Quiz 3 Flashcards
What makes up the inferior mediastinum?
Anterior mediastinum(thymus), middle mediastinum (heart) and posterior mediastinum (lots! arteries, veins, nerves, lymphatics) ; starts at sternal angle- T4 line down to diaphragm
What makes up the superior mediastinum?
Just the superior mediastinum; starts at first rib down to sternal angle- T4 line; Infection from oral region can travel down here; the DANGER SPACE
What makes up posterior mediastinum?
From base of diaphragm and crura; has sympathetic trunk (originates T1-L2)(preganglionic axons, post- ganglionic neurons destined for sweat glands, head, neck, heart, and lungs) superior surface of diaphragm, inferior surface of thorax
Greater splanchnic nerve
(T5-T9) In posterior mediastinum; These sympathetics originate in the lateral horns; course through but don’t synapse in T5-9 ganglia; they gather and course down to abdomen; synapse with a pre-aortic ganglion (ex. celiac or superior mesenteric ganglia)
Lesser Splanchnic nerve
(T10-T11); these sympathetics originate in the lateral horn; course through but don’t synapse in the T10-11 ganglia; they gather and course down to abdomen; synapse with a pre-aortic ganglion (ex. celiac or superior mesenteric ganglia)
Least Splanchnic nerve
(T12); these sympathetics originate in the lateral horn; course through but don’t synapse in the T12 ganglia; they gather and course down to abdomen; synapse with a pre-aortic ganglion (ex. aorticorenal ganglia)
Azygous system of veins
right side of thorax has azygous vein; left side of thorax has accessory hemiazygous vein (above T8) and hemiazygous vein (below T8)
Veins of the mediastinum
SVC, right brachiocephalic vein (arm), azygos vein (T4), posterior intercostal veins, anterior intercostal veins, internal thoracic vein, anastomoses of intercostal veins (connection- in case of blockage- bp builds up and goes through system in a dif. way)
Thoracic lymphatic duct
in mediastinum; cisterna chyli; drains lymph from all tissues of the body except right side of head, neck, chest and arm which are drained by right lymphatic duct
Arteries of the mediastinum
Descending aorta (T4), posterior intercostal arteries, internal thoracic artery (internal mammillary artery), anterior intercostal arteries, anastomosis of intercostal arteries
Organs in the mediastinum
Esophagus (to T10) , trachea and primary bronchi (T4), pulmonary arteries, aortic arch
Aortic arch and it’s branches
(T2, T4) (ascending, descending aorta), brachiocephalic trunk (R. common carotid, R subclavian; exists because arterial system has to go further to go to right side due to heart location on left), left common carotid artery, left subclavian artery
Major veins of mediastinum
SVC, IVC, pulmonary veins , brachiocephalic on BOTH sides, veins bring blood to heart (color just tells you if oxygenated or deoxygenated)
Heart
pericardial sac holds heart; SVC, IVC, or coronary sinus –>R. atrium–> tricuspid (R. AV) valve–>R. ventricle–> pulmonary valve–> pulmonary trunk–> pulmonary arteries–> lungs–> pulmonary capillaries(CO2/O2 exchange in alveolus) –> pulmonary veins–> L. atrium–> bicuspid (mitral, L. AV) valve–> L. ventricle (thicker to pump blood to body)–> aortic valve –> aorta (has 2 coronary arteries coming off of it just above valve)–> systemic arteries–>systemic capillaries (CO2/O2 exchange in systemic tissue)–> systemic veins
Serous membranes
Fibrous pericardium (outermost layer), serous pericardium (more inner, 2 layers, in between there is the pericardial space- has serous fluid for lubrication), parietal pericardium (fibrous parietal pericardium, serous parietal pericardium), visceral pericardium (serous visceral pericardium)
Heart orientation
right atrium forms right border, right ventricle forms the anterior border, left atrium forms posterior border, left ventricle forms inferior border; most left chamber (apex)
Right Ventricle distinguishing factors
In right ventricle there are chordae tendinae and papillary muscles with TRICUSPID VALVE
Atrioventricular valves
(tricuspid/ bicuspid) prevent blood from flowing back into atrium; open when ventricle is filling; ventricle contraction sends blood out through any hole and AV valve snaps shut, preventing back flow into atrium, chordae tendinae and papillary muscles hold valve shut; cause the S1 sound
Semilunar valves
(aortic- middle and pulmonary- most anterior) prevent back flow from great vessels into ventricles; when ventricle relaxes and fills, something needs to prevent aortic flow from reversing (blood pushes down to go down void and catches valves which snap them shut) ; cause the S2 sound
Ventricular Diastole
Chamber fills with blood
Ventricular Systole
Chamber is contracting
Auscultation
Listening to the sounds of the heart; S1 (AV) bottom of heart [mitral on left, tricuspid on right] /S2 (semilunar) top of heart [pulmonary on left, aortic on right]; are sounds made by valves closing; sternal angle (rib 2- under it is 2nd space)-T4 line down to diaphragm
S1 (LUB)
the contracting ventricles caused the AV valves to snap shut
S2 (DUB)
the relaxing ventricles caused the semilunar valves to snap shut