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116 Cards in this Set
- Front
- Back
The internal aspect of the thoracic wall is covered by the
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endothoracic fascia which separates the internal muscles from the parietal pleura
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The Thoracic Cavity
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-surrounded by the thoracic wall
-contains the thymus, heart, lungs, distal part of the trachea, and most of the esophagus |
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The Thoracic Cage
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an osteoocartilagenous structure
-portects the thoracic organs and some abdominal organs (liver) |
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Bony thorax includes
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-thoracic vertebrae (12) and intervertebral discs
-Ribs (12 prs) and costal cartilages -Sternum -manubrium sterni -body -xiphoid process |
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The bony structures define two distinct apertures in the thoracic cage
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1. Superior Thoracic Aperture (inlet)
2. Inferior Thoracic Aperature (Outlet) |
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Thoracic Inlet
(superior thoracic aperture) Borders |
Borders
-first pair of ribs and cartilages -manubrium sterni (sup border) -First thoracic vertebrae |
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Thoracic Inlet
(superior thoracic aperture) Contents |
-trachea
-esophagus -Vagus (CN X), phrenic nerves (C3,4,5 cervical plexus) -Apex of the lungs |
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Thoracic Outlet
(Inferior thoracic aperture) Borders |
Borders:
-12th thoracic vertebra (T12) -the 12th pair of ribs -Costal margin = c cartilages 7-10 |
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Thoracic cage important landmarks
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1. Xiphoid process = T10 or T11
2. Sternal angle (of louis) = lower border of T4 3. Costal cartilage of 2nd rib which correspondes directly to the manubriosternal joint |
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Angle of Louis
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-angle formed btwn the manubrium and the body of the sternum (manubriosternal joint)
-marks the level of the 2nd costal cartilage for counting intercostal spaces -denotes the level of the A. Aortic Arch B. Bifurcation of trachea (carina) C. T4/T5 intervertebral disc |
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Typical Ribs
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Ribs 3 - 9
*Rib 7 is the longest rib |
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Atypical Ribs
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1, 2, 10, 11, 12
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True Ribs
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Ribs 1-7 articulate directly with the sternum through their costal cartilages
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False Ribs
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Ribs 8, 9, 10 share a common costal cartilage
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Floating Ribs
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Ribs 11-12 do not articulate anteriorly, they end among the muscles of the body wall
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Costal grove
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located on the inferior aspect of the ribs, shelters the intercostal neurovascular bundle (VAN)
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First Rib
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Short and broad
forms part of the thoracic inlet grove for the SUBCLAVIAN vein and artery |
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Bucket Handle/Pump Handle
movements of ribs |
-middle parts of the lower ribs move laterally when they are elevated
(bucket handle movement) -when upper ribs are elevated, the AP diameter of the thorax is increase (pump handle) with greater excursion occurring inferiorly -combo of movements that occur during inspiration increase the AP and transverse diameters of the thoracic cage |
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Muscles of the Thoracic Wall
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-diaphragm
-serratus anterior -serratus posterior sup and inf -pec major and minor -intercostal muscles • External Intercostal • Internal intercostal • Innermost intercostal ---->innermost proper ---->subcostalis ---->sternocostalis |
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External Intercostal Muscle
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-fibers run downward and forward
-external intercostal membrane at the costochondral joint O: lower borders of ribs 1-11 I: Upper borders of ribs 2-12 N:Corresponding Intercostal N A: Elevate the rib cage: Inspiration |
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Internal Intercostal Muscle
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-fibers run down and backward
-internal intercostal membrane near the vertebrae O Lower Borders of Ribs 1-11 I Upper borders of ribs 2-12 N: corresponding intercostal N A: Expiration |
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Innermost Intercostal Muscle
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3 parts
1. Innermost proper btwn ribs 2. Subcostalis: angle 3. Sternocostalis (transversus thoracis) near sternum fibers run down and backward -corresponding intercostal n -expiration |
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Serratus Ant
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O: Ribs 1-8
I: costal surface of scapula, superior and inferior angles and medial border of the scapula N: Long thoracic nerve (C5,6,7) A: Rotates the scapula, abducts the arm, elevates the arm above the horizontal, assists in respiration Damage: -winging of the scapula -loss of elevation of arm -problems with respiration |
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Arteries of the Thoracic Wall
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-Internal thoracic artery (subclavian)
-Highest intercostal artery (costocervical trunk [subclavian]) -posterior intercostal arteries -subcostal arteries |
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Note to the Anterior Intercostal Arteries
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1. Anterior Intercostal arteries to ICS 1-6 come frome the internal thoracic artery
2. Anterior Intercostal arteries to ICS 7,8,9 come from the musculophrenic (internal thoracic) 3. No anterior intercostal arteries in ICS 10-11 |
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Veins of Thoracic Wall
Right Side |
-1st -- highest intercostal vein - braciocephalic vein
-2nd and 3rd = higher intercostal vein - azygos -4th -11th azygos -12 (subcostal veins) - azygos |
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Veins of Thoracic Wall
Left Side |
-1st - highest -brachiocephalic vein
-2,3,4 = accessory hemiazygos vein -5th - 11th + 12 = hemiazygos vein -the accessory hemiazygos and hemiazgyos cross over to the right side independently, or may join as a unit, and ultimately drain in the azygos -the accessory hemiazygos may drain into the brachiocephalic |
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Endothoracic fascia
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-CT layer that functions to prevent the parietal pleura from rubbing against the innermost intercostal muscle.
-This fascia is thickened over the apex of the lungs (Sibson's fascia) |
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Blood Supply of The Lungs
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Arterial:
-Bronchial arteries (thoracic aorta) -Pulmonary arteries Venous Supply: -Bronchial veins drain into the azygos system and into the pulmonary veins Lymphatic drainage: -from the hilum to the pulmonary nodes to the tracheobronchial nodes |
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Nerve Supply of the Lungs
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-Anterior and posterior plexuses of the vagus which cause bronchoconstriction and vasodilations, an increase glandular secretion
- Sensory innervation = vagus Sympathetic trunk = vasomotor innervation from T2-T5. These fibers produce bronchial dilation and vasoconstriction |
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The Trachea Relationships
Structures Anterior to the Trachea |
-sternum
-thymus -arch of the aorta -origins of the brachiocephalic trunk and left common carotid artery |
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The Trachea Relationships
Structures Posterior to the Trachea |
-esophagus
-azygos vein and right vagus, and pleura (on the right) -Aortic arch, LCC, left subclavian artery and left vagus, left phrenic, and pleura (on the left) |
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Blood Supply of the Trachea
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-Superior Thyroid artery (external carotid artery)
-Inferior thyroid artery (thyrocervical trunk [subclavian artery]) -bronchial arteries (thoracic aorta) -Internal thoracic artery (subclavian artery) |
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Nerve Supply of the Trachea
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-Vagus nerve (CN X)
-Sympathetic chain |
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Right Main Bronchus
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-wider, shorter, and more vertical than the left main bronchus
-before entering the hilum of the right lung, it gives off the superior lobar bronchus -on entering the hilum, it divides into a middle and inferior lobar branches |
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Left Main Bronchus
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-narrower, longer, and more horizontal than the right main bronchus
-it passes to the left below the arch of the aorta and in front of the esophagus -on entering the hilum of the left lung it divides into a superior and an inferior lobar branches |
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Blood Supply of the Bronchus
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1.Bronchial arteries - they supply the conductive airway (non-respiratory)
-Two on the left from the thoracic aorta -One on the right from the first posterior intercostal artery 2. Pulmonary arteries to the terminal portion of the bronchioles 3. Venous drainage is via the bronchial veins to the azygos and hemiazygos veins |
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Nerve Supply to the Bronchi
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-Vagus nerve (parasympathetic)
***activation leads to broncho constriction and mucus secretion -Sympathetic chain ***activation leads to bronchodilation |
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Superior Mediastinum
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-extends inferiorly from the superior thoracic aperture to the horizontal plane passing through the angel of Louis and the inferior border of T4
-located posterior to the manubrium -anterior to the first 4 thoracic vertebrae |
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Contents of the Supeior Mediastinum
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1. Aortic Arch
-brachiocephalic trunk: *RCC *Right Subclavain artery -LCC -Left subclavian artery 2. Brachiocephalic veins = subclavian + internal jugular 3. SVC = R + L brachiocephalic veins 4. Thymus gland 5. Esophagus 6. Trachea 7. Thoracic duct |
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Anterior Mediastinum of the Inferior Mediastinum
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-extends from the posterior surface of the sternum to the anterior surface of the pericardial sac
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Middle Mediastinum of the Inferior Mediastinum
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Heart
Pericardium Main bronchus Great vessels and phrenic nerves |
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Anterior Mediastinum of the Inferior Mediastinum
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-located posterior to the pericardial sac and diaphragm, and anterior to the bodies of the inferior eight thoracic vertebrae (T5-T12)
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Phrenic Nerve
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-C3, C4, C5
-accompanied by the pericardiophrenic artery -Right and left phrenic arteries |
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Right Phrenic Nerve
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-Right of SVC and RA
-Anterior to the root of right lung -Between the parietal pleura and fibrous pericardium |
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Left Phrenic Nerve
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-between the left subclavian and LCC arteries
-lateral to vagus and aortic arch -anterior to the root of the left lung |
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Pericardium
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-a double-walled fibroserous sac that encloses the heart and the roots of its great vessels
-located in the middle mediastinum -posterior to the body of the sternum and second to sixth costal cartilages -anterior to the T5 to T8 vertebrae |
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Pericardium Layers
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-attached to the sternum by the sternopericardial ligament, and to the diaphragm by the central tendon
1. Fibrous Pericardium--> tough external layer of fibrous tissue 2. Serous Pericardium--> internal double layered sac -Parietal pericardium -Visceral pericardium |
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Parietal Pericardium
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-fused to the internal surface of the fibrous pericardium
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Visceral Pericardium
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-reflected onto the heart where it forms the epicardium
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Pericardial cavity
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=the potential space between the parietal and visceral pericardial layers
*virtual space |
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Layers of Penetration of Pericardium/Heart
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-Pericardium
Fibrous Pericardium -Serous sac -Parietal layer -Pericardial cavity -Visceral layer (epicardium) Heart -Epicardium -Myocardium -Endocardium |
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Pericardial Sinus
Transverse Sinus |
-recesses that develop during embyronic folding of the pericardial sac
-located behind the aorta and pulmonary trunk, and in front of the left atrium and superior vena cava -important surgically during bypass procedures -a digit and a ligature can be passed through the transverse sinus btwn the great arteries and pulmonary trunk |
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Pericardial Sinus
Oblique Sinus |
-between the pulmonary trunk and inferior vena cava
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Pericardium Nerve Supply
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-parietal fibrous pericardium is supplied by the phrenic nerve (C3,4,5)
[located btwn the parietal pleura and fibrous pericardium] -also the vagus nerve -visceral layer is supplied by the coronary plexus |
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Blood Supply of the Pericardium
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-Pericardiophrenic artery ( internal thoracic)
-musculophrenic artery (internal thoracic) -Pericardial branches from the bronchial, esophageal and superior phrenic arteries (thoracic aorta) -visceral pericardium is supplied by the coronary arteries (ascending aorta) |
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Pericardiocentisis
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-large bore needle at left sternal margin ICS 4 (ICS 5 or 6)
-paraxiphoid approach, avoid internal thoracic artery |
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The Heart: Important Info
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-located in the middle mediastinum, oriented obliquely and deviated 2/3 to the left and 1/3 to the right of the median plane
-Apex of the heart is inferolateral (7-9 cm from the median plane and just medial to the midclavicular line) at IC 4 and IC5 space *pg 55 of notes corresponds to costal cartilage 6 -posteriorly it extends from T5-T8 (supine) and T6-T9 (erect) |
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Coronary grove or sulcus
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-encircles most of the superior part of the heart and separates the atria from the ventricles
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Division of ventricles
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-indicated on the surface by the anterior and posterior interventricular groves
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Arterial Blood Supply of the Heart
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-Right coronary
-left coronary -branches from these arteries anastomose at several areas -Nodal anastomoses -about the conus arteriosum -circumflex -anterior interventricular septum -posterior interventricular septum |
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Right coronary
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-ascending aorta
-right atrial branch (gives off the SA branch-nodal) -coronal branch -right marginal branch (with the small cardiac vein) -posterior intervetricular artery (clinically posterior artery descending) PAD *accompanies the middle cardiac v |
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Left Coronary
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-circumflex (gives off the left marginal artery)
-anterior interventricular artery (clinically, left anterior descending-LAD) -during its course, one or two diagonal branches may arise and descend diagonally across the anterior surface of the LV, it accompanies the great cardiac vein |
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Venous drainage of the heart
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-all the veins of the heart drain into the coronary sinus EXCEPT the anteior cardiac veins which drain directly into the Right Atrium
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Venous Blood Drainage of the Heart
Anterior Surface |
1. Anterior Cardiac veins: RA
2. Small cardiac vein: -drains the RV -accompanies the marginal artery -drains into the coronary sinus 3. Great Cardiac Vein -accompanies the LAD -tributary of the coronary sinus |
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Venous Blood Drainage of the Heart
Posterior Surface |
1. Middle cardiac vein
-travels with the left posterior interventicular ascending artery, drains into the Coronary Sinus 2. Oblique vein -coronary sinus 3. Coronary sinus -lies in the posterior atrioventricular sulcus -drains the right atrium |
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Tributaries of the Coronary Sinus
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-Great Cardiac vein
-Small cardiac vein -Middle cardiac vein -oblique cardiac vein |
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Ligamentum Arteriosum
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-it is a vestigial duct that communicates the aortic arch with pulmonary trunk or left pulmonary artery
-it obliterates after birth -located at angle of Louis -extends from the aortic arch to the pulmonary trunk or left pulmonary A -left recurrent laryngeal nerve hooks under the ligament at the angle of Louis -right recurrent laryngeal nerve passes under the right subclavian artery |
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Right Atrium
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-fossa ovalis
-limubus of the fossa ovalis -crista terminalis: free smooth edge of the pectinate muscle -opening of tricuspid valve -opening of coronary sinus (Thebesian valve) -opening of SVC/IVC -opening of the anterior cardiac veins |
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Right Ventricle
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-Tricuspid vlave
-Pulmonary trunk -Papillary muscles -Moderator band or septomarginal trabecula -Chordae Tendineae -prevent backflow of the blood into atrium -prevent eversion of valves during ventricular contraction -attach from the papillary muscles to the cusps of the tricupsid valve |
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Left Ventricle
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-bicuspid valve
-opening of the ascending aorta ***the trabeculate carneae is all the structures in the ventricles except the cusps, papillary muscles, chortae tendineae, and septomarginal trabecula |
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Left Atrium
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-pectinate muscle
-opening of the pulmonary veins -opening of the bicuspid valve |
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Auricles
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-right and left
-ear-like appendages which function like a "storage" are for blood absorbing excess hydraulic volume |
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Pulmonary Trunk
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-it leaves the RV
-it crosses the root of the ascending aorta to continue upward to the left of the aorta -it divides inot a left and right pulmonary arteries at the sternal angle of Louis *the beginning of the left pulmonary artery is attached to the aortic arch by ligamentum arteriosis |
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Ascending Aorta
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-begins behind the right auricle and pulmonary trunk
-two branches 1. Right coronary artery 2. Left coronary artery -Aortic valve is similar to the pulmonary valve except for the presence of the openings for the coronary arteries behind the two coronary cusps |
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Tricuspid Valve
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-3 cusps
Anterior, posterior, septal -on right between RA and RV -behind the right 1/2 of the sternum opposite ICS 4 -attached to the papillary muscles by the chordae tendinae |
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Mitral valve
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-anterior and posterior cusps
-on the left between LA and LV -behind the left 1/2 of sternum opp costal cartilage 4 -attached to the papillary muscles by the chordae tendinae |
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Aortic Semilunar Valve
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-ascending aorta
-nodules, lunula, fibrous ring -Left 1/2 of sternum opp ICS 3 |
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Pulmonary Semilunar valve
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-pulmonary trunk
nodules, lunula, fibrous ring -behind the medial end of the 3rd left costal cartilage |
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The Sinoatrial Node SA
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-collection of specialized cardiac muscle fibers (nodal tissue) located in the wall of the right atrium which initiate the impulses for contraction
-natural pacemaker (60-100/min) -located superior to the crista terminalis at the junction of the anteromedial aspect of the SVC and the right auricle -subepicardial -supplied by a branch of the right coronary artery |
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The Atrioventicular Node (AV)
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-it is a smaller collection of nodal tissue located in the interatrial septum on the ventricular side of the orifice of the coronary sinus
-beats 40-60 times/min -the AV node is submyocardial, it is supplied by a branch of the right coronary artery |
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AV Bundle of His
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-extends from the A-V node into the septal wall of the RA to the upper membranous part of the ventricular septum where it divides inot a right and left branches
-right branch goes to the RV by passing through the septomarginal band -left branch ends in the LV -allows ventricular contraction to proced from the apex to the base of teh heart for efficient ejection -supplied by the LAD |
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Innervation of the heart
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1. supplied by the ANS from the vagus (parasympathetic)
-slows HR and reduces the force of contraction, causes constriction of coronary arteries 2. The sympathetic trunk (T1-T5) -increases HR and force of contraction causing dilation of the coronary arteries -->more O2 and nutrients to the myocardium |
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Cardiac plexus
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-formed by branches from both the vagus and sympathetic trunks
-lies anterior to the bifurcation of the trachea -posterior to the aortic arch -superior to the bifurcation of the pulmonary trunk |
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Contents of the Posterior Mediastinum
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-Thoracic aorta
-Esophagus -Azygos venous system -Thoracic duct -Vagus Nerves -Splanchnic nerves *located posterior to the pericardial sac and diaphragm, and anterior to the bodies of the ineferior eight thoracic vertebrae (T5-T12) |
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Thoracic Aorta
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-extends from the arch of the aorta to T 12
-enters the aortic opening of the diaphragm (with the azygos, thoracic duct, and greater splanic nerve) and turns into the abdominal aorta -starts left to the vertebral column, descending anterior to it behind the esophagus Parietal branches and visceral branches |
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Parietal branches of the thoracic aorta
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-Posterior intercostal arteries 2-11
-Subcostal artery -superior phrenic artery |
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Visceral branches of the thoracic aorta
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-Bronchial arteries
-Pericardial artery -Mediastinal artery -Esophageal artery |
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Esophagus
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-extends from C6 - T10, from the lower end of the pharynx to the cardiac opening (region) of the stomach
-lies behind the trachea and left atrium -deviates to the left -posterior to the left main bronchus and it enters the diaphragm at T10 with the vagus and esophageal branch of the left gastric |
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Blood Supply of the Esophagus
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-inferior thyroid artery
-bronchial arteries -esophageal arteries -phrenic arteries -esophageal branch of the left gastric artery |
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Venous drainage of the Esophagus
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-into adjacent veins (azygus)
-Anastomoses exist between the esophageal veins and the left gastric veins. Important link between the portal and systemic circulation |
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Nerve Supply of the Esophagus
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-Vagus (esophageal plexus)
-Anterior branch - left vagus nerve -Posterior branch -right vagus nerve -Sympathetic fibers -Pain fibers (sympathetic) |
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Thoracic Duct
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-extends from the upper abdomen to the neck
-begins at L2 as the cisterna chyli -passes through the diaphragm in the aortic opening at T12 -ascends right of the aorta between the azygos and the thoracic aorta -at T5 or T6 it corsses over to the left behind the esophagus -behind the subclavian artery forms an arch which enters the left internal jugular vein or the left jugular and left subclavian vein |
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Right Lymphatic Duct
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Drains the:
1. Right upper extremity 2. Right Thoracic cavity 3. Right side of head and neck -enters the right internal jugular vein |
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Right Vagus Nerve
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-enters the diaphragm at T10
-Posterolateral to the brachiocephalic trunk -lateral to the trachea -posterior to root of the right lung -medial to right phrenic |
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Left Vagus Nerve
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-enters the diaphragm at T10
-between the LCC and left subclavian arteries -crosses the left side of the aortic arch -posterior to the root of the lung (pulmonary and esophageal plexuses) ***It is crossed by the left phrenic below the aortic arch (phrenic becomes medial and vagus becomes lateral) |
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Splanchnic Nerves
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-preganglionic sympathetic nerve fibers which originate in the thorax and pierce the diaphragm to terminate in the collateral ganglia in the abdomen
-postganglionic nerve fibers from these collateral ganglia distribute to much of the abdominal viscera |
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Greater Splanchnic Nerve
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-T5-T9
-enter the abdomen through the aortic opening -synapses in the celiac ganglion |
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Lesser Splanchnic nerve
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-T10- T11
-synapses in the superior mesenteric ganglion |
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Lowest Splanchnic Nerve
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- T12
-synapses in teh aortorenal ganglion |
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Sympathetic Trunk and Ganglia
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-nerve "strands alongside of the vertebral column
-ganglia are flat expansions along the course of the chain Three Parts 1. Ganglia 2. Trunk 3. Chain |
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ANS
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-classically described as the visceral motor system
-consists of fibers that innervate involuntary (smooth) muscle -modified cardiac muscle (the intrinsic stimulating and conducting tissue of the heart) -glands --------------------------------------------------- -visceral efferent fibers of the ANS are accompanied by visceral afferent fibers, play an important role in the regulation of visceral function as they conduct visceral pain impulses |
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Conduction of impulses from the CNS to the effector tissues or organs involves a series of 2 neurons in both systems
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1. The cell body of the 1st presynaptic, or preganglionic neuron is located in the gray matter of the CNS
2. Its axon synapses only on the cell bodies of postsynaptic, or postganglionic neurons, the 2nd neurons in the series -the cell bodies of the 2nd neurons are located in the autonomic ganglia outside the CNS with fibers terminating on the effector organ |
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Distinctions between the Sympathetic (thoracolumbar) and Parasympathetic (craniosacral) divisions of the ANS
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anatomical distinction:
based primarily on the location of the presynaptic neurons functional distinction: norepinephrine as a transmitter by the sympathetic division and acetylcholine by the parasympathetic division |
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ANS involves two neurons between the CNS and effector
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Neuron #1 is presynaptic
Neuron #2 is postsynaptic -since synapses occur in the ANS ganglia, neuron #1 is preganglionic and #2 is post ganglionic #1 is myelinated #2 is unmyleinated #1 always produces ACh as its NT, and #2 usually produces ACh or NE |
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Subdivisions of the ANS
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-Sympathetic:
neuron #1 is short relative to neuron #2 Parasympathetic neuron # 1 is long and #2 is short -actions are usually antagonistic to each other Sympathetic -fight or flight Parasympathetic -rest and digest |
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Cell bodies of the preganglionic neurons of the sympathetic division of ANS are located in
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-intermediolateral cell columns (IML) of the spinal cord
-part of the gray matter extending between T1 and L2 or L3 -also referred to as lateral horns |
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Paravertebral Ganglia
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-linked to form the right and left sympathetic chains or trunks on each side of the vertebral column extending its length
-superior cervical ganglion (paravertebral) lies at the base of the skull -ganglion impar forms inferiorly where the two (right and left) trunks unite at the level of the coccyx |
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Prevertebral Ganglia
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-located at the level of the plexuses that surround the origins of the main branches of the abdominal aorta
-Celiac ganglia-associated with the celiac trunk -Superior mesenteric ganglion - associated with the superior mesenteric artery Inferior mesenteric ganglion - associated with the inferior mesenteric artery |
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Within the sympathetic trunks, preganglionic fibers follow one of three possible paths
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1. Enter and synapse immediately with a postsynaptic neuron of the paravertebral ganglion at the same level
2. Ascend or descend in the sympathetic chain to synapse with a post synaptic neuron of a higher or lower paravertebral ganglion 3. Pass through the sympathetic trunk without synapsing, continuing on to an abdominopelvic splanchnic nerve to reach the prevertebral ganglion |
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Major effect produced by preganglionic fibers innervating the adrenal medullae
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-release of epinephrine and norepinephrine into the general circulation
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Major effects prodcued by sympathetic postganglionic fibers in spinal nerves
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-constriction of cutaneous blood vessels, reduction in circulation to the skin and to most other organs in the body wall
-accleration of blood flow to sk. muscles and brain -stimulation of energy production and use by sk. muscles -release stored lips from subcut adipose tissue -stim of secretion by sweat glands -stimulation of the arrector pili -dilation of pupils and focusing for distant objects |
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Major effects produced by postganglionic fibers entering the thoracic cavity in sympathetic nerves
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-acceleration of heart rate and increasing the strength of cardiac contractions
-dilation of respiratory passageways |
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Sympathetic Nervous System Summary pg 91
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-Neuron #1 (preganglionic) is short, #2 postganglionic is long
-synapses occurs in paravetebral chain ganglia or prevertebral collateral ganglia -#1 releases ACh, #2 usually NE -prepares for emergency action, excitatory to many organs, in hib to others (digestive) |
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Cranial parasympathetic outflow
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-in the gray matter of the brainstem
-fibers exit the CNS within cranial nerves III, VII, IX, and X |
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Sacral Parasympathetic outflow
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- in the gray matter of the sacral segments of the spinal cord (S2-S4)
-fibers exit the CNS through the vetnral roots of spinal nerves S2-S4 and the pelvic splanchnic nerves that arise from their ventral rami |