Thorax, Pericardium & Heart PDF

Thorax & Ribs CHRISTI WILLIAMS, PT, DPT, OCS, CERT. MDT This Photo by Unknown Author is licensed under CC BY-ND The Thorax –...

Thorax & Ribs CHRISTI WILLIAMS, PT, DPT, OCS, CERT. MDT This Photo by Unknown Author is licensed under CC BY-ND The Thorax – Big Picture  Region between the neck and the abdomen  Functions:  Protects thoracic organs  Provides attachment for:  UE  Intercostal muscles  Diaphragm  Abdominals  Forms rigid yet moveable walls The Thorax – Big Picture  Surface anatomy  Lines  Levels - segmented  Skeleton  Ribs – 12  Thoracic vertebrae - 12  Sternum  Apertures  Superior (thoracic outlet)  Inferior The Thorax – Big Picture  Muscles:  Intercostals (external, internal, and innermost)  Subcostal  Transversus thoracis  Neurovascular bundles  VAN  Diaphragm  Surface anatomy Sternal Clavicles angle (2nd costal cartilage and T4/T5) Suprasternal notch (T2) Xiphoid Process (T10) Xiphisternal Costal junction (T9) margin Clemente, 5th ed., Figs. 101.2 & 104.1  Surface anatomy Axillary lines: Anterior Mid- Posterior Clinically-Oriented Anatomy, 5th ed., Fig. SA1.3  Bony Framework of the Thorax Sternum 12 ribs Manubrium Body Xiphoid Process Costal cartilages Thoracic vertebrae Grant’s Atlas, 11th ed., Fig. 1.9  True Ribs, False Ribs, Floating Ribs  True ribs: Ribs 1-7 ⚫ articulate via costal cartilages with the sternum  False ribs: Ribs 8-10 ⚫ articulate via costal arches  Floating ribs: Ribs 11- 12 Plate 179, N4:185  Thoracic Apertures Superior Aperture Inlet – Manubrium, Rib 1 and costal cartilage T1 vertebrae Outlet – T12 vertebrae Inferior Ribs 11 and 12 Aperture Clinically-Oriented Anatomy, 5th ed., Fig. 1.7  Superior Aperture Passageway for: Esophagus Trachea Great vessels & nerves of head/neck Vessels of upper limbs Apex of the lung Grant’s Atlas, 11th ed., Fig. 1.22  Inferior Aperture The diaphragm is Diaphragm pushed upwards to approximately the Innervation = lower end of the phrenic N sternum. (C3, C4,C5) Costal Margin Inferior Aperture Clinically-Oriented Anatomy, 5th ed., Fig. 1.7  Muscles of the Thoracic Wall Intercostal Muscles  External Intercostals  Internal Intercostals  Innermost Intercostals  essentially the deep part of the internal intercostal Innervated by the corresponding intercostal nerves  External Intercostal Muscles Fibers run inferior & anterior “Hands in pockets” Span from back of rib (tubercles to the front at the costochondral junctions) Fibers replaced anteriorly by external intercostal membranes Elevate the ribs during forced inspiration Continuous with the external oblique muscles  Internal Intercostal Muscles Fibers run inferior & posterior “Hands on chest” (uncrossed!) From sternum on the front to rib angles posteriorly Fibers replaced posteriorly by internal intercostal membranes Most active during Continuous with the expiration internal oblique muscles INTERCOSTAL SPACES  Muscles  VAN  External intercostal  Internal intercostal  Vein  Innermost intercostal  Artery  Nerve  Neurovascular bundle  Intercostal vein  Intercostal artery  Intercostal nerve Intercostal Nerve (Anterior ramus) Medial br Lateral br External Intercostal m Internal Intercostal m Anterior cutaneous branch of intercostal n Innermost Anterior br intercostal m Lateral cutaneous branch of intercostal n Anterior ramus Posterior br (intercostal n) Plate 171, Netter’s Posterior ramus  Segmented C4 C5  Clavicle – C4  Nipples (male – T4) T4 (females – T5)  Umbilicus – T10 T10  Inguinal region – L1 L1  When you think of Sympathetic Nervous System, think….. *with a couple exceptions Cardiopulmonary & Fight or Flight Abdominopelvic Splanchnics Think of all that needs to How sympathetic fibers get to internal happen to fight or flee & structures/viscera (heart, lungs, organs, etc. you will remember the effects the SNS has on various systems It goes everywhere Sympathetic Innervates internal structures Nervous System Spinal cord: T1-L1/2 AND goes to body wall, This is where the cell bodies extremities, head are located for the first neuron Short pre-synaptic / long post-synaptic neuron Sympathetic chain ganglia The sympathetic chain is Located on each side of the vertebral column located very close to the spinal cord, so the first leg of Spans entire length of vertebral column the trip is short This is where the cell bodies are located for the second neuron*  Where is it? Can we see it in lab?? Yes! Like beads on a string on each side of the spine The beads are the Paravertebral Ganglia Interganglionic Connections Paravertebral Ganglia Para = alongside Vertebral = vertebral column Plate #229  Cervical ganglia: Where is the SNS? Superior Middle Paravertebral Ganglia Inferior  Paravertebral (alongside vertebral column) ganglia Thoracic ganglia  Right and left sympathetic trunks (chains)  Runs from base of cranium (superior cervical ganglion) to coccyx (ganglion impar)  Cervical, thoracic, lumbar, and sacral ganglia Lumbar ganglia  Cervical ganglia  Superior  Middle Sacral ganglia  Inferior  Sympathetic Neurons Presynaptic Cell Bodies This “system” originates in Intermediolateral Cell Columns (IML) the spinal cord Specifically, in the spinal cord segments of T1-L2/3 More specifically, in the lateral horns of gray matter of spinal cord IML = intermediolateral cell column T-1 to L2(3)  Sympathetic Neurons Presynaptic Neuron Presynaptic Axon Remember, it’s a 2-neuron Anterior Presynaptic system Ramus Cell Body in IML Cell bodies of the first neuron Anterior are located in the IML of the (Ventral) Root spinal cord The presynaptic neuron is Mixed Spinal Nerve SHORT Because it only has to travel to the sympathetic chain ganglia, Autonomic located on each side of the (Sympathetic) Ganglion vertebral column *All preganglionic neurons follow the same course from Length of Presynaptic Neuron: Short IML to ganglion  Sympathetic Neurons - Postganglionic Posterior Ramus 2. Postsynaptic/ Postganglionic Neurons Length of Postsynaptic Neurons: Long Locations: Body wall Autonomic (Sympathetic) Limbs Ganglion Postsynaptic Cell Body Functions: Vasomotion Anterior Ramus Sudomotion Pilomotion *Postganglionic neurons enter all branches of all spinal nerves  Anterior Rami of Thoracic Spinal Nerves (Intercostal Nerves) Right & Left Gray & White Sympathetic Rami Communicans Trunks  How does it get to the body wall of the Trunk?  Preganglionic neurons begins in IML of spinal cord (T1-L2/3) C-8  Travel to sympathetic ganglia at the T-1 same level  Synapse on postganglionic neurons in sympathetic ganglia at same level  Travel to trunk through anterior rami in intercostal nerves  (Can also travel to the back through posterior rami) Synapse at level of entry Pericardium and the Heart CHRISTI WILLIAMS, PT, DPT, OCS, CERT. MDT  “Big Picture Items”  Heart  Oxygen poor blood  venous system into the heart  4 chambers  pulmonary arteries  2 atria  2 ventricles  Oxygen rich blood  Venous input  pulmonary veins  SVC  aortic blood (and coronary vessels)  IVC  Coronary sinus (venous blood from the heart)  “Big Picture Items - con’t”  Coronary arteries  Valves of the heart - needed to keep blood flowing in one  Right direction  SA nodal branch  Tricuspid valve  Right marginal branch  Pulmonary  AV nodal branch  Mitral valve (bicuspid valve)  * Posterior interventricular branch  Aortic valve  Left  Ant IV (LAD)  Circumflex “Big Picture Items - con’t”  Fibrous skeleton of the  Innervation: heart  Vagus - parasympathetic  support (slows the heart)  electrical insulation  Sympathetic - speeds up the heart  SA Node  Phrenic (C3, 4, 5) -  AV Node embedded in the fibrous pericardium – sensory to the pericardium  Mediastinum – Standing in the middle The central compartment of the thoracic cavity Fig 1.37b - Moore and Dalley  The Pericardium  Pericardium: sac that encloses:  Heart  Roots of the great vessels  Itis comprised of 2 layers  Fibrous pericardium  Serous pericardium  The Pericardium  Function:  Keeps heart in position & protects it  Facilitates movements  Separates it from the lungs & other structures in the mediastinum  Is fused with the central tendon of the diaphragm  This containment makes it possible to perform open heart surgery without entering and accidentally introducing air into the pleural cavities  Fibrous Pericardium & Serous Pericardium Parietal layer of  Fibrous Pericardium Visceral layer of serous pericardium  Tough, outer layer serous pericardium  Serous Pericardium  Inner layer – also comprised of 2 layers  Parietal layer – lines the inside of the pericardium. Contains serous secreting mesothelial cells  Visceral layer – lines the surface of the heart  Pericardial cavity  Potential space between parietal layer & visceral layer of serous pericardium  Contains a thin layer of fluid which Fibrous allows for frictionless movement Pericardial pericardium cavity  Clinical Correlations - Pericardium  Pericarditis  Inflammation of the pericardium  Causes chest pain  Makes serous pericardium surfaces rough & causes a friction rub  If the pericardial cavity fills with fluid (pericardial effusion) it compresses the heart because the pericardial sac does not stretch, it is non-elastic  As the heart is compressed, it cannot fully expand & results in reduced cardiac output, causing it beat faster (tachycardia)  This leads to a condition called cardiac tamponade which is very serious  Pericardiocentesis will need to be performed  Needle inserted into pericardial cavity to aspirate the fluid PT – Dating Pick Up Lines Are you a pericardial effusion?  Heart & Great Vessels https://theanaestheticroom.com/cardiothoracic-anaesthesia/  4 Chambers of the Heart Left Atrium Right Atrium Right Ventricle Left Ventricle 4 Chambers continued  Poorly oxygenated blood  Right atria  Right ventricle  Oxygenated blood  Left atria  Left ventricle Great Vessels  Deoxygenated blood returns to the heart via the  Superior vena cava  Venous blood from upper body  Inferior vena cava  Venous blood from lower body Great Vessels  Deoxygenated blood from SVC & IVC enters the Right atrium  Right ventricle  To the lungs via the pulmonary trunk Great Vessels  Deoxygenated blood from the pulmonary trunk travels to the lungs via the right & left Pulmonary Arteries Great Vessels  Blood is oxygenated in the lungs and returns to the heart via the Right & Left Pulmonary Veins Great Vessels  Oxygenated blood enters the Left Atrium  Left Ventricle  To the body via the Aorta  Heart and the Great Vessels in situ Aorta SVC Pulmonary Trunk Where are the pulmonary arteries, pulmonary veins & IVC?? Heart and the Great Vessels - con’t Can you identify the openings?  Heart and the Great Vessels - con’t Aorta Superior R&L Vena Cava Pulmonary Arteries Pulmonary Pulmonary Veins Trunk Inferior Vena Cava  Heart and the Great Vessels - Veins R. Internal L. Internal Jugular Vein Jugular vein R. Subclavian L. Subclavian vein vein R&L Brachiocephalic Vein (to SVC)  RIGHT R & L Common Carotid artery Brachiocephalic trunk (not present on left) R. Subclavian L. Subclavian artery artery Aorta Heart and the Great Vessels – Arteries  Branches from Aorta COA 9th ed. Fig. 4.67 PT – Dating Pick Up Lines Are you a positive L3 myotome? Valves of the Heart Atrioventricular Valves (AV Worn by Bishops Valves)  AV valves are located between the atrium & ventricle  Mitral Valve (bicuspid valve)  Between left atrium and ventricle  2 – leaflets  2 papillary muscles with chordae tendinae  Anterior & Posterior  Tricuspid Valve  Between the right atrium and ventricle  3 - leaflets  3 papillary muscles with chordae tendinae  Anterior, Posterior & Septal What is the function of the Chordae Tendineae? Prevent backflow of blood https://www.youtube.com/watch?v=6f0n9zJWp_8  Semilunar valves (cusps)  The semilunar valves  Aortic valve  Pulmonary valve  Each have 3 cusps  Concave when viewed from above  Do not have chordae tendinae due to less force exerted on them during diastole  Prevent backflow  Bicuspid (Mitral) Valve (from left atrium to left ventricle) Papillary Muscles in Tricuspid Valve left ventricle (from right atrium to right ventricle) Chordae Tendineae Chambers of the Heart  4 Chambers – Right Atrium  Right, superior chamber of the heart  Noteworthy features  Right auricle - increases capacity of the atria  Pectinate muscles - rough  Right AV orifice - guarded by the tricuspid valve (3 flaps)  Oval fossa - remnant of the oval foramen  4 Chambers – Right Ventricle  Forms the largest part of the anterior surface of the heart  Interior of the ventricle  Trabeculae carneae - region of inflow of blood (thru tricuspid valve)  Chordae tendineae - attach from cusps to :  Ant papillary muscle  Post papillary muscle  Septal papillary muscle  4 Chambers – Right Ventricle (cont)  Other landmarks:  Inteventricular septum  Moderator band - part of the conducting system of the heart  carries the right AV bundle branch to APM  Pulmonary valve (ant, R & L) - concave superiorly Moderator Band  4 Chambers – Left Atrium  This forms most of the base of Oval fossa the heart  Entering blood - valveless  Right pulmonary veins - superior & inferior  Left pulmonary veins - superior & inferior  Left auricle  Oval fossa  Smooth walled portion and pectinate muscle portion  4 Chambers – Left Ventricle  This chamber forms the apex Oval fossa of the heart  Double-leaf mitral valve  Anterior papillary muscle  Posterior papillary muscle  Both larger than in R ventricle  Walls twice as thick as the right ventricle  Walls mostly covered with trabeculae carnae  4 Chambers – Left Ventricle (cont)  Aortic valve  Aortic valve is the passageway to the  Ascending aorta  Right coronary artery  Left coronary artery PT – Dating Pick Up Lines Do you know what muscle is responsible for rotation of my neck? Borders of the Heart & Positioning  Borders of the Heart & Surfaces  Located more on the left side (2/3rds to the left)  Apex - directed anteriorly and to the left  Base - opposite the apex  Region of pulmonary veins, and SVC & IVC  Surfaces of the heart (3)  Anterior - mainly R ventricle  Diaphragmatic - mainly L ventricle, some R ventricle  Pulmonary (left) - L ventricle  Borders of the heart (4)  Right, left, inferior, superior COA 9th ed. Fig. 4.52 COA 9th ed. Fig. 4.52 Vasculature of the Heart  Vasculature of the Heart – Coronary Arteries Left  Blood vessels normally coronary course across the artery epicardium (in some fat)  Arterial supply - from ascending aorta  Right coronary artery  Left coronary artery  Right Coronary Artery SA nodal branch  Right coronary artery  SA nodal branch  Continues as R coronary artery  Gives off right marginal branch  Usually gives off the posterior interventricular branch Posterior interventricular Right marginal branch branch  Left Coronary Artery Circumflex  Left coronary artery branch  Divides  Anterior interventricular branch (LAD)  Largest artery supplying the heart muscle (50% of the heart’s blood supply)  Known as the “Widowmaker”  Circumflex branch  gives off the left marginal artery LAD  Venous Drainage of the Heart  Venous drainage of the heart Great cardiac  Drained mainly by vein veins that empty into the coronary sinus  Main contributions Cardiac from the anterior sinus and posterior interventricular veins & great cardiac vein  Vasculature of the Heart Right SA nodal branch L Coronary Artery Great Cardiac Vein Coronary Sinus L Circumflex artery R. Coronary Artery Right Marginal Left Anterior Branch Descending Posterior Descending PT – Dating Pick Up Lines Are you a coronary artery? Conducting System of the Heart  Conducting System of the Heart  SA Node: at the junction of the SVC and the right atrium  PACEMAKER of the heart  Normal rhythm = 70 bpm  Spreads through the musculature of both atria  Cardiac plexus - both SNS and PNS supply  Signal spreads to AV Node COA 9th ed. Fig. 4.62  Conducting System of the Heart (con’t)  AV Node: located in the interatrial septum near the coronary sinus  AV node activated from SA node signal  Propagates that signal through the AV bundle of His  Divides into right and left bundles, that go to each ventricle  Moderator band in right ventricle to anterior papillary muscle COA 9th ed. Fig. 4.62 Innervation of the Heart Fight or Flight - Heart Sympathetic Innervation  How does it get to the Thoracic Viscera?  Preganglionic neurons begin in IML of spinal cord  Travel to sympathetic ganglia (at same level or by ascending or descending in sympathetic chain)  Synapse on postganglionic neurons in sympathetic ganglia  Leave the ganglia in a different direction (medially) because these nerves are not going to the body wall, they are going to viscera (i.e. the heart/lungs, etc.) that is centrally located  Therefore, they do NOT go in anterior and posterior rami of our spinal nerves Not  Instead, they travel through Exit medially laterally cardiopulmonary splanchnic nerves Cardiopulmonary splanchnic nerve Sympathetic Innervation of Thoracic Viscera Cardiopulmonary Splanchnic Nerves Exit the ganglia medially to get to the central structures rather than laterally to travel to body wall  Review: Sympathetic Innervation of Body Wall & Limbs and Thoracic Viscera To Body Wall & Limbs via Posterior Gray Ramus Communicans & Anterior Rami Paravertebral Ganglion of Spinal Nerves: (Sympathetic Trunk) Vasomotion Sudomotion Pilomotion *In the Sympathetic NS, all synapses between pre- and postsynaptic fibers Cardiopulmonary occur in the sympathetic trunks, except Splanchnic Nerve for the innervation of abdominal viscera. Thoracic Viscera Preganglionic neurons begin in IML of spinal cord Travel to sympathetic ganglia (at same level or by ascending or descending in sympathetic chain) Synapse on postganglionic neurons in sympathetic ganglia Leave the ganglia in a different direction than nerves going to the body wall and limbs (do NOT go in anterior and posterior rami) Parasympathetic Innervation  Craniosacral Outflow CNS Cranial III VII A. Cranial Site IX  Cranial outflow X  Primarily goes to the head  Sacral outflow  Primarily goes to the pelvis  The thoracic & abdominal viscera between these two outflow areas are innervated primarily by the Vagus nerve To left colic  Therefore (cranial outflow > flexure sacral outflow) S-2 Sacral C. Sacral Site S-4  Vagus Nerve (CN X) “The Wanderer” Extensive Distribution to the viscera of the thorax & abdomen Heart decreases rate & strength Lungs bronchoconstriction GI Tract – increases peristalsis & secretions Esophagus Stomach Duodenum Small intestines Ascending colon Transverse colon to left colic flexure Slows things down Rest & Digest Dally and Agur: Clinically Oriented Anatomy, 9th ed., Fig. 1.48 Cardiopulmonary Splanchnics Silverthorn: Human Physiology, 8th ed., Fig 11.5  Innervation of the Heart  Sympathetic supply  Cardiopulmonary splanchnics  Post-synaptic sympathetics  Parasympathetic supply  Presynaptic fibers of the vagus nerve  Postsynaptic cell bodies are intrinsic ganglia in the vicinity of the SA and AV nodes Clinical Implications NEXT LECTURE