Hematopoiesis is the process of producing all the cellular components of blood and blood plasma. It happens in the hematopoietic system, which includes organs and tissues like bone marrow, liver, and spleen.
Simply put, hematopoiesis is the body’s process of producing blood cells. It begins early in the development of an embryoTrusted Source, well before birth, and lasts throughout an individual’s life.
Quick hematopoiesis facts:
During the first weeks of embryonic development, hematopoiesis begins.
All blood cells and plasma are derived from a stem cell, which can differentiate into any other cell.
What exactly is hematopoiesis?
Red blood cells are responsible for transporting oxygen throughout the body.
Blood is made up of over ten different cell types. Each of these cell types is classified into one of three broad groups:
1. Red blood cells (erythrocytes) are responsible for transporting oxygen and hemoglobin throughout the body.
2. Leukocytes (white blood cells) help the immune system. White blood cells are classified into several types:
Lymphocytes: T and B cells that aid in the fight against viruses and tumors.
Neutrophils: These cells aid in the fight against bacterial and fungal infections.
Eosinophils: These help fight parasites and play a role in the inflammatory response.
Basophils: These cells produce the histamines required for the inflammatory response.
Macrophages engulf and digest debris such as bacteria.
3. Platelets (thrombocytes): These aid in blood clotting.
Current research supports the monophyletic theory of hematopoiesis. According to this theory, one stem cell produces all blood cells.
Where does it happen?
Hematopoiesis occurs in a variety of locations:
In the embryo, hematopoiesis provides oxygen to organs.
Primordial hematopoiesis is another name for this process.
According to a reliable source, hematopoiesis in the embryo produces only red blood cells capable of supplying oxygen to developing organs. The yolk sac, which feeds the seed until the placenta develops fully, controls hematopoiesis at this stage.
As the embryo develops, the hematopoiesis process moves to the liver, spleen, and bone marrow, producing other types of blood cells.
Hematopoiesis of red blood cells and platelets occurs primarily in the bone marrow in adults. It may also persist in the spleen and liver of infants and children.
The lymph system, specifically the spleen, lymph nodes, and thymus, produces lymphocytes, which are white blood cells. Monocytes are white blood cells produced by tissue in the liver, spleen, lymph nodes, and other organs.
The hematopoiesis process
The body’s requirements determine the rate of hematopoiesis. The body is constantly producing new blood cells to replace old ones. About 1% of the body’s blood cells must be replaced every day.
White blood cells have the shortest life span, often lasting only a few hours to a few days, whereas red blood cells can live for up to 120 days.
The hematopoiesis process begins with an unspecialized stem cell. This stem cell divides, and some new cells differentiate into precursor cells. These cells are destined to become a specific type of blood cell but have not yet fully developed. These immature cells, however, quickly divide and mature into blood components such as red and white blood cells or platelets.
Although scientists understand the fundamentals of hematopoiesis, there is ongoing scientific debate about how stem cells that play a role in hematopoiesis are formed.
Each type of blood cell follows a slightly different hematopoiesis pathway. All of them begin as multipotent hematopoietic stem cells (HSC). Hematopoiesis then proceeds in two distinct ways.
The production of three types of blood cells: platelets, red blood cells, and white blood cells is trilineage hematopoiesis. Each of these cells develops from the transformation of HSC into common myeloid progenitors (CMP).
Following that, the procedure varies slightly. The precursor cells become more organized at each stage of the process:
Platelets and red blood cells
Red blood cells (RBCs): CMP cells undergo five transformations before becoming red blood cells, also known as erythrocytes.
Platelets: CMP cells undergo three distinct cell type transformations before becoming platelets.
WBCs are white blood cells.
There are several types of white blood cells, each of which follows its path during hematopoiesis. All white blood cells begin as CMP cells and then differentiate into myoblasts. Following that, the procedure is as follows:
A myeloblast goes through four stages of development before becoming a neutrophil, eosinophil, or basophil.
A myeloblast must undergo three more transformations before becoming a macrophage.
A second hematopoiesis pathway produces T and B cells.
T and B lymphocytes
MHCs transform into cells known as common lymphoid progenitors, which then differentiate into lymphoblasts to produce lymphocytes. Lymphoblasts develop into infection-fighting T and B cells. Following infection, some B cells differentiate into plasma cells.
Anemia can occur when there is a lack of hemoglobin in the blood.
Even when hematopoiesis occurs, some blood disorders can affect healthy blood cells in the blood.
Cancers of the white blood cells, such as leukemia and lymphoma, can, for example, alter the number of white blood cells in the bloodstream. Blood cell counts can be affected by tumors in hematopoietic tissue that produces blood cells, such as bone marrow.
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The aging process can cause an increase in the amount of fat in the bone marrow. This increase in fat may make it more difficult for the bone marrow to produce blood cells. If the body requires more blood cells due to an illness, bone marrow cannot meet the demand. This can result in anemia, in which the blood lacks hemoglobin from red blood cells.
Hematopoiesis is a continuous process that generates a large number of cells. Estimates vary, and the precise number of cells required depends on the individual. However, on an average day, the body may generate 200 billion red blood cells, 10 million white blood cells, and 400 billion platelets.
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What You Should Know About Anemia
Symptoms \sTypes \sCauses \sTreatment
Risk Factors in Diet
Anemia occurs when the number of red blood cells in the body falls. When this happens, the blood cannot supply enough oxygen to the body. Anemia can cause fatigue and weakness.
According to Trusted Source, anemia affects approximately 3 million people in the United States.
Anemia can also be caused by other health conditions that interfere with the body’s production of healthy red blood cells (RBCs) or speed up the breakdown or loss of these cells. Anemia can cause fatigue, shortness of breath, and dizziness.
This article discusses the different types, symptoms, and causes of anemia and the treatments available.
Fatigue is the most common symptom of anemia. Other common symptoms include the following: Trusted Source:
pale skin tone
rapid or irregular heartbeat
headache and chest pain
Symptoms, however, differ from person to person. Mild anemia may cause few or no symptoms in some people.
There are several types of anemia, each with distinct symptoms. Among the most common types of anemia are:
Anemia due to iron deficiency
Anemia caused by a lack of vitamin B12
anemia of aplastic anemia
anemia caused by hemolysis
Anemia due to iron deficiency
Iron deficiency anemia, the most common type, occurs when the body produces too few RBCs due to a lack of iron. It could arise as a result of the following:
a low-iron diet
a lot of menstruation
regular blood donation
endurance training medications that irritate the gut lining, such as ibuprofen, and certain digestive conditions, such as Crohn’s disease
It can cause the following symptoms:
fatigue, dizziness, cold extremities
Learn more about anemia caused by iron deficiency.
Anemia caused by a lack of vitamin B12
Vitamin B12 is required for RBC production. RBC count may be low if a person needs to consume or absorb more B12.
Among the symptoms are
walking difficulties, confusion, and forgetfulness
A smooth, red tongue characterizes diarrhea glossitis.
Learn more about anemia caused by vitamin B12 deficiency.
Aplastic anemia is a type of anemia.
This rare blood disorder occurs when the bone marrow cannot produce enough new RBCs. It is usually caused by an autoimmune disease that damages stem cells. Despite having normal iron levels, this occurs.
It can result in symptoms like Trusted Source:
fatigue recurring infections
Skin rashes and bruising are common.
Find out more about aplastic anemia.
Anemia due to hemolysis
This type of anemia occurs when RBCs are depleted faster than the body can replace them. This can be caused by several conditions, including autoimmune diseases, infections, bone marrow problems, and inherited disorders such as sickle cell disease and thalassemia.
Hemolytic anemia can cause a variety of symptoms, including
Jaundice, dark urine, fever, and stomach pain
Find out more about hemolytic anemia.
RBCs are required by the body to survive. They carry hemoglobin, a complicated protein that binds to iron molecules. These molecules are responsible for transporting oxygen from the lungs to the rest of the body.
Anemia can be caused by various medical conditions that cause low RBC levels.
There are numerous types of anemia, and there is no single cause. It can be challenging to determine what is causing a low RBC count in some people.
Three main factors cause anemia:
Loss of blood
Iron deficiency anemia is the most common type, and blood loss is frequently the cause. Anemia can result from blood loss due to low iron levels.
When the body loses blood, it draws water from tissues outside the bloodstream to keep the blood vessels hydrated. This extra water dilutes the blood, lowering the RBC count.
Acute (short-term) or chronic blood loss (long-term).
Acute blood loss can occur due to surgery, childbirth, or trauma. Anemia is more commonly caused by chronic blood loss. A stomach ulcer, endometriosis, cancer, or another type of tumor can cause chronic blood loss.
Other reasons for anemia caused by blood loss include:
Nonsteroidal anti-inflammatory drugs, such as aspirin and ibuprofen, treat gastrointestinal conditions such as hemorrhoids, cancer, or gastritis.
heavy menstrual flow
RBC deficiency or impairment
Bone marrow is the soft, spongy tissue at the center of bones that is essential in forming RBCs. The bone marrow generates stem cells, which differentiate into RBCs, white blood cells, and platelets.
A variety of diseases can affect the bone marrow. One of these is leukemia, a type of cancer that causes an overabundance of abnormal white blood cells to be produced. This interferes with RBC production.
Bone marrow problems can also cause anemia. Aplastic anemia, for example, occurs when there are few or no stem cells in the bone marrow.
Anemia occurs in some cases when RBCs do not grow and mature normally. This happens in people suffering from thalassemia, a hereditary form of anemia.
RBCs have a typical life span of 120 distrusted Sources. However, before they complete their natural life cycle in the bloodstream, the body may destroy or remove them.
The destruction of RBCs causes autoimmune hemolytic anemia. It happens when the immune system misidentifies RBCs as foreign and attacks them.
Anemia can be treated using a variety of methods. Each aims to raise an individual’s RBC count, which increases the amount of oxygen in the blood.
The treatment required is determined by the type of anemia a person has. The following are some treatments for common types of anemia:
Iron deficiency anemia: Iron supplements and dietary changes can help; if excessive bleeding is present, a doctor will identify and treat the cause.
Vitamin deficiency anemia can be treated with dietary supplements and vitamin B12 injections.
Thalassemia treatment options include folic acid supplements from Trusted Source, iron chelation, and, in some cases, blood transfusions and bone marrow transplants.
Anemia caused by a chronic disease: The doctor will concentrate on treating the underlying condition.
Aplastic anemia is treated with blood transfusions or bone marrow transplants.
Doctors treat sickle cell anemia with oxygen therapy, pain relievers, and intravenous fluids. They may also prescribe antibiotics, folic acid supplements, blood transfusions, and hydroxyurea, a cancer treatment.
Hemolytic anemia: Treatment may include immunosuppressive drugs, infection treatments, and plasmapheresis, which filters the blood.
If nutritional deficiencies cause anemia, eating more iron-rich foods can help.
Some foods high in ironTrusted Sources include:
leafy green vegetables such as kale, spinach, and watercress iron-fortified cereal and bread
beans and pulses
red or white meats
seeds and nuts
fish \stofu \seggs
Apricots, raisins, and prunes are examples of dried fruits.
Anemia affects people of all ages, genders, and ethnicities. However, the following factors increase a person’s likelihood of developing a form of the condition:
being born prematurely and aged 6-24 months
Menstruating, being pregnant, and giving birth while eating a diet deficient in vitamins, minerals, and iron
taking medications that cause stomach lining inflammation, such as NSAIDs
having inherited anemia in one’s family
having an intestinal disorder that interferes with nutrient absorption losing blood
AIDS, diabetes, kidney disease, cancer, rheumatoid arthritis, heart failure, and liver disease are all chronic illnesses.
There are several methods for diagnosing anemia, but the most common involves a blood test called a complete blood count (CBC). This test assesses a variety of factors, including:
Hematocrit levels, which involve comparing RBC volume to total blood volume hemoglobin levels
A CBC can provide information about a person’s overall health. It can also assist a doctor in determining whether to rule out underlying conditions such as leukemia or kidney disease.
Anemia is diagnosed when RBC, hemoglobin, and hematocrit levels fall below the normal range.
However, a healthy person’s levels may fall outside of this range. A complete blood count (CBC) is not conclusive, but it is a good starting point for a doctor to make an accurate diagnosis.
The cause determines the outlook of a person suffering from anemia.
Anemia can sometimes be prevented or managed solely through dietary changes. Other types of anemia necessitate more extensive treatment protocols; some can be fatal if left untreated.
If a person is constantly tired and weak, they should see a doctor for testing.
Anemia occurs when the body has a low number of RBCs circulating. This lowers the person’s oxygen levels and can cause fatigue, pale skin, chest pain, and shortness of breath.
Blood loss, reduced or impaired RBC production, and RBC destruction is all common causes.
A CBC test can help a doctor detect anemia. Treatment may include dietary changes, supplements, medications, blood transfusions, and bone marrow transplants, depending on the type.
J.D. is a 37 years old white woman who presents to her gynecologist complaining of a 2-month history of intermenstrual bleeding, menorrhagia, increased urinary frequency, mild incontinence, extreme fatigue, and weakness. Her menstrual period occurs every 28 days and lately, there have been 6 days of heavy flow and cramping. She denies abdominal distension, backache, and constipation. She has not had her usual energy levels since before her last pregnancy.
Past Medical History (PMH):
Upon reviewing her past medical history, the gynecologist notes that her patient is a G5P5 with four pregnancies within four years, the last infant having been delivered vaginally four months ago. All five pregnancies were unremarkable and without delivery complications. All infants were born healthy. Patient history also reveals a 3-year history of osteoarthritis in the left knee, probably the result of sustaining significant trauma to her knee in an MVA when she was 9 years old. When asked what OTC medications she is currently taking for her pain and for how long she has been taking them, she reveals that she started taking ibuprofen, three tablets each day, about 2.5 years ago for her left knee. Due to a slowly progressive increase in pain and a loss of adequate relief with three tablets, she doubled the daily dose of ibuprofen. Upon the recommendation from her nurse practitioner and because long-term ibuprofen use can cause peptic ulcers, she began taking OTC omeprazole on a regular basis to prevent gastrointestinal bleeding. Patient history also reveals a 3-year history of HTN for which she is now being treated with a diuretic and a centrally acting antihypertensive drug. She has had no previous surgeries.
Case Study 1 Questions:
Name the contributing factors on J.D. that might put her at risk to develop iron deficiency anemia.
Within the case study, describe the reasons why J.D. might be presenting constipation and or dehydration.
Why Vitamin B12 and folic acid are important for erythropoiesis? What abnormalities their deficiency might cause in the red blood cells?
The gynecologist is suspecting that J.D. might be experiencing iron deficiency anemia.
In order to support the diagnosis, list and describe the clinical symptoms that J.D. might have positive for Iron deficiency anemia.
If the patient is diagnosed with iron deficiency anemia, what do you expect to find as signs of this type of anemia? List and describe.
Lab results came back for the patient. Hb 10.2 g/dL; Hct 30.8%; Ferritin 9 ng/dL; red blood cells are smaller and paler in color than normal. Research list and describe appropriate recommendations and treatments for J.D.
Mr. W.G. is a 53-year-old white man who began to experience chest discomfort while playing tennis with a friend. At first, he attributed his discomfort to the heat and had a large breakfast. Gradually, however, discomfort intensified to a crushing sensation in the sternal area and the pain seemed to spread upward into his neck and lower jaw. The nature of the pain did not seem to change with deep breathing. When Mr. G. complained of feeling nauseated and began rubbing his chest, his tennis partner was concerned that his friend was having a heart attack and called 911 on his cell phone. The patient was transported to the ED of the nearest hospital and arrived within 30 minutes of the onset of chest pain. En route to the hospital, the patient was placed on a nasal cannula and an IV D5W was started. Mr. G. received aspirin (325 mg PO) and 2 mg/IV morphine. He is allergic to meperidine (rash). His pain has eased slightly in the last 15 minutes but is still significant; was 9/10 in severity; now7/10. In the ED, chest pain was not relieved by 3 SL NTG tablets. He denies chills.
Case Study 2 Questions:
For patients at risk of developing coronary artery disease and patients diagnosed with acute myocardial infarction, describe the modifiable and non-modifiable risk factors.
What would you expect to see on Mr. W.G. EKG and which findings described in the case are compatible with the acute coronary event?
Having only the opportunity to choose one laboratory test to confirm the acute myocardial infarction, which would be the most specific laboratory test you would choose and why?
How do you explain that Mr. W.G’s temperature has increased after his Myocardial Infarction, when can that be observed, and for how long? Base your answer on the pathophysiology of the event.
Explain to Mr. W.G. why he was experiencing pain during his Myocardial Infarction. Elaborate and support your answer.