the human defence system

Question 1

pathogen

Answer 1

an organism that causes disease

Question 2

immunity

Answer 2

the ability to resist infection

Question 3

general defense system

Answer 3

acts as a barrier to all pathogens that attempt to gain entry to the body

Question 4

specific defense system

Answer 4

attack particular pathogens

Question 5

antigen

Answer 5

foreign molecule that stimulates the production of antibodies

Question 6

antibody

Answer 6

protein produced by wbc in response to specific antigens

Question 7

induced immunity

Answer 7

ability to resist diseases caused by specific pathogens by the production of antibodies

Question 8

active immunity

Answer 8

involves the production of a person’s own antibodies in response to foreign antigens that enter the body

Question 9

artificial active immunity

Answer 9

occurs when a pathogen is medically induced into the body

Question 10

first line of general defence system

Answer 10

skin
clotting
sebacous glands
lysozyme
mucuos
cilia
acid
beneficial bacteria

Question 11

skin

Answer 11

acts as a physcial barrier to the entry of pathogens

Question 12

lysozyme

Answer 12

enzyme in tears, sweat and saliva that attacks and dissolves the walls of bacteria

Question 13

sebacous glands

Answer 13

in the skin produce sebum
chemicals found in sebum kill bacteria

Question 14

mucus

Answer 14

most body systems are lined with sticky mucus
pathogens are trapped by mucus and prevented from entering the body

Question 15

cilia

Answer 15

tiny hairs that beat and create a current which moves mucus back up the respiratory system so it can be swallowed into the stomach
coughing clears mucus an pathogens from throat

Question 16

acid

Answer 16

HCL in the stomach kills many pathogens

Question 17

beneficial bacteria

Answer 17

bacteria in the vagina produce lactic acid which prevents the growth of pathogens

Question 18

second line of general defence

Answer 18

phagocytic white blood cells defence proteins

Question 19

phagocytic white blood cells

Answer 19

• when cells are damaged by invading micro-organisms they release a large number of chemicals
  -the chemicals attract white blood cells from the bloodstream
  -white blood cells engulf and destroy any bacteria , viruses or other micro-organisms that they meet
  -macrophages move around the body in bodily fluids and act as scavengers for pathogens
  -other macrophages remain fixed and filter out and destroy pathogens that are present in lymph

Question 20

defence proteins

Answer 20

complement is a set of 20 proteins in the blood plasma activated by infection these destroy viruses and other pathogens
interferons prevent viral multiplication and help to limit the spread of virus infections

Question 21

inflammation

Answer 21

when cells are infected they release a chemical that results in blood capillaries dilating and becoming more porous
this causes swelling. redness, heat and pain
it brings more WBC to the area to fight infection
it causes increased body temperature
Higher temperatures interfere with the ability of bacteria and viruses to reproduce