Title: Physiology / 02 Cardiology / Section 1- Introduction to Cardiology
Tags: 1- Cardiology:: Introduction Physeo::02 Section to Cardiology Questions

Q: List each step in the pathway of coronary circulation.
A: Coronary sinus--> Right atrium (RA)
RA-->Right ventricle (RV)
RV-->pulmonary arteries
Pulmonary arteries-->pulmonary veins
Pulmonary veins-->Left atrium (LA)
LA-->Left ventricle (LV)
LV-->Aortic root
Aortic root--> coronary arteries
Coronary arteries-->coronary sinus

Q: What is the purpose of the coronary arteries?
A: Supply oxygenated blood to the heart itself

Q: The left coronary artery (LCA) branches into the [...] and [...].
A: left circumflex artery (LCX); left anterior descending artery (LAD)

Q: Explain the difference between left and right-dominant circulation. Which is more common?
A: Left-dominant circulation = when the posterior descending artery (PDA) branches off the LCX (left circumflex). This is the LEAST common, occuring 10% of the time.
Right-dominant circulation = when the PDA branches off the right coronary artery (RCA). This is the MOST common, occuring 80% of the time.

Q: Other than the PDA (80% of the time), what other artery branches off the RCA?
A: Right marginal artery

Q: ID structures A-F
A: A = RCA (right coronary artery)
B = LCA (left coronary artery)
C = LCX (left circumflex = br LCA)
D = LAD (left anterior descending =br LCA)
E = PDA (posterior descending = 80% RCA br, 10% LCA br)
F = Right marginal artery (RMA) (br RCA)

Q: ID structures A-C.
A: A = LCX (left circumflex = LCA br)
B = Coronary sinus
C = PDA (posterior descending = 80% RCA br, 10% LCA br)

Q: What 5 structures does the RCA supply?
A: If you are very visual, below is my VERY crude representation of the areas supplied by each artery of coronary circulation.

Q: What does the RMA supply?
A: RV

Q: What 3 structures does the LAD supply?
A: Again, below is a VERY crude visual representation of areas supplied by coronary circulation.

Q: What are the 4 structures supplied by the LCX?
A: Again, below is my VERY crude visual representation of areas supplied by coronary circulation.

Q: What are the 4 areas supplied by the PDA?
A: Again, below is my VERY crude visual representation of areas supplied by coronary circulation.

Q: List each step in the SYSTEMIC pathway of blood leaving from and returning to the RA.
A: RA--> RV (tricuspid valve)
RV-->pulmonary arteries (pulmonic valve)
pulmonary arteries-->pulmonary veins
pulmonary veins--> LA
LA-->LV (mitral valve)
LV--> aorta (aortic valve)
aorta-->arteries
arteries-->arterioles
arterioles-->Capillaries (gas exchange)
capillaries--> venuoles (no deO2 blood)
venuloes--> veins
veins--> vena cava
vena cava--> RA

Q: List the location of each of the 4 valves of the heart.
A: Tricuspid = between RA and RV
Pulmonic = between RV and pulmonary arteries
Mitral (bicuspid) = between LA and LV
Aortic = between LV and aorta

Q: Where does gas exchange occur?
A: Capillaries

Q: What vessels contribute the most to total peripheral resistance (TPR)?
A: Arterioles contribute the most to TPR.

Q: How would an AV shunt alter O2 content in the tissues?
A: Decreased O2 to tissues
Explanation: AV shunts are abnormal connections between arteries and veins that allow O2 blood from arteries to travel directly to veins, skipping the capillaries. Since gas exchange occurs in the capilaries, skipping the capillaries means very little O2 is given to the tissues.

Decreased activity of the posterior aspect of the RV
Explanation: RCA suplies the posterior aspect of the ventricles.

Left atrium
Explanation:

Coronary sinus
Explanation:
~Extra credit (not in lecture but seen in UWorld and on exams): Because the myocardium is so metabolically active, it cannot contract after 60s without oxygen (aka afte 60s of ischemia).~

Increased pressure in RV, RA, and coronary sinus
Explanation: Whenever you see stenosis, think "back flow." Stenosis of an artery makes it harder for blood to flow through, causing less to be pumped through and thus essentially causing "back flow." Decreased volume through the pulmonic artery = decreased volume through the pulmonic valve = more volume in the RV = more volume in the RA = more volume in the coronary sinus. A greater volume will exert a greater pressure.