Tag: circulatory system

Exercise-Induced Pulmonary Haemorrhage (EIPH), commonly known as bleeding, is the most widely recognized of all disorders affecting racehorses. EIPH is characterized by bleeding from the lungs after strenuous exercise. Research studies have shown that horses experience unusually high blood pressures within the lungs during exercise. Deep within the lung, thousands of tiny air sac or alveoli interface with capillaries, forming the blood-gas barrier. This incredibly thin barrier readily allows oxygen to move from the lungs into the blood (and carbon dioxide to move in the opposite direction). This blood-gas barrier is not sufficiently strong in horses, to withstand high stress on the capillary wall, that exist during races or intense exercise. Due to which some lung capillaries get ruptured and release blood into the airways. The term "pulmonary capillary stress failure" is also used to describe this phenomenon. 

When the heart beats, it contracts and pushes blood through the arteries to the rest of the body. This force creates pressure on the arteries. This is called as systolic blood pressure. A normal systolic blood pressure is 120 mm hg. The diastolic blood pressure indicates the pressure in the arteries when the heart rests between beats. A normal diastolic blood pressure number is 80 mm hg.

High blood pressure is a non-infectious (non-communicable) condition. It is often caused by excessive weight and lack of exercise. 

Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. When blood vessels constrict, the flow of blood is restricted or decreased, thus increasing vascular resistance causing a reduction in blood flow. Thus, vasoconstriction usually results in an increase in systemic blood pressure.

Blood pressure (BP) is the pressure exerted by circulating blood upon the walls of blood vessels. It is usually measured at a person's upper arm. Blood pressure is usually expressed in terms of the systolic (maximum) pressure over diastolic (minimum) pressure and is measured in millimeters of mercury (mm Hg). It is one of the vital signs along with respiratory rate, heart rate, oxygen saturation, and body temperature. Normal resting blood pressure in an adult is approximately 120/80 mm Hg.

Systole refer to the contraction phase of the cardiac cycle of the heart between the first and second heart sounds of the cardiac cycle. Systole causes the contraction of the ventricles of the heart leading to ejection of blood into the aorta and pulmonary trunk.
Therefore, the correct answer is option D.

The arteries carry blood away from the heart, while veins return blood to the heart. With both, their structure is related to their function. Blood in the arteries is under high pressure generated by the heart. The arteries have thick outer walls and thick layers of muscle and elastic fibers. The blood in veins is under lower pressure than the blood in arteries. The veins have thin walls and thin layers of muscle and elastic fibers. Unlike arteries, veins have one-way valves in them to keep the blood moving in the correct direction.

The instrument used to find out the blood pressure is known as a sphygmomanometer. It is a device composed of an inflatable cuff which displays the pressure measured in mm Hg on the mechanical manometer.