CV - Lesson 8 .1

• Human
• Lower Secondary (Key Stage 3)

Cardiovascular System

Lesson 8

What is the role of antagonist muscles?

1. Provide strength for lifting tasks
2. Initiate movement in the opposite direction
3. Oppose the movement of agonist muscles
4. Stabilize joints during movement

Antagonist muscles work during which phase?

1. When muscles are injured
2. During the contraction phase
3. During the relaxation phase
4. Only at rest

Which one is an example of an antagonist/ agonist pair?

1. Bicep and Hamstring
2. Bicep and Tricep
3. Quadriceps and Glutes
4. Hamstring and Quadriceps

Lesson Objectives

- To have an understanding of the cardiovascular system.

-  To have an understanding of the purpose of our heart and lung.

- To understand the importance of the cardiovascular system.

What is the purpose of the heart and lungs?

The heart and lungs

The heart and lungs work together to ensure oxygen reaches all the cells in your body. This is needed as it is used along with nutrients from food to produce energy that cells can use.

1 - What do lungs do?

2 - What does the heart do?

3 - What type of blood cells transport blood around the body?

4 - What type of metal is used to help transport blood around the body?

Question time - open to page 35/36

During exercise, the body needs more energy for our muscles. This means that more carbohydrates is needed. And the body needs to get rid of waste products more quickly. This is why when you exercise, you sweat and you breathe harder.

If you exercise regularly, your heart and lungs adapt to the demands placed on them. This can improve your cardiovascular health and reduce the risk of some diseases. Types of exercise that help this are often called ‘cardio’ exercises. They make our heart beat faster. 

Cardio Exercises

Cardiovascular system

The cardiovascular system is a closed system of organs that pump blood, nutrients, and oxygen around the body. It is also known as the circulatory or vascular system. The cardiovascular system also removes carbon dioxide and waste products from the body's cells. 

The heart's cardiac cycle has two phases: diastole and systole. During diastole, the ventricles fill with blood, and during systole, they contract and eject blood.

Cardiovascular diseases affect the heart and blood vessels. An early diagnosis can lead to effective treatment, alongside lifestyle changes and medication. 

What might cause someone to get Cardiovascluar disease?

What are the major ORGANS that make up the cardiovascular system? 5.1

Locate the major organs that make up the cardiovascular system 5.1

Heart

Blood vessels

Lungs

Blood

Heart

Lungs

Blood Vessels

Blood

The heart is a large muscular pump and is divided into two halves - the right-hand side and the left-hand side.

The right-hand side of the heart is responsible for pumping deoxygenated blood to the lungs.

The left-hand side pumps oxygenated blood around the body.

Each side of the heart consists of an atrium and ventricle which are two connected chambers.

The a______ is the largest artery in the body. It carries oxygenated blood away from the left ventricle to the body. The v_____ cava is the largest vein in the body. It carries deoxygenated blood from the body back to the heart.

The p________ a______ carries deoxygenated blood away from the right ventricle to the lungs.

The p_________ v_____ returns oxygenated blood from the lungs to the heart.

orta

ena

ulmonary

ulmonary

rtery

ein

What is in Blood

Blood

Red blood cells

Oxgyen

Carbon dioxide

Plasma

White blood cells

Waste (urea)

Platelets

Digested food

Hormones

What makes up our blood?

Red blood cells - The most abundant cells in our blood; they are produced in the bone marrow and contain a protein called hemoglobin that carries oxygen to our cells.

White blood cells - They are part of the immune system and destroy infectious agents called pathogens.

Plasma - This is the yellowish liquid portion of blood that contains electrolytes, nutrients and vitamins, hormones clotting factors, and proteins such as antibodies to fight infection.

Platelets - The clotting factors that are carried in the plasma; they clot together in a process called coagulation to seal a wound and prevent a loss of blood. 

The average adult has about FIVE litres of blood inside of their body which makes up 7-8% of our body weight.

Blood is living tissue that carries oxygen and nutrients to all parts of the body, and carries carbon dioxide and other waste products back to the lungs, kidneys, and liver for disposal. It also fights against infections and helps heal wounds so we can stay healthy.

There are about one billion red blood cells in two to three drops of blood. For every 600 red blood cells, there are about 40 platelets and one white blood cell. 

What are the three main blood vessels?

Arteries

Arteries carry blood away from the heart.

They have thick elastic walls that stretch and can withstand the surges of high pressure caused by the heartbeat.

There are three layers of tissues in the walls of an artery.

- It is lined with smooth endothelial cells that reduce friction from blood flow.

- The middle layer is the thickest layer. It is made of elastic fibers and smooth muscle to make it stretchy.

- The outer fibrous layer protects that artery. The pulse is only felt in arteries. 

Capillaries

The semi-permeable membrane of capillary walls allows nutrients, oxygen, and water to diffuse from the blood to the tissues.

Waster products, like carbon dioxide, diffuse from the tissues into the blood.

they have a huge surface area to volume ratio, helping rapid diffusion of substances between blood and cells. 

Veins

Veins carry blood from every tissue in the body to the heart.

As the pressure is so much lower in the veins than in the arteries, there is little need for the elastic fibers and smooth muscles in the walls. 

They have a larger lumen than arteries, to reduce the resistance to flow. 

Veins as semi-lunar valves that aid the return flow of blood and prevent blood from reversing flow. 

These valves allow for muscle contractions and movement of body parts. The valves assist the return flow of blood to the heart when blood pressure is low. 

Arteries carry blood away from the heart towards an organ and veins carry blood from an organ towards the heart.

An easy way to remember this is: Arteries Away or Vein In.

Blood full of oxygen is called oxygenated blood. Blood with oxygen removed is called deoxygenated blood.

Arteries carry oxygenated blood away from the heart and veins carry deoxygenated blood back to the heart.

One important exception: unlike all other arteries and veins, the pulmonary artery (from the heart to the lungs) carries blood with oxygen removed and the pulmonary vein (from the lungs to the heart) carries blood full of oxygen. 

Vein

Artery

Capillary

Identify the different types of blood vessels 5.2

On pages 42 and 43, you need to draw the three different types of blood vessels and then answer the questions.

Think about what we have talked about during this lesson. You can use a Chromebook if need further support. 

Blood vessel	Function	Wall thickness
Artery
Vein
Capillary

5.2 continued

Oxygenated blood, away from heart

Deoxygenated blood, towards heart

Exchange of substances

1 Cell thick

Thin walls

Very thick walls

Double circulation

The human circulatory system is a double circulatory system. It has two separate circuits and blood passes through the heart twice.

- The pulmonary circuit is between the heart and lungs.

- The systemic circuit is between the heart and the other organs. 

Pulmonary Circuit

The pulmonary circuit transports blood to the lungs. The blood is oxygenated there and then carried back to the heart. Exchange of oxygen and carbon dioxide happens in the lungs:

- Carbon dioxide diffuses from the blood into the air in the alveoli.

- Oxygen diffuses from the air in the alveoli into the blood, and is absorbed by the red blood cells.

- Unlike all other arteries and veins, the pulmonary artery carries deoxygenated blood and the pulmonary vein carries oxygenated blood.

The systemic circuit transports blood around the rest of the body. It transports oxygen and nutrients from the heart to the body tissues and carries away deoxygenated blood containing carbon dioxide and other waste materials, which arrive back at the heart.

Systemic circuit

Create a storyboard or timeline to visualize the journey of a blood cell through the body. Research how a blood cell travels through the body. Look for information on the heart, arteries, veins, capillaries, and lungs.

Write a narrative that describes the journey of the blood cell based on your storyboard. Use vivid language to paint a picture of the blood cell’s travel through the body.

5.3 Describe the passage of blood through the body.

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