Transport systems (heart/blood)- Unit 2.3 Flashcards
What are the 5 main types of blood vessel?
- Arteries
- Arterioles
- Capillaries
- Venules
- Veins
Describe an insects heart.
A ‘dorsal’ heart. A long tube with chambers separated by valves. Tube rungs along insects back and pumps blood backwards through body segments.
Why do insects not need a version of haemoglobin in their blood?
They don’t carry respiratory gases in their blood, they diffuse straight from the tracheoles in the body tissues.
What is a closed circulatory system?
Blood flows through vessels.
What do all arteries carry, except for pulmonary arteries?
Oxygenated blood
Describe an open circulatory system.
Blood doesn’t flow through vessels, it is pumped out of the heart into spaces in the body cavity.
What is a single circulatory system?
Blood goes through the heart once per circuit of the body.
What is a double circulatory system?
Blood goes through the heart twice per circuit.
Describe the circulatory system of a fish.
Closed & single
Describe the circulatory system of a mammal
Closed & double
Describe the circulatory system of an insect.
Open & single
What direction of blood flow do arteries have?
From heart to body tissue
What direction of blood flow do veins have?
From body to heart
Thickness of an artery wall?
Thick
Thickness of a vein wall?
Thin
Size of lumen in an artery?
Wide
Size of lumen in a vein?
Narrow
Why are there valves in veins but not arteries?
Arteries don’t need them due to high pressure. (Blood won’t flow the wrong way)
Veins have lower pressure so need them to stop blood flowing the wrong way.
State two differences between capillaries and other blood vessels.
- Capillaries are smaller (1 layer endothelium)
* They facilitate exchange of substances between blood and body tissue.
What do the pulmonary arteries carry and where?
Deoxygenated blood to the lungs
What are arterioles?
Arteries that have divided into smaller tubes that form a network of vessels throughout the body.
What is the smallest type of blood vessel?
Capillaries
What are venules?
A network of vessels that spread away from the capillary beds towards veins.
Do veins have a lot of elastic and muscle tissues?
No
