Chapter 11 - Immune System

Question 1

Process of phagocytosis

Answer 1

1. Chemical signals attract phagocytes to pathogens. (Chemotaxis)
2. Phagocyte engulfs pathogen via endocytosis, to form a phagosome.
3. Phagosome fuses with lysosome that entered from the cytoplasm, forming a phagolysosome.
4. Lysozymes digest the pathogen.

CEFD.
(Can’t even find Dylan)

Question 2

Antigen presenting cells (APC)

Answer 2

Any type of immune cells that displays antigens of the pathogen on its surface to trigger an immune response.

Question 3

Explain the function of plasma cells

Answer 3

-plasma cells produce antibody molecules quickly.
They secrete antibodies into blood, lymph, lung lining & the gut.
Not long lived.

Question 4

What are antibodies

Answer 4

• globular glycoproteins with a quaternary structure
• immunoglobulins
• consist of 4 polypeptide chains with disulfide bonds in between.

Question 5

Explain lymphocytes

Answer 5

• a type of WBC and consists of two types: B cells and T cells
• it has large nucleus that fills most of its cells

Question 6

Explain the function of B cells

Answer 6

B cells produce & secrete specialized antibodies so they can bind to pathogens complementary to the antibody produced.
- they produce memory cells & plasma cells by mitosis to defend the body against future similar pathogen.

Question 7

Where do T cells remain

Answer 7

T cells leave the bone marrow and mature in the thymus gland

Question 8

Autoimmune diseases

Answer 8

The immune.s mistakes it’s own antigens as foreign
So immune response attacks it’s own antigens
(Like MG)

Question 9

Function of antibodies

Answer 9

• combine with viruses & bacteria toxins to prevent them entering and damaging cells.
• combine with toxins to neutralize them & make them harmless.(antibody called antitoxins)
• coat bacteria to make it easier for phagocytes too ingest them.

Question 10

Why are memory cells useful to the body

Answer 10

Memory cells circulate the body for a long time. If the same antigen gets inside it again, they will divide rapidly & develop into more memory cells and plasma cells .

Question 11

Why is the primary response slow?

Answer 11

Because at this stage there are still very few B cells specific to that antigen

Question 12

When helper T cells are activated….?

Answer 12

• release hormone like cytokines, which stimulates B cells to divide, develop in plasma cells & secrete antibodies.
• others secrete cytokines to stimulate macrophage to carry out phagocytosis more vigorously

Question 13

What’s the impact of leukemia, and the consequences?

Answer 13

• causes uncontrolled division of bone marrow stem cells, which increase the no. Of WBC and RBC in the blood.
• disrupts immune responses.

Question 14

Define ‘immune response’

Answer 14

The body’s response to non self antigens. Involves WBCs

Question 15

Macrophages

Answer 15

A type of phagocyte WBC
Produces in bone marrow
They begin as monocytes, when a response is triggered, monocytes leave their primary location through the blood and enter other organs.
After leaving blood, they develop into macrophage.
-long lived

Question 16

Why is the secondary response faster

Answer 16

Because there are more memory cells now that were produced from the first response. They will quickly divide and differentiate into plasma cells.