cardiovascular system - coronary circulation

Question 1

name the types of blood vessels

Answer 1

Arteries, veins, capillaries

Question 2

name the 3 distinct layers of the artery and vein walls

Answer 2

Tunica interna/intima
Tunica media
Tunica externa/adventitia

Question 3

explain the Tunica interna/intima layer of artery and vein walls

Answer 3

Inner endothelial lining plus connective tissue with variable number of elastic fibres

Question 4

explain the Tunica media
layer of artery and vein walls

Answer 4

SMC plus loose connective tissue and external elastic membrane

Question 5

explain the Tunica externa/adventitia
layer of artery and vein walls

Answer 5

Outer connective tissue sheath

Question 6

what is coronary circulation for

Answer 6

Supply oxygen and nutrients to the heart muscle
- Myocardium = Limited anaerobic capacity

Question 7

coronary circulation uses what percentage of circulating blood to meet own metabolic demands

Answer 7

5%

60 - 70% oxygen extracted at rest

Question 8

where are arteries placed around the heart

Answer 8

Arteries encircle heart ‘like a crown’ i.e., coronary

Question 9

name the 2 types of coronary arteries

Answer 9

Right coronary artery (RCA)
Left coronary artery (LCA)

Question 10

explain the Left coronary artery (LCA)

Answer 10

bifurcates into:

left circumflex artery (LCX)

Left anterior descending artery (LAD)

Supply LA and LV

Question 11

explain the Right coronary artery (RCA)

Answer 11

Supplies RA, RV, SA node, AV node and portions of LV

Question 12

Coronary veins drain into what and explain

Answer 12

cardiac chambers

• 20% directly into RV
• 80% to RA by:
  great & middle cardiac veins
  to
  coronary sinus
  to RA

Question 13

coronary artery disease (CAD)

Answer 13

narrowing and blocking of arteries by a blood cloth

Question 14

coronary artery disease is most common cause of what

Answer 14

of compromised coronary circulation
- Most common cause of death globally

Question 15

coronary artery disease causes a reduction in what

Answer 15

of blood flow to the heart
- Atherosclerotic plaque build up

Question 16

give some ex of coronary artery disease

Answer 16

stable angina, unstable angina & myocardial infarction

Question 17

what is myocardial infarction (MI)

Answer 17

‘heart attack’

Question 18

explain Myocardial Infarction (MI)
including symptoms and interventions

Answer 18

Coronary occlusion
- Fatty deposit (atherosclerosis) or blood clot (thrombus)

Sudden death of patch of tissue
- deprived of blood flow

Common symptoms
- Centre/left chest pain travelling to shoulder, arm, back, neck or jaw

Intervention
- Medication, angioplasty, stent or CABG

Question 19

what is Coronary Artery Bypass Graft (CABG) for

Answer 19

To reroute blood around clogged coronary arteries

can be single, double, triple or quadruple

Question 20

explain Circulatory Anastomoses

Answer 20

Union of branches of two or more arteries (or veins) supplying same region

Defence against MI

Two arteries come together and combine blood flow to one region

Alternate route if blockage.

Can occur normally in circulatory system, or due to surgical intervention

Question 21

explain Systemic circulatory routes

Answer 21

Without adequate coronary blood supply, circulation cannot be supported

Two ‘closed’ circuits:

Left = systemic
- Aorta
- Superior & inferior vena cava

Right = pulmonary
- Pulmonary trunk