The Immune System

Question 1

Non specific defences:

Answer 1

Skin
Nose hair
Cilia
Secretions (vaginal, saliva)
Gastric acid

Question 2

Is phagocytosis specific or non specific?

Answer 2

Non specific

Question 3

What is phagocytosis?

Answer 3

What a phagocyte engulfs and destroys a pathogen due to its foreign antibody
Alerts the immune system of a pathogen invasion

Question 4

Signs of an inflammatory response

Answer 4

Temperature
Redness
Heat
Swelling
Pain

Question 5

What happens during an inflammatory response?

Answer 5

1) increased blood flow- capillaries dilate so more blood flows to the area (redness)

2)accumulation of tissue fluid-fluid leaves the blood (swelling) so blood is thicker and moves slower

3)leukocytes- blood is thicker so WBC can stick to the vessel wall as, good for phagocytosis

Question 6

Natural killer cells

Answer 6

Non selective lymphocyte
Search the body for abnormal cells

Question 7

What does specific immunity contain?

Answer 7

T and B lymphocytes

Attracted to one specific antigen

Memory cells produced

Question 8

Where are T and B lymphocytes produced?

Answer 8

Bone marrow

Question 9

Where to T cells migrate to for maturation?

Answer 9

Thymus gland
Become mature under thymosin
Activated when encountering infective connective tissue

Question 10

Where do B cells mature?

Answer 10

Bone marrow

Question 11

How do T cells become activated?

Answer 11

By an APC (antigen presenting cell)
Body cell that has a pathogens antigen attached to it

Question 12

Cytotoxic T cells

Answer 12

Destroys abnormal cells by releasing toxins

Question 13

Helper T cells

Answer 13

Stimulates B cells to produce antibodies

Question 14

Regulatory T cells

Answer 14

Turns off activated T and B cells
Stops the immune response from damaging own cells

Question 15

Memory T cells

Answer 15

Responds rapidly when in contact with same antigen

Question 16

Types of B cells

Answer 16

Memory (secondary response)
Plasma (produces antibodies)

Question 17

What’s are antibodies also known as?

Answer 17

Immunoglobulins

Question 18

Function of antibodies

Answer 18

Binds to antigens

Question 19

Structure of antibodies

Answer 19

2 longer amino acids chains
2 polypeptide chains
Held together by disulphide bridges
Y shaped

Question 20

Primary response

Answer 20

Immune systems first encounter
Symptoms occur as body tries to make antibodies against the antigen
Memory cells made

Question 21

Secondary response

Answer 21

Immune system encounters the same antigen
Memory cells produces antibodies on a faster, larger rate
Symptoms less likely to occur

Question 22

Active immunity

Answer 22

Immune system has responded to antigen and made its own antibodies

Question 23

Passive immunity

Answer 23

Antibodies have been given
Antibodies break down therefore immunity is brief

Question 24

Artificial immunity

Answer 24

Weakened pathogen/toxins injected so immune system produces antibodies

Question 25

What does the lymphatic system do?

Answer 25

Maintains fluid balance by returning tissue fluid into venous blood system

Question 26

What happens in the nodes?

Answer 26

Organic matter is filtered and cleared of foreign debris and material before being returned

Question 27

Where do activated T and B cells multiply?

Answer 27

Lymph nodes

Question 28

Where are the lymphoid tissues?

Answer 28

Tonsils Thymus Spleen

Question 29

Why does the fetus risk being rejected by the maternal immune system?

Answer 29

Paternal antigens are expressed of fetal cells Maternal immune system recognises these antigens as non-self

Question 30

What hormones stop the maternal immune system from rejecting the fetus?

Answer 30

Progesterone hCG Corticosteroids

Question 31

What does the Decidua contain, stopping immune rejection?

Answer 31

Macrophages- clears debris Regulatory T cells- limit response from other T cells, inhibiting immune response Natural killer cells- destroys trophoblastic cells

Question 32

What hormone suppresses the immune system?

Answer 32

Progesterone

Question 33

What hormone causes the number white blood cells to rise?

Answer 33

Rising levels of Oestrogen

Question 34

Why does white blood cell number rises around the time of Labour?

Answer 34

Infection risk during Labour and post-birth Prevention of infection

Question 35

What do T helper cells do and why does the number decline during pregnancy?

Answer 35

Stimulates immune system to make antibodies Suppresses the immune system to inhibit the risk of fetal rejection

Question 36

Common infections in the mother:

Answer 36

-group B strep -Candida albicans (thrush) -strep A

Question 37

Common infections in the neonate:

Answer 37

-group B strep -meningitis -sepsis -candid albicans

Question 38

What happens if mum tests negative to RhD?

Answer 38

Prophylactic anti-D at 28 weeks

Question 39

What does anti-D do?

Answer 39

Destroys baby’s blood that may have mixed with maternal blood, stopping an immune reaction

Question 40

When is anti-D given?

Answer 40

-28 weeks -within 72 hours of sensitising event ( vaginal bleeding, trauma to abdomen -within 72 hours postnatal

Question 41

What is the purpose of the kleihauer blood film?

Answer 41

- estimate volume of mixing of fetal and maternal blood -maternal blood tested for fetal RBC -advice given on amount of anti-D required

Question 42

What is the purpose of Coombs test:

Answer 42

-measures volume of antibodies present Tests either maternal blood or blood from cord for antibodies

Question 43

Purpose of blood grouping:

Answer 43

Tests for ABO and rhesus status

Question 44

What happens if mum is rhD- but baby is rhD+?

Answer 44

Anti D required

Question 45

Why is anti-D important?

Answer 45

-if mum makes anti D antibodies, they can travel through the placenta and destroy fetal RBC -Causes fetal anaemia, cardiac failure, pathological jaundice