The human heart contracts from the

The human heart contracts from the first moment of life until the last one. The contractions of the heart pump the blood through the arteries to all the parts of the body. Scientists have determined that the total weight of the blood pumped by the heart daily is about ten tons.
The rate of heart contractions is regulated by two groups of nerve fibers. It varies in different persons and at different age.
Physiologists have determined that in the adult the heart makes from 60 to 72 beats per minute. In children the rate of heartbeat is much higher. Research work of many scientists has helped to determine that the rate of heartbeat increases depending on different emotions.
Each beat of the heart is followed by a period of rest for the cardiac muscle. Each wave of contraction and a period of rest following it compose a cardiac cycle.
Research work has given physiologists the possibility to find out that the heart muscle works or contracts about one third of the time of the person’s life. The period of rest is shorter during greater physical exertion and longer when the body is at rest.
Each cardiac cycle consists of three phases: physiologists have called the first phase of short contraction of both atria—the atrial systole. They have called the second phase of a more prolonged contraction of both ventricles—the ventricular systole. The period of rest of the cardiac muscle is called the diastole.
The left ventricle discharges out the blood received by the left atrium from the pulmonary circulation through the aorta to the systemic circulation.
The blood received from the systemic circulation by the right atrium is discharged out of the right ventricle to the lungs through the pulmonary arteries.
Prolonged research work of many physiologists has given the possibility to estimate the role of the ventricles which serve as the main pump. The atria act as receiving chambers. The contraction of the atria which sends the final portion of the blood into the ventricle is considerably less.

Результаты (узбекский) 1:

O'tgan bir qadar hayotining birinchi kundan boshlab, inson qalbi shartnomasi tuzildi. Yurak qisqarishini tanasining barcha qismlari uchun arteriyalar orqali qon yurishi. Olimlar yurak KUNDALIK shimib qon umumiy og'irligi o'n tonna, deb belgiladi.
Yurak qisqarishlarining darajasi nerv tolalari ikki guruhga bilan tartibga solinadi. Bu turli shaxslar va turli yoshdagi farq qiladi.
Psixologlar kattalar yurak daqiqasiga 60 72 otim dan qiladi qaror qildim. Bolalarda yurak darajasi ancha yuqori bo'ladi. Ko'p olimlar ilmiy-tadqiqot ishlari hayajon ortadi darajasi turli his-tuyg'ular qarab, deb aniqlash uchun yordam berdi.
Yurak Har bir beat yurak mushagining uchun dam bir davrda tomonidan ta'qib qilinadi. Siqilish har bir to'lqin, uni quyidagi qolgan bir davri bir yurak tsikli tashkil etadi.
Ilmiy-tadqiqot ishlari psixologlar yurak mushak ishlari yoki shaxsning hayot vaqt uchdan haqida shartnomalar topish uchun imkoniyat berdi. Tana dam bo'lganda dam davri katta jismoniy kuch-to'kish paytida qisqa va uzoq bo'ladi.
Har bir yurak tsikli uch bosqichdan iborat: psixologlar ikkala atriyumlar-atriyal sistol qisqa qisqarish birinchi bosqichi chaqirdi. Ular har ikkala qorincha-qorincha sistol yanada uzoq qisqarish ikkinchi bosqichi chaqirdi. Yurak mushagining qolgan davri diyastol deyiladi.
Chap qorincha tizimli muomalasi bilan aorta orqali o'pka muomaladan chap atrium tomonidan qabul qonini tushirildi.
O'ng atrium tomonidan tizimli muomalaga olingan qon o'pka arteriyalari orqali o'pka uchun o'ng qorincha tashqariga evakuatsiya qilinadi.
Ko'p psixologlar uzaygan tadqiqot ishlari asosiy nasos sifatida xizmat qorincha rolini baholash uchun imkoniyat bergan. Atriyumlar kameralari qabul sifatida harakat. Qorincha ichiga qon final qismini yuboradi atriyumların qisqarishi ancha kam.