[what is blood pressure?]
The heart is a year-round pump, relying on the very rhythmic diastolic (congestion)-contraction (pump blood) mechanical movement, a moment non-stop to the blood through the veins to the whole body of organs, supply oxygen, take away waste, to ensure the body's metabolism. And blood pressure, is the blood flow in the blood to the unit area of the blood vessel wall side pressure (in fact, it should be called pressure is right!). The blood pressure we measure generally refers to arterial blood pressure, which is the lateral pressure of the blood in the arteries on the arterial wall of the unit area, and generally refers to the blood pressure of the aorta (the thickest artery directly attached to the heart).
[ what is systolic and diastolic pressure?" ]
We know that blood pressure measurement results are generally written as follows: 100mmHg/80mmHg, divided into systolic and diastolic pressure, "high pressure, low pressure", what they represent separately?
Systolic blood pressure is the blood pressure in the aorta when the heart contracts the pump. Because the aorta is such a large blood vessel with elasticity, so in the heart of the blood pump into the aorta, it will swell, play a role in buffering, so the blood flow on the wall pressure increased, it in the middle of the heart contraction to reach the highest pressure value, so also called "high pressure."
Diastolic pressure is the blood pressure in the aorta during diastolic congestion in the heart. The heart does not pump blood to the outside when it relaxes, and the swelling of the elastic aorta is retracted, keep the blood flowing to the periphery, keep the blood flowing continuously, and make the arterial blood pressure drop, at the end of the diastolic to reach the lowest value, so also called "low pressure."
[ how does blood pressure form?" What are the factors that affect it? ]
The physiology book says, "The cardiovascular system has enough blood filling, heart ejection, blood vessel peripheral resistance and the aorta of the elastic receptacle function is the basic condition of blood pressure formation."
Factors that affect the formation of blood pressure:
1 blood volume filling in the cardiovascular system: since blood pressure is "blood flow in the blood vessels on the side of the vessel wall of the lateral pressure." Moreover, the more blood, the greater the pressure, it should not be difficult to understand. And note that the subtle "filling" is added here because the "blood volume" is relative to the actual volume of blood and the volume of blood vessels. Under the condition of unchanged blood volume, the blood vessel filling degree is naturally different because the blood vessels can relax and contract under the regulation of nerves and body fluids. We use the average filling pressure of the circulatory system (for short filling) to reflect the filling degree. Obviously, the higher the filling pressure, the higher the blood pressure.
2 Heart ejection: blood flow in the blood vessels is needed to overcome resistance consumption energy, and according to the Law of conservation of energy, there must be something for it to provide energy, right! That's what our hearts are doing every moment of the day. The contraction of the heart provides energy for blood flow, which can be divided into two parts: one is to maintain the kinetic energy of blood flow, the other is to form pressure on the wall of the blood vessel, which is producing potential energy.
3 Peripheral Vascular Resistance: peripheral resistance is mainly provided by small arteries and micro arteries. Peripheral resistance is also critical to the formation of blood pressure. The presence of it, on one hand, inhibits blood flow to the periphery during contraction and, on the other hand, maintains diastolic pressure during diastolic period so that it does not fall sharply.4 The role of the elastic receptacle of the aorta: I believe that all of you who read this article carefully should understand how important it is to have a flexible, expansive aorta (represented by the aorta). They turn the blood of the heart into a continuous blood flow in the arteries, while cushioning the fluctuation of blood pressure in the cardiac cycle, making the systolic pressure not too high and diastolic pressure not too low.
[what is high blood pressure?" How did it develop? "]
Hypertension is a systemic disease characterized by the continuous elevation of systolic and/or diastolic blood pressure in the circulating arteries of the body. High blood pressure can be divided into essential hypertension and secondary hypertension. According to China's 2005 guidelines, hypertension is defined as systolic pressure ≥140mmhg, diastolic pressure ≥90mmhg.
There are two kinds of hypertension. One is called essential hypertension, the most common, about 90% of hypertension, that is, you have no health problems but suddenly have high blood pressure. The primary meaning is that the etiology is unknown, so the most common cause of hypertension does not actually have a standard answer. Another is called secondary hypertension, that is, because other organs have lesions caused by elevated blood pressure, such as kidney disease can cause blood pressure rise, so that this secondary hypertension can find the cause.
Here are some ratios which are important:
1 The ratio of circulating blood volume to vascular system capacity: Under normal circumstances, blood volume and blood vessel volume are compatible, that is to say, the filling pressure changes little.
2 Output per stroke (short stroke amount): Refers to the heart contraction of a blood vessel pump into the volume. The greater the amount of stroke, the more blood injected into the aorta, the greater the pressure on the arterial wall. According to our analysis above, the increase in the amount of stroke mainly leads to a significant increase in systolic pressure, the increase in diastolic blood pressure is relatively small, because although the contraction of the aorta in the bloodstream more, but in the diastolic blood vessels back to push the blood pressure will be greater, into the peripheral blood will be more, the final result is that the elevated diastolic pressure change is not obvious.
3 Heart rate: Heart to complete the function of pumping blood requires two basic steps: diastolic--to bring venous blood back to the heart, and contraction--pump blood into the arteries, one diastolic plus one contraction to complete a cardiac cycle. When the heart rate accelerates, the diastolic shortening time is more obvious than the contraction period, thus the blood flow to the peripheral during the diastolic period is reduced, so the end of the diastolic left in the aorta blood is much, diastolic pressure rises. Of course, systolic pressure will also rise, but because blood pressure increases the flow speed is also accelerated, so the contraction period into the peripheral blood is more, so the systolic pressure is not higher than diastolic pressure significantly.
4 Peripheral Resistance: Peripheral resistance can slow the flow of blood to the peripheral. When the peripheral resistance increases, the diastolic blood decreases, so the blood on the aorta stays at the end of the diastolic and the diastolic pressure increases. Of course, systolic pressure will also rise, but because systolic pressure is higher than diastolic pressure, blood flow rate is faster, so systolic pressure is not higher than diastolic pressure.
5 The elastic receptacles of the aorta and aorta: As mentioned earlier, the elastic receptacle function of the aorta can act as a buffer against the fluctuation of blood pressure. The lower elasticity of the blood vessels than the better elasticity of the blood vessel, the increase in systolic pressure (the feeling of pressure when the ground falls), diastolic pressure reduction (relaxation of the diastolic pressure in the textbook did not find a satisfactory explanation, representing that the energy to convert to a potential power less that natural conversion into kinetic energy, flow to the peripheral blood more, diastolic aorta in the remaining blood less, so diastolic blood pressure decreases.
The formation of high blood pressure:
① circulating blood volume and vascular volume ratio: circulating blood volume ↑ or vascular volume ↓→ body circulation average filling pressure ↑→ arterial blood pressure ↑
② Stroke Amount: Each stroke amount ↑→ aorta, arterial blood volume ↑→ contraction pressure ↑.
③ heart rate: Heart rate ↑→ diastolic period shortening → heart diastolic final aortic blood volume ↑→ diastolic pressure ↑
④ Peripheral Resistance: peripheral resistance ↑→ diastolic aorta blood volume ↑→ diastolic pressure ↑
⑤ aortic and aortic elastic receptacles: elastic ↓→ systolic pressure ↑, diastolic pressure ↓