Chapter 9 Immunity

Question 1

Describe the cells that make up the innate immune system

Answer 1

• Neutrophils
• Macrophages
• Dendritic cells
• Mast cells
• NK cells
• Monocyte
• Eosinophil
• Basophil

Question 2

What are the two types of immunity from the adaptive immunity?

Answer 2

• Humoral immunity (B cells)

- Cell-mediated immunity (T cells)

Question 3

What is the purpose of cytokines?

Answer 3

Cytokines are hormones that act as messenger to facilitate communication between cells. They alert other nearby immune cells.

Question 4

What are the physical barriers of the human body against foreign invaders?

Answer 4

• Skin
• Mucous membranes
• Stomach acid
• Alkaline pH in lower intestines
• Hair-like projections in the respiratory system
• Peristaltic action of intestines

Question 5

Describe the activation of humoral immunity.

Answer 5

• The humoral immunity is activated when B cells recognizes a specific antigen on a pathogen.
• The antigen is then loaded to a MHC II molecule and presented to helper T cells.
• Helper T cells produce cytokine and stimulate B cell, which differentiates into plasma cells
• Plasma cells produce antibodies and marks the pathogen for destruction.
• After the infection subsides, some B cells become memory cells.

Question 6

Describe the activation of cell-mediated immunity.

Answer 6

• Cell mediated immunity is activated when naïve T cells recognizes an antigen presented by an Antibody Presenting Cell (APC).
• The T-cells then differentiate into helper T-cells (CD4+) and cytotoxic (CD8+) cells.
• Helper T-cells secrete cytokines and coordinate immune responses, it recognizes antigens on MHC II,
• Cytotoxic T cells kills target cells with an antigen on MHC I.