Dorothy FarrarBlood
The body fluid blood is an essential factor in the cardiovascular system. Blood fulfills a number of vital tasks in the human organism, especially in the areas of respiration, transport of substances and defense against infection.
Definition
The red-colored blood (Greek “Haima”, Latin “Sanguis”) is the liquid content of the heart and the blood vessels leading to the heart or leading away from the heart (veins or veins ).
Blood is transported through the cardiovascular system mainly by the mechanical pumping action of the heart in connection with the function of the venous valves. The amount of blood in an adult, which is primarily dependent on body weight, is around five to six liters on average.
The main components of blood are blood plasma (about 54%) and blood cells and platelets (about 45%) in roughly equal parts. The blood components also include salts , hormones , proteins , enzymes and dissolved gases in low concentrations .
Blood plasma is the cell-free blood component in which the cellular blood cells swim. Blood cells are divided into red and white blood cells. The red blood cells (erythrocytes) are about 7.5 µm in size. They have a membrane skeleton, are disc-shaped and do not form a cell nucleus. They make up the bulk of the blood cells.
Sugar , lipids and other nutrients are found in the arterial blood, while in the venous area there are products that occur during metabolism, such as urea.
Like the erythrocytes, the white blood cells (leukocytes) formed from stem cells in the bone marrow are between 7 and 20 µm in size. They have different forms depending on the task. Leukocytes are more complex than erythrocytes and have cell nuclei.
In contrast to erythrocytes, however, they lack the protein complex hemoglobin, which is responsible for binding oxygen atoms in the red blood cells. The iron-containing hemoglobin is also responsible for the red color of the erythrocytes and thus for the color of blood. Platelets (thrombocytes) are the smallest cellular components of blood with a maximum size of 3.0 µm and have a disc-shaped structure.
Erythrocytes (Red Blood Cells)
The erythrocytes are the red blood cells. They are mostly disc-shaped, slightly dented in the middle and very malleable. With a diameter of 6–8 μm and without an existing cell nucleus, human erythrocytes are particularly light and can be pumped more easily through the bloodstream. The red blood cells also contain no cell organelles.
Responsible for transporting oxygen
Inside, they almost exclusively contain several million hemoglobin molecules, with which they can absorb oxygen. They absorb this in the alveoli and release it everywhere in the body. They also absorb some of the carbon dioxide produced during respiration and transport it back to the lungs. A red blood cell is held together by an elastic membrane that allows gas exchange. At the same time, this elastic membrane is responsible for allowing the erythrocytes to deform in the smallest capillaries. The diameter of many capillaries is smaller than the diameter of a single red blood cell.
With about 25 trillion copies per person, the erythrocytes make up the largest part of the blood. They survive for around 120 days before being broken down in the spleen, liver and bone marrow. The neoplasm, on the other hand, takes place predominantly in the red bone marrow.
A healthy erythrocyte is round and biconcave in shape. All other variants are considered pathological in humans. Erythrocytes are one of the most important components in blood tests. Their number and their form can in many cases be understood as the leading symptom of certain diseases. For example, sickle cell anemia presents with sickle-shaped erythrocytes and spherical cell anemia with spherical erythrocytes.
A low erythrocyte value can indicate a deficiency
A reduced erythrocyte value means anemia. Deficiency symptoms also lead to this effect. For example, an iron deficiency can be diagnosed via smaller and generally paler erythrocytes. An increased value, on the other hand, can indicate polycythemia and provide valuable information when examining people with cardiovascular problems.
The erythrocyte value remains approximately the same throughout life (the same amount per microliter of blood) and differs between the sexes. A quantity of 4.1 – 5.1 x 10^6/microliter of blood is assumed as a reference value for women and a quantity of 4.5 – 5.9 x 10^6/microliter of blood for men.
The white blood cells are called leukocytes. They represent part of the body’s immune system and are therefore also called immunocytes. The leukocytes are mainly found in the bloodstream, bone marrow and lymphatic system, but can also be found in body tissue and organs due to their amoebic mode of locomotion.
Leukocytes (White Blood Cells)
In humans, white blood cells are produced in the red bone marrow and then released into the bloodstream. In adults, the red bone marrow is located in the breastbone and pelvis, while children also have red bone marrow in the long bones.
basis of the immune system
The leukocytes are made up of several subspecies with specific tasks: Granulocytes and macrophages are known as scavenger cells and form the basis of the immune system. They recognize foreign proteins and are therefore able to track down toxins and bacteria and render them harmless. At the same time, the scavenger cells can activate the immune system by presenting the pathogens they have absorbed to other immunocytes. This process is called antigen presentation.
Dendritic cells are also an important component of leukocytes and are fully specialized for antigen presentation. The dendritic cells function like a kind of scout by picking up pathogens and presenting them to other leukocytes. They therefore very often trigger a primary immune response. A primary immune response becomes evident in the human body through a disease state such as fever or a cold . To differentiate between foreign and endogenous cells, many leukocytes are trained in the organs of the lymphatic system. The thymus is particularly important for the formation of a healthy immune system.
Dirt and mud strengthen the immune system
During human childhood, the leukocytes in the thymus adapt to their environment. Therefore, pathogens such as viruses and bacteria are very important for the formation of a healthy immune system for children. Sterile rooms without natural environmental influences, on the other hand, can impair or even damage the immune system. Autoimmune diseases can occur because the leukocytes do not learn to distinguish between foreign and endogenous cells. As a result, the leukocytes also attack the body’s own tissue and damage human health. Parents should therefore let their children come into contact with dirt and mud in nature with a clear conscience. This strengthens the immune system and protects against allergies.
Thrombocytes (platelets)
The thrombocytes or blood platelets are an important cell component of the blood. They play a key role in blood circulation. Their main task is reliable blood clotting. They become active even with the smallest bleeding injury. They swell, stick together and form a plug. In this way, they seal off the injured vessel. In addition, they release other substances that promote coagulation. The bleeding stops. This is the beginning of regular wound healing.
Construction, lifetime and source
Platelets are disk-shaped cells without a nucleus. Their shape resembles a discus. In the event of a vascular wound, they suddenly become many times larger and form small extensions or tentacles. Both properties make the sealing function much easier. Their lifespan is one to two weeks. The spleen, the lungs and the liver are responsible for the breakdown. In order to be adequately supplied with platelets, the body produces them continuously. This happens in the bone marrow, controlled by hormones.
Reference values (standard values)
For the medical diagnosis of platelet counts, reference or standard values apply. Its abbreviation is THRO. The range goes from 140,000 to 440,000 units and is the same for men and women. In children, the values are higher and age-dependent. If there is a pathological deficiency or excess, the doctor investigates the causes. He sometimes uses other laboratory values for this purpose. Some abnormalities are harmless and easy to treat, others are serious and require treatment.
platelet excess
As a rule, deviating platelet data do not show any characteristic symptoms of the disease. They are usually signs of other disorders. An example is infections. They lead to increased cell production to repair bleeding vessels caused by inflammation. If the symptoms subside, the values normalize. It’s the same with operations. They demand maximum performance from the blood platelets when it comes to hemostasis and need them in sufficient quantities. With healing, their number is regulated. In individual cases, there is danger from the platelets themselves if they are present in large quantities. They then stick together more easily to form small clots that travel through the vessels throughout the body. If they get stuck in bottlenecks, thrombosis occurs. The possible consequences are dramatic with heart attack, pulmonary embolism or stroke.
platelet deficiency
If there is a lack of blood platelets, a more precise search for the causes is also necessary. The undersupply of folic acid or vitamin B12 is largely harmless. Drugs and an adapted diet can help. Cancer is a serious cause. Here, the platelet count can be significantly reduced by chemotherapy. Leukemia is just as serious. It damages the bone marrow and prevents the formation of new blood platelets.
Function of blood
One of the main tasks of the blood is to ensure the transport of oxygen from the lungs to the body cells and the removal of carbon dioxide from the cells , which is primarily ensured by the red blood cells . In addition, the blood supplies the cells with nutrients absorbed from the stomach and intestines and removes waste products produced during metabolism from the cells.
The blood also has important functions, including ensuring the vital constancy of the pH value in the body. A complicated system of biochemical processes called “buffering” ensures a constant blood pH of 7.35 to 7.45.
The blood functions also include the defense against diseases, carried out in particular by leukocytes, by combating invading foreign substances. The task of closing off injury-related openings in the body tissue by coagulation is also one of the essential functions of the blood.
The platelets are particularly important for the blood coagulation process. In addition, enzymes present in the blood vessels break down blood clots and thus prevent thrombosis. The constant blood circulation makes a decisive contribution to maintaining the necessary body temperature.
Hemoglobin
Hemoglobin (Hb) is the red blood pigment. It distributes the air we breathe throughout the body. To do this, it absorbs the oxygen in the lungs. The transport to all organs and body cells takes place via the blood vessels. On the way back, it brings the carbon dioxide produced during metabolism back into the lungs for exhalation.
function
The hemoglobin is in the red blood cells. It is a large, ring-shaped protein molecule that the body makes itself. An iron atom sits in the middle. During transport, this first holds the oxygen and then the carbon dioxide.
normal values
The reference values have the abbreviation Hb. For women, the normal range is 12 to 16 units. For men, the numbers are from 13.5 to 17.5. Children have different data depending on their age. If the analysis deviates from the norm, the doctor consults further laboratory values. Based on the findings, the scope of treatment ranges from simple measures to extensive therapy steps.
deficiency and excess
If the data is low, the body shows typical symptoms of illness such as dizziness, weakness or tiredness. These are signals for a low oxygen content in the tissue. In the majority of cases, the causes are easy to treat. There are often different states of deficiency. In the first place it is about not enough iron. Oxygen transport is not possible without this mineral. Other reasons are deficits in folic acid and vitamin B12. Both molecules are required to build the hemoglobin ring. In addition, there are serious disorders with low Hb levels. Examples are hidden blood loss due to stomach and intestinal diseases. Other possibilities are weakened kidney function or metabolic problems that inhibit regular blood formation.
A surplus of the red blood pigment that can be regarded as healthy occurs naturally when people permanently inhabit high mountain regions such as the Andes or the Himalayas. To compensate for the lack of oxygen in the thin air, the organism produces more red blood cells and thus more hemoglobin. Alpinists use this effect to prepare for extreme tours. Measurement results that are abnormally high indicate lung damage that impedes the exchange of oxygen. To compensate, the body makes more hemoglobin available.
Why is carbon monoxide life threatening?
The gas is produced with every combustion with too little oxygen. The danger begins with inhalation. Carbon monoxide, like oxygen, can bind to the iron in hemoglobin. It is much stronger and displaces the blood oxygen in a very short time. The resulting deficiency means the greatest danger to life. If you don’t get air as quickly as possible in such situations when nausea, dizziness or headaches begin, you can no longer be saved in most cases.
Read blood count
| Blood count – explanation | ||
| blood value | normal value | explanation |
| Hb value (hemoglobin) | 12-18 g/dl | Amount of red blood pigment: value decreases in iron deficiency, chronic inflammation, folic acid deficiency |
| erythrocytes | 4,3 – 5,9 Mio./µl | Red blood cells (contain red blood dye hemoglobin): value increases in tumors, various heart and lung diseases; Value decreases with reduced blood formation (e.g. iron deficiency, vitamin deficiency), blood loss (e.g. menstruation, childbirth) |
| leukocytes | 3.800-10.500/µl | White blood cells (defense cells): value increases with bacterial infection (inflammation), leukemia; Value decreases with virus infection (e.g. flu) |
| blood sugar | 70 – 99mg/dl (fast) | Glucose level: value increases with diabetes (diabetes); Value decreases when the blood sugar control mechanism is disturbed (e.g. due to diabetes, obesity, stress, alcohol) |
| HKT value (hematocrit) | 35-52 Vol% | Measure of the proportion of solid blood components (viscosity of the blood): the value increases when there is a lack of liquid; Value decreases in diseases of the blood |
| blood sedimentation rate (ESR) | Men: <20mm/h; Females: <30mm/hr | Sedimentation rate: The value can increase in the case of inflammation, anemia, pregnancy, menstrual bleeding, among other things |
diseases
When examining the blood count, important indications of a large number of diseases can be determined. However, blood itself can also be the field of diseases and complaints. Particularly serious blood diseases are anemia, hemophilia and leukemia.
Anemia is a lack of hemoglobin or red blood cells. As a result, the oxygen supply is disrupted. People affected by anemia suffer from shortness of breath and headaches, tire quickly and have little physical resilience.
Haemophilia, also known as “blood disease”, is a blood clotting disorder that is one of the hereditary diseases. Hemophilia almost exclusively affects men. In those affected, the blood escaping from the wounds does not coagulate or only after a long time. Under certain circumstances, wounds can also rupture spontaneously without an injury having occurred beforehand. The joint regions are particularly affected.
The blood disease leukemia, which is often incorrectly referred to colloquially as “blood cancer”, is characterized by a significant overproduction of leukocytes and their precursors. This malformation impairs blood formation in the bone marrow . Leukemia cells can also invade organs such as the spleen and liver . There they lead to significant malfunctions or even to functional failures. The symptoms of leukemia, which leads to death in most cases, are extremely diverse and non-specific.
Hello and welcome to my Health Guide & Encyclopedia! My name is Dorothy Farrar, and I'm the founder and main author of this platform.
My passion for health and wellness started at a young age when I became interested in the connection between the food we eat and the way we feel. This fascination led me to study nutrition and dietetics in college, where I learned about the importance of a balanced diet and the impact of various nutrients on the body.