Thorax 2: Mediastinum, Pericardium, and Heart

What is important to note about the attachment of the pericardium on the heart?

also covers the trunks of the great vessels (indicated by yellow line)

What are septomarginal trabeculae?

extensions of cardiac muscle from interventricular septum to papillary muscle, carries parts of the conduction system of the heart (seen in ventricles)

What vein runs with the LAD?

great cardiac vein

Describe inflow and outflow tracts of the right ventricle

inflow tract is muscular outflow tract (truncus arteriosus) is smooth

Where is the Bundle of His located?

interventricular septum right bundle - toward apex of RV, papillary muscles first then to wall left bundle - along side of IV septum, papillary muscles first then to wall

Where is the AV node located?

junction of atria and ventricles gives rise to the bundle of His

WHat is the most posterior chamber of the heart?

left atrium

What is the triangle of koch?

location of the AV node and nodal bundles in R. atrium

What are the different parts of the interventricular septum?

membranous and muscular membranous portion where most interventricular defects occur; resulting in shunting of blood from L to R ventricle large shunt will increase pulmonary flow (enlarged R. ventricle), causing HTN and heart failure

What vein runs with the posterior interventricular artery?

middle cardiac vein

What is the sternocostal surface of the heart?

most anterior aspect composed of the right ventricle

What type of blood will be found in the left atrium and what are the associated veins?

oxygenated blood from the lungs via pulmonary veins (2 on either side)

What vessels are associated with the phrenic nerve?

pericardiacophrenic vessels

What is the base of the heart?

posterior aspect composed of left atrium

What determines dominance of the heart?

posterior interventricular artery most commonly right

What type of neurons are contained within the sympathetic cardiac nerve?

postganglionic GVEs and GVAs

What type of space is the pericardial sac?

potential space: becomes real when filled with fluid (Ex: blood in cardiac tamponade)

Where are the cell bodies that sense pain in the heart located?

DRG of T1-T4

What type of blood will enter the right atrium and what are the associated veins?

Deoxygenated venous blood from the SVC, IVC, coronary sinus, and cardiac veins

What is the innervation to the serous pericardium?

visceral: vagus Parietal: Phrenic

Where are the purkinje fibers located?

walls of ventricles (endocardium) FIRSTTT innervate the wall and follow a recurrent course to the *ventricular base*, during contraction papillary muscles contract first then the walls fo the ventricle from APEX towards the roots of the great vessels

Where is the SA node located?

where right atrium meets SVC site of initiation of each cardiac cycle "pacemaker" supplied by artery of SA node from RCA

What are the layers of the pericardial sac?

1. Fibrous pericardium 2. Serous pericardium -Parietal and visceral (epicardium)

What are the layers of the heart?

1. epicardium 2. myocardium 3. endocardium below the epicardium is typically a layer of subserous fat, that surrounds the coronary vessels

Label the following

1.Catheter 2.Right coronary artery (C shape) 3.SA nodal 4.Right marginal 5.Posterior interventricular

What are the most common sites of occlusion of coronary vasculature?

1.LAD: most commonly occluded vessel, widow maker 2.Right coronary artery 3.Circumflex branch of left coronary

What does the R. atrium receive blood from?

- SVC - IVC - coronary sinus - anterior cardiac veins

What is the function of the heart's pericardium?

- anchored in thoracic cavity - maintains general position of heart - base is attached to central tendon of diaphragm (pericardiacophrenic ligament) - anteriorly attached to internal aspect of sternum (sternopericardial ligaments) - posteriorly attached to structures in posterior mediastinum by loose CT

Where does the pulmonary trunk divide?

- divides at T5 - entire pulmonary trunk is covered in pericardium - is anterior to aorta

Where is the anterior mediastinum? What does it contain?

- extends from sternum to pericardium - contains: fat, sternopericardial ligament, lymph nodes, mediastinal branches of the internal thoracic artery, thymus gland

What is the cardiac skeleton?

- fibrocartilaginous framework encircles (annulus) AV orifices, origin of aorta, pulmonary trunk - cardiac skeleton consists of 4 rings and fibrous sheets and tendons that connect them - orifices of mitral, tricuspid, and aortic orificies are interconnected

What are the parts of the tricuspid valve complex?

- orifice - valve cusps - chordae tendinae - papillary muscles 3 leaflets: anterior, posterior, septal

Label the surfaces of the heart

- sternocostal (anterior); R. ventricle - diaphragmatic (inferior); L. ventricle and some R. ventricle - pulmonary (left); L. ventricle mainly

What divisions are assoc. with T4/5?

- sup/inf mediastinum division - superior limit of pericardium - arch aorta begins and ends - SVC enters heart - tracheal bifurcation - superior limit of pulmonary trunk

What is the structure of the pulmonary valve?

- superior surface faces superior, to the left and slightly posterior - 3 SL (anterior, right and left) cusps attached to wall of pulmonary artery - sinuses

Where will the heart valves be ausculatated?

Aortic valve: right 2nd intercostal space parasternally Pulmonary: Left 2nd intercostal space parasternally Tricuspid: left 5th intercostal space parasternally Mitral Valve: Left 5th intercostal space midclavicular

What is the arterial and venous support of the pericardium and what is the innervation?

Arterial support mainly from internal thoracic artery (musculophrenic, pericardial, and pericardiacophrenic) and aorta Venous drainage: brachiocephalic vein and azygos system Innervation: vagus, phrenic, sympathetic trunks

What is the structure of the aortic valve?

- 3 SL cusps (right, left, posterior) - aortic sinuses are more prominent than the pulmonary sinuses - sinuses help prevent regurgitation and promote non-turbulent flow of blood into Ostia of coronary arteries

List the layers of the pericardial sac from superficial to deep

Fibrous pericardium, parietal layer of serous pericardium, pericardial cavity, visceral layer of serous pericardium (epicardium)

What are characteristics features of the right ventricle?

Inflow (trabeculae carnae) & Outflow tracts (smooth walls) Papillary muscles & moderator band Tricuspid Valve IV septum forms sternocostal surface of heart

What are characteristics of the left ventricle?

Inflow through mital valve (bicuspid), smooth wall towards outflow to aorta powerful expulsion pump capable fo sustaining a flow in a HP circulation

Label the following

Left side of heart

Does the serous pericardium have pain innervation?

NOOO

What are the two pericardial sinuses?

Oblique Sinus: Also called cul-de-sac, a "U"-shaped recess Transverse Sinus: Space posterior to the ascending aorta and pulmonary trunk. Anterior to the Sup. Vena Cava Everything infront of finger is vein, everything behind is finger when you put finger in this sinus

What is the function of papillary muscles and chordae tendinae?

Papillary muscles connect to valves through chordae tendinae which will pull the valves shut (seen in ventricles) want papillary muscles to contract before the heart to ensure the valves are closed

Where is pericardiocentesis performed and what layers are transversed?

Performed under the xiphoid process slightly to the left skin, superficial fascia, fibrous pericardium, parietal layer of serous pericardium, STOP!!

Where are the preganglionic and post ganglionic GVE's that go to the heart cell bodies located?

Pregang: IML T1-T4 Postgang: cervical sympathetic chain

Label the image on the right

Right 1. Left coronary artery 2. Circumflex artery 3. Left marginal artery 4. LAD

What is the diaphragmatic surface of the heart?

Right and Left Ventricles that rest on the diaphragm bottom part of heart

What are common variants of coronary vasculature?

SA nodal can come off of left Posterior interventricular can come off of left circumflex coronary artery

What are the main branches of the right coronary artery?

SA nodal, Marginal branch , and posterior interventricular Think Suck My Penis right coronary

What is the arterial support to the conducting system of the heart?

SA node is supplied most commonly by right coronary artery AV node is supplied by small vessel as the right coronary becomes posterior interventricular LAD supplies the right and left bundle branches

List the sequence of signals through the conduction system of the heart

SA node will communicate with AV node which will then communicate with bundle of HIS, bundle of His will then communicate with purkinje fibers

What is the apex of the heart?

The inferior, conical end. tip of the left ventricle

What vein of the heart will drain directly into the right atrium?

anterior cardiac veins

Where is the posterior mediastinum? What does it contain?

behind the middle mediastinum contains: - esophagus - thoracic aorta - azygos, hemiazygos - thoracic duct - vagus n. - ANS, splanchnic n. - tracheobronchial lymph nodes - primary bronchi

Where will pericardiocentesis be performed?

between parietal and visceral layer of the serous pericardium

Where is the interventricular sulcus found?

between ventricles

Where is the middle mediastinum? What does it contain?

contains: - pericardium - heart - roots of great vessels - phrenic nerves between anterior and posterior mediastinum

What causes referred pain?

convergence at dorsal root ganglion of GVA and GSA, neurons get confused and refer the pain to GSA territory don't get hung up, always pick GVA for neurons that carry the pain signal

What is shown in the following?

coronary artery bypass grafting (likely saphenous vein from leg)

What are the main branches of the left coronary artery?

cricumflex branch, LAD, marginal branch think: left handed Carl Likes Men

What are the divisions of the right atrium?

divided into two parts: anterior and posterior posterior - derived from R. horn of the sinus venosus; has SMOOTH walls and is termed sinus venarum anterior - contains pectinate muscles, walls are derived from atrium proper cristae terminalis - between smooth/rough atrial walls

Where is the coronary sulcus located?

encircles the heart between the atria and ventricles

Which coronary artery is longer?

right

What is the right pulmonary surface of the heart?

right atrium

Where is the fossa ovalis located?

right atrium on interatrial septum

What are the branches from the ascending aorta?

right coronary artery - left coronary artery

Label the following

right side of heart

What is the most anterior chamber of the heart?

right ventricle

What composes the right and left side of the heart?

right: right atrium Left: left ventricle

What vein runs with the right marginal artery?

small cardiac vein

Describe the muscle of the left atrium

smooth except for the auricle; arises from incorporation of pulmonary veins, has little pectinate muscle forms anatomical *base* of heart

How are valves of the heart anchored?

through a DCT skeleton