18.2 formation of formed elements

Erythropoietin

A glycoprotein secreted by the intersitial fibroblast cells of the kidney in response to low oxygen levels and stimulates red blood cell formation

Lymphoid stem cells give rise to

T cells, B cells, NK cells ( which are designated leukocytes)

CSFs (colony stimulating factors)

a type of BRM that is also known as *growth factors*. these do not fight cancer but rather encourage the growth of bone marrow stem cells that can be destroyed by cancer tx, particularly high-dose chemo. there are different types of these as well: - granulocyte (-macrophage) ____ - erythropoietin - IL-11 some trigger the differentiation of myeoblasts into granular leukocytes, namely, neutrophils, esinopils, and basophils

Hemopoietic stem cell (hemocytoblast)

all formed elements come from this type of cell

Hemopoiesis

begins in the red blood marrow, with hemopoietic stem cells that differentiate into myeloid and lymphoid lineages

hemopoietic growth factors

chemical signals including erythropoietin, thrombopoietin, colony-stimulating factors, and interleukins that regulate the differentiation and proliferation of formed elements

stem cell undergo mitosis plus

cytokinesis ( cellular division) to give rise to new daughter cells. one of these remains a stem cell and the other differentiates into one of many diverse cell types

Hemopoiesis begins when the the hemopoietic stem cell is

exposed to appropriate chemical stimuli collectively known as the hemopoietic growth factors, which prompt to divide and differentiate. the other daughter cell becomes wither of two types of more specialized stem cells

myeloid stem cells

give rise to other formed elements,including erythrocytes; megakaryocytes that produce platelets; and a myeoblast lineage that gives rise to monocytes and three forms of granular leukocytes: NEUTROPHILS,ESINOPHILS,and BASOPHILS

Cytokines

glycoprotein secreted by a wide variety of cells ( including red bone marrow,leukocytes, macrophages,fibroblasts, and endothelial cells) stimulate the proliferation of progenitor cells and helping to stimulate both specific and nonspecific resistance to disease. 2 major subtypes are: COLONY -STIMULATING FACTORS AND INTERLEUKINS

in children,

hemopoiesis can occur in the medullary cavity of long bones

when a disease such as bone cancer destroys the bone marrow causing

hemopoiesis to fail, extramedullary hemopoiesis may be initiated

development from stem cells to precursor cells to mature cells is again initiated by

hemopoietic growth factors

Thrombopoietin

hormone from liver and kidneys that triggers development of megakarocytes into platelets

lymphoid and myeloid stem cells do not

immediately divide and differentiate int mature formed elements

prior to birth, hemopoiesis occurs in the

in a number of tissues, beginning with the yolk sac of the developing embryo, and continuing in the fetal liver, spleen,lymphatic tissue, and eventually the red bone marrow

bone marrow transplant

infusion of healthy bone marrow cells to a recipient with matching cells from a donor

mesenchymal cell

is beneath the pluripotent stem cell; this stem cell develops only into types of connective tissue, including fibrous connective tissue,bone, cartilage, and blood, BUT NOT EPITHELIUM<MUSCLE< OR NERVOUS TISSUE

pluripotent stem cell

is the next level of stem cell, which gives rise to the multiple types of cells of the body and some of the supporting fetal membranes

totipotent stem cell

is the zygote, or fertilized egg. the stem cell gives rise to all cells of the human body

lymphoid stem cells

lymphoid stem cells quickly migrate from the bone marrow to lymphatic tissues, including the lymph nodes,spleen,and thymus,where their production and differentiation continues. b cells are so named since they mature in the bone marrow,while t cells mature in the thymus

for instance

megakaryoblasts are the precursors of megakaryocytes, and poerythroblasts become reticularocytes, which eject heir nucleus and most other organelles before maturing into erythrocytes

bone marrow biopsy

microscopic examination of a core of bone marrow removed with a needle

myeloid stem cells give rise to

most formed elements

following birth,

most hemopoiesis occurs in the red bone marrow, a connective tissue within the spaces of the spongy/cancellous bone tissue

most erythrocytes, leukocytes, and platelets

normally live a few hours to a few weeks

tissue rejection

occurs when the recipient's immune system makes antibodies against the protein markers on the donor's tissue. Most common example: for an individual requiring a transplant, a matching donor is essential to prevent the immune system from destroying the donor cells. to treat patients with bone marrow transplants, it is first necessary to destroy the patient's own diseased bone marrow through radiation and or chemotherapy.donor bone marrow stem cells are then intravenously infused. from the bloodstream, they establish themselves in the recipient's bone marrow

hemopoiesis (hematopoiesis)

production of blood cells ( word is of Greek origin)

Interleukins

proteins (cytokines) that stimulate the growth of B and T lymphocytes. an important class of cytokine signaling molecules important for homeopoisis. to date, more than a dozen interleukins have been identified, with others likely to follow. they are generally numbered 1L-1,1L-2,1L-3, etc.

the body must form new blood cells and platelets

quickly and continuously

through the process of hemopoiesis

the formed elements are continually produced, replacing the short-lived erythrocytes, leukocytes and platelets

throughout adulthood,

the liver and spleen maintain their ability to generate formed elements. this process is referred is referred to as extramedullary hemopoiesis ( meaning hemopoiesis outside the medullary cavity

in adults,

the process is largely restricted to the cranial and pelvic bones, the vertebrate, the sternum, and the proximal epiphyses of the femur and humerus

all formed elements arise from

the stem cells of the red bone marrow

these tests and procedures are often used to assist in the diagnosis and treatment of

various severe forms of anemia, such as thalassemia major and sickle cell anemia, as well as some types of cancer, specifically leukemia

when you donate blood

your body replaces the donated plasma within 24 hours, but it takes 4 to 6 weeks to replace the blood cells.