EXAMS 2 POWERPOINTS Flashcards
Functions of the hematopoietic system
- transport
- communication
- Temperature
- defense
- clotting
Blood is composed of?
- formed elements
- plasma.
what are the formed elements of blood
erythrocytes, leukocytes, and thrombocytes (platelets).
what are the Plasma
contains electrolytes, gases, nutrients, and waste products. Important plasma proteins include albumin, immunoglobulin, complement, and clotting factors.
what is a serum of blood basics
is the result of removing clotting factors from plasma.
what is
represents the volume of blood occupied by red blood cells (RBCs).
Hematocrit
represents the volume of blood occupied by red blood cells (RBCs).
Regulation of erythropoiesis is
through erythropoietin (EPO) that stimulates bone marrow to increase RBC production in response to low oxygen.
what is the oxygen-binding component of hemoglobin
iron. Iron gives blood its red color too
Persons with end stage renal disease (ESRD) may have
anemia as a consequence of decreased erythropoietin (EPO) production by the kidneys.
Nutritional deficiencies can lead
Nutritional deficiencies
anemia.
what stimulates bone marrow to increase RBC production in response to low oxygen.
erythropoietin (EPO)
Erythropoiesis requires
- vitamin B12 (cobalamin)
- folate (folic acid) and iron.
Vitamin B12 absorption requires
intrinsic factor (IF). Lack of IF results in pernicious anemia.
formation of erythropoiesis (red blood cells)
- Red cells are produced in the red bone marrow after birth
- Until 5 years of age, almost all bones produce red cells to meet growth needs; after 5 years, bone marrow activity gradually declines.
- After 20 years, red cell production takes place mainly in the membranous bones of the vertebrae, sternum, ribs, and pelvis.
IRON
- Iron is acquired from the diet.
- A large amount of iron in the body contained within proteins such as hemoglobin and myoglobin.
- The remainder of iron is found in ferritin and hemosiderin.
- Iron transferred bound to transferrin.
Iron is largely recycled and recovered as RBCs are processed in the spleen. - Iron is used to synthesize hemoglobin contained within RBCs
Granulocytes
- neutrophils 50-60%
- basophils = 0.3 -0.5%
- eosinophils = 1 to 3%
neutrophils
abundant, phagocytic, immature band forms.
Basophils
least abundant, mature into mast cells, involved in allergic responses, release histamine.
Eosinophils:
involved in allergic or parasitic infections.
Agranulocytes
monocytes and macrophages = 3 to 8% of total leukocytes
lymphocytes = 20% to 30% of total leukocytes
monocytes
form macrophages, phagocytic, inflammatory response.
Lymphocytes
include B and T cells.
facts about Neutrophils
- Primarily responsible for maintaining normal host defenses against invading substances
- First cells to arrive at the site of infection
- Have their origins in the myeloblasts found in the bone marrow
- Move to the tissue for approximately 1 to 3 days
- Die in the tissue discharging phagocytic function or die of senescence
facts about eosinophils
- Increase in number during allergic reactions and parasitic infections
- The agents associated with allergic reactions
In parasitic infections,
( the eosinophils use surface markers to attach themselves to the parasite and then release hydrolytic enzymes)
facts about basophils
- Consist of heparin, an anticoagulant, histamine, a vasodilator, and other mediators of inflammation
- Similar to mast cells
Involved in allergic and hypersensitivity reactions
facts about monocytes and macrophages
Monocytes & Macrophages
Cells survive for months to years in the tissues.
- Important role in chronic inflammation
Involved in the immune response - Activating lymphocytes
Presenting antigen to T cells
three types of lymphocytes
B lymphocytes
T lymphocytes & Natural killer cells
plasma proteins
albumin = 54% of plasma proteins
globulins = 38% of the plasma proteins
fibrinogen= 7% of the plasma proteins
what are thrombocytes
function to form the platelet plug to help control bleeding
what is Thrombopoiesis
Thrombopoiesis is the process of forming platelets.
Platelets are derived from fragmentation of MEGAKARYOCYTES and are important in hemostasis
what is thrombopoietin
thrombopoietin is a growth hormone released from the liver that stimulates thrombopoiesis
Thrombocytopenia may give rise to
Thrombocytopenia may give rise to purpura and petechiae (rash or spots due to bleeding).
facts about hematopoiesis
Continual process
Occurs in bone marrow
Original cells are self-renewing stem cells
Pluripotent
Exposure of these stem cells to environmental cues (hormones, growth factors) may give rise to many types of cells
Lineages
lifespan of blood cells
The red blood cell has a life span of approximately 120 days.
RBC are broken down by?
- It is broken down in the spleen.
The degradation products (iron and amino acids) are recycled.