Blood

Blood carries nutrients, oxygen, hormones, and waste products throughout the body.

Blood regulates body temperature, pH, and water content, ensuring a stable internal environment.

Hematocrit is the percentage of red blood cells in a blood sample.

Albumin is the most abundant plasma protein. It transports fatty acids and steroid hormones, contributes to osmotic pressure, and helps maintain blood volume.

Globulins are a diverse group of plasma proteins with various functions, including transporting iron, lipids and vitamins, and contributing to osmotic pressure.

Blood is five times thicker than water, making it resistant to flow. This impacts blood pressure and circulation.

Oxygenated blood is bright red, while deoxygenated blood is darker red. Hemoglobin, the protein in red blood cells, changes color based on oxygen levels.

Hemostasis is the process that stops bleeding from a damaged blood vessel, preventing further blood loss.

The three steps are: 1) vascular spasm (constriction of the blood vessel), 2) platelet plug formation, and 3) coagulation (blood clotting).

Platelets are small, cell fragments that stick to the damaged vessel wall, forming a temporary plug. They also release chemicals that help constrict the blood vessel and initiate clotting.

The intrinsic pathway is activated by factors within the blood itself, while the extrinsic pathway is triggered by damage to surrounding tissues. Both pathways lead to the formation of fibrin, the protein that forms the clot.

Fibrinolysis is the process of breaking down the clot after the vessel has healed. It involves the conversion of plasminogen to plasmin, which dissolves the fibrin.

Capillary beds are narrow, slowing erythrocytes' passage. This extended time allows for efficient gas exchange.

Hemoglobin contains four globin protein chains, each bound to a heme molecule with an iron ion (Fe2+).

Each iron ion in hemoglobin binds to one oxygen molecule, forming oxyhemoglobin. When oxygen is released, it becomes deoxyhemoglobin.

Normal hemoglobin levels are 115-155 g/L for females and 125-170 g/L for males.

It emits red and infrared light, which are absorbed differently by oxyhemoglobin and deoxyhemoglobin. This allows it to measure the percentage of oxygenated blood.

Erythrocyte production requires essential nutrients like glucose, lipids, amino acids, and trace elements like iron, copper, zinc, and B vitamins.

They are removed by macrophages in the bone marrow, liver, and spleen. Components are broken down and recycled.

The non-iron portion is degraded into bilirubin, which travels to the liver and is used to make bile. Bile aids in fat digestion and is excreted through feces.

Leukocytes are classified as granular or agranular based on the presence and visibility of granules in their cytoplasm.

Neutrophils are the most common leukocytes and are efficient phagocytes, consuming bacteria.

Beta plasma proteins are crucial for transporting essential substances throughout your body, including iron, lipids, and fat-soluble vitamins A, D, E, and K. They also contribute to maintaining the osmotic pressure of your blood, which helps regulate the balance of fluids.

Gamma plasma proteins, also known as antibodies or immunoglobulins, are the key players in your immune system. They recognize and neutralize harmful invaders like bacteria and viruses, protecting you from infections.

A CBC test is a common blood test that analyzes the number and characteristics of various blood cells, including red blood cells, white blood cells, and platelets. This information helps assess your overall health and detect any irregularities in your blood cell production.

Blood cells are produced in the red bone marrow, a soft, spongy tissue found inside certain bones. This process of blood cell production is called hemopoiesis.

There are two main types of stem cells involved in blood cell production: lymphoid stem cells and myeloid stem cells. Lymphoid stem cells produce lymphocytes (T cells, B cells, and NK cells), which are key players in your immune system. Myeloid stem cells produce all other blood cell types.

Erythropoietin (EPO) is a hormone produced by the kidneys in response to low oxygen levels. It stimulates the production of red blood cells, which carry oxygen throughout your body.

Cytokines are proteins that act as messengers in your immune system. They regulate the production and function of various blood cells, including red blood cells, white blood cells, and platelets. They also play a role in inflammation, immunity, and wound healing.

Erythrocytes, or red blood cells, are responsible for transporting oxygen from your lungs to your tissues and carrying carbon dioxide waste from your tissues to your lungs for exhalation. They make up a significant portion of your blood cells.

Erythrocytes have a biconcave disc shape, which means they are thinner in the center and thicker at the edges. This shape provides a large surface area for gas exchange and allows them to squeeze through narrow capillaries, efficiently delivering oxygen to your tissues.

Lysozymes are enzymes found in bodily fluids like tears and saliva. They break down the cell walls of bacteria, preventing infections.

Oxidants, like hydrogen peroxide, are chemical substances that damage and kill bacteria and other pathogens by oxidizing their components.

Defensins are proteins that puncture the membranes of bacteria and fungi, leading to leakage of their contents and death.

High neutrophil counts often indicate an infection or inflammation, primarily caused by bacteria.

Eosinophils release antihistamines to counter inflammation and have granules toxic to parasitic worms, especially those ingested through raw or undercooked seafood.

Basophils release histamine for inflammation and heparin to prevent blood clotting.

Lymphocytes are responsible for specific immunity, recognizing and attacking specific pathogens or diseased cells.

NK cells provide non-specific immunity by attacking cells lacking “self” proteins on their surface, like cancer cells or virus-infected cells.

Memory cells are long-lived B and T cells that remember past infections and launch quick responses upon re-exposure.

Monocytes are large white blood cells that transform into macrophages once they leave the bloodstream. They engulf and destroy debris, pathogens, and worn-out cells.