MED TERM CH10: anatomy & physiology

hematology

the study of blood, blood components, & blood-forming organs

blood, bone marrow, liver, & spleen

hematology system consists of…

erythrocytes

red blood cells are also called

leukocytes

white blood cells are also called

thrombocytes

platelets are also called

45%

red blood cells make up what percentage of blood volume

40-54%

hematocrit level range in men

36-48%

hematocrit level range in women

WBCS and platelets, 1%

middle “buffy” layer in a centrifuged blood sample contains what and what and makes up less than what percent of total blood volume

55%

what percentage of blood does liquid plasma make up?

phlebotomy

practice of puncturing a vein to withdraw blood

hemolysis

breakdown of RBCs due to improper handling during collection

erythropoietin

hormone that is produced by the kidneys & stimulates red blood cell production

hemoglobin (Hgb)

oxygen-carrying protein molecule in red blood cells

bilirubin

yellow substance produced due to destruction of old RBCs

jaundice

failure to metabolize old RBCs results in this yellow skin discoloration

neutrophils

40-70% of WBCs: engulf and destroy bacteria during acute bacterial infections

lymphocytes

20-45% of WBCs: play a key role in adaptive immunity by producing antibodies

monocytes

2-10% of WBCs: transform into macrophages in acute infections to clear debris

eosinophils

1-6% of WBCs: defend against parasites and release histamine during allergic reactions

basophils

0.5-1% of WBCs: release histamine and inflammatory mediators during allergic responses

platelet plug

formed by platelets to seal damaged blood vessels during hemostasis

white pulp

this spleen pulp produces WBCs

red pulp

this spleen pulp stores RBCs and platelets

hemorrhage

severe abdominal trauma causing spleen damage can lead to this life-threatening bleeding

splenectomy

surgical removal of the spleen

conjugation

liver produces prothrombin & clotting factors and chemically modifies bilirubin in this process

hepatomegaly

enlargement of the liver

A antigens

type A blood has what type of antigens on RBCs & antibodies against B antigens in plasma?

hemolytic disease of the newborn

Rh antibodies from an Rh- mother attacking an Rh+ fetus can cause

RhoGAM

this medication is given to Rh- mothers at 26-28 weeks of pregnancy & within 72 hours of birth to prevent antibody development

hematocrit

ratio of volume of RBCs to total volume of blood

bone marrow

soft tissue inside bones that produces WBCs, RBCs, & platelets

red blood cells

transport oxygen and carbon dioxide between tissues & lungs

spleen

organ that produces & stores WBCs, filters & stores RBCs and platelets, and filtrates and destructs old RBCs

liver

organ that serves as a storage site for blood and blood cells

hemostasis

platelets & clotting factors form a clot to stop bleeding in this process

transportation, thermoregulation, infection defense, & hemostasis

four main overall functions of blood

three steps of hemostasis

1) vascular spasms (vasoconstriction) 2) formation of a platelet plug 3) blood clotting (coagulation)

fibrin

fibrous protein formed during blood clotting

fibrinolysis

process of breaking down a blood clot in a healing vessel

anticoagulants

medications that prevent blood clotting such as warfarin and heparin

prothrombin time (PT)

blood clotting test: measures time required for plasma to clot

internalized normalization ratio (INR)

blood clotting test: standardized calculation based on PT

partial thromboplastin time (PTT)

blood clotting test: measures a specific group of clotting factors