RIGHT ATRIUM

(Features)

• Fossa Ovalis:  Embryonic remnant of foramen ovale.  In fetus, shunts blood from right to left atrium.
• Coronary sinus opening
• Pectinate muscles:  anterior musculature
• Crista terminalis:  separates smooth from rough wall of atrium
• Sulcus terminalis:  external ridge (counterpart of crista terminalis

RIGHT VENTRICLE

(Features)

• 3 Papillary muscles:  anterior, posterior, septal (AKA moderator band/septomarginal trabeculae)
• Chordae Tendinea:  little stringy things connecting cusps to papillary muscles that keep tricuspid valve from prolapsing
• Trabeculae carne:  musculature on anterior inner surface
• Tricuspid Valve:  Anterior, Septal, and Posterior cusp
• connect to papillary muscles via chordae tendinae
  
• Note that there are no chordae tendinae on semilunar valve.

DIAPHRAGMATIC SURFACE OF HEART

(dominating chambers)

Formed from left ventricle and small part of right ventricle

STERNOCOSTAL SURFACE OF HEART

(dominating chambers)

Diaphragm

What happens at T8, T10, and T12?

• T8 --> IVC, R phrenic nerve, R pericardiophrenic artery (pass through central tendon)
• T10 --> Esophagus, R & L Lagus Nerves (esophageal hiatus)
• T12 --> Thoracic aorta and thoracic duct pass posteriorly (aortic hiatus)

PERICARDIAL VASCULATUR

(Arterial and Venous Drainage)

• Arterial: 
• Pericardiophrenic artery (branch of internal thoracic) - major contribution
• Coronary arteries (only visceral layer of serous pericardium) - minor contribution
• Branches from thoracic aorta - minor contribution
• Venous Drainage:
• Pericardiophrenic veins --> brachiocephalic Veins
• Azygos Tributaries

PERICARDIUM

(Innervation)

• Phrenic (C3,C4,C5) - somatic only (major contributor)
• Vagus (CN X) - function unknown
• Sympathetic Trunks (vasomotor)

• Forms foundation where valves and myocardial fiber bundles attach.
• 4 fibrous rigns that are fused / fibrous skeleton.
• Pulmonary, Aortic, Mitral, and Tricuspid all connected by this shit

RIGHT LUNG

(distinguishing features)

• Fissures:  Horizontal, Oblique
• Lobes:  Superior, Middle, Inferior
• Grooves:  Arch of azygos, Brachiocephalic vein, Esophageal area and groove for esophagus
• Main Bronchus:  posterior to pulmonary arteries
• 10 bronchopulmonary segments (same as left lung)

Important Levels from Clinical Case 9/16/2011

Significant when it comes to diaphragmatic recesses

• Rib 6:  marks inferior most extent of lung at midclavicular line
• Rib 8:  marks inferior most extent of pleural cavity at midclavicular line
• Rib 8:  marks inferior most extne of lung at midaxillary line during quiet respiration
• Vertebra 10:  marks inferior most extent of lung posteiroly during quiet respiration

SPATIAL RELATIONSHIP

(VAGUS VS. PHRENIC NERVE)

• PHRENIC (C3,C4,C5):  passes anterior to root of lung
• VAGUS (CN 10):  passes posteiror to root of lung

• Anterior to SVC
• Posterior to aorta and pulmonary trunk
• Continuous from left to right side
• Important area when it comes to heart surgery

INTERCOSTAL SPACES

(Vessel Arrangment)

• Costal groove:  groove is on inferior edge of ribs and protects the VAN (superior to inferior) arrangment of vessels
• Collateral branches:  Superior to rib (NAV)
• Why it is important to go directly in middle during thoracocentesis

SUBCOSTALIS

Posteriorly span 2-3 intercostal spaces, can be considered the counterpart of transversus thoracis muscles.

• Anterior
• Spabn more than one intercostal spa e
• Looks like butterfly

ANTERIOR THORACIC WALL

(Blood Supply)

INTERNAL THORACIC DOING ITS THING

• Internal Thoracic Artery - gives off anterior intercostal arteries (usually paired)
• Internal Thoracic Artery terminates as the musculophrenic artery and superior epigastric

POSTERIOR THORACIC WALL

(Blood Supply)

• Directly from thoracic aorta
• Upper two - L & R Superior thoracic artery (branch of costocervical trunk)

BREASTS

(Arterial Supply)

• Main two contributors
• Lateral thoracic Artery (Lateral Mammary Branches)
• Internal Thoracic Artery (Medial Mammary Branches)
• Minor:
• Posterior Intercostal arteries (2nd, 3rd, and 4th)

BREASTS

(Venous Drainage)

• Lateral Mammary Veins --> Lateral Thoracic Vein --> Axillary Vein

• Medial Mammary Veins --> Internal Thoracic Vein

•  Intercostal Veins --> Azygous System

RESPIRATORY MUSCLES

(Accessory, Intercostal, and minor contributors)

*All intercostals are innervated by intercostal nerves*

• External Intercostals:  inspiration (major contributor)
• membranous anteriorly
• same direction as hands in pocket
• continuous with external oblique
• Internal Intercostals:  expiration (major contributor)
• membranous posteriorly
• run infero-lateral
• continous with internal oblique muscles
• intercostal arteries, veins, and nerves run between these and the innermost intercostals
• Innermost Intercostals 
• membranous anteriorly and posteriorly
• same direction as internal intercostals
• Accessory (forceful respiration)
• pectoralis major and minor
• Other contributors:
• Scalene, posterior serratus muscles, deep back muscles (levator costorum, transverse thoracic muscles)

BODY LANDMARKS OF THE THORACIC WALL

1. Superior angle of scapula
2. Root of spine of scapula
3. Inferior angle of scapula
4. Sternal angle
5. Jugular Notch
6. Xiphoid process
7. Breasts
8. Ribs
9. Male Nipple

1. Superior angle of scapula:  T2  (spinous process)
2. Root of spine of scapula:  T3 (spinous process)
3. Inferior angle of scapula:  T7 (spinous process)
4. Sternal angle:  T4/T5 (where 2nd costal cartilages attach).  Also known as manubrosternal joint, Angle of Louis.  Significance = Transverse Thoracic Plane
5. Jugular Notch:  T2 Vertebral Body (also known as suprasternal notch)
6. Xiphoid process:  T9
7. Breasts:  2nd - 6th costal cartilages
8. Male Nipple:  4th intercostal space (about T6 vertebral level)

THORACIC WALL MOVEMENT

(Inspiration and Expiration)

• Inspiration
• Intercostal muscles contract (exteranl intercostals)
• Diaphragm contracts
• Expands --> laterally, anteriorly, vertically
• Expiration
• Diaphragm relaxes
• Rib cage contracts (internal intercostals)

HILUM/ROOT OF LUNG

(Vertebral Level)

• At T5-T7, the parietal pleura reflects back onto itself.  This reflection forms the hilum of the lung
• The structures entering this region make up the root of the lung
• Pulmonary Ligament:  extension of two pleura continuing inferiorly allows for moement of the lung

• Loose Connective tissue layer separating the parietal pelura from the internal surface of thoracic wall (innermost intercostals)

RIBS 3-9

• Tubercle along with articular facet for transverse process, has nonarticular part for ligamentous attachments
• Superior and Inferior Articular Facets (encounter two vertebra)
• Head (has the two facets that connect to vertebra)
• Neck
• Angle
• Body
• Costal Groove (inferior part)

THREE TYPES OF RIBS

(Number the ribs per type, list defining features)

• True:  1 - 7
• attach directly to the sternum via costal cartilages
• False:  8 - 10
• attach to costal margin
• Floating:  11 - 12
• no necks
• no tubercles
• do not attach to sternum
• 1 articular facet for first vertebral body

• RIB 1 (going anterior --> posterior)
• Subclavian Vein
• Anterior scalene
• Subclavian Artery
• Middle scalene
• RIB 2
• 2 articular facets
• Tubercles for msucle attachment
• Posterior scalene

Single articular facets on their heads (attach to only one vertebra)

10 is attached to costal margin while 11 and 12 are floating

LUNGS - RECESS

Which is most important clinically?

• Recesses:  Separation of visceral and parietal pleura not invated by lung during quiet respiration
  
• Costaldiaphragmatic recesses
• Clinically important - thoracocentesis
• Below 6th rib rib in midclavicular line
• Below 8th rib in midaxillary line
• Costomediastinal Recess (left lung/anterior view) - this is because of cardiac notch...I think

DIAPHRAGM

(Blood Supply)

Most from abdominal aorta getting posterior aspect

• Other:
• Pericardiophrenic (branch of internal thoracic)
• Musculophrenic (branch of internal thoracic)
• Branches from intercostals
• Branches form thoracic aorta

DIAPHRAGM

(Innervation)

• A = Aortic = right second intercostal space
• P = Pulmonic = left second intercostal space
• T = Tricuspid = left fit intercostal space
• M = Mitral = near apex (left...postero-lateral to "T")

 LEFT LUNG

(distinguishing features)

• Fissure:  oblique
• Lobes:  2 (superior and inferior)
• Has cardiac notch (forms costomediastinal recess)
• Has Lingula)
• 10 bronchopulmonary segments (as does right lung)
• ****Main bronchus inferior to pulmonary artery

• Plane separating superior and middle mediastinum
• From Sternal Angle (2nd cotal cartilage) aka manubrosternal joint/Angle of Louis back to T4/T5 intervertebral disk
• Supine:  transects tracheal bifurcation, aortic arch above plane
• Standing:  transects aortic arch (aorta gets lower yo)

MEDIASTINUM AND POSITION

(Supine and Standing)

• Supine:
• aortic arch supeiror to transverse thoracic plane
• tracheal bifurcation is transected
• central tendon of diaphragm lies at xiphosternal junction (T9)
• Standing:
• Aortic arch transected by TTP
• Central Tendon may fall to mid-level of xiphoid process (disc between T9-T10)

• Forms most of the base of the heart
• Features:  inside wall essentially smooth except for pectinate muscle in auricle, 2 superior and 2 inferior pulmonary veins, medial wall has depression for valve of foramen ovale and wall is thicker than the right atriium.
• Less pectinate muscles because RV has already contracted, so there is plenty of pressure already

• Note the bicuspid (mitral or AV) valve
• 2 papillary muscles (anterior and posterior)
• Larger than right vitricle
• Chordae tendinea, trabeculae carneae are finer and more numerous than in the right ventricle
• Ventricular wall is 2-3 times as thick as the right ventricle
• Cusps get fibers  from both papillary muscles (same with tricuspid valve).  Some cardae tendinae go to each and that redundancy is there because if one muscle goes out, it is important that some of the muscle is left holding that flap.

• Diastole is the dilation of the heart cavities, during which they fill with blood - that the atria preceds taht of the ventricles
• Note the 3 cusps of the pulmonary and aortic valves - also note origin of the right and left coronary arteries
• Semilunars are closed because there is a lot of pressure.  The more pressure that is placed on teh cup, the tigheter they adhere to each other.

• Systole is the contraction of the heart, especially the ventricles, by which the blood is driven through the aorta and pulmonary artery to traverse the systemic andpulmonary circulations respectively
• Note the 3 cusps of the pulmonary and aortic valves - also note orgin of the right and left coronary arteries.

Opening to the right coronary artery is in the right cusp of the aortic valve

Opening of the left coronary artery is in the left cusp of the aortic valve

Lunula are in both pulmonary abnd aortic valves.

RIGHT and LEFT

CORONARY ARTERY

• Right coronary artery located in the AV groove, gives rise to the SA nodal and right marginal brtanches
• Left coronary artery divides into the circumflex and the anterior interventricular branches (LAD) lying in the atrioventricular and interventricuar gooves respectively
• KNOW THE AV GROOVE
• Gives rise to the SA node and the right marginal branches respectively

• The great (runs with circumflex of left coronary artery)and small cardiac veins drain the sternocostal surface along with the anterior cardiac veins
• The coronary sinus receives the posterior interventricular, and/or middle cardiac vein,on the diaphragmatic surface of the heart.
• It also receives the small cardiac vein on its right end and great cardiac vein on its left side.

• Both sympathetic and parasympathetic supllies contribute to the cardiac plexus located on the anterior surface of the trachea at the bifurcation and on theanterior surfae of the aortic arch.
• Sympathetic:
• Preganglionic fibers from teh upper 4 or 5 thoracic segments traverse the sympathetic chain and synapse in the cervical or upper thoracic ganglion.  Then postganglionic fibers enter the cardiac plexus
• Adrenergic (norepinephrine)
• Increase heart rate and force of contraction
• Visceral afferents carry pain back to the spinal levels in which they originated
• Parasympathetic:
• Vagus nerve
• Cholinergic (acetylcholine)
• Slows heart rate, force of contraction, and constricts blood vessels.

• The SA node is located at the junction fo the SVC and the superior ned o the crista terminalis
• It is known as the pacemaker of the heart, and initiates and regulates an impulse ~ 70 X's per minute
• The node is supplied by sympathetic and prasympathetic fibers via the cardiac plexus

• The AV node is located in the posteroinferior region of the interatrial septum near the orifice of the coronary sinus - it receives impuses from the SA node which then distribute the signals to the ventricles via the AV bundle.
• At the junction of the membranous and muscular parts of the septum, it divides into the right and left bundles to the respective ventricles.

• Lympahetics of the heart fro networks adjacent to the endocardium and the epicardium
• The efferent vessels drain along the coronary arteries and empty into lymph nodes associated with the lower end of the trachea (tracheobronchial nodes)

• Superior part: 
• recurrent larygneal nerves
• Sympathetic fibers from cell bodies in middle cervical ganglion running in on the interior thyroid arteries
• Lower 1/2:  Esophageal plexus
• parasympathetics are from the right and left vagus nerves
• left vagus gives rise to anterior
• right vagus gives rise to the posterior
• Sympathetics are from the Gray rami of the upper 4 thoracic ganglia
• Vasomotor supply is via the sympathetics