Blood

what are the functions of the circulatory system

transport, protect, and regulate

what is blood considered to be

type of connective tissue composed of cells and extracellular matrix

what is the temperature of blood and the average volume in humans

100.4 F and 4-6L

what are the components of blood

plasma and formed elements

clear to light yellow fluid that cells are suspended in and mainly consists of water (90%) but also has proteins, clotting factors, electrolytes, etc

plasma

the component of blood that consists of cells and cell fragments

formed elements

what are the typical formed elements in the blood

RBCs, platelets, WBCs

after blood fractioning with a centrifuge, what percentage of whole blood volume is plasma

55%

after blood fractioning with a centrifuge, what percentage of whole blood volume is hematocrit

45%

contributes to 1% of whole blood volume and contains WBCs and platelets

buffy coat

amount of packed RBCs in the whole blood and is the heaviest and most dense

hematocrit

what is serum

plasma- fibrinogen and clotting factors

what is the most abundant solute in plasma

proteins

what is the most abundant but smallest protein in the plasma (60%)

albumin

transports solutes, buffers and has a major roll in viscosity and osmolarity= important role in fluid shifts

albumin

besides albumin, what are the other two main categories of protein in the plasma

globulins (36%) and fibrinogen (4%)

resistance of a fluid to flow

viscosity

total molarity of dissolved particles that can not passively pass through vessel wall

osmolarity

is whole blood more or less viscous than water

4-5x more

what is osmolarity determined by in the blood

sodium, protein, and electrolytes

production of blood

hematopoiesis

site of hematopoises and produces blood cells

hematopoietic tissue

where is the site of hematopoiesis from infancy onward

red bone marrow typically found in femur, humerus, hip, sternum, ribs, and vertebrae

what produces lymphocytes

lymphatic tissues

where do all formed elements come from

multipotent or pluripotent hematopoietic stem cells

hematopoietic stem cells can produce any type of blood cell and will transform into what

myeloid or lymphoid stem cells

what happens when developing from a myeloid or lymphoid stem cell

specific colony forming units

what comes from the myeloid stem cell line

RBC, platelets, eosinophils, basophils, neutrophils, and monocytes

what comes from the lymphoid stem cell line

lymphocytes

what are blasts

very immature cell

where are the mature cells found

blood stream

what is the function of erythrocytes

transfer O2 from lung to tissues and CO2 from tissues to lungs; also aids in buffering blood

immature cell that ejects nucleus and organelles

reticulocyte

where is hemoglobin housed

red blood cells

why cant mature RBCs live awhile or reginerate

they dont have a nucleus or organelles

what does erythrocytes rely on to produce ATP

anaerobic fermentation

where is hemoglobic housed

RBC

what do spectrin and actin do in erythrocytes

cytoskeletal proteins that allow resilience and durability to pass through small capillaries

how many O2 molecules can one molecule of hemoglobin carry

four

what is a normal adult’s hemoglobin made of

4 protein chains (2 alpha and 2 beta) with each conjugated with a heme group

where is erythropoietin secreted

kidneys

when is EPO secreted in response to

low O2 levels

what does EPO tell erythrocyte CFU to transform into

erythroblasts that then multiply and build hemoglobin; nucleus shrivels and becomes reticulocytes that leave the bone marrow and enter blood stream

how long does it take reticulocytes to become mature RBCs

1-2 days

what two forms doe dietary iron exist in

ferric and ferrous iron

protein produced in stomach and binds Fe2+

gastroferritin

transport protein that binds iron in blood

transferrin

iron and apoferritin storage complex in the liver

ferritin

what is erythrocyte homeostasis controlled by

negative feedback

what triggers negative feedback for erythrocyte production

hypoxemia (low O2 levels) sensed by the kidneys

how long do RBCs typically live for

120 days

rupture of RBCs

hemolysis

when a RBC lyses, what happens to the globin chain

break down into amino acids by macrophages

when a RBC lyses, what happens to the heme portion

macrophages separate iron from heme which then combines with transferrin and is recycled; remaining heme is converted to biliverdin then to unconjugated bilirubin that is pushed into the blood stream and combines with albumin to go to the liver to become conjugated and exit through bile

too many RBCs from a cancer within RBC stem cells

primary polycythemia

too many RBCs as a result of something else like COPD or dehydration

secondary polycythemia

what are the typical causes for anemia

inadequate production, hemorrhage, or too much hemolysis

what occurs if you have abnormal hemoglobin

sickle cell or thalassemia

genetically assigned parts of the RBC membrane that allow the body to recognize cell as own and not foreign

antigens

proteins within plasma that attack unknown antigens through agglutination

antibodies

determined by presence or absence of A or B antigen on RBCs

ABO group

when do antibodies form due to responses to the bacteria in GI and cross-react with RBCs

2-8 months after birth

most common and is the universal donor

type O

rarest blood type and is the universal recipient

type AB

what does Rh+ mean

individual has the D antigen present (most common)

how do you gain Rh antibodies

if you are Rh- and come in contact with Rh+ blood

hemolytic disease of a newborn occurs how

when Rh- mom carries Rh+ baby and their blood mixes during delivery; first pregnancy relatively safe but affects all subsequent pregnancies with Rh+ baby

WBC that is the least abundant of formed elements and is an important defense against infections and diseases; only stays in blood stream shortly before migrating to CT

leukocytes

what are the two categories of leukocytes

granulocytes and agranulocytes

what are the granulocytes

neutrophils, eosinophils, and basophils

what are the agranulocytes

monocytes and lymphocytes

most abundant WBC (60-70%) and its main function is to destroy bacteria

neutrophils

accounts for 2-4% of WBCs and functions in parasitic infections, allergens, destroy inflammatory chemicals and antigen-antibody complexes

easinophils

least common WBC and functions to release substances that promote blood flow and other WBC to get to site faster

basophils

2nd most common WBC and destroys virus and malignancies; present antigens to active immune responses and produce antibodies

lymphocytes

WBC that rise during inflammation and viral infections and transform to macrophages once in tissues to phagocytize foreign antigens and dead tissues

monocytes

too little WBCs

leukopenia

too many WBCs

leukocytosis

cancer of either the myeloid or lymphoid stem cell line that produces too many abnormal WBCs in that specific family

leukemia

cell fragments of the megakaryocyte which is a cell in bone marrow

platelets

2nd most abundant formed element with a half life of 4 days (7-10 days total)

platelets

what are the functions of platelets

secrete vasoconstrictions, platelet plug formation, secrete procoagulants, initiate clot dissolution, secrete chemicals to attract WBC, destroy bacteria, and secrete growth factors to help repair vessels

production of platelets and is stimulated by thrombopoietin (TPO)

thrombopoiesis

how is TPO deactivated if it is constantly being made by the liver

circulating platelet bind to it

what does TPO stimulate the production of

megakaryocytes in bone marrow and tendrils extend into vessel lumen and break off to form platelet fragments

what are the three phase of hemostasis to control blood loss

vascular spasm, platelet plug formation, and blood clotting (coagulation)

what is the immediate protection against blood loss

vascular spasm

what occurs during vascular spasm

pain receptors cause the blood vessels to constrict and injury of the smooth muscle of the vessel attracts platelets which release serotonin (vasoconstrictor)

what are the steps in platelet plug formation

platelet adhesion to the damaged vessel, platelet activation and substance release, platelet aggregation to recruit more

what are intact vessels endothelium coated with that is a platelet repellent and secretes the vasodilator nitric oxide

prostacyclin

step 1: platelet adhesion

von willenbrand factor in plasma with binding sites for collagen acts as glue to allow platelets to adhere to injured vessel wall/collagen

step 2: platelet activation

causes platelet to change shape to increase adhesion and aggregation of other platelets and when activated release: thromboxane A2 and ADP for other platelets, serotonin and thromboxane A2 for vasoconstrictors, and vWF to promote more platelet adhesion

step 3: platelet aggregation

completes platelet plug

slowest but most effective step with the goal of converting fibrinogen (plasma protein) to fibrin

coagulation

proteins made by liver and are present in plasma and must be activated

clotting factors

sticky protein that collects WBCs and RBCs as they pass through to form fibrin clots

fibrin

two pathways to arrive at the common pathway with the goal of activating factor X

clotting cascade

initiated by damaged blood vessel

extrinsic pathway

initiated by plasma or platelets

intrinsic pathway

what is the pathway for the extrinsic mechanism for the clotting cascade

factor 3 combines with factor 7