Immunology Flashcards
1
Q
The ability of the body to resist damage from microbes (foreign substances) and internal threats, e.g., cancer.
- It is all over the body but acts as one team.
A
Immunity
2
Q
The immune system consists of 2 mechanisms.
A
a. innate mechanisms (Non specific)
b. adaptive response (Specific)
3
Q
Mechanisms that confer a nonspecific defence against pathogens. Respond immediately to any threat. Composed of epithelial cells, mucous membrane, etc. It protects against agents.
A
Innate mechanisms (Non specific)
4
Q
Reponse that provides defence against specific molecular agents and antigens (pathogens).
A
Adaptive response (Specific)
5
Q
The immune system includes all _____ & _____ that defend the body against pathogens.
A
structures and processes
6
Q
_____ include infectious organisms, toxic chemicals, radiation and other agents that damage tissue
A
Pathogens
7
Q
Humans have _____ lines of immune defence against pathogens:
A
Three
8
Q
Line of defence that includes skin and mucous membrane; these are impenetrable to most pathogens.
A
First line of defence (Mechanical)
9
Q
Line of defence that include leucocytes and macrophages, antimicrobial proteins, immune surveillance, inflammation and fever. All of these defences are present at birth and are highly effective against a wide range of pathogens
A
Second line of defence (Cellular)
10
Q
Line of defence that include adaptive (specific) immune defence – which arises from prior exposure to a pathogen, and provide future protection to the body via memory cells.
A
3rd line of defence. (Chemical)
11
Q
Dry and porous. It doesn`t allow bacteria to grow.
A
Skin
12
Q
Bacteria that can cross the stomach because it is more acidic than the stomach.
A
H. Pylori
13
Q
Decreased acid in the stomach causes ____ in bacteria that may cause them to go up to the lungs and cause pneumonia.
A
Increase
14
Q
Mucous, tears and saliva contains ____ that kills bacteria.
A
Lysosyme
15
Q
WBC leaves blood vessels
A
Diapedesis
16
Q
Immune system structures include those of the (4)
A
lymphatic system, skin, mucous membrane, and specialised proteins.
17
Q
Components of Innate Immunity
A
- Epithelial and mucous membrane
- Acid, cell secretion and enzymes
- Phagocytic cells
- Complement protein
- Inflammation
- Fever
18
Q
Function of Innate Immunity: (3)
Non-specific Resistance
A
i) Responds immediately
ii) Protects against all foreign substances
iii) Protects against agents which may have enter the body
19
Q
- They are the first line of defence against pathogens
- Block any pathogen or chemical entry into the body.
A
Physical Barrier = Epithelial and Mucous membranes
20
Q
____ is too dry and poor in nutrition to support microbial growth, except for the axillary and pubic areas.
A
Skin
21
Q
The skin surface is composed mainly of _____, a tough protein that only few pathogens can penetrate.
A
keratin
22
Q
Digestive, reproductive, respiratory and urinary tract get protection from(3).
A
mucous membrane, mucus and cilia
23
Q
Microbes trapped in respiratory mucus and cilia are removed by ____ to the pharynx and are often swallowed.
A
cilia
24
Q
Areolar tissue beneath epithelial tissue of the skin and mucous membrane contain ______ (a kind of stick gel), which blocks microbes from migrating across it.
A
hyaluronic acid
25
Only microbes that secrete ______, which breaks down this gel (hyaluronic acid) can penetrate this layer easily and cross into the body. (Snake venoms, bacteria toxins and some protozoan contain hyaluronidase, and so these substances can cross this layer.)
hyaluronidase
26
____ kills ingested microbes
Stomach
27
____ on the skin block bacteria growth
Sebum
28
Skin is coated with antimicrobial chemicals such as _____ - a peptide that kills
micro-organisms by creating holes in their membrane.
defensins
29
Skin is also coated with a thin film of ____ from sweat that inhibit bacteria growth
lactic acid
30
Mucus, tear and saliva have enzymes (lysozyme) that destroy bacteria by dissolving their _____.
cell walls
31
Those pathogens that get pass the physical and chemical barriers are often attacked by ______ and _____.
leucocytes and macrophages.
32
Five types of leucocytes contribute to resistance and immunity
i. Neutrophils.
ii. Eosinophils
iii. Lymphocytes
iv. Monocytes are leucocytes
33
WBC that wander in connective tissues and kill bacteria by phagocytosis. They also release potent chemicals that surround the pathogens and the neutrophils, and the chemicals digestives both the pathogens and the neutrophils.
Neutrophils
34
WBC found in mucous membrane- act against allergens (antigens that cause allergies) and produce superoxide, hydrogen peroxide, and toxic proteins to destroy worms
Eosinophils
35
Cells have the ability to kill pathogens and tumour cells. These cells do not have selective action as neutrophils. Eliminate a variety of infected or cancerous cells that lack self-surface markers. Are NOT phagocytes; they induce cells to undergo programmed cell death (apoptosis). Secrete potent chemicals the aid the inflammation process
Leucocytes - NK cells. (Natural Killer)
36
Leucocytes that have migrated from the blood into connective tissue and transform themselves into macrophages. They are phagocytes. They are widely distributed in connective tissue and have specialized forms and names (.e.g., microglia in neural tissue and hepatic macrophage in the liver)
Monocytes
37
Programmed cell death.
Apoptosis
38
Chemical released by cells (5)
i. Histamine
ii. Prostaglandins
iii. Pyrogens
iv. Kinins
v. Interferon
39
Chemical released by Basophils, Mast cells and Platelets that causes vasodilation, vascular permeability, mucus secretion, smooth muscle contraction e.g., bronchoconstriction
Histamine
40
A group of lipids from cells that cause smooth muscle relaxation, increased permeability and attract neutrophils and eosinophils.
Prostaglandins
41
Chemicals released by neutrophils and monocytes that stimulate fever production.
- cause body to increase hypothalamus setting (resets body temperature)
Pyrogens
42
Proteins in the plasma that stimulate pain receptors and attract macrophages.
Kinins
43
Protein secreted by when certain cells of the body (including leucocytes) when they are infected with viruses.
Interferon
44
Interferon’s function.
To alert neighbouring cells and help to prevent them from becoming infected.
45
Interferon works by binding to surface receptors on a cell and activating a _______ in a cell which then cause proteins to be made that defend the cell against the virus by breaking down viral genes and thereby preventing viral replication.
second messenger
46
Interferon also activates ____ & ____ which destroy infected cells before they released newly made viruses.
NK cells and macrophages
47
Interferon makes cells resistance to ____ and destroys ______ cells.
cancer
48
A series of about 30 powerful globulins produced by the liver and circulating in the blood plasma in an inactive form. They are activated by the presence of pathogens.
Complement
49
Function of Complement (4)
Complement activation leads to:
i. attraction of phagocytes
ii. stimulation of phagocytosis
iii. destruction of plasma membrane
iv. promotion of inflammation
50
These proteins (complement) are so called because they “______________” in destroying pathogens.
“complete the action of antibody”
51
In the inactive form, the proteins are labelled C1, C2, C3, etc.; when activated they are labelled as ____ or____ etc.
C3a or C3b
52
These proteins (complement) are active in (4)
inflammation, immune clearance, phagocytosis and cell lysing.
53
As an agent of inflammation, ______ promote phagocytosis and cell lysing of pathogens; they activate and attract neutrophils and macrophages to the site; and they stimulate basophils and mast cells to secrete inflammatory chemicals.
complements
54
When a pathogen is present in the blood:
i. Antibody-antigen complex form on the pathogen surface and this leads to activation of complement.
ii. When C3 is activated it dissociates into C3a and C3b
iii. C3a binds to neutrophils and mast cell, which (cells) release histamine and other inflammatory chemical that will cause inflammation.C3a also activates neutrophils and macrophage activity.
iv. On the other hand, some C3b binds antigen-antibody complex to red blood cells. As the red blood cells travel through the spleen, the spleen removes the antigen-antibody complex and leaves the red blood cells unharmed.
v. Some other C3b coat bacteria, viruses and other pathogen making them attractive for digestion by macrophages. The process of coating of pathogen for phagocytosis is called opsonisation.
vi. And still other C3b split other complement proteins. The split complement (proteins) then form a ring complex around the pathogen and destroy it.
55
The process of coating of pathogen for phagocytosis.
Opsonization.
56
Shivering causes ...
It cause the body to increase body heat to take up hypothalamus temperature.
57
Sweating causes ..
Removal of excess heat.
58
Acid that converts to prostaglandin.
Archodonic Acid
59
Heparin is release by ____
Basophils
60
Vasodilation causes _____ (superficial)
Redness
61
Vascular permeability causes ____ (superficial)
Swelling
62
What is immune surveillance?
- NK cells roam the body looking for pathogens and diseases cells in the body.
- NK cells attack and destroy bacteria, transplanted cells from donated tissue or organ, cancer cells, and cells infected by virus.
- Once NK cells recognize a foreign or infected cell they bind to it and release proteins called perforins which create holes in the cell membrane.
- NK cells also release a chemical that enter the cell through the holes. This chemical, once inside the cell, affects the cell’s enzyme, blocking the action of the cell’s enzyme, thus causing cell death.
63
_____ cells roam the body looking for pathogens and diseases cells in the body.
NK cells
64
____ cells attack and destroy bacteria, transplanted cells from donated tissue or organ, cancer cells, and cells infected by virus.
NK cells
65
- Once NK cells recognize a foreign or infected cell they bind to it and release proteins called ____ which create holes in the cell membrane.
perforins
66
NK cells release a ____ that enter the cell through the holes. This chemical, once inside the cell, affects the cell’s enzyme, blocking the action of the cell’s enzyme, thus causing cell death.
chemical
67
A local response to tissue damage. It is designed to prevent unlimited tissue damage.
It can occur anywhere in the body but it is most often seen at the skin.
Inflammation
68
Triggered whenever body tissue is injured.
Inflammatory response
69
Benefits of inflammation include: (3)
i. walls of affected area and contain the spread of damage
ii. Deposit of dead cells and pathogens
iii. Mop-up area and prepare it for repair
70
Cardinal signs of short-term acute inflammation are (5)
i. redness
ii. heat
iii. swelling
iv. pain
v. loss of function
71
Chemicals called _____ are involved in both immune response and inflammation.
- they small proteins that are secreted by certain cells.
- they alter the actions of the cells receiving them - they act only a short distance on neighbouring cells.
- include interferon, interleukins, and others.
Cytokines
72
When tissue is damaged, increased blood flow beyond the usual or ______ occurs in to the damaged area.
Hyperemia
73
The increased blood flow brings significantly number of _____ into the area.
leucocytes
74
The leucocytes release substances such as _______ (4)
histamine, bradykinin and other kinins, and leukotrienes.
75
Cytokines such as histamine, kinins and leukotriene released by basophils and mast cells, chemical released by damage connective tissue and cells damage by toxins or trauma start the ________.
inflammatory process
76
The endothelial cells in affect area release _____ which makes the area sticky and trap leukocytes.
selectins
77
The adhesion of leukocytes to the wall of the vessels.
margination
78
Some trapped leukocytes leave the blood vessel by a process called _____ and enter the tissue fluid around cells of the damaged tissue.
emigration
79
_____ causes removal of toxics and pathogens or waste in the area.
Hyperemia
80
Cytokines causes capillaries in the area to become more _____, thereby allowing fluid, leukocytes and plasma protein from the blood to invade the area. Proteins leaving the blood include complement, antibodies and clotting proteins, all work to fighting pathogens.
Permeable
81
Heat in inflammation results from _____.
hyperemia
82
Redness in inflammatiom results from ______ or ______.
hyperemia and RBC in the area or from burns to the area
83
Swelling in inflammation results from ______.
increased fluid from the capillaries
84
Pain in inflammation results from (4)
1. direct injury to nerves
2. pressure on nerves from the swelling (oedema), 3. stimulation of pain receptors by prostaglandins, and bradykinin,
4. and in some cases toxins from the pathogen
85
_______ produced by the inflammatory process prevents the pathogen spreading to other areas.
Containment
86
_____ that enters in the fluid clot in areas near the injury and trap pathogens.
Fibrinogen
87
Inside the injury itself, ____ prevents clotting so pathogen is trapped in a liquid environment.
heparin
88
____ and _____ (particularly, neutrophils) attack the pathogen trapped in the liquid environment.
Antibodies and phagocytes
89
Neutrophils emigrate into damage area by following the trace of bradykinin and leukotrienes (a process called _____)
chemotaxis
90
Neutrophil process (5)
Inflammation chemical release → margination → emigration → chemotaxis→ phagocytosis
91
_____ recruit macrophages and other neutrophils to the area
Neutrophil
92
Activated macrophages and T cells secrete _______ that cause the bone marrow stem cell (Haematoblast) to produce more WBC. In allergy or parasitic infection eosinophils are produced.
colony-stimulating factors
93
Process of Tissue Repair (8)
1. Monocytes that emigrated from the blood stream are the major cells that engulf and destroy bacteria and debris.
2. Oedema causes compression of veins and reducing venous drainage but opens capillaries in the lymphatic system, which now collect and remove fluid and debris faster than the veins.
3. Dead neutrophils, macrophages, dead tissue cells and debris, and tissue fluid form yellowish fluid call pus. Pus build up in the tissue is called abscess
4. Blood platelets and endothelial cells release platelet growth factor the cause increased production of fibroblasts to repair the damage tissue
5. Hyperemia cause increase O2 and protein to speed mitosis and tissue repair.
6. Fibrin clots help to provide supporting structures for tissue reconstruction.
7. Platelets in the area release growth factor that stimulate fibroblasts to multiply and make new collagen
8. Pain receptors in the area, alert the body of injury, thus ensuring the re-building process is not damaged.
94
____ that emigrated from the blood stream are the major cells that engulf and destroy bacteria and debris.
Monocytes
95
____ causes compression of veins and reducing venous drainage but opens capillaries in the lymphatic system, which now collect and remove fluid and debris faster than the veins.
Oedema
96
Dead neutrophils, macrophages, dead tissue cells and debris, and tissue fluid form yellowish fluid call _____.
pus
97
Blood platelets and endothelial cells release _____ the cause increased production of fibroblasts to repair the damage tissue
platelet growth factor
98
_____ cause increase O2 and protein to speed mitosis and tissue repair.
Hyperemia
99
____ clots help to provide supporting structures for tissue reconstruction.
Fibrin
100
Platelets in the area release growth factor that stimulate _____ to multiply and make new collagen
fibroblasts
101
_____ in the area, alert the body of injury, thus ensuring the re-building process is not damaged.
Pain receptors
102
Pus build up in the tissue is called ____.
abscess
103
An abnormal elevation of body temperature
| It results from trauma, infections, drug toxicity/reaction, brain tumours and other causes.
FEVER (Pyrexia)
104
Benefits of Fever
1. promotes the release of interferon (ensure tissure repair takes place)
2. elevate metabolic rates and accelerate tissue repair
3. inhibit reproduction of bacteria and viruses (by taking stuff that microbes need such as zinc, folic acid, etc.) cells takes up more.
105
Fever is caused by___ released in the area that stimulates neurons in the anterior hypothalamus to raise the set point of body temperature to levels higher than 380C.
Pyrogen
106
When neutrophils and macrophages eat-up pathogens, they secrete a substance called pyrogen that stimulates the anterior pituitary to secrete ___________ .
prostaglandin E (PGE)
107
It raises the hypothalamus set point for body temperature from around 370 C to 390 C or more.
PGE
108
Elevation of the set point causes the person to _____ to produce heat, and cutaneous blood vessels ______ to prevent heat loss.
shiver; constrict
109
Elevated temperature prompt the ____ and _____ to hoard Zn and Fe, so that microbes are deprives of the minerals they need for reproduction.
liver and spleen
110
Hence, at the onset of fever the person is _____ and _____.
cold and clammy to touch.
111
When the pathogen is defected and infection subside, pyrogen secretion _____ and the hypothalamus is set _______. The heat-loss mechanism is activated, cutaneous vasodilation occurs followed by sweating; the skin is warm and flush.
ceases; back to normal
112
High temperature can be dangerous to the body, why.. (2)
speeding up different enzyme pathways and adversely affecting function.
