human defence system

Question 1

what is a pathogen

Answer 1

an organism that causes disease

Question 2

give some examples of diseases caused by these pathogens: bacteria, virus, fungi, protist

Answer 2

cholera, covid 19, athlete’s foot, malaria

Question 3

what is transmission

Answer 3

a disease which the pathogen can be passed from one host to another

Question 4

how to prevent spread of transmissible disease

Answer 4

good hand hygiene
waste disposal
sewage treatment
vaccination

Question 5

what is an antigen

Answer 5

chemical substance on the surface of the cell

Question 6

what is immune response

Answer 6

interaction between antigen and antibodies that results in elimination of antigen

Question 7

what are the physical barriers that prevent us from getting sick

Answer 7

skin acts as an outer layer so pathogen wont enter
ciliated cell sweep pathogen
nose hair filters bacteria

Question 8

what are the chemical barriers

Answer 8

hcl and enzyme kills bacteria in stomach
mucus , sweat and saliva trap bacteria
tears contain lysozyme which can dissolve cell wall of some bacteria

Question 9

describe the process of phagosythesis

Answer 9

phagocytes squeeze through the capillaries and enters tissue fluid and goes into infected area
it surrounds its cytoplasm ard the pathogen and engulfs and digest it

Question 10

how does lymphocytes produce immunity response

Answer 10

a pathogen enters
antigen on pathogen signals foreign invaders
white blood cells produce
newly made wbc make antipodes specific for the antigen
release antigen to blood and boo pathogen dies

Question 11

how are memory cells made

Answer 11

some of the lymphocytes stay in the lymph nodes as memory cell. so when the same pathogen enters youll be able to attack and there fore be immune and not become sick yayyy

Question 12

how does antibody destroy antigen

Answer 12

agglutin
send signal to other immune cell
neutralising toxin
phagocytosis

Question 13

what is active immunity and when do we achieve it

Answer 13

when lymphocytes produce own antibodies

when we get sick and get vaccines

Question 14

what is vaccine and how does it work

Answer 14

weaken or dead pathogen
antigen is on its surface
lymphocytes produce antibodies
memory cells are produced and gives long term immunity

Question 15

what is passive immunity and how do we achieve it

Answer 15

short term defence against a pathogen by antibodies acquired from another individual
mothers milk and inject serum with antibody

Question 16

what is serum

Answer 16

plasma without fibrinogen

Question 17

what is an autoimmune disease

Answer 17

when immune system target and destroy own cells

Question 18

describe 1 autoimmune disease

Answer 18

type 1 disease
islet cells of pancreases cannot produce enough insulin
immune cell attack inset cells
inject insulin everyday

Question 19

what is a problem faced when during organ transplant

Answer 19

because everyone’s cell has its own antigen, the person receiving the tissue may hv tissue rejection because the immune system will reject and attack the antigien

Question 20

how to solve tissue rejection

Answer 20

ear immune suppressive drugs

get relatives to donate as they will hv similar antigen

Question 21

when donating blood we need to make sure its they same blood type, why

Answer 21

each blood cell has its own antigen

if they dont math the same blood type, blood cells can clump tgt bc wbc react to donors cells