cardiac structure conducting and cycle part 2 Flashcards
1
Q
When is coronary blood flow at its highest
A
when the ventricle is relaxing
2
Q
why is blood flow into the coronary arteries not good
A
the coronary arteries originating at the base of two of the cusps of the aortic valve causes this
3
Q
- How is heart muscle supplied with oxygenated blood
A
via the coronary arteries and their branches
4
Q
- What 2 things does narrowing or bloackage of the coronary arteries or their branches with atheroma or thrombus lead to?
A
- cardiac ischaemia (angina)
- myocardial infarction (heart attack)
5
Q
- What does the left coronary artery supply with blood?
A
supplies Left side of heart
6
Q
- Where is the coronary sinus located?
A
found in the inferior portion of the left atrioventricular groove
7
Q
- Where does the coronary sinus receive blood from?
A
many tributary veins
8
Q
- Where does the coronary sinus empty into? (think position and then the actual place)
A
posteromedial right atrium
9
Q
- What is the largest cardiac venous structure?
A
coronary sinus
10
Q
- What are the three distinct layers of the heart wall?
A
- epicardium
- Myocardium
- endocardium
11
Q
- Describe 1 feature of the epicardium layer of the heart wall
A
- Thin, external membrane that covers the heart
12
Q
- Describe the 4 features of the myocardium
A
- middle layer composed of cardiac muscle
- makes up bulk of heart
- consists of interlacing bundles of cardiac muscle fibres
- arranged spirally around circumference of heart
13
Q
- Describe the 2 features of the endocardium
A
- Thin, inner layer
- lined by the endothelium
14
Q
what is the endothelium unique to
A
unique to the circulatory system
15
Q
- How is striated muscle shortened?
A
the thick filaments pulling the thin filaments towards the centre of the sarcomere, thereby making the H zone and I bands shorter
