Chapter 20.14-15 And Chapter 24

Question 1

Homeostasis

Answer 1

The steady state of body functioning; a state of equilibrium characterized by a dynamic interplay between outside forces that tend to change an organism’s internal environment and the internal control mechanisms that oppose such changes.

Question 2

Negative feedback

Answer 2

Any control mechanism that reduces or reverses a change in the internal environment is

Question 3

Positive feedback

Answer 3

Occurs when a change triggers mechanisms that amplify that change. EX: Forming a blood clot to control bleeding from a wound and producing contractions strong enough to push out a baby are two processes that rely on …..

Question 4

Pathogen

Answer 4

An agent such as a virus, bacteria, or fungus, that causes disease.

Question 5

Immune system

Answer 5

An animal body’s system of defense against agents that cause disease

Question 6

Innate immunity

Answer 6

The kind of immunity that is present in an animal before exposure to pathogens and is effective from birth. Defenses include barriers, phagocytic cells, anti microbial proteins, the inflammatory response, and natural killer cells.

Question 7

Phagocytosis

Answer 7

Cellular “eating”; a type of endocytosis in which a cell engulfs a macromolecules, other cells or particles into its cytoplasm.

Question 8

Natural killer cell

Answer 8

A cell type that provides an innate immune response by attacking cancer cells and infected body cells, especially those harboring viruses.

Question 9

Neutrophils

Answer 9

The most abundant type of white blood cell; functions in innate immunity as a type of phagocytic cell that tends to self- destruct as it destroys foreign invaders.

Question 10

Macrophages

Answer 10

A large, amoeboid, phagocytic white blood cell that functions in innate immunity by destroying microbes and in adaptive immunity as an antigen-presenting cell.

Question 11

Interferons

Answer 11

An innate defensive protein produced by virus-infected vertebrate cells and capable of helping other cells resist viruses.

Question 12

Complement system

Answer 12

A family of innate defensive blood proteins that cooperate with other components of the vertebrate defense system to protect against microbes; can enhance phagocytosis, cause the rupture of pathogens, and amplify the inflammatory response.

Question 13

Inflammatory response

Answer 13

An innate body defense in vertebrates caused by a release of histamine and other chemical alarm signals that trigger increased blood flow, a local increase in white blood cells, and fluid leakage from the blood. The resulting inflammatory response includes redness, heat, and swelling in the affected tissues.

Question 14

Mast cells

Answer 14

A type of white blood cell residing in connective tissue that releases histamine during inflammatory responses and allergic reactions.

Question 15

Histamine

Answer 15

A chemical alarm signal released by mast cells that causes blood vessels to dilate and become more permeable in inflammatory and allergic responses