AQA ORGANISATION 4.2.2.2

The heart and blood vessels

4.2.2.2 The heart • Students should know the structure and functioning of the human heart and

lungs, including how lungs are adapted for gaseous exchange.• The heart is an organ that pumps blood around the body in a double

circulatory system. The right ventricle pumps blood to the lungs where gas exchange takes place. The left ventricle pumps blood around the rest of the body.

• Knowledge of the blood vessels associated with the heart is limited to the aorta, vena cava, pulmonary artery, pulmonary vein and coronary arteries. Knowledge of the names of the heart valves is not required.

• The natural resting heart rate is controlled by a group of cells located in the right atrium that act as a pacemaker. Artificial pacemakers are electrical devices used to correct irregularities in the heart rate.

• Students should be able to use simple compound measures such as rate and carry out rate calculations for blood flow.

01/05/2023

The heart is made out of ____________ Muscle.

It is a double _________ that squeezes the blood around the ________ and to the

________. The _________ side pumps blood to the lungs to pick up ______________. The

_________ side pumps blood around the rest of the body.

RIGHT, LEFT, CARDIAC, BODY, PUMP, LUNGS, OXYGEN

Structures of the heart

Label the diagram of the heart you have been given

We are now going to complete a heart dissection

Follow your method sheet

The cardiac cycle

rightatrium

leftatrium

rightventricle

leftventricle

aortapulmonaryartery

pulmonaryvein

vena cava

muscle

from lungs

to headand bodyto lungs

from headand body

Which structure?

Multiple-choice quiz

4.2.2.2 The heart LOs

• Know structure and function of the human heart

• Name and locate the blood vessels associated with the heart

• Understand what resting heart rate is

• Explain what a pacemaker is a why we would need one

4.2.2.2 The lungs• Students should know the structure and

functioning of the human heart and lungs, including how lungs are adapted for gaseous exchange.

• Knowledge of the lungs is restricted to the trachea, bronchi, alveoli and the capillary network surrounding the alveoli.

The lungs LOs

• Describe the structure of the lungs

• Explain how the lungs are adapted for gas exchange

4.2.2.2 The blood vessels

• The body contains three different types of blood vessel:

• • arteries

• • veins

• • capillaries.

• Students should be able to explain how the structure of these vessels relates to their functions.

Blood vessels LOs

• Describe the structure of the three types of blood vessels

• Link the structure of the blood vessels to their function

Compare the different types of blood vessels

Blood flow in veins – valves

Veins have valves to prevent backflow.

blood to the heart

backflow prevente

d vein

valve open vein

valve closed

When blood flows along veins it pushes

past the valves, which can

only open in one direction.

If blood in a vein does flow backwards, it is trapped by closed valves.

Arteries and veins • Arteries have thick muscle walls and blood is at a

high pressure.

• Veins have thinner muscle walls and valves to prevent the backflow of blood. Blood is at a lower pressure.

Compare the cross-section of a vein

Comparing cross-sections

Veins do not need to keep blood flowing quickly at high pressure and so they have much thinner

walls than arteries.

and an artery. Why are they

different?

CapillariesCapillary walls are one cell thick and

allow substances to diffuse in and out. These include oxygen, glucose,

salts and carbon dioxide.

Capillaries

Blood flow in veins – preventing backflow

Blood travels back to the heart in veins at low pressure.

If the blood pressure is too low, what, for example, might happen to the blood in leg

veins?

gravity

blood to the heart possible

backflow of blood

If low-pressure blood has to move against gravity, it mightslow down further and even flow in the wrong

direction!

Which type of blood vessels?

• The drawings show the structure of three types of blood vessel, A, B and C. They are drawn to the scales indicated.

• (a)     Name the three types of blood vessel.• A ..............................................................• B ..............................................................• C ..............................................................• (b)     Describe the job of blood vessel B.• .................................................................................

.................................................................................

...........................• ................................................................................................

The diagram shows the human circulatory system

.

(a)     Name the types of blood vessel labelled A, B and C on the diagram.A .................................................................B .................................................................C .................................................................

(b)     What is the job of the circulatory system?

......................................................................

......................................................................

......................................................................

......................................................................

c)     Give two ways in which the make up of the blood changes as it flows through the vessels labelled X on the diagram.

1 .................................................................................................................................

....................................................................................................................................

2 .................................................................................................................................

....................................................................................................................................

Practice exam question

Answers – peer assess green pen

A – arteriesB – capillariesC – Veinsb. To pump blood around the body.

Deliver nutrients to the cells and remove waste

c. Blood carbon dioxide levels decrease & blood oxygen levels increase (GAS EXCHANGE)

4.4.4.2 BLOOD• Blood is a tissue consisting of plasma, in

which the red blood cells, white blood cells and platelets are suspended.

• Students should know the functions of each of these blood components.

• Students should be able to recognise different types of blood cells in a photograph or diagram, and explain how they are adapted to their functions.

Blood LOs• Name the components of blood

• Describe the functions of the blood components

• Recognise the different blood cell types from photographs and diagrams

• Explain and link the adaptations of blood cells to their functions

Blood practical work• AT 7

• Observing and drawing blood cells seen under a microscope.

• WS 1.5

• Evaluate risks related to use of blood products.