Blood Info 1

White 1: Blood Information

T lymphocytes (a.k.a.: T Cells) (Suzanne & Arin)

Where and How Cell is Formed:

  • Start in the bone marrow as haematopic stem cells. They divide into unambiguous stem cells. The cells then travel to the thymus gland to mature (do mitosis). When they are fully matured they are released into the blood. Only about 2% of the cells will survive maturation. Thymosin regulates the growth of these cells

Three Types:

  1. Helper T cells
  2. Killer T cells
  3. Regulatory T cells

Helper T Cells Form Follows Function:

  • Have specific antigen receptors that will bind to cells infected by certain antigens. Once they bind they will send a chemical signal to other cells to come help destroy the cell.

Killer T Cells Form Follows Function:

  • Cells have antigen receptors that bind to the infected cell. The T cell will then secrete molecules to destroy cells.

Regulatory T Cells Form Follows Function:

  • These cells suppress immune responses and prevent autoimmune diseases by maintaining self-tolerance.

Basophils (Isabella)

  • It represents 0.01 to 0.03% of the circulating white blood cells of the body.
  • Can be taken out of the blood when need in a tissue.
  • Release histamine and heparin.
  • Appear in many inflammatory reactions, particularly those that cause allergic symptoms.
  • Heparin prevents blood from clotting too quickly.
  • Histamine promotes blood flow to tissues.
  • Have protein receptors on their cell surface, which bond IGE which are involved in parasite defense and allergy.

Pluripotent Heamopoeitic Stem Cell → CFU-S → CFS-basophil →Myeloblast →Promyelocyte→ Basophil myelocyte→ Basophil metamyelocyte→ Stab cell → Basophil

Eosinophils (Emily S.,)

What They Are:

  • White blood cell
  • Specialized immune cell, pro-inflammatory
  • They control mechanisms for allergic reactions and asthma
  • Generally have a nucleus with 2 lobes and look like cheetah print under the microscope.

How they are Formed:

  • Formed in the bone marrow, where they mature for 8 days, then travel to the bloodstream.
  • It generally takes 8-12 hours to arrive at destination tissues, where they stay for 1-2 weeks.
  • Interleukin-5 (IL-5): Hormone mainly responsible for the growth and development of the cells and the regulation of their functions.

Form and Function:

  • Moving to different locations in the body
  • Killing parasites and bacteria
  • Allergic reactions and inflammatory responses

Percentage within Blood:

  • In normal circumstances, they make up about 1-6% of the total white blood cells in the body.
  • They can be found in the lower GI tract, ovaries, uterus, spleen, and lymph nodes, but not in the lungs, skin, esophagus, and a few other internal organs under normal circumstances.

MONOCYTES (Shelby, Kerry, Gianna)

Monocytes: the largest white blood cells in the body, twice the size of the average erythrocyte. Their nucleus is large and usually oval or shaped like a kidney bean.

  • They account for 3-9% of the white blood cells in the body.

Function:

  • Become macrophages that phagocytize pathogens and cellular debris.

Macrophages: also stimulate other white blood cells, including lymphocytes to defend the body

Erythrocyte (RBC) (Steph, Caroline)

What is it?:

  • Erythrocytes (a.k.a. Red Blood Cells)
  • Carriers Oxygen to the resto of the body
  • 4-6 million RBCs/mm3 of whole blood

Form Follows Function:

  • Small biconcave without a nucleus when mature
  • Small size enables easy travel through Blood vessels
  • Biconcavity allows it to bind to Oxygen more readily because of increased surface area

Formation:

  • Formed by multipotent stem cells in red bone marrow from myeloid stem cells

Stem cells:Capable of dividing and producing new cells that go onto become particular types of cells

  • Myeloid stem cells divide to form erythroblasts
  • Erythroblast mature to form erythrocytes by losing the nucleus and other organelles and instead gaining hemoglobin
  • Only live 120 days due to lack of nucleus
  • Approximately 2 million RBCs die every sec.

Erythropoietin: hormone produced primarily in the kidneys which stimulates stem cells and speeds up maturation of RBCs

  • Also used to regulate oxygen levels in the blood

Thrombocytes (Sam, Isabel)

Platelets:

  • Disc Like Shape
  • Do not have a nucleus
  • Average life span: 5-9 days
  • Small purple dots in upper left corner 

Formation and Regulation:

  • Originates from cells in bone marrow (megakaryocytes)
  • Formed by cell division (mitosis)
  • Chemical signals from blood enzymes are sent to the DNA to trigger or slow down mitosis

Form and Function:

  • Essentially cell fragments, but contain structures that are critical to stop bleeding
  • Proteins on their surface→ stick to breaks on blood vessel wall and each other
  • Contain proteins similar to muscle proteins → allow them to change shape when they become sticky
  • Contain small particles that secrete other proteins → create firm plug to seal blood vessel breaks

Percentage Composition within blood:

  • 150,000 – 300,000 per mm3 blood

B Lymphocytes

(Joel, Corrissa)

  • Produced and matured in bone marrow
  • Stem cells in bone marrow produce lymphatic cells which produce lymphoblasts, which separate into b lymphocytes or t lymphocytes
  • In the presence of cytokines (chemical secretions from t cells) b cells are stimulated to divide
  • Each b cell has different antigen receptors (Antigens are like name tags that every type of cell has, and they determine if certain cells are viruses or not)
  • B cells either divide into memory b cells or plasma cells
  • Memory b cells quickly divide and give rise to more lymphocytes capable of quickly producing antibodies (antigen receptors are attached to each cell)
  • Plasma cells are the cells that produce the antibodies that bind to antigens and fight off viruses
  • In general, b lymphocytes produce antibodies to fight off infections. They contain a large nuclei to house all the proteins they need to make antibodies. Also, they need to house lots of DNA to provide instruction for these antibodies.
  • Bind with antigens to help other wbc’s to fight off infection

Neutrophils: (Erin & Rachel)

Neutrophils are a type of spherical white blood cell that fall under the Granular category (protein grains in cytoplasm). The function of white bloods cells is to fight off infection.Neutrophils are a type of phagocyte and are normally found in the bloodstream. They are 10-14 micrometers in diameter and have multi-lobed nuclei (2-5 lobes). During the beginning phase of inflammation, particularly as a result of bacterial infection, environmental exposure, and some cancers, neutrophils are one of the first-responders of inflammatory cells to migrate towards the site of inflammation. They migrate through the blood vessels, then through interstitial tissue, following chemical signals in a process called chemotaxis. They are the predominant cells in pus, accounting for its whitish/yellowish appearance. Neutrophils are recruited to the site of injury within minutes following trauma.

Where and how they are formed: They are formed in red bone marrow, which is 55% plasma and 45% formed elements. They are formed from red stem cells within the bone marrow. They have a rapid reproductive rate through mitosis and mitosis will be stimulated by proteins via chemical messengers, therefore allowing quick immune response when needed.

Types: May be subdivided into segmented neutrophils and banded neutrophils.

Percentage of the Blood: Neutrophils make up 40-70%.

Form Follows Function:

  • Large Size: There is more room in the cell therefore it is easier for them to engulf smaller sized molecules. As a result they can hold large quantities of DNA, proteins, and they can engulf pathogens. Neutrophils have a preference to engulf refined carbohydrates (glucose, fructose, etc.) over bacteria/pathogens.
  • Contain Many Lysosomes: They contain many digestive lytic enzymes (proteins) allowing them to break down waste and pathogens when needed.
  • Chemotaxis: Neutrophils have protein receptors that will respond to chemicals in an infected site, allowing migration to infected sites.