CVS Session 2- The Heart As A Pump Flashcards Preview

SOPHIE'S ESA 2 > CVS Session 2- The Heart As A Pump > Flashcards

Flashcards in CVS Session 2- The Heart As A Pump Deck (31)
Loading flashcards...
0
Q

Where is the aortic valve located?

A

Between the left ventricle and the aorta

1
Q

Where is the mitral valve located?

A

Between the left atrium and the left ventricle

2
Q

Where is the tricuspid valve located?

A

Between the right atrium and the right ventricle

3
Q

Where is the pulmonary valve located?

A

Between the right ventricle and the pulmonary artery

4
Q

Which are the atrioventricular valves?

A

Mitral and tricuspid valves

5
Q

Which are the outflow valves?

A

Aortic and pulmonary valves

6
Q

Features of cardiac muscle (6)

A
  • striated
  • branching
  • intercalated discs
  • gap junctions
  • one or two central nuclei per fibre
  • unlike skeletal muscle, the T tubules are inline with the Z bands
7
Q

What feature of cardiac muscle allows the flow of electrical current?

A

The fact that low resistance connections and gap junctions join muscle fibres.

8
Q

How long does a single contraction last?

A

280-300ms

9
Q

How many action potentials cause one heartbeat?

A

One

10
Q

Where is the SA node found?

A

The right atrium

11
Q

How long is the action potential delayed at the AV node once spread from the SA node over the atria?

A

120ms

12
Q

Describe the route of excitation of the heart myocardium.

A
  • the SA node fires an AP which spreads over the whole atria.
  • this excitation spreads to the AV node, where it is delayed.
  • it then spreads down the septum between the ventricles.
  • then across the ventricles
  • then from the endo to the epicardium of the ventricles.
13
Q

Which way do ventricles contract and relax?

A

Contract- from the apex up

Relax- from the top to the apex

14
Q

Why does the apex of the heart relax last?

A

To prevent back flow.

15
Q

When heart rate increases, what is affected and how?

A

The length of diastole.

It is shortened.

16
Q

What is the structure of ventricular muscle and why is this the case?

A

Ventricular muscle is organised into figure of eight bands. They squeeze the ventricles forcefully for the most efficient blood ejection out of the outflow valves.

17
Q

Define systole.

A

The period when the myocardium is contracting.

18
Q

Define diastole.

A

The period when the myocardium is relaxing, in between contractions.

19
Q

What shuts the valves of the heart?

A

A small amount of regurgitation of blood.

20
Q

What causes the first heart sound?

A

The closing of the atrioventricular valves.

21
Q

What causes the second heart sound?

A

Closing of the outflow valves.

22
Q

When does the first sound occur?

A

During atrial systole.

23
Q

When does the second heart sound happen?

A

Ventricular systole.

24
Q

What are murmurs caused by?

A

Turbulent blood flow, due to

  • stenosis (narrowed valves)
  • incompetence (valves not closing properly)
25
Q

What is the equation for cardiac output?

A

CO= heart rate x stroke volume

26
Q

What is the definition of cardiac output?

A

The volume of blood pumped per minute by the left heart.

27
Q

What causes the closing of the atrioventricular valves?

A

Contraction of papillary muscles.

28
Q

What causes the closing of the semi-lunar valves?

A

Regurgitation of a small amount of blood.

29
Q

Where are the openings to the coronary arteries found?

A

In the aortic wall (right) above the right and left coronary cusps.

30
Q

When does coronary artery filling occur?

A

During diastole.

Decks in SOPHIE'S ESA 2 Class (74):