leukocytes

Question 1

where are leukocytes found and functions?

Answer 1

complete colourless cells found in marrow, blood and lymph
functions include :
* fight against infection
* participate in immune responses
* remove old cells, debris and foreign objects

Question 2

leukocytes can be classified into 2 groups. what are they?

Answer 2

granulocytes
* granules in cytoplasm can be seen when stained
* have lobulated nuclei called polymorphs
* functions in tissues rather than in blood

agranulocytes
* have some granules but not easily visible

Question 3

how long on avg do neutrophils spend in circulating blood?

Answer 3

7 hours

Question 4

neutrophil morphology

Answer 4

• 10-14 µm in diameter
• lobes connected by chromatin threads
• multilobed
• small granules which stain lilac
• granules contain range of enzymes and antimicrobial proteins

Question 5

roles of neutrophils

Answer 5

• primary defense against bacteria, virus, fungus
• migrate to sites of infection
• respond to chemotactic stimuli
• rolling, adhering and diapedesis
• phagocytosis
• component of inflammation - release leukotrienes, prostaglandins
• febrile response - release an endogenous pyrogen

Question 6

neutrophils - phagocytosis process

Answer 6

Question 7

when do neutrophils increase? - physiological increases

Answer 7

• after exercise
• after meals
• pregnancy, menstruation
• mental stress
• after injection with adrenaline

Question 8

when do neutrophils increase? - pathological increases

Answer 8

• after pus-forming bacterial infections
• acute rheumatic fever
• gout
• tisssue destruction : burns, haemorrhage, myocardial infarction

Question 9

what is neutropenia and what can cause this?

Answer 9

low levels of neutrophils caused by :
* being a child
* typhoid fever
* viral infections
* malaria
* aplasia of bone marrow
* bone marrow depression

Question 10

size of eosinophils

Answer 10

10-14 µm in diameter

Question 11

functions of eosinophils

Answer 11

• defence against parasitic infection
• attack bacteria, but not as effective as neutrophils
• phagocytic but less motile than neutrophils

Question 12

morphology of eoisinophils

Answer 12

• acidophillic, appear light pink after staining
• granules are bright brick red colour from eosin dye
• granules contain lysozymes and high histamine content

Question 13

what is eosinophilia? and causes

Answer 13

increased number of eosinophils due to :
* allergic conditions e.g. asthma, hay fever
* parasitic infections
* skin disease

Question 14

what is eosinopenia? and causes

Answer 14

reduced number of eosinophils due to :
* steroid therapy
* stressfull situations
* acute pyogenic infections

Question 15

size of basophils

Answer 15

10 – 14 µm in diameter

Question 16

functions of basophils

Answer 16

main role is in allergic reactions
* release histamine
* release serotonin + others causing local vascular and tissure reactions
* prevents spread of allergic inflammatory process
* liberate heparin, which acts as an anticiaguland keeps blood flowing

mildly phagocytic but don’t attack parasites

Question 17

basophillia causes

Answer 17

• viral infections
• allergic disease
• chronic myeloid leukaemia

Question 18

basopenia

Answer 18

• steroids
• drug induced reactions
• acute pyogenic infections

Question 19

what are mast cells?

Answer 19

• large cells resemble basophils
• play role in allergic reactions
• present in bone marrow
• abundant beneath epithelial surfaces
• remain in connective tissue

Question 20

size of monocytes

Answer 20

18 – 20 µm in diameter

Question 21

what is a monocyte?

Answer 21

• single nucleus which is indented
• lots of clear cytoplasm
• no visible granules
• stains pale blue

Question 22

monocytes mature into…

Answer 22

macrophages or histocytes which phagocytose microbes

Question 23

monocytes presents ____ to ____

Answer 23

monocytes present antigens to lymphocytes

Question 24

monocytes crucial fighters against what kind of ingections?

Answer 24

chronic bacterial infections + chronic fungal infections

Question 25

roles of monocytes

Answer 25

* secrete cytokines which enhance inflammatory response * secret growth factors - promote production of neutrophils * remove parasites (malarial) * destroy RBCs at end of their life span * store released iron * kill tumour cells * synthesise complement, clotting factors, proteases

Question 26

monocytosis causes

Answer 26

* bacterial infections e.g. TB * viral infections * protozoal infections

Question 27

monocytopenia

Answer 27

* very rare * could be due to hypoplastic bone marrow

Question 28

size of lymphocytes

Answer 28

7 – 10 µm

Question 29

types of lymphocytes

Answer 29

B cells + T cells

Question 30

B cells roles

Answer 30

humoral immunity

Question 31

T cells roles

Answer 31

cellular immunity

Question 32

lymphocytosis - physiological causes

Answer 32

* healthy young children * during menstruation

Question 33

lymphocytosis - pathological causes

Answer 33

* chronic infections * lymphatic leukaemia * viral infections * autoimmune diseases

Question 34

lymphocytopenia causes

Answer 34

* steroud and immunosuppressive therapy * hypoplastic bone marrow * HIV

Question 35

images

Answer 35