immune and infection

Question 1

what is the immune system

Answer 1

the body protects itself from injury, harmful agents or infectious organisms through an elaborate system of networks called the host defence system

Question 2

3 barriers of immune system

Answer 2

1- physical and chemical barriers, 2- the inflammatory response, 3- immune response

Question 3

Immunity- bone marrow

Answer 3

found in long bones, iliac crest and sternum. Red and yellow bone marrow. Yellow is found in the shaft of the bone marrow whereas red is found at the ends. Red is responsible for producing WBC platelets and RBC

Question 4

Immunity- thymus gland

Answer 4

develops T lymphocytes, sits in pericardial cavity, larger in children and then gets smaller in adults as immunity built up

Question 5

Immunity- lymph nodes

Answer 5

holding areas for immune cells, this is close to blood vessel as cells are passed between them when required

Question 6

Immunity- spleen

Answer 6

involved in RBC recycling and also stores WBC and platelets, tonsils- holding areas for immunity cells and first line of defence

Question 7

what is cell mediated immune response

Answer 7

directed against intracellular pathogens, such as viruses, some cancer cells, and tissue transport

Question 8

Cell mediated immune response- 1

Answer 8

involves B and T lymphocytes made in the red bone marrow, T lymphocytes are released from bone marrow, but they are immature (not in functioning form), they travel to the thymus, where components are added and they are activated, they leave as mature T cells and enter lymphatic system and are stored

Question 9

Cell mediated immune response- 2

Answer 9

when the T cells are matured, they come out as either CD8 cells or CD4 cells, but they need each other. CD8 cells need circulating CD4 cells to combine and porduce cells that will do something about an invading organisms. this then forms killer T cells, which are good at phagocytosis

Question 10

what is phagocytosis

Answer 10

get rid of evading pathogens/ get rid of anything that is not recognised

Question 11

Cell mediated immune response- 3

Answer 11

CD8 T cells kill things by releasing perforin (AMC) this causes autolysis, or by releasing lymphotoxin (DNA) which effets DNA and causes death of the cell

Question 12

Cell mediated immune response- 4

Answer 12

Drugs can be used to stop killer cells being produced to attack organ replacement, this can lead to a greater risk of other infections and diseases (immune system is compromised)

Question 13

What is the memory element of the Cell mediated immune response

Answer 13

some natural killer cells recognise antigens quicker if they have seen them before

Question 14

What is the antibody- mediated immune responses

Answer 14

humoral immunity- directed against extracellular pathogens, such as bacteria

Question 15

the antibody- mediated immune responses- 1

Answer 15

this involves B lymphocytes, which are released by red bone marrow at the end of long bones and are already mature- enter straight into lymphatic system

Question 16

the antibody- mediated immune responses- 2

Answer 16

they are made with specific§ antibodies attached to them (specific to certain antigens), they recognise specific antigens and attach to them- leads to phagocytosis

Question 17

the antibody- mediated immune responses - 3

Answer 17

the B lymphocytes sit in the lymphatic system until they are required, the CD4 cells are required to help B cells to release antibodies when needed. B cells activated by helper T cells and mature into plasma cells, the plasma cells produce immunoglobulin that interact with specific antigens

Question 18

the antibody- mediated immune responses - 4- memory element

Answer 18

when exposed to specific antigens, the body makes specific antibodies

Question 19

what is the importance of the CD4 T cell

Answer 19

manages and coordinates the immune response, helper cells increase the production of T and B cells, activate CD 8 cells into killer T cells, activate B cells to mature plasma cells, act as suppressor cells, slow the immune response

Question 20

Antibody actions- agulation

Answer 20

make foreign cells stick together preventing damage

Question 21

Antibody actions- precipitation

Answer 21

antibody and antigen combine and become insoluble (meaning they cannot cause damage)

Question 22

Antibody actions- neutralisation

Answer 22

when the antibodies bind to bacteria/ antigen themselves, preventing them from joining any other cells and hence, causing damage

Question 23

Antibody actions- lysis

Answer 23

direct killing of the pathogen

Question 24

Antibody actions- opsonization

Answer 24

antigen marks the cell meaning the cells involved with phagocytosis recognise it quickly- and destroy it

Question 25

Antibody actions- compliment cascade

Answer 25

activation of the complement cascade- series of enzymes that cause some things to happen from different perspectives

Question 26

what is an infection

Answer 26

it is an extension of the inflammatory and immune processes, it is a complication of the immune response

Question 27

what is an infectious disease

Answer 27

a state of tissue destruction from the invasion of the microorganism, could be a problem with the host (e.g. seasonal or recovering from something else, or medication has reduced immunity), or the evading organisms could be strong

Question 28

What is a host

Answer 28

individual exposed to, or contracts the infection

Question 29

What is a resident flora

Answer 29

microorganisms that live on or within the body in a non-sterile area without causing harm, these areas include: skin, mucous membrane, bowel, rectum, vagina

Question 30

how can antibiotics affect the resident flora

Answer 30

strong antibiotics could disrupt resident flora and can cause harmful side effect, the resident flora can protect the body without the need for antibiotics

Question 31

What is a pathogen

Answer 31

a disease producing microorganism

Question 32

Phases of acute infection- 1

Answer 32

pathogen gets through skin and mucous membrane, triggering an inflammatory response, this should be enough to deal with pathogens in healthy individual and weak pathogens

Question 33

Phases of acute infection- 2

Answer 33

if immune defence is not enough or the pathogen is strong, assistants may be needed (antibiotics or fluid support), this should be enough to destroy pathogens

Question 34

Phases of acute infection- 3

Answer 34

if immune system or treatment is inadequate (wrong antibiotics), this can lead to serious situations and patients may require organ support (could be oxygen, or drugs to support various organisms), patient is at risk of dying

Question 35

examples of clinical manifestations of infection

Answer 35

inflammatory and immune response, pain, heat, swelling, weakness

Question 36

types of pathogens

Answer 36

bacteria, virus, fungi protozoa (moveable organism that can invade us), rickettsia (type of parasite that is intracellular), helminths- worms, mycoplasma (extracellular organisms that are very similar characteristics as virus and bacteria

Question 37

laboratory and diagnostic tests

Answer 37

WBC count- look for rise, serum antibody levels- look for specific antibody in a high number to see what is causing the problem (common in TB)
Cutlers- culture and grow pathogen on antibody agar jelly to diagnose infection and treatment
sensitivities