Infectious Disease

Question 1

What is infection

Answer 1

When barriers are broken such as epithelial barrier

Question 2

What is the upper respiratory tract and name some pathogens related

Answer 2

Oral and nasal cavity

Streptococcus, influenza

Question 3

What is the area called in the lower respiratory tract affected by things like TB

Answer 3

Parenchyma (alveoli and bronchioles)

Question 4

What are the 2 main bacteria which affect the parenchyma

Answer 4

Pneumonia - strep, staph

TB

Question 5

How does TB bacteria in parenchyma cause tubercles to form

Answer 5

They can grow inside of macrophages in lungs

Question 6

What does Tb have in cell wall which makes it resistant

Answer 6

Mycolic acid

Question 7

What are the 3 causes of gastroenteritis

Answer 7

Viral cause
Parasite (waterborne)
Bacterial

Question 8

What 2 types of gastroenteritis is there and their wbc count

Answer 8

1- secretory diarrhoea (low WBC)

2- inflammatory diarrhoea (high wbc)

Question 9

What can cause secretory diarrhoea gastroenteritis

Answer 9

Cholera or enterotoxins

Question 10

What kind of things cause inflammatory gastroenteritis

Answer 10

Shigella

Salmonella

Question 11

Which strand of salmonella is asymptomatic

Answer 11

Salmonella enterica

Question 12

What toxin does ecoli release and what happens

Answer 12

Vero cytotoxin- causes haemolytic uraemia syndrome HUS

Question 13

What kind of toxin is cholera which causes inflammatory diarrhoea

Answer 13

AB exotoxins

Question 14

What happens in cholera infect ants

Answer 14

B toxin binds to epithelial cells

A can enter via gangliosides and causes activation of adenylate cyclase

A lot of camp is produced which blocks NA movement from intestines to blood

This causes flood of Cl to move into intestines along with water

= dehydration

Question 15

Which types of pathogens cause skin infections

Answer 15

Opportunistic pathogens - organisms which are present in absence of others

Question 16

Which 3 bacteria produce skin infections

Answer 16

Streptococcus

Staphylococcus

S pyogenes

Question 17

Why is streptococcus immune

Answer 17

Coated in a capsule

Question 18

What type of things can streptococcus infect

Answer 18

Skin (impetigo, Scarlett fever)

Lungs (pneumonia)

Question 19

What type of things can staphylococcus infect

Answer 19

Skin

Brain

Lungs(pneumonia)

Question 20

What is inflammation induced by

Answer 20

Cytokine release

Neutrophil accumulation

Question 21

What are the 5 signs of acute infection (innate response)

Answer 21

1- rubor(redness)

2- calor (Heat)

3- Tumor(swelling)

4- dalor (pain)

5- change in function - change in tissue structure due to pain

Question 22

Why does rubor and calor occur

Answer 22

Increased blood flow to area of infection

Question 23

Why does tumor occur

Answer 23

Movement of plasma to the tissue affected causes swelling

Question 24

What causes dalor

Answer 24

Tumour which stretches skin pressing on nerves and pain receptors

Question 25

What does adaptive immunity refer to

Answer 25

Humoral immunity - producing antibodies from B cells Cellular immunity - T cell attack Memory and specificity - targeted response Antibody dependant cytotoxicity

Question 26

What is bacteremia

Answer 26

Bacteria presence in the blood Use host mechanisms to attach eg via fim H

Question 27

What is septicaemia

Answer 27

The response to bacteraemia It causes septic shock which is an inflammatory response

Question 28

What happens in septic shock for it to be more dangerous than infection

Answer 28

Excess cytokine release Causes damage to organs due to blood vessel leakage

Question 29

Which other illness is similar to septicaemia but inflammatory response is in brain

Answer 29

Meningitis

Question 30

What 3 ways to bacteria, viruses, parasites enter

Answer 30

Wounds Orally Bites