levo

The Cardiovascular System

The cardiac conduction system and heart rate control

  • 3 things to know
  • Paper 1

Overview

Myogenic cardiac muscle, the SA node, AV node and route of the impulse, the cardiac control centre, sympathetic and parasympathetic control, the anticipatory rise, adrenaline and carbon dioxide.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

Why is cardiac muscle described as myogenic?

Key term

Where is the sinoatrial (SA) node, and what does it do?

Key term

What happens as the impulse spreads from the SA node across the atria?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    Why is cardiac muscle described as myogenic?

    Model answer

    Cardiac muscle generates its own electrical impulse without needing nervous stimulation. The impulse starts in the sinoatrial node.

  2. 2

    Where is the sinoatrial (SA) node, and what does it do?

    Model answer

    The SA node lies in the wall of the right atrium. The SA node acts as the pacemaker, sending out the impulse that starts each heartbeat.

  3. 3

    What happens as the impulse spreads from the SA node across the atria?

    Model answer

    The atria contract, which is atrial systole. Blood is forced through the atrioventricular valves into the ventricles.

  4. 4

    Why does the atrioventricular (AV) node delay the impulse?

    Model answer

    The AV node holds the impulse for about 0.1 seconds. The delay lets the atria finish contracting before the ventricles contract.

  5. 5

    Describe the route of the impulse after it leaves the AV node.

    Model answer

    The impulse passes down the bundle of His in the septum and into the bundle branches. The Purkinje fibres then spread it through the ventricle walls, causing ventricular systole.

  6. 6

    Put the parts of the cardiac conduction system in order, from the start of a heartbeat.

    Model answer

    The order is the SA node, the AV node, the bundle of His, the bundle branches and the Purkinje fibres.

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

The Cardiovascular System
The Respiratory System
The Neuromuscular System
The Musculo-Skeletal System and Movement Analysis

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

The democratic leader is .
person-orientedtask-orientedautocratic

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

ADrug testing protects athletes' health.
BDrug testing keeps competition fair.
CDrug testing deters cheating.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

Scalar means a quantity described by size alone.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in The Cardiovascular System, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.