week 4 part 1

Question 1

pathogen

Answer 1

a micro-organism that can cause

Question 2

infection

Answer 2

a pathogen has reproduced in the hosts body

Question 3

pathogenicity

Answer 3

the capability of a microbe to cause disease

Question 4

virulence

Answer 4

the degree of pathogenicity

Question 5

infectious disease are caused by

Answer 5

pathogens (including bacteria, viruses, fungi , protozoa

Question 6

bacteria

Answer 6

• contain DNA, ribosomes and RNA
• can survive and divide without a living host
• name is based on there shape
• prokaryotic single cell organsim have a rigid cell wall

Question 7

viruses

Answer 7

• small intracellular parasite
• a protein coats with a core that contains DNA or RNA
• REQUIRES a living host to relipucate and spread through the body

Question 8

virion

Answer 8

is a virus when it lives outside of the host cell

Question 9

steps of viral infection

Answer 9

1. virus
2. attachment to host cell and penetration
3. uncoating viral DNA or RNA enters host cell nucleus and takes control of host cell DNA
4. host cell synthesizes viral component
5. assemble new viruses
6. releases of many new virus ands host cells

Question 10

characertisic of Covid 19

Answer 10

contains a spike protein coat
RNA core

Question 11

how can viruses intrefear with Cancer

Answer 11

some viruses may alter the host cell chromosomes– malignant cells develop
E.g. certain strains of HPV  Increased risk of cervical cancer

Question 12

how can you use a virus to treat cancers

Answer 12

Oncolytic Virus Therapy
* Engineer a known virion so that it targets and infects tumor cells and promotes their
destruction
(+) insert immune stimulating gene
(-) remove disease causing genes (selective targeting of tumors)

Question 13

fungi

Answer 13

• found everywhere in the environment
• eukaryotic single cells or chain of cells
  can produce spores that become air-bone
  only certain fungi are pathogenic

Question 14

protozoa

Answer 14

• parasites( the pathogenic protozoa)
• complex eukararyotic organism
• uni cellular motile

Question 15

prions

Answer 15

• don’t not contain any genetic material
• infection is transmitted by protein particles that are able to self propagate
  (Induces proteins in the brain to misfold  nonfunctional  neurodegeneration)

Question 16

reservoir

Answer 16

the source carrying the infection

Question 17

how an infection enters your system

Answer 17

• reservoir (human, animal…)
  -portal of exit (nasal mucosa)
  -mode of transmission(insect bite , nasal droplets, semen)
  -portal of entry (nasal mucosa, skin punture, skin abrasion)
  -susceptible victim (unimmunzied)

Question 18

the bodies defence against a host

Answer 18

-first line -skin and mucous membrane, body secretions
-* Interferons are proteins made by human host cells
* Increase cell resistance to viral invasion, interfere with viral replication, stimulate the immune
response

Question 19

incubation period

Answer 19

the period between exposure to an infection and the appearance of the first symptoms.

Question 20

prodromal period

Answer 20

the period after incubation and before the characteristic symptoms of infection occur

Question 21

acute period

Answer 21

having the short duration of the infection being present

Question 22

local

Answer 22

pathogen confined to a specific location in the host

Question 23

focal

Answer 23

pathogen spreads to other tissues

Question 24

Systemic

Answer 24

infection spreads through circulatory system
* Bacteremia – bacteria in the blood
* Toxemia – toxins in the blood
* Viremia – viruses in the blood
 Septicemia – multiplication of pathogens in the blood, causes sepsis

Question 25

acute infection

Answer 25

rapid onset, more intense symptoms, short lived

Question 26

chronic infection

Answer 26

persistent, often less sever symptoms

Question 27

local signs of inflammation

Answer 27

pain, swelling, redness warmth
If bacterial—purulent exudate
* If viral—serous, clear exudate