Immune system

Question 1

The three components of the immune system

Answer 1

lymphoid tissue
various immune cells
chemical signals that coordinate responses

Question 2

Functions of the immune system

Answer 2

protect against pathogens
foreign substances
remove damaged cells
remove abnormal cells

Question 3

Types of immune system pathologies

Answer 3

autoimmune diseases
overactive immune responses
lack of immune responses

Question 4

what are the two lines of defense

Answer 4

Physical or chemical barrier : skin, cilia epitheal linings, acids, mucus, lysozymes.

Immune defenses:

Question 5

name the two types of immune responses

Answer 5

Innate immunity: Non-specific- responds to a range of signals
- It is an immediate response

Acquired/adaptive immunity

specific: responds to specific signals
- Slower but stronger response
- Keeps memory for if the pathogen attacks again

Question 6

Physical and chemical barriers

Answer 6

Physical/mechanical barriers: skin, mucous membrane, lacriminal apparatus ( produces tears ), saliva, epiglottis.

Chemical
sebum: secreted by sebacious glands and has a low pH that inhibits microbial growth
Perspiration: Flushes skin of micobes and has lysozymes
Gastric juice: low pH and has enzymes
Urine

Question 7

The timeline for response

Answer 7

for the first 6hr: innate response
Epitheal barriers 
phagocytes 
complement
NK cells

After:
Adaptive immunity:
B lymphocytes 
T lymphocytes 
antibodies 
Effector T cells

Question 8

the four steps to immune responses

Answer 8

detection of the foreign substance
communication with other immune cells
Recruitment of other immune cells
destruction or suppression of the invader cells

Question 9

Lymphatic system

Answer 9

a system that collects tissue fluid from cells and returns it the blood.
Lymph is constantly monitored for pathogens0

Question 10

Types of lymphoid tissues

Answer 10

primary lymphoid tissues: Bone marrow , thymus
encapsulated lymphoid tissues : lymph nodes, spleen.
diffuse lymphoid tissues/ lymph nodules

Question 11

The thymus gland

Answer 11

this is a 2 lobed organi located above the heart.
It produces: T-lymphocytes and
peptides: thymosin,
thymopoietin, thymulin .
theses are necessary for the maturaion of T lymhocytes
Grows to its full size i adolescence then it shrinks and turns into adipose

Question 12

lymphoid nodules

Answer 12

Loose connective tissue with densely packed lymphocytes
not surrounded by a capsule
germinal centre is where lymphocytes divide
Their size is highly dependant on the amount of lymphocytes in them

Question 13

where are lymphoid nodules found

Answer 13

under the epithileal layers of organs connected to the outside world eg. the digestive, resporatory and urinary tract

Question 14

interferons

Answer 14

signaling proteins produced by a virus infected cell to alert nearby cells to heighten their viral defences

Question 15

parts of lymph nodes

Answer 15

afferent and efferent lymph vessels
Paracortical area( has mostly T-Cells
Medullary (macrophages and plasma cells)
primary lymph follicle (b cells mostly)

Question 16

Leukocytes

Answer 16

Granulocytes
Neutrophils
basophils
eusonophils

Agranulocytes
Monocytes
lymphocytes
dendritic cells

Question 17

macrophages

Answer 17

Act by phagpcytosis and bactericidal mechanisms

antigen presentation

Question 18

dendritic cells

Answer 18

antigen uptake in perpheral sites

antigen presentation

Question 19

neutrophil

Answer 19

phagocytosis and activation of bactericidal mechanisms

Question 20

mast cells

Answer 20

release granules containing histamine and active agents

Question 21

eusinophil cells

Answer 21

killing antibody coated parasites

Question 22

Natural killer cells

Answer 22

release lytic granules that kills some virus infected cells

they induce apoptosis
they attack tumor cells
they secrete interferons alpha and beta that stop viral replication
Interferon gamma activates microphages

Question 23

First line of defence

Answer 23

barriers that keep the pathogens from entering physically or with chemicals eg the skin, mucous membranes and secretions of the stomach, that are acidic

Question 24

what is the difference between the way pathogens with and those without caosules are phagocytosisized

Answer 24

those without are directly and those with have antibodies that attach first and then they are ( well you know the word)

Question 25

how are ingested pathogens killed

Answer 25

with lysozymal enzymes

Question 26

How do Anitgen presenting cells work

Answer 26

they ingest the pathogen, break it down and then they present them on the surface of the cell.

Question 27

Inflammation

Answer 27

this is a local non specific response to infection

Question 28

beneficial roles of inflammation

Answer 28

attract immune cells to the site of infection
create a physical barrier so that infection does not spread
promote tissue repair

Question 29

steps to inflammatory responses

Answer 29

cytokines are released to the site
acute phase proteins help prevent damage
cytokine encourage the production of histamine from mast cells which cause vasodilation to allow more white blood cells faster and edema due to osmotic effect of the plasma proteins

Question 30

action of cytokines

Answer 30

small roteins that are produced by macrophages they increase permiability and cause fever and attract other immune cells

Question 31

other chemicals in inflammatory responses

Answer 31

interleukins- subset of cytokines. They cause fevers and blood vessels become more permeable to WBC and proteins , acute phase proteins

Bradykinin: cause pain and swelling
complement proteins: are inactive as plasma proteins
the complement cascade produces membrane attack complex that inserts into foreign cells and results in lysis.

Question 32

how does the membrane attack complex act

Answer 32

complement proteins insert themselves in the membrane of pathogens and water and ions go in and cause lysis

Question 33

immune response chemicals functional classes

Answer 33

acute phase proteins : enhane the inflammatory response and act as opsonins
chemotaxins: they attract phagocytes to infection sites
cytokines : affect growth and activity of other cells
opsonins : coat pathogen
pyrogens: fever producing

Question 34

acquired immuntity

Answer 34

acts to and reacts to a specific antigen

Question 35

the difference between active and passive immunity

Answer 35

active: when the lymphocytes are exposed to foreign antigens in the body
Passive when we receive foreign antibodies from elsewgere
Memory cells are also produced

Question 36

Mechanism of adaptive responses

Answer 36

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