lecture 10 - immunology

Question 1

what is the immune system?

Answer 1

A complex network of cells, tissues, and organs and substances that they make that help fight off of infection and disease

Question 2

what is generative/primary in the immune organs, and what are examples of it?

Answer 2

• it is the origin
• ex. Bone Marrow, thymus

Question 3

what is peripheral/secondary in the immune organs, and what are examples of it?

Answer 3

• they are mature cells
• ex. lymph-nodes, spleen, lymphoid tissue, cutaneous immune system.

Question 4

what are the organs of the immune system?

Answer 4

• thymus
• bone marrow
• spleen
• lymph nodes
• lymphatic vessels

Question 5

what is the thymus?

Answer 5

• glandular organ near heart where T cells learn their job

Question 6

what is the bone marrow?

Answer 6

• blood producing tissue found inside certain bones

Question 7

what is the spleen?

Answer 7

• a filter for the blood (removed old + damaged abc, and removes infectious agents and uses them to activate lymphocytes)

Question 8

what are lymph nodes?

Answer 8

• small organs that filter out dead cells, antigens, and other things to present to lymphocytes.

Question 9

what are lymphatic vessels?

Answer 9

• collect fluid that has leaked out of blood and into tissues, and returns it to circulation

Question 10

what are peripheral lymphoid organs?

Answer 10

• organs that remove and destroy antigens in the blood and lymph

Question 11

what are central lymphoid lymphoid organs?

Answer 11

• organs where cells mature (thymus and bone marrow) and respond to foreign antigens

Question 12

what is the innate (nonspecific) defence system?

Answer 12

• first line of defence (external body membranes)
• second line of defence (antimicrobial proteins, phagocytes, and others)

Question 13

what is the adaptive (specific) defence system?

Answer 13

• third line of defence (attacks particular foreign substances)

Question 14

what is found in the second line of defence?

Answer 14

• phagocytes
• NK cells
• inflammatory response
• antimicrobial proteins
• fever

Question 15

what do phagocytes do?

Answer 15

• active in innate immunity by by eliminating bacteria, fungi and malignant cells (neutrophils and macrophages are phagocytes)

Question 16

what are natural killer (nk) cells?

Answer 16

• nonphagocytic large lymphocytes that attack cell surface receptors (MHC class 1) and kill by inducing apoptosis

Question 17

what is a fever?

Answer 17

• when leukocytes and macrophages are exposed to foreign substances that secrete pyrogens

Question 18

what are pyrogens?

Answer 18

substances that can produce a fever

Question 19

why is a high, prolonged fever concerning?

Answer 19

• can cause brain damage
• can cause convulsions
• can cause seizures in adults
• causes dehydration, and sometimes stroke, sometimes even death

Question 20

benefits of moderate fever

Answer 20

• causes liver and spleen to sequester iron and zinc
• increases metabolic rate which increases rate of repair

Question 21

what is an adaptive immunity?

Answer 21

• immunity that occurs after exposure to an antigen either through a pathogen or a vaccine (activated when innate immunity isn’t powerful enough)

Question 22

characteristics of adaptive immunity?

Answer 22

• specific
• systemic
• memory
• activates complement
• amplifies inflammatory response

Question 23

what are the 2 types of adaptive immunity?

Answer 23

1. humoral
2. cellular (cell-mediated)

Question 24

what is humoral immunity?

Answer 24

• Antibodies produced by B cells circulate in body fluids
• bind temporarily to target cells and mark it for destruction by phagocytes

Question 25

what is cellular immunity?

Answer 25

- T cell lymphocytes act against target cell - Directly - killing infected cells - indirectly - releasing chemicals that enhance inflammatory response or activate other lymphocytes or macrophages (histamines + cytokines + kinins + prostaglandins) - has cellular targets

Question 26

what are the 2 types of active humoral immunity

Answer 26

- naturally acquired - formed in response to actual infection - artificially acquired - formed in response to vaccine

Question 27

what are 2 types of passive humoral immunity

Answer 27

- naturally acquired -antibodies passed from mother to fetus - artificially acquired - through injections

Question 28

what are antigens?

Answer 28

- substances that can mobilize adaptive defences and provoke an immune response - can be complete or incomplete (haptens)

Question 29

what is HIV and AIDS?

Answer 29

- Human immunodeficiency virus cripples immune system by interfering with helper T cells

Question 30

how does HIV enter the body?

Answer 30

- blood transfusions - sexual intercourse/oral sex - mother to fetus