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85 Cards in this Set

  • Front
  • Back
Midline region between the right and left pulmonary cavities; Space bounded by the superior thoracic aperture (1st ribs, manubrium, T1) above and the diaphragm below; Houses all thoracic organs except the lungs
sternal angle (separates sternum manubrium and body), separates superior and inferior mediastinum, where trachea bifurcates and carina is found, arch of aorta
lymphoid organ largely replaced by fat by adulthood; posterior to manubrium and extends anteriorly to pericardium
superior / inferior mediastinum
separated by horizontal plane passing through sternal angle and T4/T5 IV disc
serous membrane surrounding the heart and proximal portions of the great vessels; consists of fibrous, parietal, and viscerous layers; innervated superficially by phrenic nerves
serous pericardium
parietal layer: lines inner surface of fibrous pericardium; visceral layer: adhered to surface of heart, continuous with parietal layer of pericardium at great vessels (analagous to pleura)
fibrous pericardium
tough external layer, inelastic and so protects the heart against overfilling, attached to the central tendon of the diaphragm
transverse pericardial sinus
located posterior to aorta and pulmonary trunk; allows surgeon to clamp aorta and pulmonary trunk to control arterial outflow
pericardial cavity
potential space between parietal and visceral layers; contains thin layer of serous fluid
inflammation of serous pericardium; results in roughened surfaces that produce a pericardial friction rub during auscultation
cardiac tamponade
heart compression; fluid accumulates in pericardial cavity and restricts heart's ability to expand and fill with blood (due to inelastic fibrous pericardium)
performed to drain fluids from pericaridal cavity; needle inserted to the left of the xiphoid process and directed superiorly deep to costal margin (subxiphoid approach)
borders of the heart and position of chambers
right border: right atrium between SVC and IVC; inferior border: right ventricle; left border: left ventricle; superior: right and left atrium; right ventricle more anterior and left atrium more posterior
apex of the heart
directed anteroinferiorly and to the left; formed by left ventricle
base of the heart
directed posteriorly and is formed primarily by the left atrium
great vessels associated with heart
brachiocephalic veins, SVC, internal jugular and subclavian veins, IVC, aorta, common carotid artery, subclavian artery
difference between right and left brachiocephalic veins
Left bc vein is much longer than the right as it crosses anterior to the major arteries arising from the arch of the aorta
brachiocephalic veins
blood flow from arm and head; Internal jugular and subclavian veins join to form left and right bc veins ; Left and right bc veins join to form the SVC
superior vena cava
returns blood from structures superior to the diaphragm to the right atrium
inferior vena cava
returns blood from structures inferior to the diaphragm; travels through caval opening (T8) in central tendon of diaphragm
branches of the arch of aorta
(proximal to distal); brachiocephalic trunk (gives rise to right subclavian and right common carotid arteries), left common carotid artery, left subclavian artery
ascending aorta emerges from left ventricle; arch of aorta begins at the level of the sternal angle, arches over the right pulmonary artery and courses superoposteriorly; continues as the thoracic (descending) aorta after reaching level of sternal angle again
parasympathetic innervation of the heart
via vagus nerve, decreases heartrate; preganglionic CB in the brain; preganglionic fibers constitute vagus nerves; postganglionic CB in heart; postganglionic fibers in wall of target organ
location of (pathways of) vagus nerves of the heart
left and right vagus nerves course into the mediastinum just lateral to common carotid arteries and travel posterior to the root of the lungs
right vagus nerve
Gives off right recurrent laryngeal nerve, which courses posterior to the right subclavian artery; Contributes to the cardiac plexus and right pulmonary plexus; Contributes to the esophageal plexus and continues into abdominal cavity
left vagus nerve
gives off left recurrent laryngeal nerve, which courses under the arch of the aorta; Contributes to the cardiac plexus and left pulmonary plexus; Contributes to the esophageal plexus and continues into the abdominal cavity
left recurrent laryngeal nerve
branch of left vagus nerve; courses under deep arch; travels deep to the ligamentum arteriosum; innervates muscles of larynx; compression of nerve caused by aneurysm of the aortic arch or enlargement of lymph nodes causes hoarseness of voice
ligamentum arteriosum
remnant of fetal ductus arteriosus, which extends from the inferior margin of arch of the aorta to the left pulmonary artery
what may cause hoarseness of voice?
an aneurysm of the aortic arch or enlargement of the lymph nodes in the area (due to carcinoma of the lungs or esophagus) can compress the left recurrent laryngeal nerve nerve. As the recurrent laryngeal nerves innervate the muscles of the larynx, the patient may present with hoarseness of voice.
sympathetic innervation of the heart
increases heart rate; preganglionic CB in lateral horn of thoracic spinal cord; preganglionic fibers travel from ventral root to spinal nerve to white ramus communicans to sympathetic trunk; postganglionic CB lie in upper thoracic and cervical paravertebral (chain) ganglia; postganglionic fibers (cardiac nerves) travel from paravertebral ganglia to cardiac plexus in mediastinum
cardiac pain innervation
Visceral sensory fibers follow the pathway of the sympathetic nerves back to the thoracic spinal cord
cardiac referred pain
phenomenon whereby visceral pain (e.g., due to ischemia of the heart during a cardiac arrest) is perceived as pain arising from a superficial part of the body (e.g., medial aspect of upper extremity; T1 dermatome)
path of blood through the heart
body -> RA -> RV -> lungs -> LA -> LV -> body
what separates the chambers of the heart?
septa (interatrial septum, interventricular septum)
grooves on the surface of the heart
coronary (atrioventricular) groove, anterior interventricular groove, posterior interventricular groove, coronary vessels sit in these grooves
coronary arteries
arise from ascending aorta; right and left
right coronary artery
Courses in the coronary groove; Usually gives off sinoatrial (SA) nodal branch; also branches into right marginal branch and posterior interventricular branch (in posterior interventricular groove)
left coronary artery
branches into anterior interventricular branch (left anterior descending, LAD) in anterior interventricular groove towards the apex; also into circumflex branch in coronary groove which then branches into left marginal branch
myocardial infarction
an area of heart muscle has undergone necrosis, is usually caused by ischemia due to occlusion of coronary arteries.
lack of adequate blood supply
coronary bypass surgery
technique used to shunt blood around narrowed/blocked coronary arteries
coronary sinus
venous drainage into right atrium; Occupies posterior portion of the coronary groove; Collects blood from several other cardiac veins (all without valves); Tributary patterns can vary (usually a great, middle, small cardiac vein)
right atrium
openings of the SVC, IVC, and coronary sinus; separated by LA by interatrial septum; contains fossa ovalis, pectinate muscles on right auricle, crista terminalis, and right atrioventricular orifice
right auricle
appendage of the right atrium with pectinate muscles
crista terminalis
Ridge separating auricle and smooth posterior wall
right atrioventricular valve
tricuspid; cusps open passively during atrial contraction; papillary muscles/chordae tendineae function to hold tricuspid valve closed during ventricular contraction, preventing backflow of blood into the right atrium
fossa ovalis
oval-shaped depression in interatrial septum that is the remnant of the embryonic foramen ovale
right ventricle
contains trabeculae carnea muscle; Anterior, posterior, and septal papillary muscles, Chordae tendineae, interventricular septum, septomarginal trabecula, pulmonary orifice
chordae tendineae
in right ventricle: extend between papillary muscles and valves of tricuspid valve; in left ventricle: extend btwn pap muscles and cusps of mitral valve
septomarginal trabecula / moderator band
Muscle bundle extending from interventricular septum to anterior papillary muscle; Carries a portion of the right bundle branch (part of the conducting system)
pulmonary valve
three cup-shaped cusps, three pulmonary sinuses, When ventricles relax, blood fills the sinuses above the cup-like cusps; as the sinuses fill, they hold the valve closed
left atrium
Openings of the pulmonary veins; Left auricle with pectinate muscles; Left atrioventricular orifice
mitral valve
between LA and LV; bicuspid, open passively during atrial contraction; Papillary muscles/chordae tendineae of LV function to hold mitral valve closed during ventricular contraction, preventing backflow of blood into the left atrium
left ventricle
wallls over twice as thick as RV, contain trabeculae carneae, anterior and posterior papillary muscles, cordae tendinae, aortic orifice
aortic valve
Three cup-shaped cusps; Three aortic sinuses; When ventricles relax, blood fills the sinuses above the cup-like cusps; as the sinuses fill, they hold the valve closed; Blood in the aortic sinuses flows into coronary arteries
postnatal blood flow
Oxygen-poor blood in IVC, SVC, coronary sinus enters right atrium flows into right ventricle enters pulmonary trunk > left and right pulmonary arteries > lungs; Oxygen-rich blood in pulmonary veins enters left atrium flows into left ventricle enters ascending aorta > arch of aorta > major branches (to head, upper extremities) or thoracic aorta > body
umbilical vein
how oxygen rich blood enters fetus
ductus venosus
oxygen rich blood from umbilical is shunted past liver via the ductus venosus, as there is no need to filter/process the blood; DV leads into the IVC
inferior vena cava in fetal circulation
from ductus venosus, carries oxygen rich blood to right atrium
bypasses in fetal heart
no need to oxygenate blood in lungs; foramen ovale and ductus arteriosus
foramen ovale
allows blood to pass from RA to LA; from here it passes to LV > aorta > body
ductus arteriosus
allows blood that does enter RV and pulmonary trunk to bypass pulmonary arteries; shunting the blood to arch of aorta > body
what kind of blood flows into the right ventricle and pulmonary trunk of a fetus?
usually oxygen poor blood from SVC which does not mix with oxygen rich blood from IVC
pulmonary circulation in fetus
little blood flows through due to high vascular resistance in collapses fetal lungs; blood follows path of least resistance (via foramen ovale, ductus arteriosus)
fetal circulation changes at birth
with first intake of air, vascular resistance in lungs is reduced and blood flow takes on adult pattern, fetal bypasses atrophy
adult remnants of fetal circulation
Round ligament of the liver (fetal umbilical veins); Ligamentum venosum (fetal ductus venosus); Fossa ovalis (fetal foramen ovale); Ligamentum arteriosum (fetal ductus arteriosus); Medial umbilical ligaments (fetal umbilical arteries)
fetal blood flow pathway
umbilical vein > ductus venosus > IVC > RA > foramen ovale > LA > LV > aorta > body > umb arteries; SVC > RA > RV > pulmonary trunk > ductus arteriosus > aortic arch > body > umb. arteries
conducting system of the heart
sinoatrial node > atrioventricular node > atrioventricular bundle (bundle of His)
sinoatrial node
Located at junction of SVC and right atrium; “Pacemaker” of the heart, initiates impulse for contraction of the cardiac muscle of the atria; Stimulated by its sympathetic innervation (increases heart rate), inhibited by its parasympathetic innervation via the vagus nerve (decreases heart rate)
atrioventricular node
Located in the interatrial septum; Receives signal of SA node via atrial walls; Sends signal to ventricles via the AV bundle
atrioventricular bundle
bundle of His, Located in the interventricular septum; Divides into right and left bundle branches ; Right bundle stimulates interventricular septum/walls/papillary muscles of the right ventricle (e.g., via moderator band); Left bundle stimulates interventricular septum / walls / papillary muscles of the left ventricle
posterior mediastinum
esophagus, thoracic/descending aorta, azygos system; thoracic duct; right lymphatic duct; sympathetic trunks
esophagus (description, location)
Fibromuscular tube (typically flattened) between the pharynx and stomach; Lies posterior to the trachea in the superior mediastinum; Lies to the right side of the thoracic aorta; Lies posterior to the base of the heart (primarily the left atrium);Passes through the esophageal hiatus of the diaphragm (T10)
thoracic aorta (description, location)
descending aorta; Continuation of arch of aorta at the sternal angle; Lies to the left of midline; Passes through the aortic hiatus of the diaphragm (T12)
branches of thoracic aorta
Anterior (midline) branches: bronchial arteries, esophageal arteries; Paired branches: posterior intercostal arteries course along costal grooves of ribs (part of VAN); subcostal arteries
what makes up the azygos system?
no valves, azygos vein, hemiazygos vein, accessory hemiazygos vein
azygos vein
Lies to the right of midline; Collects blood from mediastinal structures (via esophageal, bronchial veins), thoracic wall (via posterior intercostal veins) and posterior abdominal wall (via lumbar veins); Drains primarily into the SVC; To reach the SVC, it arches superior to the root of the right lung
hemiazygos vein
Lies to the left of the midline; Courses posterior to the esophagus to join the azygos vein
accessory hemiazygos vein
Lies to the left of the midline, superior to the hemiazygos vein; Courses posterior to the esophagus to join the azygos vein
thoracic duct
Collects lymph from most of the body; Courses on the anterior surface of the vertebral bodies, between the azygos vein and esophagus; Drains into left venous angle
right lymphatic duct
Collects lymph from the right upper quadrant (right side of head/neck/thorax, right upper extremity); Drains into right venous angle
sympathetic trunks
Connects series of paravertebral ganglia; Extends from cervical to sacral region; Connected to intercostal nerves (which are ventral rami of thoracic spinal nerves) via white and grey rami communicans
left/ right venous angle
where R/L subclavian and R/L internal jugular veins join; thoracic duct drains into left, right lymphatic into right
sympathetic innervation to skin of body wall (blood vessels, arrector pili muscles, sweat glands)
preganglionic CB in lateral horn of thoracic spinal cord; preganglionic fibers travel from ventral root > spinal nerve > white ramus communicans > sympathetic trunk (can ascend/descend or stay to synapse); postganglionic CB in paravertebral ganglia; postganglionic fibers travel from grey ramus communicans > ventral or dorsal rami > body wall
sympathetic innervation to abdominal organs
via thoracic splanchnic nerves; greater, lesser least splanchnic nerves emerge from sympathetic trunks in posterior mediastinum; carry preganglionic fibers that synapse in prevertebral ganglia in abdomen