Introduction to the Immune System

Question 1

What is immunology?

Answer 1

The study of an organisms defence system(immune system) in health and disease

Question 2

What is the immune system composed of?

Answer 2

Organs, cells and molecules

Question 3

What is the immune system?

Answer 3

An organised system of organs, cells and molecules that interact together to defend the body against disease (pathogenic micro-organisms and cancer)

Question 4

what diseases are affected by the immune response?

Answer 4

Infectious diseases, inflammatory diseases and cancer

Question 5

What are examples of infectious diseases?

Answer 5

HIV/AIDS, tuberculosis, influenza, malaria, SARS-CoV-2

Question 6

What are examples of inflammatory diseases?

Answer 6

Arthritis/rheumatism, allergy/asthma, lupus, diabetes, chyrons’s disease/inflammatory bowel disease, multiple sclerosis

Question 7

what are microbes?

Answer 7

Viruses, bacteria, fungi and protozoa

Question 8

What are the small microbes?

Answer 8

Viruses and bacteria (prokaryotes)

Question 9

What are the larger microbes?

Answer 9

Fungi and protozoa (eukaryotes)

Question 10

what are some microbes?

Answer 10

Pathogens

Question 11

What are pathogens?

Answer 11

Disease causing microbes

Question 12

What are the organs of the lymphatic system?

Answer 12

Tonsils, thymus, spleen, bone marrow, lymph nodes

Question 13

What are the two types of lymphoid organs?

Answer 13

Primary and secondary

Question 14

What happens at primary lymphoid organs?

Answer 14

Production of white blood cells (lymphocytes)

Question 15

What happens at secondary lymphoid glands?

Answer 15

Sites where immune responses are initiated

Question 16

What are the primary lymphoid organs?

Answer 16

Bone marrow and thymus

Question 17

What is the bone marrow?

Answer 17

A rich source of stem cells (pluripotent) that develop into cells of the ‘innate’ and ‘adaptive’ immune responses

Question 18

What happens at the thymus?

Answer 18

Where white blood cells become T cells and learn not to react to themselves

Question 19

What are the secondary lymphoid organs?

Answer 19

Spleen and lymph nodes

Question 20

What is the spleen?

Answer 20

The site of initiation for immune responses against blood-borne pathogens (disease causing microbes)

Question 21

Where are lymph nodes located?

Answer 21

Along lymphatic vessels

Question 22

What happens at lymph nodes?

Answer 22

Lymph fluid from blood and tissue is filtered and it is the site of the initiation of immune response

Question 23

What are the 3 layers of defence?

Answer 23

Chemical and physical barriers, innate arm, adaptive arm

Question 24

What are the layers of the skin?

Answer 24

Epidermis and dermis

Question 25

What is the epidermis?

Answer 25

The outer layer of the skin composed of densely packed dead cells, keratin and phagocytic immune cells

Question 26

What constantly renews?

Answer 26

The outer layer of the dermis

Question 27

What is the dermis?

Answer 27

Thick layer of connective tissue, collagen and blood vessels and phagocytic immune cells beneath the epidermis

Question 28

What is also in the skin?

Answer 28

Dendritic cells (immune cells)

Question 29

What are the chemical defences of the skin?

Answer 29

Antimicrobial peptides (skin defensins), lysozyme, sebum and salt

Question 30

What do antimicrobial peptides (skin defensins) do?

Answer 30

Form pores in microbial cell membranes causing them to leak nutrients and die

Question 31

What does lysozyme do?

Answer 31

Breaks down bacterial cell walls

Question 32

What is sebum?

Answer 32

Produced by the sebaceous glands and has a low pH which microbes don't like the acidic environment

Question 33

What is salt?

Answer 33

Produced in sea by the sweat glands and causes the microbes to desiccate (dry out) and die

Question 34

What is the mucous membranes composed of?

Answer 34

Epithelium

Question 35

What is the epithelium?

Answer 35

Tightly packed live cells which are constantly renewed, mucus producing goblet cells

Question 36

How many layers in a mucous membrane?

Answer 36

1-2

Question 37

Where are mucous membranes found?

Answer 37

Lining parts of the body that lead to the outside and are exposed to air (ocular, respiratory, oral, urogenital/rectal)

Question 38

What happens in the mucociliary escalator?

Answer 38

Cilia move mucus which contains trapped microbes and dust particles up to the pharynx to be removed from the respiratory tract

Question 39

What are the chemical defences of mucosal surfaces?

Answer 39

Stomach-low pH, gall bladder- bile, intestine- digestive enzymes, mucus, defensins, lysozyme (tears, urine)

Question 40

What action do the chemical defences of mucosal surfaces have?

Answer 40

A flushing action to get rid of things

Question 41

How do skin and mucous membranes compare in the number of cell layers?

Answer 41

Skin=many and mucous membrane=1 to a few

Question 42

How do skin and mucous membranes compare in the packing of cells?

Answer 42

Both have tightly packed cells

Question 43

How do skin and mucous membranes compare in cells being dead or alive?

Answer 43

In skin outer cells are dead and inner cells are alive while in mucous membranes all are alive

Question 44

How do skin and mucous membranes compare in mucus being present?

Answer 44

Only present in mucous membranes

Question 45

How do skin and mucous membranes compare in lysozyme and defensins being present?

Answer 45

Present in skin but only in some cases the mucous membrane

Question 46

How do skin and mucous membranes compare in sebum being present?

Answer 46

Present in skin but not mucous membranes

Question 47

How do skin and mucous membranes compare in cilia being present?

Answer 47

Not present in skin but present in trachea and uterine tubes which are mucous membranes

Question 48

What is the two arms of the immune system?

Answer 48

Innate and adaptive defenses

Question 49

What is included in innate defences?

Answer 49

Surface barriers and internal defences

Question 50

What is included in surface barriers?

Answer 50

Skin and mucous membranes

Question 51

What is included in internal defences?

Answer 51

Phagocytes, natural killer cells, inflammation, antimicrobial proteins and fever

Question 52

What is included in adaptive defences?

Answer 52

Humoral and cellular immunity

Question 53

What is included in humeral immunity?

Answer 53

B cells

Question 54

What is included in cellular immunity?

Answer 54

T cells

Question 55

How is innate immunity described?

Answer 55

Already in place, rapid (hours), fixed (not much variation in cells), limited specificities (detects molecular components shared by many pathogens), has no specific memory

Question 56

How is adaptive immunity described?

Answer 56

Improves during the response, slow (days to weeks), variable, highly specific (detects molecular components specific to individual pathogens, has memory