ch 3 - production & formed elements (rbc, wbc, platelets)

lifespan of erythrocytes, leukocytes, platelets

few hours to a few weeks

component of blood that is replaced the quickest

plasma

hemopoiseis / hematopoiesis

process by which formed elements are replaced

location where formed element production occurs (be specific)

stem cells in red bone marrow - connective tissue located in spongy bone spaces

examples of spongy bones

• cranial bone

• pelvic bone

• vertebrae

• sternum

• proximal epiphyses

describe/draw out the pathway of cell division/specialization for the following:

• platelets

• erythrocyte

• leukocytes

going from a stem cell to a mature cell is initiated by ____ ____

[growth factors]

growth factor producing erythrocytes

erythropoietin (EPO) hormone

erythropoietin (organ secreting it in response to ____, uses)

• secreted by kidneys in response to low oxygen levels

uses

• performance-enhancing drug

• treats anemia (erythrocyte or hemoglobin deficiency)

name of the most common formed element of blood

erythrocytes

erythrocytes:

• % of body’s cell makeup

• amount present per microliter

• lifespan

• size (diameter, organelles or no organelles)

• main function

• 25% of all cells in body

• 5.2 million per microliter

• 120 day lifespan

• diameter of 7-8um, no organelles

• functions:

  • picks up oxygen from lungs → transports to body tissues

  • picks up CO2 produced by tissues → transports to lungs for exhalation

structure of hemoglobin

4 folded protein chains of globin attached together

• each globin bound to heme molecule (red pigment mlc)

• heme mlc contains an iron cation

reason why hemoglobin has one iron cation on each globin’s heme mlc

iron cation can bind to one oxygen mlc, so hemoglobin binds up to 4 oxygen for transporting from lungs → body tissues

(and one CO2 mlc can bind to each globin chain)

anemia

insufficient numbers of erythrocytes or hemoglobin

polycythemia

overproduction of erythrocytes - blood viscosity increases, therefore increasing blood pressure

leukocytes:

• function

• amount per uL of blood

• size (larger/smaller than erythrocytes, inner cell structure)

• lifespan

• location once they leave the blood

• defense against disease, routinely leaves blood vessels

• 5,000-10,000 per uL of blood

• larger than erythrocytes, full nucleus and organelles

• short lifespan

after leaving the blood

• some reside in lymphatic tissue, bone marrow, spleen

• migrate through tissues (diapedesis)

differential count

blood test measuring percentage of different white blood cell types in one’s body

leukocyte categories & subcategories

granular:

• neutrophils

• eosinophils

• basophils

agranular:

• monocytes (matures into macrophages

• lympocytes

granular leukocytes (% of total leukocyte count, colour when stained, # of nucleus lobes)

neutrophils

• 50-70% total leukocyte count

• pale purple granules

• 2-5 nucleus lobes

eosinophils

• 2-4% of total leukocyte count

• red-orange granules

• 2 nucleus lobes

basophils

• less than 1% total leukocyte count

• dense dark purple granules

• single lobe nucleus

agranular leukocytes (% of total leukocyte count, function)

monocytes:

• 2-8% of total leukocyte count

• leaves blood to become macrophages

• phagocytosing debris, pathogens, dead/damaged cells

lympocytes:

• 20-30% of total leukocyte count

• adaptive immune response

• types

  • T cells

  • B cells

  • Natural Killer cells

T cells

(leukocyte → agranular type → lymphocyte → T cell)

• secrete chemicals communicating/activating cells

• destroy pathogen-infected cells

B cells

(leukocyte → agranular type → lymphocyte → B cell)

• can become plasma cells producing antibodies

Natural Killer cells

(leukocyte → agranular type → lymphocyte → Natural Killer cell)

• part of innate immune response

platelets:

• function

• location

• structure: size

• amount per uL of blood

• lifespan

• limiting blood loss, providing repairing growth factors

• fragments of megakaryocytes’ cytoplasms

• small, 2-4 uM in diameter

• 150,000-160,000 per uL of blood

• lives only 10 days

thrombocytosis

condition where body produces too many platelets, leading to unwanted blood clots

thrombocytopenia

condition where body does not produce enough platelets → blood does not clot properly

identify the figures in the photo