Monday, February 11, 2019

Health Related Information in 2019.

One of the most important parts of the human body is the cardiovascular system or the circulatory system. It governs our heart, helps our blood, and it is the literally lifeline of our human existence. It is the organ system that allows blood to circulate and transport nutrients (like amino acids and electrolytes), oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body. This system allows the body to receive nourishment and help to fight disease, stabilize temperature plus pH, and maintain homeostasis. The cardiovascular system deals with the lymphatic system too as that system circulate lymph. The passage of lymph for example takes much longer than of blood. Blood is a fluid. It has plasma, red blood cells, white blood cells, and platelets that is circulated by the heart though the vertebrate vascular system. It carries oxygen and nutrients to and waste materials away from all body tissues. Lymph is recycled exceeds blood plasma after it has been filtered from the interstitial fluid (between cells) and returned to the lymphatic system. The cardiovascular (from Latin words meaning "heart" and "vessel") system comprises the blood, heart, and blood vessels. The lymph, lymph nodes, and lymph vessels form the lymphatic system, which returns filtered blood plasma from the interstitial fluid (between cells) as lymph.

The circulatory system of the blood is seen as having two components, a systemic circulation and a pulmonary circulation. Humans are vertebrates with a closed cardiovascular system. That means that blood never leaves the network of arteries, veins, and capillaries. Some invertebrates have an open cardiovascular system. The lymphatic system has an open system with a route for excess interstitial fluid to be returned to the blood. The diploblastic animal phyla lack circulatory systems. Many diseases affect the circulatory system. This includes cardiovascular disease, affecting the cardiovascular system, and lymphatic disease affecting the lymphatic system. Cardiologists are medical professionals who specialize in the heart, and cardiothoracic surgeons specialize in operating on the heart and its surrounding areas. Vascular surgeons focus on other parts of the circulatory system. 

The human cardiovascular system includes the heart, blood, and blood vessels. There is the pulmonary circulation or a loop through the lungs where blood is oxygenated. Later, circulation follows a loop through the rest of the body to provide oxygenated blood. There are macrocirculation and microcirculation. An average adult has five to six quarts or 4.7 to 5.7 liters of blood. Blood represents about 7 percent of total body adult weight. Blood consists of plasma, red blood cells, white blood cells, and platelets. Also, the system works with the circulatory system to provide the nutrients the system needs to keep the heart pumping. The cardiovascular systems of humans are closed, meaning that the blood never leaves the network of blood vessels. In contrast, oxygen and nutrients diffuse across the blood vessel layers and enter interstitial fluid, which carries oxygen and nutrients to the target cells, and carbon dioxide and wastes in the opposite direction. The other component of the circulatory system, the lymphatic system, is open. Blood travels by leaving the left atrium and the left ventricle to the rest of the body via arteries. Then, that blood travels from parts of the body via veins to the right atrium, the right ventricle, to the pulmonary artery and the pulmonary vein. Then, the cycle starts all over again. Oxygenated blood entered the circulation when leaving the left ventricle, through the aortic semilunar valve. The first part of the systemic circulation is the aorta, a massive and thick-walled artery. The aorta arches and gives branches supplying the upper part of the body after passing through the aortic opening of the diaphragm at the level of thoracic ten vertebras, it enters the abdomen. Later it descends down and supplies branches to abdomen, pelvis, perineum and the lower limbs. The walls of aorta are elastic. This elasticity helps to maintain the pressure throughout the body. When the aorta receives almost five liters of blood from the heart, it recoils and is responsible for pulsating blood pressure. Moreover, as aorta branches into smaller arteries, their elasticity goes on decreasing and their compliance goes on increasing. Arteries branch into small passages called arterioles and then into the capillaries. The capillaries merge to bring blood into the venous system. After their passage through body tissues, capillaries merge once again into venules, which continue to merge into veins. The venous system finally coalesces into two major veins: the superior vena cava (roughly speaking draining the areas above the heart) and the inferior vena cava (roughly speaking from areas below the heart). These two great vessels empty into the right atrium of the heart. The heart is filled with oxygen and nutrients too and it has coronary circulation. The general rule is that arteries from the heart branch out into capillaries, which collect into veins leading back to the heart. Portal veins are a slight exception to this. In humans, the only significant example is the hepatic portal vein which combines from capillaries around the tract where the blood absorbs the various products of digestion; rather than leading directly back to the heart, the hepatic portal vein branches into a second capillary system in the liver.

The heart pumps oxygenated blood to the body and deoxygenated blood to the lungs. The human heart has one atrium and one ventricle for each circulation. It has the following four chambers: left atrium, left ventricle, right atrium, and right ventricle. The right atrium is the upper chamber of the right side of the heart. The blood that is returned to the right atrium is deoxygenated (poor in oxygen) and passed into the right ventricle to be pumped through the pulmonary artery to the lungs for re-oxygenation and removal of carbon dioxide. The left atrium receives newly oxygenated blood from the lungs as well as the pulmonary vein which is passed into the strong left ventricle to be pumped through the aorta to the different organs of the body. Blood helps the brain and the kidneys. The circulatory system develops in the embryo. Veins show during weeks 4-8 of embryogenesis. Helping the cardiovascular system is key in building up our health. Ancient Egyptians, ancient Muslim scholars, ancient Romans, Michael Servetus, and others studied the circulatory system among the thousands of years of human history.

The respiratory system is very important to know and study. It is made up of organs used for gas exchange. It includes lungs and small air sacs called alveoli. They are call atria in birds. The alveoli have strong blood supply. These air sacs communicate with the external environment via a system of airways, or hollow tubes, of which the largest is the trachea, which branches in the middle of the chest into the two main bronchi. These enter the lungs where they branch into progressively narrower secondary and tertiary bronchi that branch into numerous smaller tubes, the bronchioles. In birds, the bronchioles are termed parabronchi. It is the bronchioles, or parabronchi that generally open into the microscopic alveoli in mammals and atria in birds. Air has to be pumped from the environment into the alveoli or atria by the process of breathing which involves the muscles of respiration. The respiratory system has the naval cavity, the pharynx (or near the throat). The larynx is found on inside of the neck. The tube next to the lungs is called the trachea. It has branches holding up the two lungs in the body. The lungs are surrounded by bronchial tubes. Therefore, the upper tract includes the nose, nasal cavities, sinuses, pharynx and the part of the larynx above the vocal folds. The lower tract (Fig. 2.) includes the lower part of the larynx, the trachea, bronchi, bronchioles and the alveoli. The respiratory tree has the trachea, mainstem bronchus, labor bronchus, segmental bronchus, bronchiole, alveolar duct, and the alveolus. Lungs expand and contact during the breathing cycle.  The primary function of the respiratory system is to exchange oxygen and carbon dioxide. Inhaled oxygen enters the lungs and reaches the alveoli. Oxygen passes quickly through this air-blood barrier into the blood in the capillaries. Similarly, carbon dioxide passes from the blood into the alveoli and is then exhaled.

In life, we learn new things constantly. Even after I’m 35 years old, I continue to learn new facts about the human body and genetics. Controlling muscular hypertrophy is done by myostatin proteins. Age, height, weight, genetics, sex, and training can determine how much muscular hypertrophy a person can experience.  Muscle hypertrophy is a term for the growth and increase of the size of muscle cells. Hypertrophy happens as a product of physical exercise like weightlifting. Examples of increased muscle hypertrophy are seen in various professional sports, mainly strength related sports such as boxing, Olympic weightlifting, mixed martial arts, rugby, professional wrestling and various forms of gymnastics. Increased muscle hypertrophy can be found in athletes who do basketball, baseball, ice hockey, and soccer (i.e. a center in basketball can be bigger to overpower opponents). This is achieved by cardiovascular and muscular endurance training. A human being is a product of both nature and nurture, so using both in performing great exercise output is important. Both men and women can increase their physical fitness capacity via training. Some people have myostatin deficiency. Muscles are made up of bundles, fascicle, muscle fiber, muscle cells, and other components like the myofibril. Many genes are associated with muscular strength and functioning like ACTG1, PEX14, TGFA, and SYT1. All of this relates to DNA. DNA is found in the human cell nucleus. The human embryo has 46 chromosomes. A chromosome has double stained DNA. DNA is held by four chemical called bases. They are adenine, cytosine, guanine, and thymine. DNA is made up of a double helix too. DNA forms chromosomes in the cell nucleus. Section of DNA form genes. Genes act as directors for proteins. Exercise, nutrition, and supplements can improve the human body. In the 21st century, we live in a new time. The average life expectancy worldwide has increased via medicine, surgery, and health science. Men tend to weigh more and have greater muscle mass than women. Men have 40–60 percent greater upper-body strength and 25–30 percent more lower-body strength. However, with training and nutritional guidance on par with men’s, female power lifters, for example, have narrowed the gap in actual strength to between 0 and 8 percent.

There have even been studies where women’s lower-body strength used in performing leg-presses has exceeded that of men. Males weigh about 15% more than females, on average. For those older than 20 years of age, men in the US have an average weight of 86.1 kg (190 lbs.), whereas women have an average weight of 74 kg (163 lbs.). On average, men are taller than women, by about 15 cm (6 inches). American men who are 20 years old or older have an average height of 176.8 cm (5 ft. 10 in). The average height of corresponding American women is 162 cm (5 ft. 4in). Women have a larger hip section than men, an adaptation for giving birth to infants with large skulls. Women show higher performance levels on tests of verbal fluency. This may be because the female auditory cortex is denser than that of the male. This difference and other sensory differences like it could be because of the sex hormones that impact the fetal brain during development. Some studies have shown that women have a more sensitive sense of smell than males, both in the differentiation of odors, and in the detection of slight or faint odors. Sex is determined by biology like gamete size, genital morphology, and the presence of absence of a Y chromosome including sex hormone levels. Gender deals with social roles based on the sex of a person or personal identification of one’s own gender. There are similarities among men and women too. Both are human beings, we have the same hormones (with variations of hormone levels and patterns in each human), and we all have equal value as persons living on this Earth.

By Timothy

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