Blood

• Blood is one of the three components of the cardiovascular system of a human body.
• It is the only liquid connective tissue that consists of cells surrounded by an extracellular matrix (also known as blood plasma).
• A normal adult has approximately 4-6 liters of blood depending on his/her size and weight.
• Interstitial fluid, also known as tissue fluid, is a mixture of water, ions, and small solutes that are forced out of the blood plasma by the systolic pressure created when the heart pumps
• Blood is considered the river of life since blood carries all the nutrients and oxygen required for life and the majority of bodily processes.
• The study that associates blood is called hematology, which plays a crucial role in understanding and treating various diseases related to blood components.
• Functions of the Blood

  1. Transportation
  2. Regulation
  3. Protection
• The main function of the blood is for transportation. First, blood transports and distributes oxygen from the lungs to the tissues and cells of the human body and carbon dioxide from the body cells to the lungs for exhalation. Also, blood acts as the carrier of nutrients from the gastrointestinal tract to the body cells and hormones. It also transports heat and waste products to organs for elimination from the body.
• In the circulation of our body system, blood is present to help maintain homeostasis of all body fluids, regulates pH through the use of buffers (chemicals converting strong acids into weaker ones), and adjust body temperature through the heat-absorbing and coolant properties of water in blood plasma.
• One of the main functions of the blood is for protection. The blood consists of two formed elements that are responsible for protection namely, white blood cells and platelets. WBCs are part of the immune system that are in charge of fighting infections and diseases. Meanwhile, platelets are involved in blood clotting, the process that protects our body against its excessive blood loss after an injury.
• The pH level of the blood is slightly alkaline, ranging from 7.35 to 7.45.
• . It is also known to be thicker (more viscous) and denser than water.
• The blood temperature is one degree higher than the normal body temperature, which is 38 °C.
• The oxygen content of the blood determines its color; if the blood is bright red blood, it is saturated with oxygen. If the color of the blood is dark red in appearance, it is unsaturated with oxygen.
• Blood is formed by its two components: 1) 55% of blood plasma, 2) 45% of formed elements (blood cells and cell fragments).
• Normally, more than 99% of formed elements consists of red blood cells, and its <1% consists of white blood cells, and platelets.
• The main fluid component of blood, makes up 55% of its composition
• Consists of water, proteins, and other solutes.
• Water transports heat, while plasma proteins regulate blood viscosity and pH.
• Pl asma proteins include albumin (54%), gl obulin (38%), and fibrinogen (7%)
• A process of forming elements in a fetus's yolk sac, liver, spleen, thymus, and lymph nodes, is primarily found in red bone marrow
• BLOOD CELLS

  • Red blood cells (RBCs)
  • White blood cells (WBCs)
  • Platelets
• ERYTHROCYTES - RBC
• Erythrocytes

  • 44% of the blood's composition
  • Play a vital role in the circulatory system, transporting oxygen and nutrients to tissues
  • Maintaining blood pH, and carrying waste products like carbon dioxide for exhalation
• Normal adult human RBCs have Bi concave disc shape, 7.5-8.7 um in diameter and 1.7-2.2 um thick
• Dysmorphic RBCs (eg. sickle cells, t arget cells) are often indicative of an underlying condition
• Color:

  • Healthy red blood cells are bright red due to their presence of hemoglobin
  • RBC appears to be in dark red color due to the absence of oxygen
• Development, Life Span, and Destruction of RBC:

  • Production occurs in bone marrow through erythropoiesis
  • Red blood cells have a short lifespan of 120 days
  • Recycled by macrophages in the spleen and liver
• Blood Groups:

  • Categorizes blood types antigens on red blood cells
  • ABO and Rh factor systems.
  • Crucial based on for safe blood transfusions, donations, and organ transplants
• Antigens - are substances that can trigger an immune response
• Antibodies are proteins produced by the immune system to fight antigens
• A, B, AB, and O, are determined by the presence or absence of antigens on red blood cells.

  • Blood Type A has A antigens and anti-B antibodies.
  • Blood Type B has B antigens and anti-A antibodies.
  • Blood Type AB is the universal recipient
  • Blood Type O is the universal donor
• RH FACTOR

  • Also known as Rhesus
  • Determines an individual's blood type's negative (-) and positive (+) signs.
  • If you have a positive blood type, then your RBCs have this Rh protein
  • If you have a negative blood type, then your RBCs do not have this Rh proteim
• • White blood cells/ leukocytes are part of our immune system and are utilized by the body to fight infection.
  • WBC are larger than RBC since they contain a nucleoid.
  • 12-15 micrometers (μm) and are colorless or pale.
• MAIN TYPES OF LEUKOCYTES

  • Granulocytes
  • Agranulocytes
• • Neutrophils - granules are smaller than other granulocytes
  • Nucleus - two to five lobes, which are connected by filaments
  • The first one to respond to kill bacteria, fungi, and other foreign debris
  • responsible for secretion of lysosomes
• basophils - they have the stain of dark purple and basic dye.

  • nucleus - s shaped or bilobed
  • responsible for production of allergic responses, inflammation, and heparin
• eosinophils - they have the stain of red with acidic dyes.

  • the granules of eosinophils are large
  • nucleus - bilobed with a strand of nuclear material connecting them together
  • they identify and fight parasite and cancer cells
• 1. Monocytes - Largest type of white blood cells.

  • Nucleus: kidney-shaped or horseshoe-shaped.
  • Cytoplasm: blue-gray and foamy appearance.
  • that has a kidney-shaped nucleus with a blue-gray and foamy appearance of the cytoplasm.
  • The most active cell in phagocytosis, the process of ingesting bacteria and dead matter.
• Lymphocytes - They are the smallest white blood cells.

  • The cytoplasm of lymphocytes stains sky blue and forms a rim around the nucleus.
  • Two types of lymphocytes:
  • B cells: form cells that produce antibodies
  • T cells: natural killer cells