Unit 3: The circulatory system 2024

• Biologie
• Middelbare school
• vwo
• Leerjaar 3

Unit 3: The circulatory system

§3.1 Blood

Blood

The transportation system of your body

Consists of blood plasma (±55%) and blood cells (±45%)

What is blood plasma?

91% water

7% blood proteins

2% dissolved substances

Blood cells

Red blood cells

White blood cells

Platelets

Red blood cells

The majority of blood cells (±25 * 10¹² cells )

Disc shaped, no nucleus

Carry oxygen/CO₂ through your body

They use the protein haemoglobin 

White blood cells

Elimination of pathogens

No fixed shape, can move through smallest openings 

Platelets

Broken cell parts

Play an important role in blood clotting

What blood cells are there?

What do you know about blood?

 §3.1

Make 1-4, 6-10

Unit 3 Circulatory system

§3.2 The circulatory system

Blood vessels

'Roads' of blood

3 types:

- Arteries

- Veins

- Capillaries

3 types of blood vessels 

Blood vessels in a human hand

Double circulatory system

Pulmonary circulation

'short circulation'

Systemic circulation

'long circulation'

Arteries

From heart towards organs

Thick muscle layer

High blood pressure

Deeper in the body

Veins

From organs towards heart (exception: portal vein)

Thin muscle layer; valves

Low blood pressure

Close to body surface

Valves

Capillaries

Very thin cell wall; thickness of 1 cell layer

Ideal for gas/nutrient exchange

&

movements of white blood cells

Make §3.2

Exercise 1-4, 6-10

Unit 3: The Circulatory System

§3.3 The heart

Blood vessels

Bloodvessels are the roads of blood

3 types:

- Arteries

- Veins

- Capillaries

Double circulatory system

Pulmonary circulation

To the lungs and back to the heart

Systemic circulation

To the rest of the body and back to the heart

The heart

The 'pump' of your blood:

- Consists of a left half and a right half

- Supported by coronary arteries & veins

Large veins:

Pulmonary vein & inferior/superior venae cavae

Large arteries:

Pulmonary artery & aorta

Blood flow

Right and left are turned around

Right half --> pulmonary circulation 

Left half --> systemic circulation

Blood flows into the heart at the atria, then through heart valves into ventricles

Then it flows from ventricles through the semilunar valves into arteries

How the heart works

Heart valves and semilunar valves allow blood to flow in 

one direction only (it cannot flow back!)

How the heart works

Heart valves and semilunar valves allow blood to flow in 

one direction only (it cannot flow back !)

Cardiac cycle

Muscles in walls of atria and ventricles contract, pushing blood in one direction.

A cardiogram shows one cardiac cycle

Make §3.3

3, 5, 6, 7, 8, 9

Unit 3: The Circulatory System

§3.5 Immunity

What is immunity?

Virus

Bacteria

First line of defence

Skin/Endoderm

Mucous layers

HCl in stomach

White blood cells

Guardians of our bodies against antigenes/pathogens

2 types:

Macrophages

B-cells/T-cells (antibody producing)

Phagocytosis - non-specific immunity

Antibody production 

- specific immunity

Neutralization of pathogen

Make §3.5

1, 2, 6, 9

Unit 3: The Circulatory System

§3.5 Immunity II

What is not an example of a pathogen?

1. Virus
2. Bacterium
3. Antibody
4. Mercury

In which two ways does the body respond to pathogens?

This lesson

What is natural immunity?

What is artificial immunity?

What are allergies?

Antibody production after infection

Smallpox

Poliomyelitis

Artificial immunity

Vaccinations

Allergic response

Hypersensitive immune response

Asthma

Wasp allergy

Choosing your test subject

Make §3.5

Exercise 1-4, 6-11

Unit 3: The Circulatory System

§3.6 Healthy lifestyles

How to live healthy?

Form groups of 6 persons and choose a subject:

Smoking

Alcohol

Unhealthy food

Sport

Psychological Stress

Search for effects on the circulatory system (±20 min)

Look for positive and negative effects (preferably on the WWW)!

Discussion afterwards (±3 min per subject)