blg 111 week 1

what are the three functions of blood?

transportation, regulation, protection

what are the transport functions in blood?

Delivering O2 and nutrients

transporting metabolic wastes to lungs and kidneys

transporting hormones from endocrine organs to target organs

what are the regulation functions of blood?

maintaining body temperature

maintaining normal pH

how does blood maintain body temperature?

through vasoconstriction / vasodilation

what is vasodilation? relation to heat?

widening of blood vessels, gets rid of heat

what is vasoconstriction? relation to heat?

narrowing of blood vessels; preserves heat

what is the normal pH of blood?

7.35-7.45

how does blood regulate pH?

chemical buffers

how does blood protect?

prevents blood loss (clots)

prevents infection (antibodies, WBC's)

what are the components of whole blood?

plasma & formed elements

what are the two parts of formed elements?

buffy coat, erthyrocytes

what is the buffy coat?

white blood cells and platelets

what is the least dense component of blood?

plasma

what is the most dense component of blood?

formed elements (specifically erthyrocytes)

what is blood plasma made of?

water & it's solutes: proteins, electrolytes, nutrients, gases, hormones, wastes

what is the most abundant solute in plasma?

albumin

what does albumin do?

regulates osmotic pressure, transports molecules (e.g. drugs)

what is osmotic pressure?

pressure that helps blood retain water

what are globulins? where are they found?

antibodies & transport proteins in plasma

what is the function of fibrinogens?

blood clotting

plasma is a nonliving \____.

matrix

what are erythrocytes?

red blood cells

what shape are RBCs? what function does this serve?

biconcave

bendy so they can flow easily

large surface area for oxygen to pass through

what are the characteristics of red blood cells?

anucleate

no organelles

filled with Hb for gas transport

what does Hb stand for

hemoglobin

what does hemoglobin do?

binds reversibly with oxygen

what are the 2 parts of hemoglobin?

heme and globin

what is heme?

iron-containing red pigment

what is globin?

protein made of 4 polypeptide chains

what are the four chains of globin?

2 alpha, 2 beta

how many hemes are in hemoglobin?

four; one per chain

where are RBCs produced? from?

red bone marrow; stem cells

what is hematopoietic tissue?

red bone marrow

where is red bone marrow found in newborns?

everywhere; medullary cavities & all spongey bone

where is red bone marrow found in adults?

heads of femur & humerus

flat bones, hip bone

stem cells produce all \_______.

formed elements

what is the life span of RBCs?

100-120 days or 3-4 months

what is erythropoiesis (EPO)?

production of red blood cells

what stimulates EPO? due to?

hypoxia

decreased RBC
decreased amount of Hb
decreased availability of O2

what is hypoxia?

lack of oxygen

what are the steps of EPO?

kidney release erythropoietin

stimulates red bone marrow

increases RBC

O2 carrying ability rises

what is erythropoietin?

EPO - hormone that stimulates RBC production

what is hemostasis?

stoppage of bleeding in a blood vessel

what are the three steps of hemostasis?

1. vascular spasm
2. platelet plug formation
3. coagulation

what happens during step one of hemostasis; vascular spasm?

smooth muscle contracts, causes vasoconstriction

what happens during step two a) of hemostasis; platelet plug formation?

injury to lining of vessel exposes collagen fibers

platelets adhere

what happens during step two b) of hemostasis; platelet plug formation?

platelets release chemicals that make nearby platelets sticky

platelet plug forms

what happens during step three of hemostasis; coagulation?

uses clotting factors numbered I- XII

what is needed to synthesize clotting factors?

Vitamin K

why are newborns given vitamin K shots?

vitamin k doesn't cross the placenta or get into breast milk well

needed for clotting factors (thrombin)

what is thrombin? what does it do?

an enzyme in blood plasma that causes the clotting of blood by converting fibrinogen to fibrin

thrombin converts \_____ to \_____

fibrinogen to fibrin

what does fibrin do?

makes clot by creating a mesh that glues platelets together

what are thromboembolic conditions? the three types?

undesirable clot formations

thrombus
embolus
embolism

what is a thrombus?

a clot that develops & persists in an unbroken blood vessel

why are thrombus dangerous?

can block circulation, leading to tissue death

what is an embolus?

thrombus freely floating in bloodstream

what is an embolism?

embolus obstructing a vessel

what are the three things that need to be considered when determining compatibility of blood types?

which antigens are found on the PM

what type of antibodies are floating in the plasma

what is being transferred?

what do antigens determine for blood types?

the letter; A, B , AB, O

people who are blood type AB have \______ antigens

A & B

What is agglutinogen?

antibodies clump RBCs together, body begins to destroy this

how does the protein Rh affect blood type?

determines whether its positive or negative

why are antibodies important in blood types?

there cannot be an interaction between antigens & antibodies

what antibodies does type O have?

anti-A & anti-B

what blood type is the universal reciepent? why?

AB

no antibodies, therefore no reaction from any other blood type

what antibodies does type AB blood have?

none

what is the universal blood donor? why?

O, it has no antigens so it cannot envoke a reaction from other blood types

what are the different types of blood trasnfusions?

whole blood
plasma
platelet
packed RBCs (PRBCs)

why is Rh important to consider in blood transfusions?

can cause agglutination; although to a lesser effect than incompatible antigens/antibodies

what does rh negative / postive mean?

rh negative \= rh antibodies

rh positive \= no rh antibodies

you could put A \__ into A \_____, but it will \________.

positive, negative, agglutinate

what blood types can type A recieve? why?

A & O; has anti-b antibodies due to type a antigens

what blood types can type B receive? why?

B & O; has anti-a antibodies due to type b antigens

what blood types can type O receive? why?

O; has both anti-a & anti-b antibodies & no antigens

what blood types can type AB recieve? why?

any; has no antibodies, only a & b antigens

what is the lifespan of a RBC?

100-120 days

what happens when RBCs die?

HB begins to breakdown
Macrophages in spleen breakdown the RBC

When a RBC dies, the body \___________ it

recycles

when a RBC dies, Hb breaks down into globin: what does this do?

further breaks down into amino acids / proteins

what is ferritin?

a protein that stores & releases iron

what is transferritin?

iron transport protein in blood

after a RBC dies, Hb breaks down into heme, which further breaks down into:

iron and bilirubin

where does bilirubin from heme go? (breakdown of RBC)

to the liver, which secretes it into the intestine to be excreted

more erythrocyte disorders are classified as \_____ or \_____

anemia

polycythemia

what is polycythemia?

too many RBCs

what is anemia?

not enough RBCs

what are the three categories that cause anemia?

too much blood loss

not enough RBCs produced

too many RBCs destroyed

what type of anemia is caused by excessive blood loss?

hemorrhagic anemia

what is a subtype of hemorrhagic anemia?

chronic hemorrhagic anemia

what is hemorrhagic anemia? how is it treated?

rapid blood loss, treated by blood replacement

what is chronic hemorrhagic anemia? how is it treated?

slight but persistent blood loss

the primary problem must be treated to stop the blood loss

what is an example of something that may cause chronic hemorrhagic anemia?

hemorrhoids, bleeding ulcer, etc

what are the four types of anemia caused by low RBC production?

iron-deficiency anemia

pernicious anemia

renal anemia

aplastic anemia

what is iron deficiency anemia? cause? impact?

RBCs are microcytes & cannot synthesize enough hemoglobin

caused by low iron intake / impaired absorption

what are microcytes?

small, pale RBCs often found in people with iron-deficiency anemia

what is the treatment for iron-deficiency anemia?

iron supplements

what is pernicious anemia? effect?

autoimmune disease that destroys GI mucosa

can't absorb B12, & RBCs are macrocytes

what are macrocytes?

large RBCs that can't divide & don't hold as much Hb

pernicious anemia can be caused by an autoimmune disease, or \________

a low dietary intake of B12