Simple Question on Veins (1 Viewer)

[odd_one_out]

I'm trying to do my dot points from the syllabus for bio and I have two contradicting books. Stupid books.

Anyway I just need to know whether veins are thick walled or thin, one says they are thin the other thick. Thanks for the help I know your going to give me

 

[Guernica]

Veins have thinner walls than arteries. But thicker than capillaries.

I think.

 

[odd_one_out]

Alright thank you for clearing that up

 

[Guernica]

I'm not sure. I have only just started the HSC course. Haha.. you should probably double check.

 

[Survivor39]

You are correct. Veins have thinner wall, but a wider diameter in its lumen where blood flows, compared to arteries.

 

[Bokky]

Arteries are thick-walled vessels which carry oxygenated blood away from the heart under HIGH pressure, and effectively pumps blood to all parts of the body.

Veins are thin-walled vessels carrying de-oxygenated blood TO the heart under low pressure, and have valves present to prevent back flow.

Capillaries are one-cell thick (so very thin) and the wall allow the diffusion into and out of the transport system.

 

[Dr_Doom]

And don't veins increase and decrease in size at different temperatures?

 

[Survivor39]

And don't veins increase and decrease in size at different temperatures?

Yes they do, but that's only because of adaptation. But if the examiners ask you to compare the structure and size of the arteries and veins, you assume that both vessles are under physiological conditions.

Vasodilation - increase in blood vessel diametre in repsonse to heat (a physiological response)
Vasorestriction - decrease in blood vessel diametre in repsonse to cold (a physiological response as well)

Note: applies to endotherms only.

 

[SmileyCam]

Arteries are thick-walled vessels which carry oxygenated blood away from the heart under HIGH pressure, and effectively pumps blood to all parts of the body.

Veins are thin-walled vessels carrying de-oxygenated blood TO the heart under low pressure, and have valves present to prevent back flow.

Capillaries are one-cell thick (so very thin) and the wall allow the diffusion into and out of the transport system.

Arteries don't always carry oxygenated blood

and viens don't always carry de-oxygenated blood

remember the pulmonary artery and vien people

 

[Bokky]

Yeah, but generally/usually Arteries carry oxygenated and Veins carry de-oxygenated, we are excluding abnormal people in this case. The syllabus doesnt ask us to discuss the people with those conditions.

 

[SmileyCam]

bokky: what?
the pulmonary artery and vein are connected to the lungs(pulmonary)
the pulmonary artery carries de-oxygenated blood away from the heart to the lungs
the pulmonary vein brings oxygenated blood from the lungs to the heart

There has been a question in the HSC based entirely on this technicallity, so I would say you do need to know it