18.2 Production of the Formed Elements

what type of leukocyte can survive for years

memory cells

what are memory cells

type of leukocyte that can survive for years

most erythrocytes, leukocytes, and platelets normally live for

a few hours to a few weeks

what must the body do to ensure you have enough blood

form new blood cells and platelets quickly and continuously

how long does it take for your body to replace blood cells after donation of the blood

4 to 6 weeks

your body typically replaces donated plasma within

24 hours

what is hemopoiesis

production of blood cells

what is another name for hemopoiesis

hematopoiesis

what does the greek root hemo mean

blood

what does the greek root poiesis mean

production

where does hemopoiesis occur prior to birth

yolk sac of embryo, liver, spleen, lymphatic tissue, and red bone marrow of fetus

where do most hemopoiesis or hematopoiesis occur

in red bone marrow

what is red marrow

connective tissue within the spaces of spongy cancellous bone tissue

where can hemopoiesis or hematopoiesis occur in children

medullary cavity of long bones

where can hemopoiesis or hematopoiesis occur in adults

cranial, pelvic bones, vertebrae, sternum, and proximal epiphyses of the femur and humerus

what is the extramedullary hemopoiesis

ike a backup plan if unable to make blood cells in bone marrow (medullary cavities) in adults

where can extramedullary hemopoiesis happen

liver and spleen

what is medullary cavity

hollow tube like space inside the shaft of long bone

what is produced within the medullary cavity

red bone marrow

when would extramedullary hemopoiesis be initiated

when a disease like bone cancer destroys the bone marrow, causing hemopoiesis to fail

what kind of cells do all formed elements arise from

stem cells of the bone marrow

what are stem cells

cells that undergo mitosis and cytokinesis to give 2 new daughter cells where one remains a stem cell and the other becomes a diverse cell

what is the totipotent stem cell

zygote, fertilized egg, that is capable of differentiating into any and all cells of the body, enabling the full development of an organism

what kind of system can stem cells be viewed as

hierarchal system

what is the pluripotent stem cell

derives from totipotent stem cell and is capable of differentiating into many but not all cell types

what does zygote mean

fertilized egg

what is the mesenchymal cell

stem cell that develops only into types of connective tissue

what types of connective tissue does mesenchymal cells develop into

fibrous connective tissue, bone, cartilage, and blood

what is the hematopoietic stem cell

type of pluripotent stem cell that gives rise to all formed elements of blood

what is another name for hematopoietic stem cell

hemocytoblast

what is hemopoietic growth factors

a chemical stimuli that prompt hematopoietic stem cells to divide and differentiate

when does hemopoiesis begin

when hematopoietic stem cell or hemocytoblast, is exposed to hemopoietic growth factors

what happens to the daughter cells when a hematopoietic stem cell divides

one remains a hematopoietic stem cell while the other becomes a lymphoid or myeloid stem cell

why must one of the daughter cells of a divided hematopoietic stem cell remain the same

so that hemopoiesis can continue

what are the 2 types of specialized stem cells

lymphoid and myeloid

what are lymphoid stem cell

type of hematopoietic stem cell that develops into lymphocytes

what does NK stand for

natural killer

where do lymphoid stem cells migrate to after leaving the bone marrow

lymphatic tissues, including lymph nodes, spleen, and thymus

why are B cells named that way

they mature in bone marrow

why are T cells named that way

they mature in the thymus

what does “give rise to” mean in context of biology

develop into or produce

what are the 3 types of lymphocytes

t cells, b cells, and natural killer (NK) cells

what do lymphocytes function in

immunity

what are myeloid stem cells

type of hematopoietic stem cell that develops into some formed elements (other blood cell types)

what type of cells do myeloid stem cells develop into

erythrocytes, megakaryocytes, and myeloblast

what do myeloblast give rise to (develop into)

monocytes

what are the 3 forms of granular leukocytes that arise from the myeoblast lineage

neutrophils, eosinophils, and basophils

do lymphoid and myeloid stem cells immediately divide and differentiate into mature formed elements

no

what are the intermediate stages of cells between stem cells and mature formed elements called

precursor cells

what suffix do many precursor cells have in their names

blast

what type of cell does a megakaryocyte become

megakaryocyte

what is the sequence of cell development from proerythroblast to mature red blood cell

proerythroblast to reticulocyte, erythrocyte (after ejecting nucleus and organelles)

what is another name for precursor cells

forerunner cells

give examples of hemopoietic growth factors

erythropoietin (EPO), thrombopoietin, cytokines

what initiates the development of stem cells into mature cells

hemopoietic growth factors

what is erythropoietin (EPO)

glycoprotein that triggers the bone marrow to produce RBCs

where is erythropoietin (EPO) secreted

interstitial fibroblast cells of the kidneys

what does the erythropoietin respond to

low oxygen levels

what is blood doping

synthetic EPO, a performance enhancing drug to increase RBC counts and increase oxygen delivery to tissues throughout the body

how is EPO used medically

in treatment of certain anemia

what causes anemia

cancer, other diseases

what is the effect of EPO in medical use

increases RBCs

what is thrombopoietin

glycoprotein hormone produced by the liver and kidneys

what does thrombopoietin trigger

development of megakaryocytes into platelets

what are cytokines

glycoproteins that help cells communicate and respond to threats, promoting cell growth and disease resistance

what cells secrete cytokines

red bone marrow, leukocytes, macrophages, fibroblasts, and endothelial cells

how do cytokines act locally

as autocrine or paracrine factors

what do cytokines stimulate

the proliferation of progenitor cells and helping to stimulate both nonspecific and specific resistance to disease

what are the 2 major subtypes of cytokines

colony stimulating factors (CSFs) and interleukins

what are colony stimulating factors (CSF)

glycoproteins that trigger the proliferation and differentiation of myeloblasts into granular leukocytes

what are the granulocyte CSFs

neutrophils, eosinophils, and basophils

what is another thing the CSF produces

monocytes called monocyte CSFs

both granulocytes and monocytes are stimulated by

GM-CSF

what cells are stimulated by the multi-CSF

granulocytes, monocytes, platelets, and erythrocytes

why are synthetic forms of hemopoietic growth factors administered to patients with cancer

to revive their WBC counts after chemotherapy

what are interleukins

signaling molecules that may function in hemopoiesis, inflammation, and specific immune responses

what is the role of interleukins in hemopoiesis

differentiation, maturation of cells, producing immunity, and inflammation

interleukins are generally numbered as

IL-1, IL-2, etc

what is a bone marrow biopsy

diagnostic test of a sample of red bone marrow

what is a bone marrow transplant

treatment in which a donor’s healthy bone borrow, and its stem cells, replaces the faulty bone marrow of a patient

why is bone marrow biopsy performed

to assist in the diagnosis of anemia or cancer

why was the iliac crest of the pelvic bone previously preferred for bone marrow sampling or transplant

because of its location close to the body surface and relative isolation from vital organs

what is a newer alternative to direct bone marrow sampling

isolating stem cells from a patient’s blood sample, growing them in culture using hemopoietic growth factors, and analyze or freeze for later use

why is a matching donor essential for a bone marrow transplant

to prevent the immune system from destroying the donor cells (tissue rejectorion)

what types of conditions are often treated with bone marrow transplatns ot biopsies

severe forms of anemia (thalassemia major and sickle cell anemia) and certain types of cancers like leukemia