Diseases - Immune System

Question 1

Defense system

What’s the top layer of skin composed of?

Answer 1

Dead cells containing the indigestible protein keratin

Question 2

Defense system

What is the purpose of sebum?

Answer 2

Sebum is produced by the skin to lower the pH, inhibiting the growth of pathogens

Question 3

Defense system

What is the purpose of extracellular lysozymes?

Answer 3

Lysozymes are anti-bacterial enzymes found in saliva, sweat, tears and breast milk

Question 4

Defense system

What is the primary defense against ingested bacteria?

Answer 4

Many ingested bacteria are destroyed in the stomach by acid (HCl)

Question 5

Defense system

What is the primary defense against pathogens inhaled?

Answer 5

A sticky substance in the respiratory tract, mucus, traps pathogens, before being wafted towards the throat by cilia

Question 6

Defense system

How are pathogens and foreign substances dealt with after the body’s “first line of defense”

Answer 6

Foreign materials and pathogens are targeted by the immune system

Question 7

Inflammatory response

What is the role of white blood cells in the process of inflammation?

Answer 7

White blood cells release histamine into the wound

Question 8

Inflammatory response

what are the effects of histamine?

Answer 8

histamine increases vasodilation and vascular permeability

Question 9

Inflammatory response

what are the effects of increased vasodilation?

Answer 9

vasodilation increases local blood flow causing the to the area become red and warm

Question 10

Inflammatory response

what are the effects of increased vascular permeability?

Answer 10

increased vascular permeability allows the release of tissue fluid into the affected tissues, this may cause local swelling

Question 11

Inflammatory response

what makes tissue fluid a good defense against pathogens?

Answer 11

tissue fluid contains plasma proteins (anti bodys)

Question 12

Phagocytosis

what allows the phagocytes to break down pathogens?

Answer 12

phagocytes contain digestive enzymes within lysosomes

Question 13

Phagocytosis

what is the primary purpose of neutrophils?

Answer 13

neutrophils primarily engulph bacteria

Question 14

Phagocytosis

what is the primary purpose of macrophages?

Answer 14

macrophages primarily engulf larger partials; including old, damaged or infected erythrocytes (red blood cells)

Question 15

Phagocytosis

where are phagocytes naturally found in the body?

Answer 15

phagocytes are found in the blood, lymph systems, and (in lower concentrations) in the tissues

Question 16

Phagocytosis

how do phagocytes enter the tissues from the blood?

Answer 16

phagocytes squeeze through the walls in the venules to reach enter the tissue

Question 17

Phagocytosis

why do phagocytes travel through the bloodstream?

Answer 17

phagocytes travel through the bloodstream because it allows them to move faster to tissues infected with pathogens

Question 18

Phagocytosis

how are phagocytes attracted to pathogens/infected tissues?

Answer 18

phagocytes are attracted by chemotaxis

Question 19

Phagocytosis

how does the opsonization of bacteria by antibodies improve the process of phagocytosis?

Answer 19

binding between the opsonized bacteria (bacteria coated in antigens) and the phagocyte is improved

Question 20

Phagocytosis

when a particle is first engulfed by a phagocyte, what two structures are formed around it?

Answer 20

the phagocyte forms a (1) phagocytic vesical (phagosome) within a protrusion of the cytoskeleton known as a (2) pseudopod around the particle

Question 21

Phagocytosis

once ingested, how does the phagocyte digest the pathogen?

Answer 21

lysosomes fuse with the phagosome, releasing digestive enzymes, digesting the pathogen into harmless, component nutrients (and sometimes pieces of the cell wall)

Question 22

Phagocytosis

if no extensive vasculature is present at the site of infection, what is formed?

Answer 22

puss, a mixture of immune cells (mostly dead) and digested pathogens/foreign particles, is formed.

Question 23

Antigens

what process is stimulated by antigens stimulate?

Answer 23

an immune response is stimulated by antigens

Question 24

Antigens

what are antigens made of?

Answer 24

usually proteins, although they can also be polysaccharides, nucleic acids or lipids

Question 25

Antigens

where are self antigens found?

Answer 25

self antigens are on the host’s own cells

Question 26

Antigens

what type of antigens typically trigger an immune response: self or non-self?

Answer 26

typically, non-self-antigens trigger an immune response while self-antigens don’t

Question 27

Antigens

the genes coding for antigens are highly polymorphic, as such, there are many of what at each loci

Answer 27

there are several alleles at each loci

Question 28

Antigens

there’s great what in genes coding for antigens between individuals of a species?

Answer 28

there’s great genetic variability in genes coding for antigens between individuals of a species