lecture 30 - intro to immunology

Question 1

What are the overall components of the immune system that defend the body against disease?

Answer 1

Organs, cells, antibodies

Question 2

What is the name for a microbe that causes disease?

Answer 2

Pathogen

Question 3

What are primary lymphoid organs?

Answer 3

Organs that produce white blood cells/lymphocytes

Question 4

What are the two primary lymphoid organs?

Answer 4

Bone marrow, thymus

Question 5

What is the function of bone marrow?

Answer 5

Source of stem cells that develop into cells of the innate and adaptive immune responses.

Question 6

What is the function of the thymus?

Answer 6

Produces T cells (T lymphocytes) and ‘teach’ them what to react to and how. They learn not to react to self in order to prevent auto-immunity.

Question 7

What are secondary lymphoid organs?

Answer 7

Sites where immune responses are initiated

Question 8

What are the two secondary lymphoid organs?

Answer 8

Spleen, lymph nodes

Question 9

What is the function of the spleen?

Answer 9

Site of initiation of white blood cell immune responses to blood-borne pathogens. Filters blood to remove old cells.

Question 10

What are lymph nodes?

Answer 10

Nodes along lymphatic vessels where lymph fluid from blood and tissue is filtered. Site of initiation of immune responses.

Question 11

What are the two key layers of the skin?

Answer 11

Epidermis, dermis

Question 12

What is the structure of the epidermis?

Answer 12

Contains dead cells, keratin, and phagocytic cells. It is constantly being renewed.

Question 13

What is the dermis?

Answer 13

A thick layer of connective tissue, collagen, blood vessels and phagocytic immune cells.

Question 14

What are the chemical defences of the skin?

Answer 14

Antimicrobial peptides, lysozyme, sebum, salt

Question 15

What is the functions of antimicrobial peptides, e.g. defensins?

Answer 15

Form pores/holes in microbial cell membranes

Question 16

What is the function of lysozyme?

Answer 16

Sits in skin and breaks down bacterial cell walls.

Question 17

What is the function of sebum?

Answer 17

An oily secretion that gives the skin a low pH, making it hostile to bacteria.

Question 18

How does salt defend the skin from pathogens?

Answer 18

It makes the skin hypertonic, desiccating bacteria.

Question 19

How many layers of cells do mucous membranes have?

Answer 19

1-2 layers

Question 20

What is the structure of mucous membranes?

Answer 20

They have an epithelium: layer of tightly packed live cells and mucous producing goblet cells.

Question 21

Do mucous membranes produce sebum?

Answer 21

No

Question 22

What parts of the body do mucous membranes line?

Answer 22

Parts that lead to the outside and are exposed to air - ocular, respiratory, oral and urogenital/rectal

Question 23

What structure lines the respiratory tract and traps particles?

Answer 23

Musociliary escalator

Question 24

What is the function of the musociliary escalator?

Answer 24

Lines the respiratory tract and is responsible for trapping particles in mucus and propelling them up and out of the lungs via cilia.

Question 25

How do cilia move mucus up the pharynx in the musociliary escalator?

Answer 25

They beat in tandem.

Question 26

What two mucous membranes have cilia?

Answer 26

Respiratory tract and uterine tubes

Question 27

What are examples of chemical defences of mucosal membranes?

Answer 27

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

Question 28

What are the two systems of immune system defence?

Answer 28

Innate and adaptive immunity

Question 29

What are the characteristics of innate immunity?

Answer 29

Already in place, rapid, fixed, limited specificities, no specific memory

Question 30

What surface barriers are employed by the body’s innate immune defences?

Answer 30

Skin, mucous membranes

Question 31

What are the internal defences of the innate immune system (5)?

Answer 31

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

Question 32

What are the characteristics of the adaptive immune response?

Answer 32

Improves during the response, slow, highly specific, long term specific memory

Question 33

What make up the humoral immunity component of adaptive defences?

Answer 33

B cells

Question 34

What make up the cellular immunity component of adaptive defences?

Answer 34

T cells (B cells come under humeral category)

Question 35

What is the difference between humoral and cellular adaptive immunity?

Answer 35

Humoral immunity involves antibodies (produced by B cells) to combat extracellular pathogens/toxins, while cellular involves the attack of intracellular pathogens via T cell action and apoptosis.