Flashcards
Blood vessels
Flashcards do conjunto (22)
- 1What are the 3 components in blood vessels and what do they do?Elastic fibres - stretch and recoil for flexibility
Smooth muscle - Contracts or relaxes to change size of lumen
Collagen - Structural support - 2What do arteries do?Carry blood away from the heart
- 3What is the pressure in arteries?High
- 4What are the components in arteries?- Elastic fibres
- Smooth muscle
- Collagen - 5What do the elastic fibres do in the arteries?- Withstand high pressure
- Contract to maintain continuous flow - 6What is the end of an artery called?Endothelium
- 7What do Arterioles do?Link arteries and capillaries
- 8What components do arterioles have?More smooth muscle and less elastin which constrict and dilate to control blood flow.
- 9What is vasoconstriction?When smooth muscle contracts to prevent blood flow into a capillary bed.
- 10What is vasodilation?When smooth muscle relaxes to allow blood flow into capillary beds.
- 11What do capillaries do?Link arterioles and venules
- 12Where are capillaries?An extensive network through the tissues
- 13What is the purpose of capillaries?Substances diffuse through the capillary walls.
- 14How do substances leave the capillaries?Through the gaps between the endothelial cells that make up the capillaries, this excludes capillaries in the nervous system which have tight junctions.
- 15How are capillaries adapted to their role?- Large surface area for diffusion
- Smaller area than arteriole to slow blood flow for more time to exchange substances
- Single cell thick, thin layer for diffusion - 16What do veins do?Carry blood to the heart
- 17What the blood pressure in the veins?Low
- 18Which veins have valves?Medium veins
- 19Properties of veins?- Collagen and little elastic fibres in walls
- Wide lumen
- Smooth, thin lining for easy flow - 20What do venules do?Link capillaries and veins
- 21Properties of venules?- Thin wall
- Smooth muscle - 22Adaptation of the veins for their function?- Valves stop backflow
- Big veins in muscles so muscle contraction causes blood flow
- Breathing movement works as a pump when the pressure changes in the chest cavity.
Informações
- Descrição
- AS level Biology (Chapter 08 - Transport systems in Animals ) FlashCards sobre Blood vessels, criado por Bethany Westwood em 03-03-2017.
- Criado por
- Bethany Westwood
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