lecture 3

Question 1

wbc function as a

Answer 1

functions as a “cleanup crew” removes worn-out cells
(e.g. aged RBCs) & tissue debris (e.g. ones damaged by
trauma or disease) wound healing & tissue repair
* identifies and destroys cancer cells that arise in the body
* “seek out and attack” strategy

Question 2

5 types of leukocytes

Answer 2

all circulating
Neutrophils - most
* Eosinophils - 4th
* Basophils - least
* Monocytes - 3trd
* Lymphocytes - 2nd

Question 3

Polymorphonuclear granulocytes

Answer 3

Polymorphonuclear (meaning “many-shaped nucleus”
PMNs) granulocytes (meaning “granule-containing cells”)

Question 4

Neutrophils

Answer 4

phagocytic specialists
* engulf and destroy bacteria intracellularly
* Release web of extracellular fibers called
neutrophil extracellular traps (NETs) that contain
bacteria-killing chemicals

Question 5

Eosinophils

Answer 5

Killing of antibody coated parasites
through release of granule contents

• Increase in circulating eosinophils
  (eosinophilia) is associated with:
• Allergic conditions such as asthma and hay fever
• Internal parasite infestations, such as worms
• Attach to worm and secrete substances to kill it

Question 6

Basophils

Answer 6

Chemotactic factor production
* Least numerous and most poorly
understood of the leukocytes (controlling immune responses
to parasites)
* Synthesize and store
* Histamine: release is important in allergic reactions
* Heparin: speeds up removal of fat particles from blood
after fatty meal

Question 7

Mononuclear (“single nucleus”)
agranulocytes (“cells lacking granules”

Question 8

Monocytes

Answer 8

Phagocytosis, antigen presentation,
cytokine production and cytotoxicity
Emerge from bone marrow while still immature; circulate for
1-2 days; settle down in various tissues
* Mature and enlarge in resident tissue macrophages

Question 9

macrophage

Answer 9

Tissue resident Macrophages (macro means “large”; phage means “eater”) first to sense invading microorganisms /secrete cytokines/chemokines/ recruit neutrophils and other leukocytes

Question 10

lymphocytes large

Answer 10

Natural Killer (NK) cells
* Effector cells of the innate
immune response
* Extremely effective against
virally infected cells
make cytokines

Question 11

Lymphocytes; Small lymphocytes

Answer 11

Small lymphocytes of adaptive immune response
Cytokine production, antigen recognition, antibody
production, memory, cytotoxicity
B Lymphocytes: humoral immunity
* Produce antibodies (as a plasma cell)
* Responsible to antibody-mediated immunity
T Lymphocytes: cell-mediated immunity
* Do not produce antibodies
* Directly destroy specific target cells by
releasing chemicals that punch holes in the
victim cell
* Target cells include body cells invaded by
viruses and cancer cells

Question 12

All blood cells ultimately
originate from

Answer 12

All blood cells ultimately
originate from same
undifferentiated
pluripotent
hematopoietic stem cells
in red bone marrow
* Granulocytes and
monocytes are produced
only in bone marrow