Phagocytosis

Question 1

If a pathogen is to infect the body, what must first occur?

Answer 1

The pathogen must first gain entry into the body

Question 2

What are the body’s two first lines of defence?

Answer 2

The body’s first line of defence is to form a physical or chemical barrier to entry.

Question 3

What is the next line of defence after the physical and chemical barriers?

Answer 3

The second line of defence are the white blood cells

Question 4

There are two types of white blood cell. What are the two types?

Answer 4

The two types of white blood cell are phagocytes and lymphocytes

Question 5

White blood cells have a specific and nonspecific response, which type of white blood cell performs each response?

Answer 5

Phagocytes carry out the non - specific response and the lymphocytes carry out the specific response

Question 6

Where are phagocyte found?

Answer 6

Phagocytes are found in the blood and in tissues

Question 6

What is a phagocyte?

Answer 6

A phagocyte is a macrophage, that carries out phagocytosis

Question 7

What is meant when phagocytosis is described as a specific response?

Answer 7

This means phagocytes will respond the exact same no matter what the non - self cell detected is, it is not specific to a certain antigen

Question 8

What are phagocytes involved in?

What are lymphocytes involved in?

Answer 8

Phagocytes ingest and destroy pathogens by phagocytosis before they can cause harm

Lymphocytes are involved in immune responses

Question 9

After all the line of defences, what occurs to prevent the harm caused by pathogens?

Answer 9

The next line of defence is phagocytosis

Question 10

What is the process of phagocytosis?

Answer 10

1* Phagocytes detect chemicals being released/debris from pathogens or abnormal cells, causing them to move towards these cells

2*Phagocytes with several receptors on their cell surface membrane recognise and attach to chemicals on the surface of the pathogen

3*Phagocyte changes shape to engulf pathogen

4* Once pathogen is engulfed, a vesicle is formed, known as a phagosome

5* A lysosome move towards the vesicle (phagosome), attaches itself and releases digestive enzymes (lysozymes) into the non self cell to destroy its cell walls

6* The pathogen is destroyed and the soluble products (like proteins) from the pathogen are absorbed and used by the phagocyte