4.Analyse the results by comparing the total score with the following
descriptors:
30 marks- you take very good care of your heart. Well done!
25 marks- you take good care of your heart. Keep it up!
20 marks- you take reasonably good care of your heart but need to work
on a few aspects where you scored 0.
15 marks- you need to take better care of your heart.
0-10 marks- you do not look after your heart at all. It’s time to make a
change to a healthier lifestyle.
Assessment Rubric
|
0- not done1- poorly presented. 2- average presentation of results, but missing
some detail.3- average presentation of results, including all salient featuresand information.4- good presentation of results, but missing some detail.5-
good presentation of results, including all salient features and information. |
|
5 |
Rich media:
Khan Academy
http
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www
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khanacademy
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org
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video
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circulatory
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system
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and
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the
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heart
?
playlist
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Biology
Cardiac Magnetic Resonance imaging of Beating heart: Large magnets are used to
create images of the heart inside the body, without the need for surgery.
http://upload.wikimedia.org/wikipedia/commons/7/73/Four_chamber_cardiovascular_m
agnetic_resonance_imaging.gif
View from the top
http://commons.wikimedia.org/wiki/File:Beating_Heart_axial.gif
View from the side
http://commons.wikimedia.org/wiki/File:Cardiac_mri_ani_sagittal_bionerd.gif
Blood vessels
Structure and functioning of arteries, veins, capillaries and valves
Arteries
- Arteries carry blood from away from the heart. The pressure created by the
pumping heart forces blood down the arteries.
- Arteries have three layers.
- Outside layer – connective tissue
- Middle layer – smooth muscle, allows contraction of the arteries to
regulate blood flow and pressure
- Inside layer – single layer of tightly connected simple squamous
endothelial cells
- The large arteries close to the heart branch into smaller arterioles (smaller
arteries) and eventually branch into capillaries.
Capillaries
- Capillaries are little more than a single layer or endothelial cells.
- Capillaries form intricate networks throughout the tissues.
- They allow water, nutrients and gasses to diffuse out of the blood and waste
materials to diffuse into the blood.
- This exchange occurs between the blood and the interstitial fluid.
- The interstitial fluid is the fluid surrounding the cells.
- The blood never comes into contact with the cells.
- The blood and interstitial fluid exchange material, and the interstitial fluid
then exchanges material with the cells.
Veins
- The intricate networks formed by the capillaries eventually converge to form
venules, (small veins)
- The venules then converge to form veins which return the blood to the heart.
- Veins only consist of two layers.
- The outer layer is made up of connective tissue
- The inner layer is made up of endothelial cells.
Valves
- Once the blood has passed through the capillaries very little blood pressure
remains to return blood to the heart.
- Instead of pressure from the heart veins use a series of valves to force blood
to return to the heart.
- Contraction of the muscles squeezes the veins, pushing the blood through them.
- The valves cause the blood to flow in only one direction, back to the heart.
