YR2-CH5&6-LSN4

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

HAVE READY:

GOOGLE CLASSROOM

KERBOODLE PAGE 67-71

your homework FOR TODAY

TODAY:

- discuss difficult hw assignments

- theory on circulation

- work on in class assignments.

CLASS ASSIGNMENTS LSN 3:

-  Complete the exercises on tb pages 78 and 79

ANSWER SHEET IS ON CLASSROOM, CHECK & DISCUSS THE ANSWERS

ANY QUESTIONS ABOUT THE HW ASSIGNMENTS:

Lesson 4: Circulation

- I understand why a circulatory system is required in multicellular organisms

- I understand the relationship between how the heart is built how that functions to optimize circulation

- I understand and recognize the differences in types of blood vessels

double circulatory system 

- The heart is a double pump 

 - Left side pumps oxygenated

    blood towards your body.

- Oxygenated blood is depicted in RED

- Right side pumps deoxygenated blood                 towards your lungs 

- Deoxygenated blood is depicted in BLUE

- LEFT = RIGHT & RIGHT = LEFT

The heart

- Double pump

- Pumping = putting high pressure on blood so that it starts moving

- 2 Atria (sing: Atrium)

- Atria: support pumps 

- 2 Ventricles

- Ventricles: main pumps

- One direction blood flow

- Valves prevent back flow

Blood flow

LEFT

pulmonary vein > left atrium > left ventricle > aorta

RIGHT

vena cava > right atrium > right ventricle > pulmonary artery

Valves

- Valves allow bloodflow in one direction ONLY!

If pressure on the otherside increases, valves close so backflow is prevented

Heart cycle

1. atrial contraction

- artery valves closed

- heart valves open

> pushes blood to the ventricles

2. ventricular contraction

- artery valves open

- heart valves closed

> pushes blood to the major arteries

3. heart pause (both atria and ventricles are relaxed)

- all valves open

- relaxing atria and ventricles create suction

> allows the heart to refill from the vena cava

From which chamber of the heart does blood leave to go to the lungs?

1. Right ventricle
2. Right atrium
3. Left ventricle

Which chamber produces the highest pressure in the blood?

1. Right atrium
2. Left atrium
3. Left ventricle

How is it possible that blood only flows one way?
Because:

1. of the blood pressure
2. blood cells know how to flow
3. there are valves, preventing back flow
4. of how the heart contracts

Aorta

pulmonary artery

pulmonary vein

vena cava

right atrium

right ventricle

left atrium

left ventricle

tricuspid valve

aortic  valve

mitral valve

pulmonary valve

septum

apex

Heart itself needs blood too!

The heart cells require a lot of energy. A lot of cellular respiration is taking place

The heart requires a lot of oxygen and glucose

This is provided by the coronary arteries that run on the the outside of the heart.

Blood vessels types

• Arteries - carry blood away from the heart
• Veins - Carry blood back to the heart
• Capillaries - go to every cell in the body (oxygen and CO2 exchange)

Arteries

• Elastic walls which stretch to cope with high pressure of the blood
• They contract and bounce back because of the blood pressure rising and falling with the heart cycle
• Lie deeper within the body

Veins

• Are wider than arteries
• Thinner walls because of lower blood pressure 
• blood is squeezed along by your muscles 
• backflow is prevented with valves

Capillaries

• Smallest blood vessels
• Very thin walls 
• Just one cell layer thick
• Allows for optimal diffusion
• Large surface area
  
  

	Wall	Pressure	Speed	Valves
Artery
Vein
Capillary

One cell thick

thick, elastic

thin

high

high

low

low

high to low

high to low

yes

no

no

Which statement is true?

1. In general, the circulatory system looks like this: Heart -> veins -> capillaries -> arteries -> heart
2. In general, the circulatory system looks like this: Heart -> arteries -> capillaries -> veins -> heart

Which blood vessel has a wall which is only 1 cell layer thick?

1. All of them
2. Arteries
3. Capillaries
4. Veins

1. 1.artery 2. vein 3. capillary
2. 1. capillary 2. artery 3. vein
3. 1. vein 2. capillary 3 artery
4. all answers are wrong

Naming of the blood vessels

• Arteries: organ it is going to + artery (for example pulmonary artery, liver artery) (exception: aorta)
• Veins: organ it is coming from + vein, for (example pulmonary vein, liver vein) (exceptions: 
• Capillaries: are not named!

Blood route question: an oxygen molecule flows from the capillaries in the lung to the capillaries in the kidney. 

Drag the major blood vessels and parts of the heart through which this oxygen molecule passes in the right order. BE AWARE! Not all blood vessels and parts of the heart are part of this route!

1

2

3

4

5

pulmonary artery

left atrium

right atrium

right ventricle

aorta

pulmonary vein

renal artery

renal vein

left ventricle

superior vena cava

Lesson 4: Circulation

- I understand why a circulatory system is required in multicellular organisms

- I understand the relationship between how the heart is built how that functions to optimize circulation

- I understand and recognize the differences in types of blood vessels

WHAT TO DO NOW:

- WORK ON THE IN CLASS ASSIGNMENTS FOR LESSON 4

- COMPLETE THESE FIRST

- STUDY FOR YOUR TESTWEEK!!