PATH 201 - LECTURE 5

what is haematopoiesis controlled by

cytokines and growth factors

what are leucocytes

white blood cells

what are the three main types of white blood cells

granulocytes

monocytes

lymphocytes

what lineage do granulocytes come from

myeloid

what lineage do monocytes belong to

myeloid

what lineage do lymphocytes belong to

• lymphoid

which of the white blood cells are polymorphonuclear

all the granulocytes

• neutrophils

• basophils

• eosinophils

which of the white blood cells are mononuclear

lymphocytes and monocytes

what does polymorphonuclear mean

• poly means many

• morpho means shapes

• nuclear means nucleus

• so the many different shapes of the nucleus

what colour is the granules of a neutrophil

pink

what do the granules of neutrophils contain and what does this allow them to do

• lysosyme and superoxide which allows them to phagocytose and kill things

describe the nucleus of a mature neutrophil

• segmented 2-5 lobes

describe what neutrophils do

• theyre phagocytic

• recruited by chemokines (IL-8)

• have complement receptors

• secrete antimicrobials and neutrophil extracellular traps

how long are neutrophils in the tissue

24-72 hours

what is it called when we have a lot of neutrophils

neutrophillia

what causes neutrophillia

• bacterial infection

• inflammation

• drug induced (steroids)

• malignancy (myeloid leukemia)

what is too few neutrophils called

neutropenia

when do we see neutropenia

• viral infection

• severe bacterial infection (all of them have been utilised)

• immunosuppresion

• drug toxicity

• african and middle eastern individuals

what am i looking at

• neutrophils

• with pale cytoplasm and pink almost neutral granules

what am i looking at

neutrophils that have taken up some bacteria

describe the nucleus of eosinophils

segmented with 2-3 lobes

describe the granules of eosinophils

large, refractile, orange

• contains major basic protein

• eosinophil cationic protein

• peroxidase

what is the function of eosinophils

• Immune defence against parasites and pathogens

• phagocytic

what is eosinophilia

• infiltration of eosinophils

what is eosinophilia caused by

allergic reactions, asthma, parasitic infections, malignant disease of myeloid cells

describe the nucleus of basophils

• bilobed

describe the granules of basophils

dark purple

• histamine

• leukotrienes

• heparin

• vasoactive mediators

describe what a basophil does

• weakly phagocytic

• inflammatory role

• allergic role

• binds IgE

what is the cause of basophilia

• blood cancer (chronic myeloid leukemia)

• anaphylaxis

• insect/snake venom

describe the nucleus of monocytes

• kidney shaped nucleus

what colour is the cytoplasm of monocytes

blue/grey

what do monocytes become in tissue

• macrophages

how long do monocytes circulate for

20-40 hours

what is monocytosis

• lots of monocytes

what causes monocytosis

• any long chronic infection

• tubercolosis

• glandular fever

• myelodysplastic syndrome

do all macrophages some from monocytes

• no

• there is also macrophages that that are fetal derived

what are functions of macrophages

• phagocytosis

• produce proinflammatory cytokines

• present antigen to T cells

• initiate healing

describe the nucleus of lymphocytes

• non segmented

what do T cells do

• CD4 secrete cytokines

• CD8 induce apoptosis

what do B cells do

produce antibody

is there more B cells or more T cells

T cells

why is lymphocytosis normal in children

because everything children see is new

when do we see lymphocytosis in adults

• with many acute viral infections and whooping cough

• malignancy (chronic lyphocytic leukemia)

what is lymphopenia

• when there is fewer than normal lymphocytes

when do we see lymphopenia

• drug therapy against autoimmune disease

• AIDS

• severe stress

what do natural killer cells do

• activated by low MHC-I or receptors on target ells

• induce apoptosis on target cells

what do natural killer T cells do

• see antigen presented on CD1

• produce lots of cytokines

what is a leukopenia

deficiency of white blood cells

what are the two types of proliferative disorders (in terms of diseases fo white blood cells)

• reactive

• neoplastic

what are the 2 neoplastic proliferative disorders of white blood cells

• myeloid neoplasms

• lymphoid neoplasms

what is clonal proliferation

• when cells have uncontrolled growth and fail to die

what happens when clonal proliferation gets out of hand

• it begins to replace normal marrow and infiltrate into other tissues, replacing and destroying normal cells