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129 Cards in this Set

  • Front
  • Back
occupied by the mass of tissue between the two pulmonary cavities, center of thoracic cavity, contains heart
superior mediastinum
extends from superior thoracic aperture to the horizontal plane (transverse thoracic plane) that includes the angle of Louis and the 4th ICS, contains trachea and superior parts of the great vessels
inferior mediastinum
extends from the horizontal plane that includes the angle of Louis and the 4th ICS inferiorly to the diaphragm, further divided into the anterior, middle, and posterior parts
middle mediastinum
contains the heart and the great vessels
posterior mediastinum
contain parts (e.g. esophagus) that pass through multiple layers of the mediastinum
fibroserous membrane that covers the heart and the beginning of its great vessels, composed of 2 layers, fibrous pericardium and serous pericardium
fibrous pericardium
tough, external layer of the pericardium, continuous with the central tendon of the diaphragm and the tunica adventitia of the great vessels, attached anteriorly to the sternum by the sternopericardial ligaments, controls filling/expansion of heart, intimate with the parietal serous pericardium
parietal layer of serous pericardium
lines internal surface of the fibrous pericardium, glistening serous membrane, reflected on the heart at the great vessels as the visceral layer of serous pericardium
visceral layer of serous pericardium
covers the heart intimately, epicardium
pericardial cavity
potential space between opposing layers of the parietal and visceral layers of serous pericardium, normally contains a thin film of fluid that enables the heart to move and beat in a frictionless environment
transverse pericardial sinus
lies between the great vessels (aorta/pulmonary trunk and SVC/IVC/veins), posterior to aorta and anterior to the SVC, superior to the atria
oblique pericardial sinus
lies between the IVC and pulmonary veins, created from pericardial reflection around veins, posterior to the base of the heart (L. atrium), can be entered inferiorly, elevates heart on the posterior side
pericardiacophrenic artery
branch of the internal thoracic artery, often accompanies the phrenic nerve to the diaphragm, arterial supply of the pericardium
musculophrenic artery
terminal branch of the internal thoracic artery
bronchial, esophageal, and superior phrenic arteries
branches of the thoracic aorta
coronary arteries
first branches of the aorta, innervate the visceral layer of serous pericardium
venous drainage of pericardium
pericardiacophrenic veins (tributaries of the brachiocephalic veins) and variable tributaries of the azygos venous system
nerve supply of the pericardium
-phrenic nerve-(C3-C5), primary source of sensory fibers, pain sensations conveyed by these nerves are commonly referred to the C3-C5 dermatomes, somatic

-vagus nerve-unknown function

-sympathetic trunk-vasomotor
a double, self-adjusting, suction and pressure pump, work in unison to propel blood to all parts of the body
right heart
receives poorly oxygenated blood from the SVC and IVC and pumps it through the pulmonary trunk to the lungs for oxygenation
left heart
receives well-oxygenated blood from the lungs through the pulmonary veins and pumps it into the aorta for distribution to the body
left and right, receiving chambers that pump blood into the ventricles
atrioventricular pumps
two, left and right, pumping action, constitute the cardiac cycle
begin cardiac cycle, period of ventricular filling and elongation
end cardiac cycle, period of ventricular shortening and emptying
lub sound
occurs as the blood is transferred (sucked) from the atria into the ventricles, sound of the pulmonary and aortic valves closing
dub sound
occurs as the ventricles expel blood from the heart, sounds made by the snapping shut of the valves
thin internal layer, lining membrane of the heart that also covers its valves
thick, helical middle layer composed of cardiac muscle, esp. thick in ventricle
thin external layer (visceral serous pericardium)
fibrous skeleton of the heart
anchor heart muscle fibers, network of dense collagen forming four fibrous rings, a R. and L. fibrous trigone, and the membranous parts of the interatrial and interventricular septa, has four functions
1. keeps the orifices of the AV and semilunar valves patent
2. provides attachments for the leaflets and cusps of the valves
3. attachment for myocardium, which forms a ventricular myocardial band
4. forms an electrical insulator, separates impulses of the atria and ventricle (so they contract independently
fibrous rings
surround the orifices of the valves
fibrous trigone
formed by connections between rings
coronary or atrioventricular groove
separate the atria from the ventricles, (L. sulcus)
anterior and posterior interventricular grooves
separate the r. and l. ventricles
apex beat
where sounds of mitral valve closure is maximal
base of the heart
formed mainly by the left atrium
anterior (sternocostal) surface of the heart
formed by the right ventricle
diaphragmatic (inferior) surface of the heart
formed mainly by the left ventricle and partly by the right ventricle
right pulmonary surface
formed mainly by the right atrium
left pulmonary surface
formed mainly by the left ventricle, forms the cardiac impression of the left lung
pulmonary trunk
5 cm long and 3 cm wide, is the arterial continuation of the right ventricle and divides into r. and l. pulmonary arteries, conduct poorly oxygenated blood from the heart to the lungs
right atrium
receives blood from SVC, IVC, and coronary sinus (receives cardiac veins), interior contains:

-smooth, thin walled sinus venarum on which the venae cavae and coronary sinus open

-rough, muscular anterior wall composed of pectinate muscles

-right AV orifice through which blood is sent to the right ventricle
right auricle
conical muscular pouch that projects from this chamber like an add-on room, INC capacity of the atrium, overlaps the ascending aorta
sulcus terminalis (or terminal groove)
externally separate the smooth and rough parts of the atrial wall
crista terminalis
vertical ridge, internally separate the smooth and rough parts of the atrial wall
interarterial septum
separates the atria, has oval fossa (remnant of the oval foramen in the fetus)
oval foramen
helps shunt blood from the right atrium to the left atrium in the fetus, avoid the immature lungs
right ventricle
almost the entire inferior border of the heart, supplies blood to the lungs for oxygenation
conus arteriosus
infundibulum, leads into the pulmonary trunk
trabeculae carnae
irregular muscular elevations on the interior of the right ventricle
supraventricular crest
thick muscular ridge, separates the ridged muscular wall of the inflow part of the chamber from the smooth wall of the conus arteriosus (outflow part)
right AV (tricuspid) orifice
separates blood flow from the right atrium to the right ventricle, posterior to the body of the sternum at the 4th and 5th ICS,
tricuspid valve
guards the right AV orifice, bases of the valve cusps are attached to the fibrous ring, valve cusps prevent backflow of blood
tendinous cords (chordae tendineae)
attach to the free edges and ventricular surfaces of the anterior, posterior, and septal cusps, like the cords of a parachute, arise from the papillary muscles
papillary muscles
give rise to the chordae tendineae, circular muscular projections with bases attached to the ventricular wall, three types (anterior, posterior, septal), covered by enodcardium
interventricular septum (IVS)
composed of muscular and membranous parts, is a strong, obliquely placed partition between the right and left ventricles, is 2 to 3 times thicker on the side of the left ventricle
septomarginal trabeculae (moderator band)
curved muscular bundle that traverses the right ventricular chamber from the inferior part of the IVS to the base of the anterior papillary muscle, it carries part of the right branch of the AV bundle
right branch of the AV bundle
part of the conducting system of the heart to the anterior papillary muscle
supraventricular crest
deflects the incoming flow into the main cavity of the ventricle and the outflow into the conus arteriosus
pulmonary valve
at the apex of the consu arteriosus is at the level of the left 3rd costal cartilage
left atrium
most of the base of the heart, entry point for the valveless pairs of right and left pulmonary veins, interior has a larger smooth-walled part and a smaller muscular auricle containing pectinate muscles, and 4 pulmonary veins entering the smooth posterior wall, slightly thicker wall than that of the right atrium, an interatrial septum, and a left AV orifice through which the left atrium discharges the oxygenated blood it receives from the pulmonary veins into the left ventricle
left auricle
tubular and muscular, forms the superior part of the left border of the heart and overlaps the root of the pulmonary trunk
left ventricle
forms the apex of the heart, nearly all its left surface and border, and most of the diaphragmatic surface, performs more work than the right ventricle
-interior-walls that are two to three times thicker than that of the right ventricle, mostly covered by a mesh of trabeulae carnae, a conical cavity that is longer than that of the right ventricle, anterior and posterior papillary muscles that are larger than those in the right ventricle, aortic vestibule, and mitral valve (double leaftlet)
aortic vestibule
smooth walled, non-muscular outflow part leading to the aortic orifice and aortic valve
aortic orifice
beginning of ascending aorta
mitral valve
two cusps, receives tendinous cords from more than one papillary muscle
semilunar aortic valve
between left ventricle and the ascending aorta
semilunar cupsps of the pulmonary valve and aortic valve
three, concave when viewed superiorly, do not have tendinous cords attached to them, smaller in area than the AV valves, and force exerted on them is less than half exerted on the AV valves
right aortic sinus
the mouth of the right coronary artery
left aortic sinus
the mouth of the left coronary artery
posterior arotic (non-coronary) sinus
no artery arises from here
coronary arteries
the first branches of the aorta, supply the myocardium and epicardium, arise from the corresponding aortic sinuses, supply both the atria and the ventricles
right coronary artery (RCA)
passes to the right side of the pulmonary trunk, running in the coronary groove, usually gives off an ascending sinuatrial nodal branch and right marginal branch, RCA then turns to the left and continues to the posterior aspect of the heart, at the crux (junction of the septa and walls of the four heart chambers) the RCA gives rise to the atrioventricular nodal branch
-supplies: right atrium, most of the right ventricle, part of the left ventricle, part of the IV spetum, SA node (60% of people), and AV node (80% of people)
sinuatrial nodal branch
supplies the SA node, originates from the right coronary artery or arises from circumflex of LCA in 40% of people
right marginal branch
supplies the right border of the heart as it runs toward the apex of the heart
atrioventricular nodal branch
supplies the AV node
posterior interventricular (IV) branch
suppled by the RCA 67% of the time, descends down the posterior IV groove toward the apex, supplies both ventricles and sends perforating interventricular septal branches
left coronary arter (LCA)
arises from left aortic sinus of the ascending aorta, can give rise to the SA nodal branch, as it enters the coronary groove, divides into the anterior IV branch and the circumflex, lies between the pulmonary trunk and left auricle

-supplies: left atrium, most of the left ventricle, part of the right ventricle, most of the IVS, including the AV bundle, the SA node (40% of people)
anterior IV branch
passes along the IV groove to the apex, then it commonly anastomoses with the posterior IV branch, supplies adjacent parts of both ventricles, gives rise to a lateral branch, most common for coronary disease
left marginal artery
follows the left margin of the heart and supplies the left ventricle, usually terminates before crux but in 1/3 of people it runs to the posterior IV groove and gives rise to the posterior IV branch
venous drainage of the heart
drained mainly by veins that empty into the coronary sinus and partly by small veins that empty into the right atrium
coronary sinus
main vein of the heart, runs from right to left in the posterior part of the coronary groove
great cardiac vein
main tributary of the coronary sinus, its first part (anterior IV vein) beins near the apex and ascends with the anterior IV branch of the LCA
middle cardiac vein (posterior IV vein)
accompanies the posterior IV branch, drain areas supplied by the RCA
small cardiac vein
accompanies the right marginal branch of the RCA, drain areas supplied by the RCA
anterior cardiac veins
begin over the anterior surface of the right ventricle, cross over the coronary groove and usually end directly in the right atrium, sometimes entering the small cardiac vein
smallest cardiac veins
begin in the capillary beds of the myocardium and open directly into the chambers of the heart, may carry blood from the heart chambers to the myocardium, allow for collateral circulation (reversal of flow to brin luminal blood to the capillary beds of the myocardium, providing some additional collateral circulation)
subepicardial lymphatic plexus
lymph in the myocardium go here, pass to the coronary groove and follow the coronary arteries
inferior trachobronchial lymph nodes
end point for cardiac lymph nodes
sinuatrial (SA) node
located anterolaterally just deep to the epicardium at the junction of the SVC and right atrium, small collection of nodal tissue, specialized cardiac muscle fibers and associated fibroelastic CT, pacemaker of the heart, initiates and regulates the impulses for contraction, impulse of 70 times/min., stimulated by symp. and inhibited by parasymp., sends impuls right and left (to atrium)
atrioventricular (AV) node
smaller than the SA node, located in the posteroinferior region of the interatrial septum near the opening of the coronary sinus, receives impulse from the SA node, then distributes the impulse to the ventricles through the AV bundle, stimulated by symp. and inhibited by the parasym.
right and left bundles of the AV bundle
split at the junction of the membranous and muscular parts of the septum
subendocardial branches (purkinje fibers)
extend into the walls of the respective ventricles, coarse to moderator band
cardiac plexus
autonomic nerve fibers that supply the heart
superior mediastinum
superior to the transverse thoracic plane, contain thymus, great vessels, inferior continuation of the cervical viscera and related nerves, thoracic duct and lymphatic trunks
a lymphoid organ, located in the inferior part of the neck and the anterior part of the superior mediastinum, veins of the thymus end in the left brachiocephalic, internal thoracic, and interior thyroid veins, the lymphatic vessels of the thymus end in the parasternal, brachiocephalic, and trachobronchial lymph nodes
left brachiocephalic vein
union of the internal jugular and subclavian veins, more than twice as long as the righ bec. it passes from the left to the right side, passing over the anterior aspects of the roots of the three major branches of the arch of the aorta, shunts blood from the head, neck and left upper limb to the right atrium
superior vena cava
returns blood from all structures superior to the diaphragm except the lungs and heart, ends at the level of the 3rd costal carilage, right side o fthe superior mediastinum
right phrenic nerve
lies between the SVC and the mediastinal plura,
ascending aorta
begins at the aortic orifice, only branches are the coronary arteries
arch of the aorta
curved continuation of the ascending aorta, ends by becoming the thoracic aorta

-branches: brachiocephalic trunk, left common arotid artery and left sublclavian artery
ligamentum arteriorsum
remnant of fetal ductus arteriosus, passes from the root of the left pulmonary artery to the inferior surface of the arch of the aorta
brachiocephalic trunk
first and largest branch of the arch of the aorta, divides into the right common carotid and right subclavian arteries), only one, on the right side
left common carotid artery
second branch of the arch of the aorta, enters the neck by passing posterior to the left SC joint, right common carotid comes from brachiocephalic while left comes from aorta
left subclavian artery
third branch of the arch, comes from the aorta not from the brachiocephalic
vagus nerve (superior mediastinum)
exits the cranium and descend through the neck posterolateral to the common carotid arteries
right vagus nerve
enters the thorax anterior to the right subclavian artery, gives rise to the right recurrent laryngeal nerve
recurrent laryngeal nerve
hooks around the right subclavian artery and ascends between the trachea and esophagus to supply the larynx, associated with the ligamentum arteriosum (used to be ductus arteriosum)
phrenic nerves
supply the diaphragm with motor and sensory fibers, the latter accounting for approx. 1/3 of the nerve’s fibers, also supply sensory fibers to the pericardium and mediastinal pleura, enters the superior mediastinum between the subclavian artery and the origin of the brachiocephalic vein

-arise from cervical spinal nerves (C3-C5 contribute to the formation of the phrenic nerve), C3, 4, and 5 keep the heart alive
right phrenic nerve
passes along the right side of the right brachiocephalic vein, SVC, and pericardium
left phrenic nerve
descends between the left subclavian and left common carotid arteries,
descends anterior to the esophagus and enters the superior mediastinum, inclining a little to the right of the median plane
extends from the pharynx to the stomach, enters the superior mediastinum between the trachea and the vertebral column
posterior mediastinum
contains the thoracic aorta, thoracic duct and lymphatic trunks, posterior mediastinal lymph nodes, azygos and heiazygos veins and esophagus and esophageal nerve plexus
thoracic aorta
continuation of the arch of the aorta
thoracic aortic plexus
autonomic nerve network that surrounds the thoracic aorta
thoracic duct
lies on the anterior aspect of the bodies of the inerior 7 thoracic vertebrae, it is the largest lymphatic channel in the body, conveys most lymph of the body to the venous system, originates from the chyle cistern in the abdomen, usually thin walled and dull white, ascends in the posterior mediastinum w/ the thoracic aorta on its left and the aygos vein on its right, often receives the jugular, subclavian, and bronchomediastinal lymphatic trunks, empties into the venous system near the union of the left internal jugular and subclavian veins
azygos system of veins
on each side of the vertebral column, drains the back and thoracoabdominal walls as well as the mediastinal viscera, arches over primary bronchus
azygos vein
forms a collateral pathway between the SVC and IVC and drains blood from the posterior walls of the thorax and abdomen, ascends in the posterior mediastinum, communicates with the vertebral venous plexuses that drain the back, vertebrae, and structures in the vertebral canal, also receives the mediastinal, esophageal, and bronchial veins
hemiazygos vein
arises on the left side by the junction of the left subcostal and ascending lumbar veins, goes to T9 vertebra, here it crosses to the right, posterior to the aorta, and joins the azygos vein, receives the inferior three posterior intercostal veins, the inferior esophageal veins, and several small mediastinal veins
accessory hemiazygos vein
begins at the medial end of the 4th or 5th ICS and descends on the left side of the vertebral column from T5 through T8, receives tributaries from veins in the 4th-8th ICS, crosses over the T7 or T8 vertebrae posterior to the aorta where it joins the azygos vein, sometimes joins the hemiazygos vein
thoracic sympathetic trunks
continuity with the cervical and lumbar symp. trunks
lower thoracic splanchnic nerves (greater, lesser, and least)
part of the abdominopelvic splanchnic nerves, supply viscera inferior to the diaphragm, presynaptic fibers from 5th through the 12th sympathetic ganglia
anterior mediastinum
smallest subdivision of the mediastinum, lies between the body of gthe sternum and the transverse thoracic muscles anteriorly and the periocardium posteriorly, consists of loose connective tissue (sternopericardial ligaments)
pericardiophrenic artery and vein
innervate the heart, branch of the internal thoracic artery
crista terminalis
prominent ridge where the pectinate muscles end
Bundle of His
bundle of conduction tissue that leaves the node and passes through the fribrous skeleton and enter ventricle region, only electrical connection between the atria and ventricle, splits into two (left and right), r descends down right ventricular septum and spreads out that radiate out to the right ventricular branches, purkinje fibers (the terminal filaments), Left bundle branch, splits very quickly into 5 or 6 branches, stimulate myocytes of the left heart to contract, called pukinje fibers as well
placement of stethoscope for valves
-aortic-right 2nd ICS, lateral to sternum

-pulmonary-left 2nd ICS, lateral to sternum

-tricuspid-left 4th ICS, lateral to sternum

-mitral-5th ICS, lateral to costal cartilage