16-3: Leukocytes

Question 1

Leukocyte

Answer 1

larger cells that lack Hg, but do contain a nucleus; not nearly as numerous as RBCs, making up <1% of blood volume

Question 2

What is the function of leukocytes?

Answer 2

protect the body from damage by bacteria, viruses, parasites, toxins, and tumor cells

Question 3

diapedesis

Answer 3

WBCs are able to slip out of the blood vessels and enter the damaged or diseased tissues

Question 4

What two cells make up the buffy coat?

Answer 4

WBCs and platelets

Question 5

leukopenia

Answer 5

(“white deficiency”) a WBC count less than normal (under 4000/mm^3 - often cause by drugs like glucocorticoids

Question 6

leukocytosis

Answer 6

(“white cell condidition”) a WBC count of over 11000/mm^3 (larger than normal); thisi s the body’s homeostatic response to a bacterial or viral invasion fo the body

Question 7

What is the body’s homeostatic response to a bacterial or viral invasion?

Answer 7

leukocytosis

Question 8

What is a white blood cell deficiency called?

Answer 8

leukopenia

Question 9

WBCs have a ___ life span.

Answer 9

short, due to eating bacteria and debris - only a few days (during infections, may only live a few hours)

Question 10

What are the two major categories of leukocytes?

Answer 10

grouped on basis of structural and chemical characteristics:

granulocytes - contain visible granules in cytoplasm

agranulocytes - lack obvious granules

Question 11

leukopoiesis

Answer 11

the production of WBCs

Question 12

granulocytes and monocytes arise from ___, and lymphocytes arise from ___.

Answer 12

myeloblasts; lymphoblasts

Question 13

What are the three types of granulocyte?

Answer 13

neutrophils, eosinophils, and basophils

Question 14

What are the two types of agranulocyte?

Answer 14

monocytes and lymphocytes

Question 15

neutrophils

Answer 15

most numerous WBC, cytoplasm stains pale purple with barely visible granules; nuclei have 3-6 lobes

Question 16

What is the function of a neutrophil?

Answer 16

phagocytize bacteria - good for short term infections since they have a short lifespan

Question 17

High neutrophils can indicate:

Answer 17

an acute bacterial infection

Question 18

Eosinophils

Answer 18

2-4% of WBCs, cytoplasm has coarse red granules, nucleus has 2 lobes

Question 19

What is the function of an eosinophil?

Answer 19

kill paracitic worms, complex role in allergies

Question 20

High eosinophils can indicate:

Answer 20

parasitic worms or allergies

Question 21

Basophils

Answer 21

rarest WBC, cytoplasm contains large dark bluish-purple granules that make the purple, U-shaped nucleus hard to see

Question 22

What is the function of a basophil?

Answer 22

release histamines (inflammatories) and contain heparin (anticoagulent)

Question 23

High basophils can indicate:

Answer 23

inflammatory disease or allergy

Question 24

Granulocytes

Answer 24

all are spherical in shape and larger than RBCs, they have lobed nuclei and their cytoplasmic granules stain specifically with Wright’s stain

Question 25

Agranulocytes

Answer 25

lack visible granules and have spherical or kidney-shaped nuclei

Question 26

monocytes

Answer 26

largest WBC, pale blue cytoplasm, Kidney or U-shaped purple nuclei

Question 27

What is the function of a monocyte?

Answer 27

phagocytosis - migrate to infected tissue, leaving the blood, and become wandering macrophages (arrive later but stay longer - better for chronic infections)

Question 28

High monocytes may indicate:

Answer 28

viral infection or chronic bacterial infection (eg. TB)

Question 29

lymphocytes

Answer 29

2nd most numerous WBC (smallest); round purple nucleus with a thin rim of light blue cytoplasm around it. Most are found in lymph tissue, where they play a critical role in immunity

Question 30

What are the two types of lymphocytes?

Answer 30

B-cells and T-cells

Question 31

B-cells

Answer 31

when a foreign substance (antigen) enters the body, the B-cells become plasma cells, which then produce antibodies (proteins that attach to the antigen and neutralize them)

Question 32

T-cells

Answer 32

function in the immune response by acting directly against virus-infected cells and tumor cells