The content of blood

What are my objectives while studying this topic?

The effects of sugar, salt and adrenaline have different effects upon the action of the heart. The body has to meet these ever-changing demands and balance the content of the blood. The heart is the central organ within the circulatory system.

You will study the structure of the heart and the specialized cells that make up the tissues forming the heart. This will help you understand the function of the heart within the cardiac cycle. You will also study the composition of the blood and how its content is maintained in the circulatory system.

Why is this important?

Fitness and healthcare professionals measure and monitor heart function and the control of the blood flowing to and from the rest of the body by taking physiological measurements. These measurements assist healthcare professionals improve the well being and performance of an individual’s circulatory system as well as diagnosing cardiovascular diseases.

Can I get an introduction to this topic?

Yes, why not have a look at the following link:


Diffusion and osmosis

What will I be expected to be able to do after studying this topic?

  • State factors that affect the balance of blood

  • Be able to describe osmosis

  • Relate osmosis to the regulation of salts in the body

  • Know and describe the regulation of the blood by hormones

    (Osmotic pressure on blood cells)

Content of blood

What are the key words to learn and use for this topic?

  • Hormone

  • Salts

  • Ions

  • Glucose

  • Adrenaline

  • Diabetic

How long will this topic take to study?

On average you’ll be looking at about two to three hours of taught time and independent study.

What are the main activities on this topic?



  • The body’s cells: what they need, and the maintenance of the correct environment

  • The need for glucose for cellular respiration, and meeting the needs of cells during exercise

  • The relevance of adrenaline as related to 'fight or flight', upping the heart rate and relating to glucose levels

  • The nervous control of systems leading to either low or high blood pressure, eg during a fitness training program

  • The impact of increased salt in the blood causing hypertension


Take a look at the following link to help you with this activity:


Prepare a case study of a diabetic patient, for example. In your report think about how they test their blood glucose levels and regulate this by diet, tablets or insulin injections.

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