Hands, Feet and Legs - Circulatory Issues - Doctor's Scratching Heads

April 4, 2022 11:56 PM

ikynMd I have major issues with spine from cervical area to lumbar, including a spinal surgery at l3/l4. Now hands, legs and feet are cold, purple and red. Doctor's who I have seen have no clue. It is no rheumatory, not auto immune but there is extensive inflammation throughout my body. This is not Raynaud's, though it might have started out as such. To figure this out - am trying to understand how the body works.

Doppler has showed impeded flow of blood to legs. Arterial flow of blood from neck was appropriate as per doppler, as were to hands. There is no issue of smoking or formation of plaque.

For my investigative work, finding out what is going on I need help with simple mechanics of biology.

So - without further ado -

Which main arteries are involved in circulation? Which nerve pathways connect them and what is their starting point, circulatory flow and circuitry? Are there animations that show this in 3D? What role does the spine have in transmission of blood flow and neurological impedance? And finally is there are physiological mechanism by which flow is determined by the ANS as in- stop/start and repeat? If so, what is this termed? Please include in your replies all 3 stations of flow - hands, legs and feet. Thank you so much.

posted by watercarrier to Health & Fitness (4 answers total)

Best answer: I applaud your effort to understand how the body works, and to be an energetic advocate for your health.

Let's start with the fundamentals. The heart is the pump that keeps blood moving. From the heart, it goes through arteries, then arterioles, then to the capillaries. Instead of a pipes-and-valves metaphor, I invite you to consider a traffic metaphor: these vessels branch out like highways, major roads, and residential streets.

The capillaries - the cul de sacs , in our metaphor - are where oxygen and other nutrients are delivered to the body tissues. The capillary walls filter the good stuff out into the tissues, and the rest of the blood keeps moving, through venules, to the veins, then the vena cava, then back to the heart. In our traffic analogy, after dropping off some packages, the van keeps moving, back on to the major street, then the highway, then the warehouse. Separately, the lymph vessels also collect excess fluid from the tissues and takes them to the lymph nodes. This can be pictured as a separate recycling pickup service.

The movement of blood through big vessels is circulation. This is affected by the heart's pump action, your fluid load, and also the arteries, which are elastic and muscular. Regulation involves blood pressure sensors (baroreceptors), the autonomic system ("fight or flight"), and also long-term signals from the kidneys. When they did ultrasounds on bigger vessels, they were ruling out blockages in the highways.

Now, the delivery of good stuff to tissues, as well as the removal of waste products, is called perfusion. Just like you can have good luck on the highways, then get into a traffic jam a few blocks from your house, you can have an all clear on arteries, but still have poor perfusion. This can show up as cold, purple patches of skin.

One lesser-known fact about circulation is that blood flow in the arteries are actively pumped forward, but the blood and lymph flow back into the heart are purely passive. The veins have one-way valves in them, and every time you contract a muscle, it squeezes the blood forward. This is why they ask you to make a first and relax it, over and over agian, when donating blood. The lymph vessels are also passive. That's why many people find benefit in massage; massage strokes are meant to push lymph out of the tissues and back toward the lymph nodes.

It sounds like you are experiencing perfusion issues at the capillary and tissue level. Capillaries can constrict in response to local sensory signals like cold. They can also stop flowing if the veins and lymph vessels aren't carrying away enough of the extra fluid. Inflammation means that the capillary walls are thickened and rigid: the van doors are sticky and there are obstacles along the streets. And yes, capillaries also respond to autonomic signals. Some autonomic signals travel up to the brain and back down again, and so spinal injuries can affect them. The autonomic system is a huge topic, but here are a few notes: it is not so much an on/off switch as a tug-of-war. It's the balance between the push-pull of the sympathetic and parasympathetic branches. They act using both direct nerve signals and indirect chemical signals (e.g. adrenaline).

I hope the above gave you a good start and a working mental image. Your three stations are different neighborhoods served by different roads. They operate on the same principles, but will involve different spinal segments. The keywords to search for are perfusion, capillary tone, and dysautonomia.
posted by dum spiro spero at 1:10 AM on April 5, 2022 [25 favorites]

Response by poster: Thank you ever so much dum spiro spero for the wonderfully worded and explained answer to my query. THANK YOU. I do have question regarding the capillaries, and rather than risk the question being deleted for violation of yet another term (previously it was), may I memail you for this purpose?
posted by watercarrier at 1:46 AM on April 5, 2022

Best answer: yes of course!
posted by dum spiro spero at 1:46 AM on April 5, 2022 [2 favorites]

Do you have pernio?
posted by FungusCassetteBicker at 10:30 AM on April 6, 2022