Mod 4 Anatomy

Think that the "flow" is going with gravity

• Inlet: 1st rib end
•   -contains: major arteries from aorta, major veins to SVC, esophagus, trachea, phrenic n, vagus n

• Outlet: bottom ribs end
•   -IVC, descending aorta, esophagus, sympathetic nn, vagus nerve plexus

• Think about what is close to the normal 1st rib. 
• -T1 and C8 ribs
• -subclavian artery and veins

These could all get compressed

The angle of the rib

Listening posts for the aortic and pulmonary valves, second rib attaches here, inferior border of sup. mediastinum, T4/T5 level

• from outside the inside:
• -external intercostal mm (hands in front pockets)
•      -from costovertebral to costochondral joint
• -Internal intercostal muscles (hands in back pockets)
•     -from sternocostal joint to 5cm from costovertebral
• -(costal VAN here)
• -Innermost intercostal muscles
•     -lateral aspect of ribcage
• -Subcostal muscles (span 2 ribs)
•     -close to vertebrae
• -transverse thoracic
•     -rib to sternum

• visceral: closest to the heart
• parietal: visceral reflects back on itself and forms the pericardial cavity
• fibrous: tough and designed to protect the heart

Pericardial cavity: friction free movement of the heart

Transverse sinus: can clamp the the great vessels via this sinus during heart surgery

• Anterior: Rt Atrium, Ant. I/V groove, Rt vent
• Posterior: Lt Atrium
• Inferior: Lt Vent, Post. I/V groove, (heart sits on this)
• Apex: Lt vent

• Right: Rt atrium (area b/n SVC and IVC; 3rd to 6th ribs)
• Left: Lt Ventricle (+lt atrium) (5th rib apex->2nd rib)
• Inferior: Right ventricle (along 5th intercostal space)
• Superior: roots of the aorta/pulmonary artery/SVC (2nd rib)

• 8 - auricle
• 7 - pectinate muscles
• 3 - fossa ovalis
• 6 - SA node
• 5 - AV node
• 2 - coronary sinus
• 4 - Rt AV orifice
• 

• 1 - trabeculae carne
• 7 - moderator band
• 5 - Conus arteriosus (smooth to pulm. artery)
• 2 - Papillary muscles (septal, anterior, posterior)
• 

lateral to the aorta. 1 papillary muscle on anterior wall, 1 papillary muscle on posterior wall.

• 1) leaflets - the flaps that close
• 2) papillary muscles - contract to hold the leaflets closed during contraction
• 3) chordae tendinae - attach the papillary muscles to the leaflets

• stenosis: narrowing of the opening (causes ventricular hypertrophy and murmers (turbulent flow)
• regurgitation: dilation of affected chamber, increased backpressure, murmers

• right second I/C space: aorta
• left second I/C space: pulmonary artery
• Right 4th I/C space: tricuspid valve
• left 5th I/C space (midclavicular line): mitral valve

• -Left Coron. a: All others branch off of this
• -LAD: branches off of LCA, supplies anterior I/V septum, supplies part of R and L vents
• -Circumflex: continues in coronary groove to posterior heart, supplies Lt vent and atrium
• -Left marginal artery: off of circumflex and supplies left border of heart

• Right coronary artery: all others rise off of this
• Right marginal artery: along inferior border, supplies rt ventricle
• Post. I/V artery: post. I/V groove to apex, supplies Av node, post 1/3 of I/V septum, can come off circumflex if LD
• SA nodal a: off RCA near its origin (can come off left coronary in 40% of people)
• 

• -great CV: travels with LAD and is continuous with coronary sinus
• -middle CV: travels with posterior I/V 
• -small CV: first travels with right marginal, then with right coronary and drains into coronary sinus. drains RV

• -SA node (70-80BPM): sets the rhythm of the heart, conducts through innternodal pathways and Bachmann's bundles to contract atria and stimulate 
• -AV node (40-60BPM): in septum, supplied by posterior I/V a
• -AV bundle: membranous portion of I/V septum
• -R and L bundle branches: down I/V septum
• -Purkinje fibres: from apex to rest of ventricular wall. 

sympathetic: from T1-6; throughout heart; increase contractility, vasodilation of C aa, increased HR

parasympathetic: from Vagus n; decreased HR and contractility, vasoconstriction

The visceral sensory fibres are close to the somatic sensory fibres, causing them to fire and making it feel like you have pain in areas where T1-4 have somatic sensory innvervation (shoulder, chest, etc)

• Anterior: manubrium
• Poster.: T1-T4 vertebrae
• superior: Thoracic inlet
• inferior: angle of Louis to T4/5

• -Thymus (beneath sternum)
• -Brachiocephalic veins: unite to make SVC, left is longer in goes behind manubrium (all nn tuck behind this)
• -SVC: right lung is aterior (think SVC syndrome), ascending aorta is medial
• -aorta: ascending and arch, behind the brachiocephalic veins,
• -ligamentum arteriosum (between pulmonary artery and aorta)
• -phrenic nerves (C3-C5):  
• -vagus nerves (cranial): parasympathetic of cardiac, pulmonary, esophagus plexi.; recurrent laryngeal nerves off of these
• -trachea: behind all these vessels
• -esophagus: behind the trachea

• superior: T4/5
• inferior: diaphram
• anterior: heart
• posterior: T5-12

• -Thoracic aorta
• -thoracic duct: between azygos and aorta
• -azygos and hemiazygos veins: hemiazygos flows into azygos which connects to both IVC and SVC
• -esophagus: innervated by the vagus nn plexus
• -thoracic sympathetic trunk: run parallel to the spine, sympathetic inn to cardiac, pulmonary, and esophgeal plexuses
• -vagus nerve plexus

• everything below diaphram
• Left thorax and left upper limb
• head and neck

• Vena caval hiatus - T8 - IVC
• Esophageal hiatus - T10 - esophagus, vagus nn
• Aortic hiatus - T12 - Aorta, thoracic duct, azygous