coronary arteries

Question 1

define coronary vascular reserve

what condition diminishes this

Answer 1

The capacity of the coronary circulation to increase blood flow, The maximum increase in blood flow above the normal resting volume, determines how much you can increase the delivery to get more o2

since the heart already extractrs like all the o2 the only way to increase o2 extraction is to increase flow

diminished by stenosis- arteries already dialated so cant respond to increased demand

Question 2

what are the ways to influence increased coronary reserve

Answer 2

local dialators: adenosine

endothelium: shear stress –> prostacyclin, NO, EDHF to go to VSMC
nervous: increases vasoconstri BUT the impact on HR and contractility overrides for an overall vasodilation

Question 3

what artery supplies the SA node

Answer 3

RCA in 60% of cases

Question 4

what supples the RV

Answer 4

right marginal from RCA, PDA, some of LAD (anterior)

Question 5

what supples the LV

Answer 5

LCA and PDA

Question 6

what does the PDA supply

Answer 6

RV, LV, posterior 1/3 of interventricular septum…. anatomizes with left and determines dominance of the heartàbranches of RCA in 67% of people

Question 7

what does the LCx supply

Answer 7

LA and LV

Question 8

what supplies the majority of the anterior septum

Answer 8

septal branch of the LAD

Question 9

what are the most common sites of occlusion

Answer 9

1. Proximal LAD, 40-50% of all occlusions
2. Proximal RCA*, 30-40% of occlusions
3. LCx, 15-20% of occlusions
4. LMCA
5. Proximal PDA
6. RCA distal to marginal a.

Question 10

where does the coronary sinus drain into

Answer 10

The coronary sinus opening is in the right atrium superior to the septal leaflet of the tricuspid valve. This opening is guarded by the Thebesian valve. Most of the cardiac veins drain into the coronary sinus.

Question 11

what does the great cardiac vein run with

middle

small

Answer 11

LAD

PDA

right marginal

Question 12

what two veins The following two veins drain directly into the heart. They do not drain into the coronary sinus.

Answer 12

•Anteriorcardiacveindrains the anterior RV and drain directly into the RA.

Venaecordisminimae(“smallest cardiac veins”, see above) also drain directly into the four chambers of the heart. They are found on both the heart’s anterior and posterior surfaces

Question 13

what is the difference between the R and L vagus nerve

Answer 13

R- SA

L- AV

Question 14

differentiate preganglionic and post ganglionic

Answer 14

•Sympathetic motor

• Preganglionicsoriginate in the intermediolateral columns at spinal levels T1 to T4/5. Some travel up to the cervical ganglia
• Postganglionicsdeliver signals to the SA and AV nodes, atrial and ventricular cardiomyocytes, and coronary vessels

•The preganglionic sympatheticssynapse in the cardiac plexus on the way to the heart; the parasympatheticstravel through the cardiac plexus without synapsing.

Question 15

what is the nerve responsible for cardiac referred pain

Answer 15

ntercostobrachial nerve

Question 16

what make up the borders of the AV node triangle

Answer 16

Question 17

what is the source of most atrial tachyarrythmias.

Answer 17

Disruption of the anterior interatrial bundle (Bachmann’s bundle) is the likely source of most atrial tachyarrythmias.

Question 18

where is the AV node located

Answer 18

The AV bundle travels through the fibrous skeleton of the heart (central fibrous body) and is found along the R posterior surface of the membranous septum. In the image to the left it is labeled “penetrating segment”.

•At the muscular septum, the AV bundle bifurcates into the right and left bundle branches.

Question 19

what supplies the anterior and posterior fascicle of the LBBB and the RBBB

Answer 19

LAD supplies RBB anterior

RCA-posterior

Question 20

Which of the following associations is incorrect?

A.greatcardiac vein—ascends parallel to the anterior interventricular artery

B.middlecardiac vein—ascends parallel to the posterior interventricular artery

C.anteriorcardiac veins—terminate in the coronary sinus

D.obliquevein of left atrium—terminates by forming coronary sinus with great cardiac vein

E.coronarysinus—traverses the posterior aspect of the coronary groove

Answer 20

C

Question 21

6.Persistent hyperglycemia secondary to diabetes mellitus is associated with degeneration of Schwann cells. In the ANS, the structures most susceptible to damage are the relatively smaller, nonmyelinated axons. Which of the following is most likely to be affected?

A.Cardiacnerve branches of the cervical ganglia.

B.Cardiacnerve branches of the vagus nerve

Answer 21

6.A—these are the unmyelinated sympathetic postganglionics. The cardiac nerve branches of the vagusare preganglionic.