This unit was about the circulatory system and cardiovascular health. The circulatory system transports materials like oxygen & glucose and removes waste materials like carbon dioxide and urea from cells. The major organs of this system include the heart, many arteries and veins that surround the heart and lead to all different parts of the body, and blood. Arteries carry oxygen-rich blood away from the heart and to the organs, veins bring back oxygen-poor blood back to the heart, and capillaries is where oxygen and other nutrients are transferred between the bloodstream and body tissues. The nodal system is accountable for the heart beating, and the SV node also known as the "pacemaker" which starts each heartbeat and sets the pace for the whole heart.The heart has four chambers, the left and right ventricle and the left and right atrium. The left side of the heart deals with oxygenated blood and the right deals with deoxygenated blood. We also learned about blood pressure and how it is a measure of the force exerted by the blood onto the walls of the arteries. The systolic & diastolic pressure should be 120/80. But this number varies with age, weight, race, mood, activity level & posture. We did a blood pressure lab where we get a opporunity to measure our partners blood pressure and it was a great way to learn the traditional way of taking blood pressure.
We also learned about the different components of blood. Blood is 55% plasma and 45% cellular material. The main function of blood is to transport nutrients, regulate body temperature, and protect from infection.There are 4 types of blood, A,AB, B & O based on presence of antigens. Red blood cells have no nucleus, no genetic material and contain hemoglobin that carry oxygen. They have a 120 day life span and get recycled in spleen and liver when worn out. Anemia is when there is reduced oxygen carrying capacity of blood and tissues in return have inadequate amounts of oxygen. Sickle cells anemia is when the red blood cells turn crescent shaped. White blood cells fight off microbes and their lifes span ranges from a few days to years. There are 5 types of white blood cells, neutrophils, basophils, eosinophils, lymphocytes, & monocytes. They all have unique roles in responding to bacteria, parasite, and viruses. Also, platelets initiate blood clotting.
Cardiovascular disease revolves around damaged blood vessels. A heart attack can occur when blood supply to the myocardium is severely reduced or damaged that leads to damaged or death of heart cells. The cause of heart attack is usually due to atherosclerosis in the coronary arteries. The long term of a heart attack can result in the myocardium dying and the heart can lose some of its' strength over time.The heart attack does not kill a person immediately but rather the cardiac arrest a person encounters as a result of the heart attack. During a cardiac arrest the heart stops beating and everything malfunctions. A stroke is essentially a heart attack in the brain. Most strokes are ischemic and that means they occur when arteries get blocked by a blood clot. But what triggers it is when the plaque ruptures and travels to the brain and everywhere else. The clot can cut off blood supply to the brain and two million brain cells can die every minute causing irreversible damage. However, there is a drug called tissue-plasminogen activator (tPA) that can break up the clot and restore the brain's blood supply. An aneurysm is when a section of a blood vessel wall is thin and weakened. This is very life threatening and they most commonly occur in the aorta and the arteries at the base of the brain. An aneurysm can burst at any time known as dissection but there is treatment available.
Most cardiovascular diseases are a result of atherosclerosis. It is a chronic inflammation caused by excess sugars and polyunsaturated fats, excess omega-6, and damaged blood vessels allowing LDL to easily stick to and cause a plaque to develop. In the atherosclerosis reading it informed us that typical LDL levels in Western society exceed what the body needs and can actually promote arterial disease. This may come from the fact that the diet consumed in our society is so high in red meats and carbs it is potentially detrimental to our health. Fortunately, there are methods to help reduce the risk of heart attack and disease by having a healthy diet, lowering blood pressure, exercising regularly and losing weight.