esophageal hiatus at the T10 level.
• The superior border of the liver and esophageal hiatus, containing the esophagus and vagal trunks are at this level.

Fetal Circulation

• In the fetal circulation, conductivity is between the aorta and the pulmonary trunk.
• Oxygenated blood flows mainly from placenta(umbilical cord).
• The oval hole is between the atria

Cancer Symptoms

• Peau d'orange characteristic is a symptom of breast cancer.
• It is primarily a result of the blockage of cutaneous lymphatic vessels.
• It can also be due to shortening of the suspensory ligaments by cancer in the axillary tail of the breast.

Pleural Cavity

• Anterior part of the right pleural cavity descends vertically downwards in midline from sternal angle to the level of fifth costal cartilage during percussion
• Lower border extends laterally from 6th costal cartilage and crosses the 8th rib in the midclavicular line

Post CABG Pain

• Post coronary artery bypass graft surgery sharp pain occurs as a result of the movement irritating the parietal pleura.
• The Parietal pleura is innervated by somatic nerves.

Aortic Aneurysm Effects

• An aneurysm in the arch of aorta can affect the left subclavian artery and the left common carotid artery.
• It can compress the left recurrent laryngeal nerve

Esophageal Sympathetic Innervations

• The thoracic part of the esophagus receives splanchnic outflow from T5 contribution to the greater splanchnic nerve.
• Presynaptic neurons emerge from T1-T5 ventral roots

Accessory Hemiazygos Vein

• Drains lower eight to nine left posterior intercostal veins -Enters into the hemiazygos and azygos vein at the level of the 8th intercostal space on the left

Occlusion in Right Coronary Artery

• A significant occlusion in the beginning of the right coronary artery will reduce blood flow to the right (acute) marginal artery.
• It also reduces blood flow to the sinuatrial nodal artery and the atrioventricular nodal artery.

Right Bundle Branch Block

• A right bundle branch block due to ischemia to the AV nodal artery.
• Indicates issue with Moderator band (septomarginal trabecula)

Left Coronary Artery Stenosis

• Symptoms with stenosis in the initial part of the left coronary artery may include myocardial infarction.

Esophagus Supply

• The middle portion is supplied by the esophageal branches of the aorta(thoracic)
• Venous drainage from the middle portion drains to the azygos and hemiazygos vein along with the accessory hemiazygos vein

Asthma Nerve Innervations

• In asthma, the vagus nerve in charge of innervations of bronchial smooth muscle.

Lung Airways Statements

-Hilum is located more anteriorly in the right and left lungs

• Righ main bronchus is wider, shorter and runs more vertically than the left main bronchus
• The pulmonary ligament hangs inferiorly from the pleural sleeve around the lung root

Right Lymphatic Duct

• Receives anterior and posterior mediastinal trunk.

Pectoralis Major

• Is supplied by the pectoral nerves (lateral and medial)

Ascending Aorta

• Begins at the semilunar valves.
• Is a highly muscular artery (ELASTIC).

Thoracic Wall

• Pectoralis minor muscle is a useful surgical landmark. -Serratus anterior muscle is paralyzed when the long thoracic nerve is injured.

Anatomy -Thoracic Wall

• The scapular lines cross the inferior angles of the scapulae, parallel to the posterior median lines.
• The sternal angle is formed at the junction of the manubrium with the body of the sternum. -The posterior median line is a vertical line along the tips of the spinous processes of the vertebrae.

Anatomical Bundle (His bundle)

• Divides into right and left bundle branch.
• Desends behind the septal cusp.

Structures in Posterior Mediastinum

• The esophagus.
• The hemiazygos vein.
• The thoracic duct.

Superior Mediumstinium : borders & contents

• Borders includes below thoracic inlet and above horizontal plane (below T4)
• Contents includes: sternohyoid, thymus gland, brachialcephalic veins, SVC, aortic arch + branch

Vessels of Superior Mediastinum

• the usual branches of the arch of the aorta include the brachiocephalic trunk, left common carotid artery, and the left subclavian artery
• The superior vena cava is located to the right of the trachea
• The ligamentum arteriosum passes from the root of the left pulmonary artery to the inferior surface of the arch of the aorta

Mediumstinium : middle

• In the middle mediastinum is located : left brachiocephalic vein

Ventricular Systolic

• During ventricular systole the following valves is open : pulmonic & aortic valves

Atrial Septal Defect - ASD

• The condition is most likely Due to incomplete closure of Foramen Ovale

Chordae Tendinae Location

• Left Ventricle is the location.

Phrenic

• Course posterior to Hilium(root)
• Provides Sensory innervation to pericardium + motor
• Irritation is a source of hiccups.

Sympathetic trunk

• Passes to abdomen behind the literal accurate ligament
• Sends preganglionic Fibers to the greater splanchnic Nerve
• Sends post Ganglionic to the cardiac Plexus
• Has ganglia most of which live anterior to ahead of rib

Right Pleural Nerve

• Located in superior mediastinum.
• Supplies fibrous Pericardium

Fetal

• Mixing of oxygenated and non- Oxygenated blood occurs in the right atrium.

Right Cornary Artery

• Located superior - Arial Node.

Intercordal Artery

• Right posterior Intercordal Artery gives off right Bronchial Artery.
• Anterior Intercordal Artery arises from the Internal Thoracic Artery.

Pulmonary Trunk

• Lies within the Pericardial Sac.
• Lays posterier to Transverse Sinus.
• Devolped from the Truncus Aortosis.

Right Atrium

• Receives Coronary Sinus.
• Sinu- arial in its wall.
• Cristal Terminalizes seperating the smooth and rough points.

Accurate Liagmenets Diaphgram

• Lateral Accurate Liagement extends from transvesrion Proccess of one vertebra to 12 th Rib.

1st Rib

• Its nack is related to Sympathisic Trunck.

Agzyos Vien

• Recieves the Superior Intercoral Vein And Aches over The Route Of The Right Lung,

trecha

• Containe Hyline Cartalidges
• Biferates @ the level of sternal angel

Intercornal nerves

• Anterior primary rammus of the 12 th Thoracic is the Subcostal nerve.

Veins draining into the Right Boncical

• Veberial

Direct Branches Of thethorcia Aorta

• posterior intercostal arteries
• Superior Phrenis Arteries
• Soome of the Bronchial Atreies.
• Essogegal ARtereis

Aortic opening in the diaphragm

• Trasmine Azygos Vien

Plural Cupula

• Layer is sperated from Thoracic Wall by the endochoratic Fascia..
• Extends above the colvical.

Venous Drainage of the Heart

• Cardiac arteries is Largest Contributor.
• Middle And Small cardiac veins drain areas by the left.

Pulmalary CIrculation

• carriees from the Right ventrical to The lungs
• Pulmalary veins carreies O to left Artium.

Female Breast

• Blood Partially Delievered by branches to ANterior intercostalers.

Blood returned to heart thru :

• cornary Sinu
• Pulmonary Vien
• Agyzos vein
• Inferier Venacaive

Parts In Figure

• Oesphasgea Hyatus2

1 Rib

• Relates to the Sympatjhatic Trunck at the neck.

Deoxygenation

• Pumlonary Artieres

Devolepement

• Pumary Veins

Lungs

• ANterior Venticle Run betwenn anota & righy Article

Vessels

• Right SVvien & Internal Jubular Vine

azygos vein

• Not A Tributary of. SVC
• It Passes Thru medial Fischer Of RIGHT crus of aiptramg,

Bronchioal tree in odeder

• Lobar Bronchos Segemenst - Termianl & Resopaty

##AV bundle of His

• It Divides intro left & right Banches

Accessory

• DIaptmram

Right ventrcle compontents

• Spteal Pillaer MUscle
• Codndy Endiness.

Apex hart positon

V Intervstalr space + mpre to the lfet.

Thorarcicpart of sympathetic Trunk Branches.

• Great and lesser splaninic nerves

Tracheal carina

• Found at the site of trachiel berfuracaiton

Thymus

• Is the sit o T lomphocte Mutation
• Is upploes by Infieririty And THoracic Artes.

DIophram in esphogels hiatus

• Anreiros vagal Truck

Risk areas

• Light artium
• postiers papiilalry Muscles of the right ventricle

Sternocosatal Triangle

• contains superior epigastric artery and vein

Thymus Tuor

• Supperessios Superior vena cava

Fallot

• Memrbnous Septime.

9 year ald wht cough

• N Vague

lung plexus claums

• mantains fibres from Vagus to nerve

SiunsTransversuss preicarda

• LIimisted from back thr SVC

##Lung turmps calions

• Meduim daxte is into Bounsis

###Phrenic

• impaired Innovation IN meduistal pleura and Pericadia

###DURING Arterial Irfac

• Nodus A triovieniclares

###Tetorlaogy Fallot

• MOvning Artertoa to the rignt

###mammary Fascia

• Lactiforios is cponstrs by oxytin

inspiartin muscles

• SCM

Charectirics poitnrs of test

• Angklw of Stenum indacats 2 nd intercistla sprace

Topahray

• Surnicosteral tairngle tcontaus espagric artery and vein

cacer

• axxilly lnodhdes or amit