Lecture 5: Leucocytes and Inflammation

Question 1

what are leucocytes

Answer 1

white blood cells

Question 2

what is production of blood cells

Answer 2

haematopoeisis

Question 3

what is production of leucocytes

Answer 3

leucopoeisis

Question 4

what are the two major leucocyte lineages

Answer 4

• lymphoid which make lymphocytes

- myeloid which make granulocytes

Question 5

what are the types of lymphocytes

Answer 5

• T cell
• B cell
• Natural Killer cells

Question 6

what is the blood cells’ route?

Answer 6

from blood marrow to lymphoid tissues to thoracic duct and back to bloodstream

Question 7

where is lymphoid tissue found

Answer 7

• back of the throat on tonsils
• junction of the ear (Adenoids)
• lymph nodes in armpit and groin
• just in front of the heart (thymus)
• in the gut all along small intestine (Peyer’s patch)
• spleen

Question 8

what is the function of B cells

Answer 8

mature into plasma cells to produce antibodies

Question 9

what is the function of T cells

Answer 9

• CD8 deal with intracellular infections

- CD4 helper cells direct the activity of the immune system

Question 10

what is the function of Natural Killer cells

Answer 10

thought to be important in dealing with intracellular infection and tumours

Question 11

give examples of cytokines

Answer 11

• tumour necrosis factor (TNF) alpha
• interferon gamma (IFG)
• interleukin 1 and 6 (IL-1 and IL-6)

Question 12

actions of cytokines

Answer 12

• endocrine: cytokine released into the blood like a hormone
• paracrine: acting on nearby surrounding cells
• autocrine: acts on the same cell that released it

Question 13

what are chemokines

Answer 13

• small proteins like cytokines
• different structure and receptors to cytokines
• involved in temporal and spatial organisation
• eg CXCL8 which attracts neutrophils to site of infection

Question 14

what is juxtacrine signalling

Answer 14

direct cell-cell signalling, eg with increased expression of a ligand

Question 15

what are the features of inflammation (latin and english)

Answer 15

• pain (dolor)
• heat (calor)
• redness (rubor)
• swelling (tumour)

Question 16

outline the steps of inflammation

Answer 16

1) pathogen breaches a barrier and enters tissue
2) met with a tissue macrophage
3) phagocytosis
4) response amplified by release of cytokines and chemokines

Question 17

effects of cytokine and chemokines

Answer 17

local inflammation:

• vasodilation increasing blood flow
• adhesion molecules making leucocytes stop at blood vessel and migrate to endothelium
• increased permeability so more leucocytes can move from blood cell to tissues

Question 18

features of systemic inflammation

Answer 18

• fever
• fatigue
• muscle pain
• anorexia (loss of appetite)

Question 19

action of cytokines on the liver

Answer 19

• stimulates production of acute phase proteins

- leads to activation of complement opsonisation

Question 20

action of cytokines on the bone marrow endothelium

Answer 20

• increased production of neutrophils (neutrophilia)

- leads to phagocytosis

Question 21

action of cytokines on the hypothalamus

Answer 21

• increases body temperature

- leads to decreased bacterial and viral replication

Question 22

action of cytokines on fat and muscle

Answer 22

with chronic inflammation, fat and muscle is mobilised to use energy for inflammation

Question 23

outcomes of acute inflammation

Answer 23

• resolution: insult removed, tissue heals completely
• fibrosis: insult removed but tissue is scarred
• chronic: insult cannot be removed
• abscess formation: insult removed but dead and necrotic cells form an abscess filled with pus