Login

Join for Free!
119246 members


Artery vs Vein

Human Anatomy, Physiology, and Medicine. Anything human!

Moderator: BioTeam

Artery vs Vein

Postby bionewbie » Mon May 23, 2005 11:32 pm

Hi, I just have a question regarding blood pressure. Which has a lower pressure: brachial artery or vena cava? Why?
bionewbie
Coral
Coral
 
Posts: 113
Joined: Sun Nov 07, 2004 9:54 pm

Postby Poison » Tue May 24, 2005 5:38 pm

I'm not sure about the answer but as much as I know, as vena cava is a vein, blood pressure in an artery is higher. Because, heart pumps blood to the arteries; but blood is collected back with veins by different methods.
It matters not how strait the gate
How charged with punishment the scroll
I am the Master of my fate
I am the Captain of my soul.
User avatar
Poison
Inland Taipan
Inland Taipan
 
Posts: 2322
Joined: Sun Jan 02, 2005 12:44 pm
Location: Turkey

Postby MrMistery » Tue May 24, 2005 7:46 pm

Deffinetly vena cava has lower blood pressure. Actually in vena cava blood pressure is negative(that is what books say, in my opinion pressure canm not be negative. I have emailed a professor at Cambridge and he agreed with me but gave me an explanation that i could't understand :lol: :lol: ).Anyway, that is what your regular biology book will say

PS: I like the title, Artery vs Vein, it's funny
"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
User avatar
MrMistery
Inland Taipan
Inland Taipan
 
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)


Further discussion

Postby bionewbie » Fri May 27, 2005 3:08 am

Thank you both for answering the question, as an extension to the original question, what about veins and capillary beds? Which one has lower pressure and why?
bionewbie
Coral
Coral
 
Posts: 113
Joined: Sun Nov 07, 2004 9:54 pm

Postby clarence » Fri May 27, 2005 6:30 am

The capillary beds still have higher blood pressure than veins.

As blood leaves the aorta and flows through the systemic circulation, its pressure falls progressively as the distance from the left ventricle increases. Blood pressure decreases to about 35mmHg as blood passes from systemic arteries to systemic arterioles and into capilliaries. At the venous end of capilliaries, blood pressure has droped to about 16mmHg. Blood pressure continues to drop as blood enters systemic venules and then veins because these vessels are farthest from the left ventricle. Finally, blood pressure reaches 0mmHg as blood flows into the right ventricle.

I hope this helps. If you need more details, just ask.
Ideology...is indispensable in any society if men are to be formed, transformed and equipped to respond to the demands of their conditions of existence. -- Louis Althusser, For Marx
clarence
Garter
Garter
 
Posts: 42
Joined: Sun May 01, 2005 2:47 pm
Location: Manila, Philippines

Postby D_Juggz » Sat May 28, 2005 3:51 am

venous pressure is lower than arterial.
D_Juggz
Garter
Garter
 
Posts: 18
Joined: Sat May 28, 2005 3:39 am

Postby biostudent84 » Sat May 28, 2005 4:23 pm

MrMistery wrote:Deffinetly vena cava has lower blood pressure. Actually in vena cava blood pressure is negative(that is what books say, in my opinion pressure canm not be negative. I have emailed a professor at Cambridge and he agreed with me but gave me an explanation that i could't understand :lol: :lol: ).Anyway, that is what your regular biology book will say

PS: I like the title, Artery vs Vein, it's funny


Out of curiosity, what did the professor say?
User avatar
biostudent84
Site Admin
Site Admin
 
Posts: 974
Joined: Thu Nov 11, 2004 6:00 am
Location: Farmville, VA

Postby D_Juggz » Sun May 29, 2005 3:33 pm

there may be a negative pressure inside the atrium, but i've never heard of a negative pressure in the vena carva itself. do you have a reference to a book or a site for me ? :?
D_Juggz
Garter
Garter
 
Posts: 18
Joined: Sat May 28, 2005 3:39 am

Postby MrMistery » Sun May 29, 2005 8:54 pm

@Kyle
Well I don't have that email any more but i am pretty sure i printed it. I will look for it and see if i can find it. It was a really strange thing with composing diffrent forces... I don't like physiscs. I just asked out of curiosity. By the way, i was really surprised when he answered. :lol: :lol:
From what i still remember, a force of aspiration can be interpreted as negative pressure. But as we know from physics 101: pressure=force/sufrace. So, the value of a force can not be negative, therefore pressure can not be negative. But his explinantion was much more complicated... some of those words i can't even pronunce :D
"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
User avatar
MrMistery
Inland Taipan
Inland Taipan
 
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)

Postby ewokgod » Tue May 31, 2005 9:03 am

vein has smaller pressure than the artery because the left ventricle must be able to pump the blood around the body parts therefore the pressure must be pretty big. the veins only rely on muscle pumps or arterial smooth muscles (some veins are located directly below arteries). plus veins are generally wider than arteries and used as blood reserve also veins have to fight gravity to pump deoxygenated blood back to the heart.
this is why when you cut arteries, blood sprays out and when you cut veins, blood tends to ooze out (from kungfu movies).
ewokgod
Garter
Garter
 
Posts: 12
Joined: Sun May 15, 2005 10:59 am
Location: grim and frostbitten yeti forest

Arthery vs Vein

Postby victor » Tue Jun 07, 2005 7:21 am

As far as I know is Aorta gets a higher pressure because it's directly pumped out from the left ventricle meanwhile vena cava gets a lower pressure because it's pumped not directly from the heart but from other move of the body, example like the move of our muscles, effects from arthery pumping, etc.
User avatar
victor
King Cobra
King Cobra
 
Posts: 2668
Joined: Sat Apr 30, 2005 12:01 pm
Location: Yogyakarta, Indonesia..

Re: Artery vs Vein

Postby chanhankiang » Fri Oct 17, 2008 8:01 am

Arteries pressure 120mmHG
Capillaries between 15-40mmHG
Veins 10-15mmHG
It reached almost 0mmHG in the venue cavae, just before the venae cavae open into the right atrium of the heart.

why?

Arteries for the immense pressure when blood is pump out of from the left ventricle. As it flows from the

heart-artery-arteries-arterioles-capilaries-venules-veins-vein-heart

blood pressure keeps dropping as it goes further away from the heart because it loses kinetic energy with distance increase. Furthermore blood flowing from the lower limbs back to heart through the inferior vena cava is aginst gravitational pull. thats why vena cava, veins all have semi lunar valve to prevent backflow of blood.
chanhankiang
Garter
Garter
 
Posts: 1
Joined: Fri Oct 17, 2008 7:40 am


Return to Human Biology

Who is online

Users browsing this forum: No registered users and 1 guest