Innate defense: Natutural killer cells

Question 1

What are natural killer cells?

Answer 1

Small group of lymphocytes, other than T cells and B cells

Question 2

What do NK cells do?

Answer 2

Defend the body against viruses and cancer cells by secreting cytolytic substances called perforins, which lyse cell membranes of pathogens

Question 3

What do NK cells also secrete?

Answer 3

substances that enhance inflammation

Question 4

What is phagocytosis?

Answer 4

Engulfment and digestion of pathogens, foreign particles, and debris

Question 5

What are most phagocytes and what do they do?

Answer 5

neutrophils and monocytes, which leave bloodstream by diapedesis (squeezing between adjacent cells of the capillary walls) in areas of injury

Question 6

What are phagocytes attracted to?

Answer 6

injured area by chemotaxis, in which they are attracted by chemicals from injured cells

Question 7

What do Neutrophils do?

Answer 7

engulf smaller particles; monocytes attack larger ones

Question 8

What do monocytes give rise to?

Answer 8

macrophages outside the blood, which are either free or become fixed in various tissues

Question 9

What do Neutrophils + monocytes + macrophages =

Answer 9

phagocytic system or reticuloendothelial system