Adult heart

Question 1

transverse thoracic plane

Answer 1

(through sternal angle)

T4-T5 interspace

Question 2

superior mediastinum

Answer 2

roots of great vessels, aortic arch, ligamentum arateriosum, thoracic duct

Question 3

anterior mediastinum

Answer 3

thymus, retrosternal fat, nerves

Question 4

posterior mediastinum

Answer 4

descending aorta, esophagus, vagus n. etc

Question 5

T8-T9 interspace

Answer 5

between heart and diaphragm

Question 6

cardiothoracic (CT) ratio

Answer 6

~0.5 (heart width to thoracic cavity width)

Question 7

phrenic n. is located between

Answer 7

parietal pleura and fibrous pericardium

travels with pericardiacophrenic vessles

Question 8

phrenic n.

Answer 8

C3, 4, 5

Question 9

vagus n. runs ____ to root of lung

phrenic n. runs ___ to root of lung

Answer 9

vagus n. runs posterior to root of lung

phrenic n. runs anterior to root of lung

Question 10

pericardial hematoma

Answer 10

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

Question 11

water bottle silohuette on CXR

Answer 11

highly suggestive of pericardial effusion

Question 12

cardiac tamponade

Answer 12

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

Question 13

transverse pericardial sinus

Answer 13

Permits expansion of great vessels during systole.

Behind aorta/pulmonary trunk.

Question 14

oblique sinus

Answer 14

permits expansion of LA during exhalation

^should be attached at 8 spots

Question 15

right behind sternum

Answer 15

right ventricle

Question 16

function of coronary sulcus

Answer 16

reduce friction against pericardial sac

facilitate coronary artery perfusion by minimizing compression of the arteries

Question 17

Reperfusion strategies during CAD

Answer 17

1. coronary artery collateralization (new capillary growth)
2. reverse blood flow in thebesian veins
3. endogenous bypass via vasa vasorum

If insufficient –> CABG

Question 18

most commonly occluded CA

Answer 18

LAD

then RCA, then circumflex branch

Question 19

used for bypass grafts

Answer 19

great saphenous vein
L. internal thoracic a.
radial a.

(arteries have greater longevity than veins)

Question 20

coronary sinus

Answer 20

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”

Question 21

region between “smooth and rough” parts of inner heart

Answer 21

crista terminalis

smooth –> sinus venarum
rough –> pectinate muscles

Question 22

fossa ovalis

Answer 22

vestige of former foramen ovale (shunt from RA to LA, lets fetal blood bypass non-ventilated lungs)

Question 23

pectinate m. are in _____, while trabeculae carnae are in ______

Answer 23

pectinate m. –> in atria

trabeculae carnae –> in ventricles (facilitate contraction and provide blood turbulence)

Question 24

_______ muscles contract before the ventricular myocardium. How is this initiated?

Answer 24

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

Question 25

which pump allows for coronary a. perfusion

Answer 25

the elastic recoil of the distended aorta

closes valves, R/L aortic sinuses catch the backflow during diastole

Question 26

w/ blocked coronary a., what is particularly susceptible to damage?

Answer 26

purkinje fibers

Deepest layer, farthest from artery and penetrating arterioles

Question 27

pericardium

Answer 27

Dense CT.
Can expand if slow accumulation of fluid (pericardial effusion).
Rapid accumulation of fluid is not tolerated bc not elastic enough

Question 28

pericardial effusion

Answer 28

accumulation of fluid in cardiac cavity

Question 29

thebesian veins

Answer 29

Tiny vessels in the 4 chambers of the heart.

Drain directly into RA.

Question 30

coronary artery disease (CAD)

Answer 30

Damage to coronary arteries.
Due to cholesterol deposits (atherosclerotic plaque).
Leading cause of death in US (both men and women)

Question 31

valve of IVC

Answer 31

Shunted blood toward foramen ovale during fetal development

Question 32

sympathetic innervation of heart

Answer 32

Cardiac plexus: T1-T4

Increase heart rate

Question 33

parasympathetic innervation of heart

Answer 33

CN X: Vagus Nerve
Decrease heart rate

Always on – normal is 100 bpm, but PNS dampens to 72 bpm

Question 34

nervous input of transplanted hearts

Answer 34

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).