The Immune System

Question 1

what is the immune system?

Answer 1

cells and organs that destroy or neutralize pathogens that cause disease or death

Question 2

what is the lymphatic system?

Answer 2

vessels, cells, organs that carry excess fluids to the bloodstream and filters pathogens from the blood

Question 3

what is the interstitial fluid?

Answer 3

Fluid found in the spaces around cells. It comes from substances that leak out of blood capillaries

Question 4

what is lymph?

Answer 4

the extra interstitial fluid that drains from your body’s cells and tissues

Question 5

what is a lymph node?

Answer 5

small bean shaped organ throughout lymphatic system

Question 6

where are lymph nodes found?

Answer 6

chest
neck
groin
abdomen

Question 7

how many lymph nodes are there in the body?

Answer 7

500-600

Question 8

what is the difference between the lymphatic system and the cardiovascular system?

Answer 8

lymph is pumped by body movement whereas blood is pumped by the heart

Question 9

what is the function of the semi lunar valves in the lymphatic system?

Answer 9

they keep lymph moving towards the heart

Question 10

what are the temporal phases of immune function?

Answer 10

• barrier defenses
• innate response
• adaptive response

Question 11

what are the two main divisions of the immune system?

Answer 11

innate: (physical protection & phagocytes)
adaptive: (t lymphocytes/ b lymphocytes)

Question 12

list the innate means of physical protection

Answer 12

skin - cough - tears - mucos - stomach acid

Question 13

list the innate phagocytes

Answer 13

• monocytes
• macrophages
• neutrophils
• NK cells
• dendritic cells

Question 14

list the adaptive T-lymphocytes

Answer 14

Helper T

Suppressive T

Cytotoxic T

Question 15

list the adaptive B lymphocytes

Answer 15

clonal B lymphocytes

memory B lymphocytes

Question 16

list the blood cells involved in immune response that arise from hematopoieses

Answer 16

• phagocytic cells
• lymphocytes
• cells with cytoplasmic granules

Question 17

حفظ

Answer 17

قلنا حفظ

Question 18

how are t/b lymphocytes differentiated?

Answer 18

• surface protein markers t→ TCR/CD3/CD4/CD8 B→ check link (IgM/IgD/MHC II)
• molecules they secrete t→ cytokines b→antibodies
• maturation t → thymus , b → bone marrow

Question 19

define antibodies

Answer 19

group of proteins that bind to pathogen-associated molecules

Question 20

define antigens

Answer 20

pathogen-associated molecules on their surface

Question 21

what are plasma cells, and what do they do?

Answer 21

they are the activated form of b-lymphocytes bound to pathogen surface antigens.

they secrete soluble antibodies

Question 22

what is the function of t lymphocytes?

Answer 22

• secrete soluble factors to communicate with other cells of adaptive tissue
  
  • destroy cells infected with intracellular pathogens

Question 23

describe the structure of plasma cells?

Answer 23

they contain cytoplasm that is packed with rough endoplasmic reticulum that has protein synthesizing machinery

Question 24

what is a natural killer cell? and what do they do?

Answer 24

circulating blood cell that contains cytotoxic granules in its cytoplasm, they destroy virally infected cells

Question 25

what are the primary lymphoid organs?

Answer 25

• bone marrow: site of haematopoiesis
• thymus gland: site of energy storage
  *

Question 26

where do t/b cells develop and mature

Answer 26

they are both developed in the bone marrow

HOWEVER, B→ mature in bone marrow

t→ mature in Thymus

Question 27

where is the thymus gland located?

Answer 27

between the sternu and the aorta

Question 28

compare and contrast the thymus cortex with the thymus medulla

Answer 28

• cortex:

epithelial cells/lots of thymocytes/macrophages/dendritic cells/densely packed

• medulla:

thymocytes migrate to it before leaving the gland

epithelial cells

dendritic cells

less packed

Question 29

what are the secondary lymphoid organs

Answer 29

lymph nodes (LNs)

spleen

Peyer’s patches (PPs)

mucosal tissues- the nasal associated lymphoid tissue (NALT)

adenoids

and tonsils

Question 30

what do the secondary lymphoid organs do?

Answer 30

fighting off germs and foreign substances

Question 31

what is a naive lymphocyte?

Answer 31

one that has left primary organ and enter secondary lymphoid organ

Question 32

what do the secondary lymphoid organs have in common?

Answer 32

• presence of lymphoid follicle where lymphocytes form
• reticular fibers (fixed macrophages)
• germinal centers (site of division and differentiation)
• high endothelial venules (allows cells in blood to enter tissues)