Chapter 12 - Blood Cells

Question 1

What are the formed elements of blood?

Answer 1

• RBC, WBC, platelets

Question 2

What is in the plasma of peripheral blood?

Answer 2

reflects that of the extracellular fluid

useful in diagnosis

clotting proteins - prothrombin and fibrinogen

albumin - made by liver and maintains osmotic pressure, main drug binding protein in plasma

complement - system of proteins that destroy microorganisms like pathogens and trigger inflammation

immunoglobulins- antibodies

lipoproteins - carry cholesterol and triglycerides from liver to tissues

serum - liquid remaining after clotting proteins are removed from plasma

Question 3

How is the plasma and formed elements separated? Why?

Answer 3

• centrifuge
• can determine packed cell volume of RBC (hematocrit)

Question 4

Blood smears

Answer 4

1 drop of blood is spread evenly on a microscope slide, then dried

stained with Giemsa or Wright’s stain

Question 5

RBCs

Answer 5

• biconcave disks that are flexible, shape maximized surface area for gas exchange

anucleate, lack mitochondria, golgi, ER, lysosomes

major protein is hemoglobin - binds O2 in pulmonary capillaries releases O2 in peripheral capillaries/bindsO2

lifespan of about 120 days

derived from erythroblasts in bone marrow

Question 6

Reticulocytes

Answer 6

young, newly released RBCs

increased reticulocyte count normally indicates hematologic stress - hemorrhage, altitude change

matured by EPO from kidneys

Question 7

Old RBCs are tagged by..?

Answer 7

glycosylation

removed from circulation by macrophages in spleen, bone marrow, or liver

Question 8

ABO blood group antigens are glycolipids in the RBC membrane, and they are -

Answer 8

genetically determined

Question 9

Recombinant EPO

Answer 9

used to boost RBC production in some cancer pts

also used to enhance performance in athletes - more RBCs = more O2 carrying capacityB

Question 10

Blood doping

Answer 10

during training, blood is collected from athletes, later RBCs are given IV

Question 11

HbA1c

Answer 11

Hb is glycosylated as it ages

diebetics have a higher HbA1c - reflects blood glucose levels

Question 12

What are the types of WBCs?

Answer 12

• granulocytes - neutrophils, eosinophils, basophils
• agranulocytes - monocytes, lymphocytes

Question 13

Neutrophils

Answer 13

multilobed nucleus, barr body may appear

pale lavender-gray nucleus

most numerous leukocyte

phagocytosis of opsonized bacteria - ingested bacteria is killed by respiratory burst when phagosome fuses with a lysosome, and pus is accumulated

Question 14

Eosinophils

Answer 14

eosinophilic granules in cytoplasm

nucleus appears bi-lobed

phagocytize antigen-antibody complexes; releases cytokines that attract other leukocytes to a site of infection

defend against parasites - eosinophilia common in persons with infections and allergies

Question 15

Basophils

Answer 15

basophilic granules

very rare

nucleus is multi-lobed, but usually obscured by granules

releases heparin and histamine upon IgE binding, can migrate into CT - similar to mast cells

Question 16

Monocytes

Answer 16

large nucleus that appears indented or kidney bean shaped

migrate into tissues and mature into macrophages

very important in defending against pathogens in lungs, liver, kidney, CT

produced in bone marrow

Question 17

Lymphocytes

Answer 17

same size as RBCs

large, darkly staining nucleus, usually only a thin rim of cytoplasm is visible

migrate from blood into tissues

B- cells - lymphocytes that mature in bone marrow, produce antibodies

T- cells - lymphocytes that mature in thymus, function in cell mediated immunity

Question 18

Platelets

Answer 18

aka thrombocytes

not intact cells, fragments pinched off from megakaryocytes in bone marrow

control hemorrhage through:
- platelet agg. at the site of damage, around the RBCs that are released
- blood coagulation - forms fibrin by cleaving fibrinogen
- clot retraction and removal

Question 19

Complete blood count

Answer 19

determination of amount of each type of BC

blood collected in tubes coated with EDTA or citrate to prevent clotting

variation from normal range assist in diagnosis of infection, anemica, leukemia, etc.

Question 20

Leukemia

Answer 20

malignant clones of leukocyte precursors
- lymphocytic - occurs in lymphoid tissues
- myelogenous - in bone marrow

abnormally high numbers of immature leukocytes released into circulation

diagnosed by CBC and/or bone marrow biopsy