Anatomy & Physiology of the Vein
This information about veins IS in
Gray's Anatomy and Guyton's Physiology (as well as other A&P texts used at the graduate or medical
However, this information is not in the nursing, lab, phlebotomy,
or x-ray programs textbooks.
Vein Access Technologies is the only program which includes this information
in ALL our texts - How to Locate a Healthy Vein and in Part 1 of our
If you currently draw blood, start IVs, inject
contrast intravenously, or work for a blood donation organization . . . .
definitely need to know this Vein Anatomy & Physiology!
There are 3 things about the vein that need to be described and discussed
in regards to vein access -
1. the lumen (the space within an artery or vein)
2. the vein wall thinness and the vein wall layers
3. the innervation of the vein wall.
1. Compare the lumen of
the vein to the lumen of the artery.
The lumen of this vein is very large,
holding LOTS of blood. This will make it
very easy to locate when you palpate because it will have the same bounce
as a long skinny water balloon. (The artery
2. Compare the thin vein wall to the thick
Also, notice that all
blood vessel walls (arteries and veins) have 3 layers to the wall (intima,
The middle layer (media) is composed of smooth muscle. This muscle layer has a very important
function in #3.
The thin vein wall makes
it a very pliable structure - just like the wall of the water balloon.
3. The walls of all blood vessels are
INNERVATED - they have NERVE
ENDINGS - they can F E E L HOT,
COLD, (gentle) TOUCH and PAIN;
and the muscle
in the wall will react to those stimuli in a specific and predictable
manner - they will vaso-D I L A T E or vaso-C
O N S T R I C T.
|Veins have "feelings" too!
(heat) dilates. Touch (gentle) dilates.
constricts. Pain constricts.
So, what does this have to do with vein access? Well currently, many health care professionals
will smak, slap, flick,
or tap the
vein with the intention of making the vein larger. BUT, after learning the anatomy and physiology of the vein,
YOU now know that pain will cause vasoCONSTRICTION - the exact opposite of their intention.
So, how do you get the vein to dilate?
You should palpate the vein to dilate
Learn how by starting with Locate a Healthy Vein on the menu.
This description and instruction is based on scientific facts found in Gray's Anatomy, Guyton's Physiology, and College
Physics by Miller.
Within these science texts are the basic facts about the human body and the laws of nature. Vein Access Technologies
has the only
program that applies this SCIENCE BASED information
to the clinical skills of vein access.
Get all the details and science facts about vein
anatomy and physiology and how it relates to vein
by reading our books - How to Locate
a Healthy Vein, or one of the profession-specific
books The Science Behind the Skill of Vein Access, OR enroll in our accelerated Vein
Access Training Program.
Purchase a Book
Enroll in Training Program
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