Blood Health
[vc_row][vc_column][vc_column_text woodmart_inline=”no” text_larger=”no”]Blood is a fluid that transports oxygen and nutrients to the cells and carries away carbon dioxide and other waste products. Technically, blood is a transport liquid pumped by the heart (or an equivalent structure) to all parts of the body, after which it is returned to the heart to repeat the process. Blood is both a tissue and a fluid. It is a tissue because it is a collection of similar specialized cells that serve particular functions. These cells are suspended in a liquid matrix (plasma), which makes the blood a fluid. If blood flow ceases, death will occur within minutes because of the effects of an unfavourable environment on highly susceptible cells.
A red blood cell travels from the heart to the lungs and other body tissues to exchange oxygen and carbon dioxide. In a circuit through the cardiovascular system, red blood cells transport oxygen from the lungs to the body tissues and transport carbon dioxide from the body tissues to the lungs.
The constancy of the composition of the blood is made possible by the circulation, which conveys blood through the organs that regulate the concentrations of its components. In the lungs, blood acquires oxygen and releases carbon dioxide transported from the tissues. The kidneys remove excess water and dissolved waste products. Nutrient substances derived from food reach the bloodstream after absorption by the gastrointestinal tract. Glands of the endocrine system release their secretions into the blood, which transports these hormones to the tissues in which they exert their effects. Many substances are recycled through the blood; for example, iron released during the destruction of old red cells is conveyed by the plasma to sites of new red cell production where it is reused. Each of the numerous components of the blood is kept within appropriate concentration limits by an effective regulatory mechanism. In many instances, feedback control systems are operative; thus, a declining level of blood sugar (glucose) leads to accelerated release of glucose into the blood so that a potentially hazardous depletion of glucose does not occur.
Blood system
Unicellular organisms, primitive multicellular animals, and the early embryos of higher forms of life lack a circulatory system. Because of their small size, these organisms can absorb oxygen and nutrients and can discharge wastes directly into their surrounding medium by simple diffusion. Sponges and coelenterates (e.g., jellyfish and hydras) also lack a blood system; the means to transport foodstuffs and oxygen to all the cells of these larger multicellular animals is provided by water, sea or fresh, pumped through spaces inside the organisms. In larger and more-complex animals, transport of adequate amounts of oxygen and other substances requires some type of blood circulation. In most such animals the blood passes through a respiratory exchange membrane, which lies in the gills, lungs, or even the skin. There the blood picks up oxygen and disposes of carbon dioxide.
The cellular composition of blood varies from group to group in the animal kingdom. Most invertebrates have various large blood cells capable of amoeboid movement. Some of these aid in transporting substances; other are capable of surrounding and digesting foreign particles or debris (phagocytosis). Compared with vertebrate blood, however, that of the invertebrates has relatively few cells. Among the vertebrates, there are several classes of amoeboid cells (white blood cells, or leukocytes) and cells that help stop bleeding (platelets, or thrombocytes).[/vc_column_text][vc_column_text woodmart_inline=”no” text_larger=”no”]
Composition of blood
Oxygen requirements have played a major role in determining both the composition of blood and the architecture of the circulatory system. In some simple animals, including small worms and mollusks, transported oxygen is merely dissolved in the plasma. Larger and more-complex animals, which have greater oxygen needs, have pigments capable of transporting relatively large amounts of oxygen. The red pigment hemoglobin, which contains iron, is found in all vertebrates and in some invertebrates. In almost all vertebrates, including humans, hemoglobin is contained exclusively within the red cells (erythrocytes). The red cells of the lower vertebrates (e.g., birds) have a nucleus, whereas mammalian red cells lack a nucleus. Red cells vary markedly in size among mammals; those of the goat are much smaller than those of humans, but the goat compensates by having many more red cells per unit volume of blood. The concentration of hemoglobin inside the red cell varies little between species. Hemocyanin, a copper-containing protein chemically unlike hemoglobin, is found in some crustaceans. Hemocyanin is blue in colour when oxygenated and colourless when oxygen is removed. Some annelids have the iron-containing green pigment chlorocruorin, others the iron-containing red pigment hemerythrin. In many invertebrates the respiratory pigments are carried in solution in the plasma, but in higher animals, including all vertebrates, the pigments are enclosed in cells; if the pigments were freely in solution, the pigment concentrations required would cause the blood to be so viscous as to impede circulation.
This article focuses on the main components and functions of human blood. For full treatment of blood groups, see the article blood group. For information on the organ system that conveys blood to all organs of the body, see cardiovascular system. For additional information on blood in general and comparison of the blood and lymph of diverse organisms, see circulation.
In humans, blood is an opaque red fluid, freely flowing but denser and more viscous than water. The characteristic colour is imparted by hemoglobin, a unique iron-containing protein. Hemoglobin brightens in colour when saturated with oxygen (oxyhemoglobin) and darkens when oxygen is removed (deoxyhemoglobin). For this reason, the partially deoxygenated blood from a vein is darker than oxygenated blood from an artery. The red blood cells (erythrocytes) constitute about 45 percent of the volume of the blood, and the remaining cells (white blood cells, or leukocytes, and platelets, or thrombocytes) less than 1 percent. The fluid portion, plasma, is a clear, slightly sticky, yellowish liquid. After a fatty meal, plasma transiently appears turbid. Within the body the blood is permanently fluid, and turbulent flow assures that cells and plasma are fairly homogeneously mixed.
The total amount of blood in humans varies with age, sex, weight, body type, and other factors, but a rough average figure for adults is about 60 millilitres per kilogram of body weight. An average young male has a plasma volume of about 35 millilitres and a red cell volume of about 30 millilitres per kilogram of body weight. There is little variation in the blood volume of a healthy person over long periods, although each component of the blood is in a continuous state of flux. In particular, water rapidly moves in and out of the bloodstream, achieving a balance with the extravascular fluids (those outside the blood vessels) within minutes. The normal volume of blood provides such an adequate reserve that appreciable blood loss is well tolerated. Withdrawal of 500 millilitres (about a pint) of blood from normal blood donors is a harmless procedure. Blood volume is rapidly replaced after blood loss; within hours, plasma volume is restored by movement of extravascular fluid into the circulation. Replacement of red cells is completed within several weeks. The vast area of capillary membrane, through which water passes freely, would permit instantaneous loss of the plasma from the circulation were it not for the plasma proteins—in particular, serum albumin. Capillary membranes are impermeable to serum albumin, the smallest in weight and highest in concentration of the plasma proteins. The osmotic effect of serum albumin retains fluid within the circulation, opposing the hydrostatic forces that tend to drive the fluid outward into the tissues.[/vc_column_text][vc_column_text woodmart_inline=”no” text_larger=”no”]
Types of blood cells
Rbc
Red blood cells (RBCs, also called erythrocytes; say: ih-RITH-ruh-sytes) are shaped like slightly indented, flattened disks. RBCs contain hemoglobin (say: HEE-muh-glow-bin), a protein that carries oxygen. Blood gets its bright red color when hemoglobin picks up oxygen in the lungs. As the blood travels through the body, the hemoglobin releases oxygen to the different body parts.
Each RBC lives for about 4 months. Each day, the body makes new RBCs to replace those that die or are lost from the body. RBCs are made in the inside part of bones called the bone marrow.
Wbc
White blood cells (WBCs, also called leukocytes, say: LOO-kuh-sytes) are a key part of the immune system. The immune system helps the body defend itself against infection. Different types of WBCs fight germs, such as bacteria and viruses. Some types of WBCs make antibodies, which are special proteins that recognize foreign materials and help the body get rid of them.
There are several types of WBCs, and their life spans vary from hours to years. New cells are constantly being formed — some in the bone marrow and some in other parts of the body such as the spleen, thymus, and lymph nodes.
Blood contains far fewer WBCs than red blood cells, although the body can increase WBC production to fight infection. The white blood cell count (the number of cells in a given amount of blood) in someone with an infection often is higher than usual because more WBCs are being made or are entering the bloodstream to battle the infection.
Platelets
Platelets (also called thrombocytes, say: THROM-buh-sytes) are tiny oval-shaped cells that help in the clotting process. When a blood vessel breaks, platelets gather in the area and help seal off the leak. Platelets work with proteins called clotting factors to control bleeding inside our bodies and on our skin.
Platelets survive only about 9 days in the bloodstream and are constantly being replaced by new platelets made by the bone marrow.[/vc_column_text][vc_column_text woodmart_inline=”no” text_larger=”no”]
Circulation of blood in body
With each heartbeat, the heart pumps blood throughout our bodies, carrying oxygen to every cell. After delivering the oxygen, the blood returns to the heart. The heart then sends the blood to the lungs to pick up more oxygen. This cycle repeats over and over again.
The circulatory system is made up of blood vessels that carry blood away from and toward the heart.
Two types of blood vessels carry blood throughout our bodies:
Arteries
Arteries carry oxygenated blood (blood that has gotten oxygen from the lungs) from the heart to the rest of the body.
Veins
Blood then travels through veins back to the heart and lungs, so it can get more oxygen to send back to the body via the arteries.
As the heart beats, you can feel blood traveling through the body at pulse points — like the neck and the wrist — where large, blood-filled arteries run close to the surface of the skin.[/vc_column_text][vc_column_text woodmart_inline=”no” text_larger=”no”]
Different blood groups
A person’s blood type is determined by the antigens on the red blood cells. Antigens are protein molecules on the surface of these cells.
Antibodies are proteins in plasma that alert the immune system to the presence of potentially harmful foreign substances. The immune system protects the body from the threat of disease or infection.
Knowing a person’s blood type is essential if they are receiving an organ donation or blood transfusion. Antibodies will attack new blood cells if the blood is the wrong type, leading to life threatening complications. For example, anti-A antibodies will attack cells that have A antigens.
Red blood cells sometimes contain another antigen called RhD. Doctors also note this as part of the blood group. A positive blood group means that RhD is present.
Humans can have one of four main blood groups. Each of these groups can be Rhd-positive or -negative, forming eight main categories.
Group A positive or A negative: A antigens are present on the surfaces of blood cells. Anti-B antibodies are present in the plasma.
Group B positive or B negative: B antigens are present on the surfaces of blood cells. Anti-A antibodies are present in the plasma.
Group AB positive or AB negative: A and B antigens are present on the surfaces of blood cells. There are no antibodies in the plasma.
Group O positive and O negative: There are no antigens on the surfaces of blood cells. Both anti-B and anti-A antibodies are present in the plasma.
People with group O blood can donate to virtually any blood type, and people with group AB+ blood can usually receive blood from any group.
People can talk with their doctor to find out their blood type or find out by donating blood.
Blood groups are important during pregnancy. If a pregnant person has RhD-negative blood, for example, but the fetus inherits RhD-positive blood, treatment will be necessary to prevent Trusted Source a condition known as hemolytic disease of the newborn.[/vc_column_text][vc_column_text woodmart_inline=”no” text_larger=”no”]
Blood diseases
Disorders and diseases of the blood can impair the many functions that blood performs.
Some common blood disorders are:
Anemia: This happens when low red blood cell or hemoglobin levels Trusted Source mean the cells do not transport oxygen effectively, leading to fatigue, pale skin, and other symptoms.
Blood clotting: Clotting helps wounds and injuries heal, but blood clots that form inside a blood vessel can create a blockage, which can be life threatening. If clots become dislodged and move through the heart to the lungs, a pulmonary embolism can form.
Sickle cell disease: An inherited trait causes red blood cells to take on a crescent shape. It affects over 100,000Trusted Source people in the U.S., mostly Black Americans. It can severely impact how blood functions and can be life threatening.
Thalassemia: This is also a type of inherited anemia in which the body produces an unusual form of hemoglobin. It affected around 1,000Trusted Source people in the U.S. in 2008 and is most common in people from around the Mediterranean and parts of Asia.
If symptoms suggest a person may have a blood disorder, they should seek medical advice. A doctor may refer them to a specialist in blood disorders, known as a hematologist.
Blood cancers: Cancers such as leukemia, myeloma, and lymphoma occur when blood cells start to divide uncontrollably without dying off at the end of their life cycle.
Hemophilia: If a person has low levels of clotting factors in the blood, they can bruise or bleed Trusted Source very easily. They may bleed for too long after a minor injury or surgery, or during menstruation. It affects around 18,000 people Trusted Source in the U.S.[/vc_column_text][vc_column_text woodmart_inline=”no” text_larger=”no”]
Best foods for Blood health
Cayenne Pepper
Cayenne pepper gets its spicy flavor from a phytochemical called capsaicin. Capsaicin promotes blood flow to tissues by lowering blood pressure and stimulating the release of nitric oxide and other vasodilators or compounds that help expand your blood vessels. Vasodilators allow blood to flow more easily through your veins and arteries by relaxing the tiny muscles found in blood vessel walls. Study indicates that ingesting cayenne pepper increases circulation, improves blood vessel strength and reduces plaque buildup in your arteries
Beets
Many athletes supplement with beet juice or beet powder to help improve performance.
This is because beets are high in nitrates, which your body converts into nitric oxide. Nitric oxide relaxes blood vessels and increases blood flow to muscle tissue.
Beet juice supplements improve oxygen flow in muscle tissue, stimulate blood flow and increase nitric oxide levels all of which can boost performance
Aside from assisting athletes, beets improve blood flow in older adults with circulatory issues.
Turmeric
Increased blood flow is one of turmeric’s many health benefits.
In fact, both Ayurvedic and traditional Chinese medicine have utilized turmeric since ancient times to open blood vessels and improve blood circulation
Research suggests that a compound found in turmeric called curcumin helps increase nitric oxide production, reduce oxidative stress and decrease inflammation.
What’s more, these spicy peppers are frequently included in pain-relieving creams because they can encourage blood flow to the affected area
Pomegranate
Pomegranates are juicy, sweet fruits that are particularly high in polyphenol antioxidants and nitrates, which are potent vasodilators. Consuming pomegranate as juice, raw fruit or supplement may improve blood flow and oxygenation of muscle tissue, which could especially aid active individuals.
A study in 19 active people, found that ingesting 1,000 mg of pomegranate extract 30 minutes before working out increased blood flow, blood vessel diameter and exercise performance.
Greens
Leafy greens like spinach and collard greens are high in nitrates, which your body converts into nitric oxide, a potent vasodilator. Eating nitrate-rich foods may help improve circulation by dilating blood vessels, allowing your blood to flow more easily.
In a 27-person study, those consuming high-nitrate (845 mg) spinach daily for seven days experienced significant improvements in blood pressure and blood flow compared to a control group
Onions
Onions are an excellent source of flavonoid antioxidants, which benefit heart health.
This vegetable improves circulation by helping your arteries and veins widen when blood flow increases. In a 30-day study in 23 men, taking 4.3 grams of onion extract daily significantly improved blood flow and artery dilation after meals
Fish
Fatty fish like salmon and mackerel are excellent sources of omega-3 fatty acids. These fats are especially beneficial for circulation because they promote the release of nitric oxide, which dilates your blood vessels and increases blood flow. Omega-3 fats also help inhibit the clumping of platelets in your blood, a process that can lead to blood clot formation. What’s more, fish oil supplements are linked to reduced high blood pressure and improved blood flow in skeletal muscle during and after exercise.
Walnuts
Walnuts are loaded with beneficial compounds, such as l-arginine, alpha-lipoic acid (ALA) and vitamin E which all stimulate the production of nitric oxide. Eating walnuts may reduce blood pressure, improve blood vessel function and decrease inflammation, which may be particularly helpful for those with diabetes
People with diabetes often have circulation issues and high blood pressure due to blood vessel damage caused by uncontrolled blood sugar levels
Citrus Fruits
Citrus fruits like oranges, lemons and grapefruit are packed with antioxidants, including flavonoids. Consuming flavonoid-rich citrus fruits may decrease inflammation in your body, which can reduce blood pressure and stiffness in your arteries while improving blood flow and nitric oxide production
In a study in 31 people, those who drank 17 ounces (500 ml) of blood orange juice per day for one week had significant improvements in artery dilation and large reductions in markers of inflammation such as IL-6 and CRP compared to a control group
Cinnamon
Cinnamon is a warming spice that has many health benefits — including increased blood flow.
In animal studies, cinnamon improved blood vessel dilation and blood flow in the coronary artery, which supplies blood to the heart.
Rats fed 91 mg per pound (200 mg per kg) of body weight of cinnamon bark extract daily for eight weeks exhibited better heart performance and coronary artery blood flow after exhaustive exercise compared to rats in the control group. Plus, research shows that cinnamon can effectively reduce blood pressure in humans by relaxing your blood vessels. This improves circulation and keeps your heart healthy
Garlic
Garlic is well known for its beneficial impact on circulation and heart health. Studies suggest that garlic specifically, its sulfur compounds, which include allicin can increase tissue blood flow and lower blood pressure by relaxing your blood vessels. In fact, diets high in garlic are associated with better flow-mediated vasodilation (FMD), an indicator of blood flow efficiency.[/vc_column_text][/vc_column][/vc_row]
