NBC HOW BLOOD PRESSURE WORKS and High Blood Pressure
HOW BLOOD PRESSURE WORKS and High Blood Pressure
If you lined up all the blood vessels in your body,
they'd could well extend to 95,000 kilometers long.
Everyday,your blood vessels carry the equivalent of over 7,500 liters of blood,
Dont worry its the same four or five liters recycled over and over,
delivering oxygen, and precious nutrients like glucose
and amino acids to the body's tissues.
Your Blood uses a force on the muscular walls of the blood vessels.
That force is named blood pressure,
and it rises and falls with the phases of the heartbeat.
It's at its highest when the heart contracts to force blood through the arteries.
This is called your systolic blood pressure.
When the heart is at rest between beats,
blood pressure falls to its lowest value, and named the diastolic pressure.
A typical healthy individual should produce a systolic pressure
between 90 and 120 millimeters of mercury,
and diastolic pressure between 60 and 80.
Taken together, a normal reading is a bit less than 120 over 80.
The blood goes through the landscape of the body
through the pipes of the circulatory system.
As in any plumbing system,
several things can increase the force on the walls of the pipes:
such as the properties of the fluid, extra fluid, or narrower pipes.
So if the blood thickens,
a higher pressure is needed to push it, so the heart will pump harder.
A high-salt diet will lead to a similar result.
The salt promotes water retention,
and the extra fluid increases the blood volume and blood pressure,
and stress, like the fight or flight response,
releases hormones, like epinephrine and norepinephrine
that constrict key vessels,increasing the resistance
to flow and raising the pressure upstream.
Blood vessels can usually handle these fluctuations easily.
Elastic fibers embedded in their walls make them resilient,
but if your blood pressure regularly rises above approx. 140 over 90,
We call this hypertension, and if it stays there,
it can cause serious problems.
That's because the extra strain on the arterial wall
can produce small tears.
When the injured tissue swells up, substances that
respond to the inflammation, like white blood cells,
collect around the tears.
Fat and cholesterol floating in the blood latch on, too,
eventually building up to form a plaque that can stiffen
and thicken the inner arterial walls.
This condition is called atherosclerosis,
and it can have dangerous consequences.
If the plaque ruptures, a blood clot forms on top of the tear,
clogging the already narrowed pipe.
If the clot is big enough,
it can completely block the flow of oxygen and nutrients to cells downstream.
In vessels that feed the heart, that will cause a heart attack,
when oxygen-deprived cardiac muscle cells start to die.
If the clot cuts off blood flow to the brain,
it can be the cause of a stroke.
Dangerously clogged blood vessels can be widened
by a procedure called an angioplasty.
in this procedure Doctors thread a wire through the vessel
to the obstructed site, and then place a deflated balloon
catheter over the wire.
When the balloon is inflated, it forces the passageway open again.
Another procedure is where a rigid tube called a stent
is placed in a vessel to help hold it open, letting the blood flow freely
to replenish the oxygen-starved cells downstream.
Staying flexible under pressure is a tough job for arteries.
The fluid they pump is composed of substances
that can get sticky and clog them, and your typical healthy
heart beats about 70 times a minute, and at least 2.5 billion
times during an average lifetime.
That may sound like an insurmountable amount of pressure,
but don't worry, your arteries are well suited for the challenge.
Thanks for watching NBC my name is Neil Branson.
Have a happy and healthy day
More importantely remember my videos are a guide only
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contact your Doctor or qualified practitioner
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