A Brief Note On The End Diastolic Volume

Exercise increases heart rate by a process of sympathetic autonomic stimulation. Sympathetic (adrenergic) nerves increase the excitability of the sino-atrial node and reduce the P-R interval .As exercise continues, the physiological changes in the body are continuously monitored by a number of physiological systems and the balance of activity of the sympathetic system (speeding up) and the parasympathetic system (slowing down) is constantly adjusted. When exercise is over, the heart rate does not drop immediately as the body has to undergo a period of re adaption to return to the resting state.

Veins are made up of more elastic tissue and less smooth muscle and carry blood to the heart from the body. The heart wall has three layers that surround the heart. The outer most layer is the epicardium, middle layer is the myocardium, inner layer is the endocardium.

7. Why is most of the blood volume in the veins, and how is blood returned to the heart in this low pressure system?

The general charactertics of blood are color, composition, and pH. The composition of blood is determined by collecting blood from a person then it’s placed in a centrifuge which shows plasma is 55% of whole blood and 45 % is erythrocytes. Another name for red blood cells is erythrocytes which are small sacs of blood that carry oxygen and

R E V I E W S H E E T 30 Anatomy of the Heart

I found the differences between arteries and veins are their functions they provide to the heart as well as their structure. Arteries transfers blood away from the heart into the periphery resulting in the pressure of the blood in the arteries being high. Where as, the veins transfer blood towards the heart. Arteries carry oxygenated blood distributing it in the periphery as the pulmonary artery moves deoxygenated blood into the lungs for purification. The wall of an artery consists of three layers machining it thicker than veins. The elasticity within the layers of the muscle allows arteries to handle great pressures of blood within it. The thickest layer is known as tunica media as the other two are recognized as tunica externa, and tunica interna. The vein obtains blood from the periphery and carries it towards the heart. Veins are known to carry deoxygenated blood and transfers it the heart for purification. The pulmonary vein is known to carry oxygenated blood. However, there are semilunar valves found within the vein that does not allow retrograde flow of blood in preventing blood to flow in the opposite direction. Veins are thinner when compared to arteries consisting of thin elastic muscle layers with one thick layer being the tunica adventitia. Arteries consist of: carrying oxygenated blood expect for the pulmonary artery; deeply found in the body; thick walled and

To name the two major components of blood and state their average percentages in whole blood.

Blood is made up of straw coloured plasma, the matrix, in which various types of blood are carried. Plasma is mainly water where substances are carried such as oxygen and carbon dioxide, nutrients such as glucose and amino acids, salts, enzymes and hormones. Also there is a combination of important proteins which help with blood clotting, transport,

Systolic BP increases bit by bit while diastolic BP stays about the same. Diastolic BP may even diminishing because of vasodilation, or the slight widening of veins brought about by the heart pumping harder to spread more oxygen all through the body. Diastolic circulatory BP is the estimation of base pulse, when weight is weakest, and systolic shows weight at pinnacle times, when heartbeats constrain blood through the veins. Since systolic BP is straightforwardly associated with how the heart works, it is influenced the most by work out.

Vasoconstriction- The sympathetic nervous system on the brain causes the heart rate to increase making your veins constrict. This is called vasoconstriction and the blood flow will be directed right to the muscle to help it work harder. Temperature increases to help the flow of blood around the body. Your reflexes will be quicker and your muscles tense. This facilitates the blood carrying oxygen and removing waste products.

Arteries carry blood away from the heart and are the largest of the blood vessels. Arteries are the largest and most muscular because of their function. They carry oxygenated blood away from the heart and therefore has force placed on them as the heart contracts and pumps. Veins carry blood back to the heart and lungs to be oxygenated again. The walls of veins are thin, elastic, and the flow of blood through veins are much slower and rely on surrounding muscles to push blood back to the heart. (They also have valves to prevent the backflow of

* To understand how to interpret a graph of blood Bessel radius versus blood flow rate.

     The Parasympathetic nervous system is an antagonist to the sympathetic nervous system. Its primary function is to give you the ability to rest and relax, in times when you are tired or stressed. The parasympathetic nervous system works to save energy and allow your blood pressure to also decrease. Your heartbeat reduces becoming much slower, and digestion can start. Notice again in figure

The arteries are thicker and more elastic because of the fast pumping of blood that leaves the heart to other organs to the body, as where the veins are small due to the low blood flow because of the slow movement from the capillaries to the veins not like the forceful pumping from the heart to the arteries to the rest of the body. The Oxygenated blood goes through the arteries except the pulmonary arteries. Then Deoxygenated blood goes through the veins except the pulmonary veins. The lumen of the artery is narrow, were as the lumen of the veins is wider. There are not valves in the arteries, were as the valves are present in veins. In the arteries, endothelial cells of tunica intima are more long then wider, and have more elastic membrane that is more developed. Then the Tunica media is more muscular, and the tunica extrema is not as developed. In veins, the endothelial cells of tunica intima are not as long and have more elastic membrane then being developed. The Tunica media is less muscular were the tunica extrema is more developed. Arteries are deep within and the veins are more superficial. Capillaries are microscopic vessels; they carry blood from the arterioles then go to the small veins or venules. The wall of the capillary made up of a

The other components of the blood such as the erythrocytes and leukocytes occupy the remaining 1% of the total blood volume in the entire circulatory system.