Essential Roles of White Blood Cells in Wound Repair

For my STEM project my objective is describe the various WBC and their functions.

White blood cells (WBCs), also known as leukocytes, play essential roles in the immune system by defending the body against infections and promoting tissue repair. Among various types of WBCs such as basophils, neutrophils, monocytes, eosinophils, and lymphocytes—each serves unique functions in orchestrating the body’s response to inflammation and wound healing.

In response to injury, mast cells and basophils release histamine, triggering the release of pro-inflammatory cytokines and chemokines.

This amplifies the immune response, recruiting white blood cells to the injury site. Basophils further enhance blood flow to the area, aiding immune cell delivery for tissue repair. The process of vasodilation, characterized by the relaxation of smooth muscle cells in blood vessel walls, leads to an increase in the diameter of blood vessels. This widening allows for a greater influx of blood to the affected area, carrying with it a higher concentration of WBCs, oxygen, and nutrients crucial for tissue repair. Additionally, an increase in vascular permeability, achieved through the loosening of endothelial junctions lining blood vessels, facilitates the migration of WBCs from the bloodstream into the affected tissue, where they can actively participate in the inflammatory and healing processes.

Neutrophils, often referred to as the body’s “first responders,” are rapidly recruited to sites of injury or infection.

These cells are guided by chemotactic signals released by damaged tissues or invading pathogens. Upon arrival at the site of inflammation, neutrophils adhere to the top of the capillary walls and slip into tissues, where they engage in the phagocytosis process, engulfing and destroying pathogens and cellular debris. Additionally, neutrophils release antimicrobial peptides and proteolytic enzymes, aiming to neutralize pathogens and clear the affected area. 

Monocytes, circulating in the bloodstream, are another type of WBC involved in inflammation and wound healing.

Upon reaching the site of injury, monocytes differentiate into macrophages, which are versatile immune cells capable of phagocytosis and antigen presentation. Macrophages play crucial roles in clearing cellular debris, apoptotic cells, and pathogens, thereby creating a conducive environment for tissue regeneration and repair. Macrophages secrete various growth factors, cytokines, and extracellular matrix components that promote angiogenesis, collagen deposition, and wound closure, facilitating the restoration of tissue integrity. 

Lymphocytes, including T cells, B cells, and natural killer (NK) cells, are integral components of the adaptive immune response and contribute to inflammation and wound healing.

T cells, for instance, modulate the inflammatory response, promoting resolution and tissue remodeling, while B cells produce antibodies to neutralize pathogens. NK cells, on the other hand, play a role in enhancing the inflammatory response by inducing apoptosis in target cells.

Eosinophils and basophils, although less numerous, possess specialized functions in inflammation and tissue repair. 

Eosinophils are particularly involved in combating parasitic infections and modulating allergic responses through the release of cytotoxic granules and inflammatory mediators. Basophils, meanwhile, contribute to the inflammatory response by releasing histamine and other pro-inflammatory molecules. 

In conclusion, white blood cells play a pivotal role in the body’s immune response, acting as defenders against infections and facilitators of tissue repair. Inflammation serves as a vital mechanism, signaling the adaptive immune cells to coordinate actions such as cleaning, fighting pathogens, and restoring tissue integrity post-injury or infection. Understanding the diverse functions of white blood cell types is essential for promoting tissue repair and maintaining overall health, offering valuable insights into the intricate mechanisms of inflammation.

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Sources Cited

“Tissue Inflammation.” Fingerprints, Bite Marks, Ear Prints: Human Signposts, Jan. 2005, p. 63. EBSCOhost, research.ebsco.com/linkprocessor/plink?id=6c3e545e-dfed-37c9-8187-9abdd6ae1bd1.

Rohland, L. (2022). White blood cell. Salem Press Encyclopedia of Health. White blood cell. – EBSCO (alaska.edu)

Gurtner, G. C., Werner, S., Barrandon, Y., & Longaker, M. T. (2008). Wound repair and regeneration. Nature, 453(7193), 314–321. https://doi-org.ezproxy.uas.alaska.edu/10.1038/nature07039

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Unmasking the Rise of Cardiovascular Diseases-MI

In recent years, with the accelerated pace of social life, work pressure, and the prevalence of bad habits, the proportion of people with high blood pressure has gradually increased, and the incidence of cardiovascular diseases in society has also gradually climbed, which myocardial infarction has become the focus of people’s concern. Cardiovascular disease (CVD) and breast cancer (BC) are significant causes of mortality globally, imposing a substantial health burden. The common risk factors for cardiovascular disease, such as hypertension, diabetes, obesity, aging, and physical inactivity, are discussed, emphasizing their modifiability. (Obeidat, O., Charles, K. R., Akhter, N., & Tong, A. 2023)

This topic will focus on the pre-symptoms, causes, and effective prevention methods of cardiovascular diseases, especially myocardial infarction, to draw attention and vigilance to heart health.

Reasons for the increase of cardiovascular diseases in society

The fast-paced life of modern society, high-pressure work, intense competition, poor dietary habits, and lack of exercise have created favorable conditions for the increase of cardiovascular diseases. Studies have shown that poor lifestyles, such as excessive stress, diets high in fats and sugar, and long-term lack of exercise, are directly and closely related to the occurrence of cardiovascular diseases. Today, there is also a gradual increase in the number of people with high blood pressure, which is usually a silent disease; as a result, people with high blood pressure may fail to recognize the severity of their condition and thus fail to follow a treatment plan. The result is usually a heart attack or stroke. Hypertension may also lead to aneurysms (swelling of blood vessels due to weak vessel walls), peripheral arterial disease (blockage of blood vessels in the body’s peripheral regions), chronic kidney disease, or heart failure.

Pre-symptoms of myocardial infarction

Pre-myocardial infarction symptoms are often the “yellow light” of the disease, reminding us to pay attention to heart health. Common symptoms include:

  • Chest pain or discomfort: The patient may feel heaviness or pressure in the chest or experience severe chest pain.
  • Shortness of breath: Difficulty breathing and shortness of breath are typical symptoms of myocardial infarction.
  • Pain or discomfort in arms or shoulders
  • Feeling weak, lightheaded, or faint
  • Pain or discomfort in the jaw, neck, or back
  • Cold sweats and nausea: Patients may experience cold sweats, nausea, and vomiting, accompanied by dizziness and lightheadedness at times.
  • Stomach or abdominal discomfort.
  • Irregular heartbeat: palpations

 (Birnbach, B., Höpner, J., & Mikolajczyk, R. 2020).

This figure traces the sequential flow of blood through the chambers of the heart and blood vessels of the body.  The heart is a double pump, with each side supplying its own circuit. Each side pumps at the same time. 

- Pulmonary circuit:  oxygen-poor blood  returns from body tissues back to the heart via the   superior vena cava (SVC), inferior vena cava (IVC), and coronary sinus. It enters the right  atrium of the heart and moves through the tricuspid valve to the right ventricle, then through  the pulmonary semilunar valve to the pulmonary trunk. 

 Two pulmonary arteries carry the oxygen-poor blood to the lungs to be oxygenated. This is  the pulmonary circuit.
- Systemic circuit:  in the pulmonary capillaries in the lungs, blood takes on oxygen to become  oxygen-rich, then returns to the heart via the four pulmonary veins. It enters the left atrium  of the heart, then travels through the mitral valve to the left ventricle, then through the aortic  semilunar valve to the aorta. Arteries branch from the aorta to carry the oxygen-rich blood to  body tissues where in the systemic capillaries of the body, blood gives off oxygen while  taking on waste products. Oxygen-poor again, the blood enters the venules and veins to  be carried back to the heart. It enters the right atrium of the heart and the cycle begins again.
Know the path of blood through the heart and circulatory system(Unit11 Cardiovascular and Circulatory Systems Objectives):

Blood enters the right atrium from the somatic circulation through the superior vena cava and inferior vena cava, then is pushed into the right ventricle, enters the pulmonary circulation through the pulmonary artery, becomes oxygenated blood after gas exchange through the pulmonary capillaries, returns to the left atrium, then is pushed into the left ventricle, and finally enters the somatic circulation through the aorta, which transports the oxygenated blood to all tissues and organs of the body. The heart plays a vital role in maintaining normal body functions.  (Lecture note: Cardiovascular and Circulatory Systems P25 see attached picture)

Causes of Heart Attack

Myocardial infarction (MI) is the official term for what is commonly referred to as a heart attack. Myocardial infarction is usually caused by a lack of blood flow and oxygen to the region of the heart, resulting in the death of heart muscle cells. Myocardial infarction usually occurs when a buildup of atherosclerotic plaque consisting of lipids, cholesterol, fatty acids, and white blood cells blocks the coronary arteries. Myocardial infarction also occurs when a portion of unstable atherosclerotic plaque crosses the coronary artery system and blocks one of the smaller vessels. The resulting blockage restricts blood and oxygen flow to the heart muscle, resulting in the death of heart muscle tissue. (Anatomy and Physiology 2e 19.1 Heart Anatomy)

What is the connection between heart disease, such as heart attack, and blood circulation pathways?

Heart disease is usually caused by impeded circulation or an inadequate blood supply. As mentioned above, blood circulates through the heart, which acts as the body’s pumping mechanism to transport blood throughout the body while delivering oxygen to all parts.

In heart attacks and other heart diseases, insufficient blood supply to the arteries leads to ischemia or necrosis of the heart muscle. This ischemia or necrosis is usually caused by coronary artery disease (e.g., atherosclerosis), which leads to narrowing or blockage of the coronary arteries, preventing the heart from receiving adequate oxygen and nutrients. Therefore, the close relationship between heart disease and blood circulation pathways means that the progression and severity of heart disease is closely related to the smoothness of blood circulation.

Ways to prevent heart disease.

  • Take beta-blockers on time: Medications prescribed by your doctor should be taken regularly to help control blood pressure and reduce the burden on your heart.
  • Reduce salt intake: Excessive salt intake is closely associated with high blood pressure, and a moderate reduction in salt intake is essential for heart health.
  • Maintain good fitness habits to stay in shape: Regular moderate aerobic exercise and weight control can help maintain a healthy cardiovascular system.
  • Eat plenty of fruits and vegetables: Fruits and vegetables rich in vitamins, minerals, and fiber can help lower cholesterol levels and maintain a healthy heart.
  • Seek medical advice if you have any discomfort: If you experience chest pain, shortness of breath, or other unusual symptoms, it is vital to seek medical advice promptly and undergo a thorough physical examination to ensure early detection and treatment.

By focusing on cardiovascular diseases, raising public awareness of heart health, and taking proactive and effective preventive measures, we can better protect our hearts, reduce the incidence of cardiovascular diseases, and embrace a healthier and more fulfilling life. Let’s work together to make heart health the bottom line of life.

Citation:

Anatomy and Physiology 2e 19.1 Heart Anatomy & 20.4 Homeostatic Regulation of the Vascular System

Birnbach, B., Höpner, J., & Mikolajczyk, R. (2020). Cardiac symptom attribution and knowledge of the symptoms of acute myocardial infarction: a systematic review. BMC Cardiovascular Disorders20, 1-12.Explain the structure and function of the heart.

Obeidat, O., Charles, K. R., Akhter, N., & Tong, A. (2023). Social Risk Factors That Increase Cardiovascular and Breast Cancer Risk. Current Cardiology Reports25(10), 1269-1280.

Lecture note: Cardiovascular and Circulatory Systems P25