6.2

Question 1

Why is immune system organs called lymphoid organs and how is the lymphoid organs connected

Answer 1

they are called lymphoid organs because lymphocytes are found there

lymphoid organs are connected by blood vessels and the lymph vessels

Question 2

what is lymph

Answer 2

clear fluid

essenntuially extracellular fluid that has left capillaries and filter through tissue

lymph is conduit for immunologicallly active cells to travel through

Question 3

whare are lymphe nodes located

Answer 3

at strategic positions , knee, grouin , elbow, shourder and neck

Question 4

what are the regions of the body ourside lymphoid organs

Answer 4

perifery

Question 5

what er the two types of lymphoid organs

Answer 5

primary and seccondary

Question 6

primary lymphoid organs

wha originate and mature here

Answer 6

organs where lymphocytes develop

• bone marrow - all blood cells originate here

b lymmphocytes mature here

thymus - T lymphocites (cells) mature here)

Question 7

what is secondary lymphoid organs

Answer 7

organs where lymphocytes interact and initiate responses

filter blood and lymph - for pathogens and pathogen containing lymphocytes

Question 8

what does the structure of secondary lymphoid organs reflect

Answer 8

thier function

Question 9

what does afferent lymph vessel bring

Answer 9

bring in lymphocytes from periphery

Question 10

what does efferent lymph vessels do

Answer 10

allows them to keep circulating

Question 11

what does the pulp inside the lymph node do

Answer 11

allows mixing od lymphocytes and other leukocytes

Question 12

what do arterues and veins do

Answer 12

supply nutrients and O2, plus non-lymphocytic leukocytes

Question 13

what are spleen and lymph nodes surrounded by fibrous wall

Answer 13

encapsulated

Question 14

what are tonsils and GALT

Answer 14

secondary lymphoid organstonsils and GALT are unencapsulated tissues - diffuse

Question 15

what is the main player in the immune system and talk size and where and how it could be

Answer 15

leukocytes

Larger in size than RBC and less numerous

able to leave the blood stream and function extravascularly (in the tissue)

Question 16

life span of leukocytes

Answer 16

variuos lifespans

Question 17

6 main types of leukocytes cells

Answer 17

• esinophils
• Basophils (mast cells)
• nuetrophils
• monocytes (macrophages)
• Lymphocytes
• dendritic cells

Question 18

in what ways can leukocytes be subdevided by function and or morphology

Answer 18

• granulocytes
• phagocytes
• cytotoxic cells
• antigen precenting cells

Question 19

granulocytes

Answer 19

• have prominent cytoplasmic granues
• eosinophils, basophils and nuetrophils

Question 20

phagocytes

Answer 20

• can engulf and ingest pathogens
• neutrophils, macrophagesm dentritic cells

Question 21

cytotoxic cells

Answer 21

• kill other cells, even self-cells
• eosinophils and some lymphocytes

Question 22

antigen precenting cells

Answer 22

• display fragments of pathogens on cell surface
• some lymphocytes, dendritic cells and macrophages

Question 23

antigen

Answer 23

substances tahat are recognized by an antibody and induces an immune respoce

Question 24

what are anitibodys

Answer 24

proteins that bind specifically to Ag’s and targe pathogens for destruction

Question 25

structure and function of esinophils

Answer 25

cytotoxic granulocytes with bright pink staining granules role in defence against parasites and function in allergic response

Question 26

where are esinophils found and how ling they live

Answer 26

few in perifery circulation, only live for 6-12 hours - found in digestive tract, lungs, genital ract, and skin

Question 27

how does eosinophils respond

Answer 27

by binding to an antibody-coated parasite and degranulate - spew granule contents granule contets damage and kill parasites - cytotoxic

Question 28

what happes to eosinophils in allergic responses

Answer 28

they degranulate

Question 29

basophil looks and function

Answer 29

granulocytes involved in allergic responses have large dark blue staining granules (granulocyte)

Question 30

where basophils found

Answer 30

blood (rare in numbers), mast cells in tissue-found in digestive tract, lungs and skin

Question 31

what do granules in basophils contain

Answer 31

histamine, heparin, cytokines

Question 32

in allergic responses cells what do basophils do

Answer 32

they degranulate

Question 33

what is granulocytes that are phagocytic and most abundant leukocyte

Answer 33

nuetrophils

Question 34

how long can nuetrophils live and how many manny bacteria can in injest

Answer 34

1-2 days 5-20 bacteria

Question 35

what does nuetrophils do and how it do

Answer 35

can leave circulotory system to attack pathogens in tissues granules contain cytokines that cause fever and start other inflamotory responses

Question 36

what are monocytes and what are they precursors of

Answer 36

they are precursor cells of tissue macrophages and are uncommon in blood

Question 37

how long do monocytes be in blood and what they do after

Answer 37

they in blood for 8 hours and then move into tissues to become macrophages

Question 38

what are macrophages

Answer 38

large ameoboid cells and function as scavengers by phagocytosing old red blood cells and dead nuetrophils can phagocytose up to 100 bacteria

Question 39

what do macrophages have a role in

Answer 39

adaptive immune response - phagocytosed pathogens are digested, and fragments are placed on the cell surface (APCs)

Question 40

what are lymphocytes

Answer 40

key players in the adaptive immune response make up 20-30% of all leukocytes

Question 41

where are lymphocyes found

Answer 41

5% in ciruclation most are found in lymphoid tissues 10^12 per individual at any given time

Question 42

what are dendritic cells and structure

Answer 42

phagocytic antigen presenting cells (APCs) have long thin processes

Question 43

where are dendritic cells found

Answer 43

skin and other organs

Question 44

how do dentritic cells function

Answer 44

they recognise and engulf pathogens pathogens are digested and placed on cell surface activated cells then migrate to secondary lymphoid organs to present the antigen to lyphocytes

Question 45

explain haematopoiesis

Answer 45

all blood cells are produced in the bone marrow derived from pluripotent haematopoietic stem cells give rise to commited progenitor cells - develop into each cell type the path takes is guided by cytokines

Question 46

what are teh two types of lymphocytes

Answer 46

B lymphocytes ( B cells) T lymphocytes (T cells)

Question 47

wehre are B lymphocytes produced

Answer 47

bone marrow

Question 48

what do B lymphocytes do, and where they found

Answer 48

produce antibodies - can be found on the cell surface as receptors or secreted AB's in the plasma

Question 49

where T lymphocytes produced and where they mature

Answer 49

produced in the bone marrow and develop in the thymus

Question 50

What and what T cells bind to

Answer 50

use contact-depending signalling (cell-cell comuniatoion) via T-cell receptors expresed on the T cell membrane - can only bind to MHC-antigen complexes T-cell recceptor cannot bind to free Ag (anitgens)

Question 51

what is an MHC

Answer 51

protiens expressed on the surface of cells that display "self-antigens" and "non-self- anitigens" to T cells

Question 52

what are the two claasses of MHC that interact with T cells and where they found

Answer 52

class I (all nucleated cells) class II (cytotoxic Tcells)

Question 53

what are teh subtypes of T cells:

Answer 53

cytotoxic T cells or killer T cells helper T cells Regulatory T cells

Question 54

cytotoxic T cells or killer T cells

Answer 54

- recognizes Ag presented on class I MHC Kills cell that expresses appropriate Ag

Question 55

Helper T cells (Th)

Answer 55

recognizes Ag presented on class II MHC Promote differentiation of B cells and Tc Cells (cytotoxic T cells) and can activate macrophages

Question 56

regulatory T cells

Answer 56

recognize Ag presented on class II MHC supress other immune cells to preent excessve immune responses