Login

|
|
blood vesselsModerator: BioTeam
19 posts • Page 2 of 2 • 1, 2
Re: blood vessels
i hope it would be capillaries,, and if it is specific. then vena cava,, i hope..
the vena cava has the absolute lowest pressure
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
pressure mainly depends upon the thichness of blood vessel, and and flow of blood... and since the flow of blood in nearly same,, but in thickness veins r smaller.. thats y...
Mistery is right - the vena cava carries blood with low pressure towards the heart. The high pressure in the aorta is due to the fact that the heart pumps pumps blood very strongly into the aorta so that the blood going TO the body organs would have enough pressue to filter out at the capillaries (to form tissue fluid). The pressure at the capillaries continues to build up because the blood is going from the relatively wide artery (or arteriole) to the much, much narrower capillary. A decrease in the "volume" causes an increase in pressure, thus the components of blood which filter out of the capillaries, may filter out. (They need a high pressure to filter out) As blood continues to move through the body it tends to lose the initial pressure which it had upon leaving the heart, until finally the blood ends up in the vena cava where the blood has lost most of its pressure. That's why there are valves in veins - to prevent the backflow of blood!!.. because, among other reasons, the blood has little pressure. Also, the blood from the vena cava ends up in the heart. The heart functions to PUMP blood (to sort of give it that pressure it needs to continue to move around your body). This means that the blood in the vena cava has lost so much pressure that it must go to the heart to gain that pressure.
With regards to where pressure is the greatest it would either be the aorta of the Bowman's capsule at the kidneys. wizzie
Deffinetly the aorta. The pressure in the cappilaries of the Bowman capsule is only 75 mm Hg(which is still about twice that of usual papilaries since the way from the abdominal aorta to there is very small...)
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
19 posts • Page 2 of 2 • 1, 2
Who is onlineUsers browsing this forum: No registered users and 2 guests |
© Biology-Online.org. All Rights Reserved. Register | Login | About Us | Contact Us | Link to Us | Disclaimer & Privacy