Adult heart Flashcards
transverse thoracic plane
(through sternal angle)
T4-T5 interspace
superior mediastinum
roots of great vessels, aortic arch, ligamentum arateriosum, thoracic duct
anterior mediastinum
thymus, retrosternal fat, nerves
posterior mediastinum
descending aorta, esophagus, vagus n. etc
T8-T9 interspace
between heart and diaphragm
cardiothoracic (CT) ratio
~0.5 (heart width to thoracic cavity width)
phrenic n. is located between
parietal pleura and fibrous pericardium
travels with pericardiacophrenic vessles
phrenic n.
C3, 4, 5
vagus n. runs ____ to root of lung
phrenic n. runs ___ to root of lung
vagus n. runs posterior to root of lung
phrenic n. runs anterior to root of lung
pericardial hematoma
poss because myocardium ruptures through an old infarction
presents w/ muffled heart sounds, jugular venous dissension, low arterial pressure
CXR –> water bottle silhouette, highly suggestive of pericardial effusion
water bottle silohuette on CXR
highly suggestive of pericardial effusion
cardiac tamponade
acute pericardial effusion
BECKS TRIAD
- muffled heart sounds due to blood insulation, weakened beat
- jugular distension due to reduced venous return
- low arterial pressure due to reduced SV/CO
pathognomonic –> sx so characteristic that they’re essentially diagnostic
transverse pericardial sinus
Permits expansion of great vessels during systole.
Behind aorta/pulmonary trunk.
oblique sinus
permits expansion of LA during exhalation
^should be attached at 8 spots
right behind sternum
right ventricle
function of coronary sulcus
reduce friction against pericardial sac
facilitate coronary artery perfusion by minimizing compression of the arteries
Reperfusion strategies during CAD
- coronary artery collateralization (new capillary growth)
- reverse blood flow in thebesian veins
- endogenous bypass via vasa vasorum
If insufficient –> CABG
most commonly occluded CA
LAD
then RCA, then circumflex branch
used for bypass grafts
great saphenous vein
L. internal thoracic a.
radial a.
(arteries have greater longevity than veins)
coronary sinus
collects drainage from great cardiac vein, middle cardiac vein and small cardiac vein
exception to rule that all venous is “cardiac” while arterial is “coronary”
region between “smooth and rough” parts of inner heart
crista terminalis
smooth –> sinus venarum
rough –> pectinate muscles
fossa ovalis
vestige of former foramen ovale (shunt from RA to LA, lets fetal blood bypass non-ventilated lungs)
pectinate m. are in _____, while trabeculae carnae are in ______
pectinate m. –> in atria
trabeculae carnae –> in ventricles (facilitate contraction and provide blood turbulence)
_______ muscles contract before the ventricular myocardium. How is this initiated?
papillary
moderator band shortcut
SA node impulse travels through moderator band to papillary m. first
–> puts tension on chordae tendineae so they won’t snap
which pump allows for coronary a. perfusion
the elastic recoil of the distended aorta
closes valves, R/L aortic sinuses catch the backflow during diastole
w/ blocked coronary a., what is particularly susceptible to damage?
purkinje fibers
Deepest layer, farthest from artery and penetrating arterioles
pericardium
Dense CT.
Can expand if slow accumulation of fluid (pericardial effusion).
Rapid accumulation of fluid is not tolerated bc not elastic enough
pericardial effusion
accumulation of fluid in cardiac cavity
thebesian veins
Tiny vessels in the 4 chambers of the heart.
Drain directly into RA.
coronary artery disease (CAD)
Damage to coronary arteries.
Due to cholesterol deposits (atherosclerotic plaque).
Leading cause of death in US (both men and women)
valve of IVC
Shunted blood toward foramen ovale during fetal development
sympathetic innervation of heart
Cardiac plexus: T1-T4
Increase heart rate
parasympathetic innervation of heart
CN X: Vagus Nerve
Decrease heart rate
Always on – normal is 100 bpm, but PNS dampens to 72 bpm
nervous input of transplanted hearts
NO external input.
Cannot reattach cardiac plexus.
Endogenous rhythm maintains bpm of 90-110.
Catecholamines in circulation can increase/decrease, but is delayed.
No sensory input (angina).
