Download File - Sanders School

Circulatory system
LQ: What does it contain?
Alveoli
Alveoli – 480 million in the lungs
http://www.gettyimages.co.uk/detail/video/alve
oli-stock-footage/116034549
•
•
•
•
•
•
•
•
•
•
How are alveoli adapted for their function?
Thin wall – only 1 cell thick
Why is this an advantage?
Gases can diffuse into/out of alveoli quicker
Surrounded by blood vessels
Allow for faster diffusion
Moist lining
Allows gases to be dissolved in liquid and diffuse quicker
LARGE SURFACE AREA
Millions of alveoli allow more gases to diffuse into the
blood
• Stretched out flat, the alveoli in your lungs
would cover a football field!!!!
Lungs questions – purple books
1. What happens when you inhale? (5 things)
(grade 4)
2. What happens when you exhale? (5 things)
(grade 4)
3. Why do you think some people can inhale more
than others? (grade 5)
4. Give two adaptations of the alveoli. For each
adaptation, explain why this adaptation allows
for better gas exchange in the lungs (grade 6)
5. What would happen to your breathing if you
punctured your lungs? (grade 7)
Breathing In:
• Your intercostal muscles contract . They raise your ribs
upwards and outwards.
• The muscles in your diaphragm contract . Your
diaphragm flattens.
• These increase the volume of your chest.
• The pressure inside your chest decreases.
• Ribs move up And out
Breathing Out:

Your intercostal muscles relax. This lowers your ribs
downwards and inwards.

The muscles in your diaphragm relaxes . Your diaphragm
bulges upwards.

These decrease the volume of your chest.

The pressure inside your chest increases.

Ribs move down And in.
3. Larger lungs, larger chest area, stronger
diaphragm
4. You could not take in more air without it
leaking out, you could not breathe in and out
(pressure would be same in and out of chest so
no air would be forced in/out)
Starter
• What is in the circulatory system?
• Heart, blood vessels, blood
• What is the function of the heart / circulatory
system?
• To transport blood around the body and transport
essential food/oxygen to cells and remove waste
material e.g. carbon dioxide/urea
• What does the heart do?
• Beats – contracts and relaxes
• What is the heart made of?
• muscle (cardiac)
• https://www.youtube.com/watch?v=XwU42o
B4zDg
• https://www.youtube.com/watch?v=Bjn3TwM
r4xs
• https://www.youtube.com/watch?v=W4VjN7s
cvBA
Double circulatory system
Label the heart
G
H
I
Questions
1. Which label shows the main artery that pumps blood
to the body
2. Which label shows the main artery that pumps blood
to the lungs
3. Which label shows the main vein from the body to
the heart
4. Which label shows the main vein from the lungs to
the heart
5. What is the function of part B?
6. Why is the left side of the heart thicker than the right
hand side?
Pacemaker
• Why does your heart beat?
• Group of cells in the right atrium
• Produce an electrical impulse that spreads to the
heart muscle cells, causing them to contract
• What is an artificial pacemaker?
• If someone has an irregular heartbeat this is
fitted under the skin
• It has a wire going to the heart that produces an
electrical impulse to keep the heart beatng
regularly
Questions
1. What is the function of the circulatory system?
2. What is the function of each circuit in the
circulatory system?
3. Name the four chambers of the heart.
4. Describe how blood flows through the heart
from the vena cava
5. Describe how the resting heart rate is controlled
in a healthy heart.
6. How does an artificial pacemaker work.
Label the heart