Baroreflex, or baroreceptor reflex, is one
of the mechanisms the body uses to maintain stable blood pressure levels or homeostasis. Baroreflex is a rapid negative feedback loop
in which an elevated blood pressure causes heart rate and blood pressure to decrease. Reversely, a decrease in blood pressure leads
to an increased heart rate, returning blood pressure to normal levels. The reflex starts with specialized neurons
called baroreceptors. These are stretch receptors located in the
wall of the aortic arch and carotid sinus. Increased blood pressure stretches the wall
of the aorta and carotid arteries causing baroreceptors to fire action potentials at
a higher than normal rate. These increased activities are sent via the
vagus and glossopharyngeal nerves to the nucleus of the tractus solitarius – the NTS – in
the brainstem. In response to increased baroreceptor impulses,
the NTS activates the parasympathetic system – the PSNS – and inhibits the sympathetic
system – the SNS. As the PSNS and SNS have opposing effects
on blood pressures, PSNS activation and SNS inhibition work together in the same direction
to maximize blood pressure reduction. Parasympathetic stimulation decreases heart
rate by releasing acetylcholine which acts on the pacemaker cells of the SA node. Inhibition of the sympathetic division decreases
heart rate, stroke volume and at the same time causes vasodilation of blood vessels. Together, these events rapidly bring DOWN
blood pressure levels back to normal. When a person has a sudden drop in blood pressure,
for example when standing up, the decreased blood pressure is sensed by baroreceptors
as a decrease in tension. Baroreceptors fire at a lower than normal
rate and the information is again transmitted to the NTS. The NTS reacts by inhibiting parasympathetic
and activating sympathetic activities. The sympathetic system releases norepinephrine
which acts on the SA node to increase heart rate; on cardiac myocytes to increase stroke
volume and on smooth muscle cells of blood vessels to cause vasoconstriction. Together, these events rapidly bring UP blood
pressure levels back to normal. Baroreflex is a short-term response to sudden
changes of blood pressure resulted from everyday activities and emotional states. If hypertension or hypotension persists for
a long period of time, the baroreceptors will reset to the “new normal” levels. In hypertensive patients for example, baroreflex
mechanism is adjusted to a higher “normal” pressure and therefore MAINTAINS hypertension
rather than suppresses it.
amazing work
thanks
BEST WORK.THANKS
good job
👍
thanks so much, this really help me have a better understanding of how it works
thank you very much for understanding this mechanism 😊😊
Would be much better without the computerized voice.
Good video
I LOVE YOU AMM!!!
What effects are observed when the body is inverted such as during certain yoga and gymnastic exercises?
Heard that the baroreflex mediated by the carotid sinuses gets 'stimulated' by inversion and thereby produces a reduction of BP; this effect is said to become sustained with repetition of the exercises.
what will be the effect vasodilator and vasoconstrictor drug
Why you are not saying cardiac center than nts
Heard that recent studies disagree with this mechanism and it's effect. On bl.p
EXCELLENT VIDEO AND MANY THANKS FOR SHARING!
can u plz xplain brain brigde reflx
Thank
Thx
THANK YOU SO MUCH
Please….Make a video on Sympathetic and Parasympathetic Nervous system
Still has less of a monotonous voice than my prof
NTS?what's that
Great video.
I really love your videos. Thank you so much.
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Thank you so much!
Muita Boa a aula # Moçambique
this helped thanks!
is a 3 minute voiceover really too much to ask?
That’s a good video.Thank you so much.
This is out of the scope of the video, but is there a way to reverse the new hypertensive normal after chronic hypertension?
I can't ever thank you enough. God bless you.
Thank Very much!
The video is good but the voice is soo annoying 🤕
It's great
software voice is disturbing
Thanks 😁😁😁 it's so benefit for me …. I was need it 🙂☺
uhhhh!!
That's voice is just so much annoying.
But the animation along with the process was good.
Voice is annoying.
Thank you so much
God pless you
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how do you expect me to pay good attention with that voice
this is the ideal male voice
lam not understanding when the body using the baroreflexe ?? during response any effect ??? please anyone answer
It maintains from 50 to 200 mm hg
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