Download Distributing materials - VCE

Distributing materials
Key understanding:
To discuss features of effective transport
systems and give examples of transport
systems in multicellular organisms
• Why do we have transport systems?
• What needs to be transported?
• What are the features of effective transport
systems?
Circulatory systems
Open circulatory systems
• Open ended vessels
• Fluid flows freely between cells of the body
• Very low pressure and long circuit times
Closed circulatory systems
• Fluid (blood) is entirely enclosed within system of vessels
and pumped around body by muscular heart
• High blood pressure
• Blood is separated from interstitial fluid by vessel walls
which allows it to have greater specialisation
• (page 165)
Blood circulation in mammals
• 2 sequential pathways involved:
1) Pulmonary vessels to and from the lungs
2) Systemic vessels to and from the rest of the
body
• Arteries carry blood AWAY from the heart
• Veins carry blood TO the heart
Transport systems in
multicellular organisms
http://www.teachersdomain.org/ass
et/tdc02_vid_circulator/
Label diagrams
Heart dissection
Heart dissection (see page 173 of biozone)
http://www.youtube.com/watch?v=z3UHpvEJMns&featu
re=related
•
-
Try to identify:
Left and right atria
Left and right ventricles
The atrioventricular valves
Pulmonary artery and vein
Aorta
Vena cava
Coronary arteries
• Identify the flow of blood on your diagrams(p167)
• Deoxygenated blood FROM body flows into RIGHT
ATRIUM via the VENA CAVA
• When atria contract it then flows into RIGHT
VENTRICLE
• When RIGHT VENTRICLE contracts blood flows into
PULMONARY ARTERY
• Blood becomes oxygenated
• Re-enters the heart through PULMONARY VEIN into
LEFT ATRIUM, then into LEFT VENTRICLE
• When LEFT VENTRICLE contracts blood flows to rest of
the body via the AORTA
• Use different colours for oxygenated and deoxygenated
blood
• http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hh
w_pumping.html
Blood pressure
• Pressure can be felt as a pulse when the heart contracts
• A persons blood pressure is usually measured by systolic pressure
and diastolic pressure e.g. 120/80
• See pages 1743-174
•
•
-
Diastole (minimum blood pressure)
Ventricles relax and fill with blood
Arterial valves close
Systole (maximum blood pressure)
Ventricles contract and push blood into the arteries
Atrioventricular valves close
- Gives a ‘lub-dub’ sound – this is the sound of the valves closing shut
Blood vessels
1) Arteries (page 168)
- Muscular walls
- High blood pressure
2) Veins (page 171)
- More easily stretched
3) Capillaries (page 171)
- Very thin walls made of only single layer of
epithelial cells
- To enable exchange of substances between blood
plasma and interstitial fluid
Tasks and homework
• Biozone - Mammalian Transport p167-174
• Extra reading Heinemann 152-158
Other animals
• Biozone - Circulatory systems (general)Pages
164- 166