Lecture 2 [unfinished]

Question 1

Although there are a huge range of diverse disease what is strange about the human bodies response to these many diseases?

Answer 1

The responses to the diseases given by the body are very limited and fall into distinct categories e.g Inflammation can be a symptom of a viral infection but also a chronic autoimmune disorder

Question 2

What are the five types of infectious agents (microbes)?

Answer 2

Bacteria 
Protozoa
Fungi
Viruses 
Helminth

Question 3

Which of the microbes can typically be viewed under a light microscope?

Answer 3

Bacteria
Protozoa
Fungi
Helminth

Question 4

Which of the microbes cannot be seen under a light microscope and what microscope would have to be used?

Answer 4

Viruses - They can only be viewed under an electron microscope

Question 5

What are some of the routes of microbial infection?

Answer 5

Ear, eye, nose, mouth, placenta, genitals, urethra, anus, insect bite, broken skin

Question 6

How can infections cause damage?

Answer 6

• Direct cell death - through entry into the cell or changes to the cellular metabolism
• Release of toxins e.g (Botulinum toxin)- kills cells at a distance through enzyme release or damage to the blood vessels causing ischemic necrosis
• Induce immune responses - causing additional inflammation

Question 7

What are some of the ways that a lab will diagnose infectious agents?

Answer 7

Culture the pathogen and use biochemical identification (e.g gram stain for bacteria)
Serologic identification which detects and measures levels of antibodies in a blood sample
Histochemical staining (not a preferred method) staining tissue with dyes

Question 8

What happens during inflammation?

Answer 8

The allocation of cells and molecules of host defence sites where they are needed to eliminate agents (microbes, toxins etc)

Question 9

What are some of the causes of inflammation?

Answer 9

• Infection
• Tissue necrosis
• Foreign bodies
• Immune reactions (hypersensitivity)
• Fibrosis

Question 10

What are the clinical signs of inflammation?

Answer 10

• Heat
• Redness (edema)
• Swelling (vascular recruitment of molecules in the tissue)
• Pain
• Loss of function

Question 11

What is acute inflammation?

Answer 11

• Usually a short duration (up to a few days)
• Characterised by the accumulation of neutrophils leading to the formation of puss [made up of tissue fluid, dead neutrophils ana microorganisms]

Question 12

What is chronic inflammation?

Answer 12

• Longer duration of more than a week
• There is an accumulation of specialised immune cells (B and T lymphocytes) and plasma cells that secrete immunoglobulin and macrophages that try to repair the damaged tissue after the cause of the inflammation has been removed
• If prolonged there may be a production of new blood vessels (angiogenesis) and fibrosis