Heart and Mediastinum Anatomy Flashcards Preview

Cardiovascular > Heart and Mediastinum Anatomy > Flashcards

Flashcards in Heart and Mediastinum Anatomy Deck (45):

systemic circulation

the circulation of the body as a whole bu separate from the pulmonary circulation


caval system

the venous side of the systemic circulation as it returns blood to the heart via the superior and inferior vena cavae


pulmonary circulation

circulation from the heart to the lungs and back


azygous system

system of veins (intercostals and hemizazygous veins) draining the thoracic wall converging on the azygous vein that drains into the superior vena cava


hepatic portal system

venous circulation from GI organ capillaries to the venous sinusoids of the liver via the portal vein and its branches



connections between the small branches of two larger arteries or veins

it provides for collateral circulation between them if one is occluded

end arteries have no anastomoses such as renal arteries or the central artery of the retina of the eye


coelomic sacs

enclosed serous sacs that line the body cavities

visceral pleura lines the lung surface

parietal pleura lines the body wall


parietal pericardium

the sac that surroudns the heart with visceral and parietal serous layers that reduce friction as the heart beats

has a fibrous pericardium on the outside and a serous inner layer


visceral pericardium

also known as the epicardium, the serous layer covering the fat/coronary vessels of the heart


cardiac tamponade

compression of the heart from an abnormal collection of fluid in the pericardial cavity

fibrous pericardium has low compliance, so increased fluid accumulation increases pressure outside the heart

this restricts filling of the heart with blood


Describe the position of the heart in the thorax.

spans anterior ribs 2-6, the length of the body of the sternum

a horizontal plane through the ventricles is at vertebral body T7/T8


Describe the orientation of the heart in terms of its anterior, posterior boundaries as well as its right and left margins.

anterior - right ventricle

posterior - left atrium

right margin - right atrium

left margin - left ventricle


What parts of the lungs butt against the heart?

the middle lobe of the right lung and the lingula of the upper lobe of the left lung


Describe the bloodflow through the heart.

superior and inferior vena cava -> right atrium -> right atrio-ventricular (tricuspid) valve -> right ventricle -> pulmonary semilunar valve -> pulmonary trunk -> pulmonary arteries -> lungs -> pulmonary veins -> left atrium -> left atrio-ventricular (mitral or bicuspid) valve -> left ventricle -> aortic semilular valve -> aorta -> systemic circulation


crista terminalis

crest between pectinate muscle and smooth posterior wall

it contains pacemaker tissue in addition to the sino-atrial node


fossa ovalis

remnant of the fetal foramen ovale, a blood shunt from right to left atrium


conus arteriosus

smooth top of the right ventricle tapering into the pulmonary semilunar valve


trabeculae carnae

"fleshy little beans" of muscle lining most of the ventricles


papillary muscles

specialized trabeculae stabilizing the atrioventricular valves via the chordae tendinae

prevents back swining of the vvalve cusps into the atria during ventricular systole


septomargiinal trabeculae

ridges between the smooth conus arteriosus and the trabecular wall below

a significant one is the moderator band from the interventricular septum to the papillary muscles


aortic vestibule

a structure of the left ventricle

the smooth upper part of the chamber equivalent to the conus arteriosus of the right ventricle



What prevents the semilunar valves from allowing backflow?

the blood-filled sinus between each valve cusp and arterial wall prevents the open valve cusps from sticking to the wall


Where is the best place to hear the aortic and pulmonary valves?

the 2nd intercostal space


Where is the best place to hear the tricuspid and mitral valves?

the 5th left intercostal space


Describe the arrangement of heart muscle and how this affects the contraction process.

the muscle layers are arranged in a spiral fashion, and contraction proceeds form the apex upwards, squeezing blood toward the AV valves like wringing a towel


What does the left coronary artery branch into?

anterior interventricular (LAD), circumflex, and left marginal branches


What heart structures does the left coronary artery supply?

most of the left atrium and ventricle

anterior part of the right ventricle adjacent to anterior interventricular artery

anterior 2/3 of the IV septum

AV bundle branches in the septum


What does the right coronary artery branch into?

marginal, nodal (right atrial), posterior interventricular (descending) branches


What heart structures do the right coronary artery supply?

most of the right atrium and ventricle

posterior part of the left ventricle adjacent to the posterior interventricular artery

posterior 1/3 of the IV septum

SA (60%) and AV (80%) nodes


left dominant circulation

a variation where the left coronary artery gives rise to the posterior interventricular artery (fromt he circumflex, the anterior interventricular, or both) in addition to its typical branches


coronary sinus

an endothelial-lined, venous channel imbedded in heart muscle in the posterior atrioventricular groove rather than a typical, free-standing vein

it drains blood from most of the heart into the right atrium


Where do the anterior cardiac veins drain?

directly into the right atrium


great cardiac vein

begins in the anterior interventricular groove and continues on as the coronary sinus


middle cardiac vein

joins the coronary sinus from the posterior interventricular groove


venae cordis minimae

smallest cardiac veins that connect capillary beds directly to heart chambers, and blood may flow in either direction


stellate ganglion

the enlarged, star-shaped ganglion of the sympathetic trunk that supplies much of the heart and lungs

it is the fusion of the inferior cervical ganglion and T1 ganglion

sympathetics from the stellate ganglion and visceral sensory fibers that pass through it from T1 supply the ventricless


cardiopulmonary splanchnic nerves

nerves that carry fibers from lower cervical and upper thoracic levels of the sympathetic trunk

postsynaptic neurons whose cell bodies are in the sympathetic trunk


parasympathetic innerveation of the heart

comes from the vagus nerve via the plexus on the bifurcation of the trachea

the postsynaptic parasympathetic neurotransmitter acetylcholine functions on the SA node to slow the heart rate


visceral sensory innervation of the heart

sensory fibers travel from the heart via the cardiopulmonary splanchnic nerves

from the sympathetic trunk they travel in communicating rami into the spinal nerves and enter the spinal cord via dorsal roots

cell bodies are in the dorsal root ganglia


middle mediastinum

contains the heart and pericardium, beginning of the great vessels, primary bronchi, and the arch of the azygous vein


anterior mediastinum

contains fatty connective tissue, the remains of the thymus gland, deep parasternal lymph nodes, and the internal thoracid (mammary) vessels


posterior mediastinum

contains the esophagus, thoracic duct, azygous and hemiazygous veins, thoracic sympathetic trunk and splanchnic nerves, thoracic (descending) aorta, posterior intercostal arteries and nerves, and lymph nodes


superior mediastinum

contains the great vessels, trachea, upper esophagus and thoracic duct, ,vagus and phrenic nerves, left recurrent laryngeal nerve, and upper part of the thymus gland


azygous system

a system of veins that receives blood from the intercostal veins

left posterior intercostal veins drain into the hemiazygous veins that pass over the vertebral bodies to join the azygous vein

it arches over the root of the right lung to empty all intercostal blood into the superior vena cava