Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Unit 4 Biology > Immunology & Disease > Flashcards

Immunology & Disease Flashcards

(46 cards)

Start Studying
1
Q

KEY TERMS

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Pathogenic

A

An organism that causes damage to its host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Infectious

A

A disease that may be transmitted from one individual to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Carrier

A

Shows no symptoms when infected but can pass the disease onto another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Disease Reservoir

A

Where a pathogen is normally found

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Endemic

A

A disease, which is always present at low levels in an area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Epidemic

A

Where there is a significant increase in the usual number of cases of a disease, often associated with a rapid spread

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Pandemic

A

A global epidemic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Vaccine

A

Uses non pathogenic forms to stimulate an immune response, which confers protection against subsequent infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Antibiotic

A

Substances produced by microorganisms that affect the growth of other microorganisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Antibiotic Resistance

A

Where a microorganism, which should be affected by an antibiotic, is no longer susceptible to it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Antigen

A

A molecule that causes an immune response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Antibody

A

A protein produced by the immune system to recognise and destroy antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Vector

A

A living organism which transfers a disease from one individual to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Toxin

A

A chemical produced by a microorganism which causes damage to its host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Antigenic Type

A

Organisms with the same or very similar antigens on the surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

DISEASES

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Cholera
(endemic)

A

Causative Agent:
-gram negative bacteria

Tissue Affected:
-toxins affect the gut lining causing watery diarrhoea leading to dehydration and death

Mode of Transmission:
-water borne

Control Method&Treatment:
-treatment of water, rehydration therapy, antibiotics, vaccine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Tuberculosis

Study These Flashcards
A

Causative Agent:
-bacteria

Tissue Affected:
-lungs, neck, lymph nodes
-causes coughing, chest pain, coughing up blood

Mode of Transmission:
-airborne droplets through coughs and sneezes

Control Method&Treatment:
-antibiotics, BCG vaccination

20
Q

Smallpox

Study These Flashcards
A

Causative Agent:
-the variola major virus

Tissue Affected:
-mouth, throat, lymph nodes, blood stream
-characterised by fluid filled blisters on the skin

Mode of Transmission:
-contact, person to person or from contaminated objects

Control Method&Treatment
-low antigenic variation of the virus led to a highly effective vaccine

21
Q

Influenza

Study These Flashcards
A

Causative Agent:
-virus, 3 sub groups with many antigenic types

Tissue Affected:
-lining of the upper respiratory tract
-leading to sore throat, coughing and fever

Mode of Transmission:
-airborne droplet infection

Control Method&Treatment
-quarantine, hygiene, annual vaccination(not always effective)

22
Q

Malaria
(endemic)

Study These Flashcards
A

Causative Agent:
-protoctistan parasite

Tissue Affected:
-liver and red blood cells, red blood cells full of virus burst infecting more cells
-corresponds with bouts of fever

Mode of Transmission:
-vector, passed to humans by the female mosquito when taking a blood meal

Control Method&Treatment
-stop the vector with nets, clothing, insect repellant, insecticides
-kill the parasite

23
Q

Bacterial Diseases

Study These Flashcards
A

Can be caused by gram positive or gram negative bacteria

Gram negative have a thin peptidoglycan cell wall with a layer of lipopolysaccharide. They stain red using gram staining technique. The additional layer of lipopolysaccharide protects the bacterial cells from lysozyme and from penicillin type antibiotics.

Gram positive have a thick peptidoglycan cell wall and no lipopolysaccharide layer. They stain purple using gram staining technique. They are susceptible to lysozyme and penicillin.

24
Q

Viral Diseases

Study These Flashcards
A

Cannot reproduce on its own. Is an intracellular parasite and needs a host cell metabolism, to produce more virus particles. This causes pathogenic effects by:

  1. Viral DNA/RNA instructs the cell to make virus particles, when full cell lysis occurs, and the virus escapes the cells to infects other cells
  2. Production of toxic substances
  3. Viral cell transformation, where they can trigger cells to become cancerous
  4. Viruses infecting white blood cells suppress the immune system
25
BODY DEFENCES
26
Skin
-A tough barrier -Strong connective tissue maintained by vitamin C that prevents microbes entering the body -Skin flora competes with pathogenic bacteria to avoid infection
27
Lysozyme
-An enzyme in tears, saliva and stomach acid that kills bacteria
28
Ciliated Mucous Membranes
-Mucus traps microbes in inhaled air -Passes up cilia waft mucus containing trapped microbes up the trachea for swallowing and destruction in the stomach
29
Blood Clotting
-Seals wounds in skin quickly to prevent infection
30
Inflammation
-Raised temperature is unfavourable to microbes and increase in blood flow delivers phagocytes to the area
31
Blood
-White blood cells called phagocytes kill invading microbes in a process called phagocytosis: 1. phagocyte detects the foreign microbe 2. phagocyte engulfs microbe 3. phagocyte digests microbe
32
ANTIBIOTICS
33
Bacteriostatic & Bactericidal
These drugs don't affect the host cells but disrupt bacterial metabolism. Bacteriostatic - prevents the growth of bacteria Bactericidal - kills bacteria
34
Penicillin
-Peptidoglycan bacterial cell walls are strengthened by polysaccharide cross-linked by amino acids, this stops osmotic lysis -Penicillin affects the formation of the cross links by inhibiting the enzyme that makes them, the wall is weakened and osmotic changes can cause cells to burst -Gram negative bacteria have an outer lipopolysaccharide layer that protects the cells from penicillin
35
Tetracycline
-Tetracycline acts as an inhibitor of the second anticodon biding site on the 30S subunit of bacterial ribosomes, it prevents the binding of a tRNA molecule to its complementary codon -This prevents protein synthesis common to all bacteria -Tetracycline is a broader spectrum antibiotic -As viruses have no metabolic pathways, they are unaffected by antibiotics
36
Antibiotic Resistance
Overuse of antibiotics has led to the development of antibiotic resistance 1. Bacteria divide rapidly and have a high mutation rate. Bacteria can also obtain plasmids that carry antibiotic resistance genes from other resistant bacteria by conjugation 2. Some mutations confer resistance to antibiotics, overuse of these antibiotics gives the resistant strain a selective advantage 3. Numbers of the resistant strain increase, making infections more difficult to treat with the usual antibiotics
37
ANTIBODIES
38
Antibodies
These are produced by white blood cells called lymphocytes Antibodies are proteins, they are Y shaped and formed from four polypeptide chains with two binding sites They are specific to the antigen and they bind to form an antigen-antibody complex, this renders the antigen inactive by: 1. agglutination 2. marking for phagocytosis
39
IMMUNE RESPONSES
40
Humoral Immune Response
1. Stem cells in the bone marrow make B lymphocytes that mature in the spleen and lymph nodes and have receptors for the detection of specific antigens on the surface of foreign cells 2. When the B lymphocytes are activated by a corresponding antigen, they divide rapidly forming antibody secreting plasma cells. This clonal expansion is increased by the cytokines from the cell mediated response 3. B lymphocytes also make memory cells that remain in the bloodstream and divide rapidly if the antigen is encountered again
41
Cell Mediated Immune Response
1. Stem cells in the bone marrow make T lymphocytes, which are activated in the thymus gland 2. Detecting a foreign antigen causes proliferation of T lymphocytes as: - T killer cells (causes lysis of target cells) - T memory cells (remain in bloodstream) - T helper cells (release cytokines) -Cytokines stimulate the clonal expansion of B cells and to produce antibodies -Cytokines activate phagocytes to engulf and digest the foreign cells
42
Primary Response
1. On first exposure to the antigen, there is a latent period when antigen presenting cells carry out phagocytosis and incorporate foreign antigen into their cell membranes 2. T helper cells detect these antigens and secrete cytokines that stimulate B cells to undergo clonal expansion and stimulate macrophages to carry out phagocytosis 3. Some B cells then differentiate to become antibody-secreting plasma cells with short lives, others become long-lived memory cells that retain the ability to undergo mitosis in case of secondary infection -Low level of antibody is secreted, which clears the infection and symptoms over a period of 2-3 weeks
43
Secondary Response
Following re-exposure to the same antigen, there is a very short latent period due to the presence of memory cells Only a very small amount of antigen is required to stimulate rapid production of plasma cells -Antibody levels increase to between 10 and 100 times greater than the initial response in a very short time frame -Antibody levels stay high for longer and no symptoms develop
44
Active Immunity
Individual produces antibodies Protection is long lasting due to production of antigen specific memory cells Natural - following an infection Artificial - following vaccination
45
Passive Immunity
Individual receives antibodies from someone else Protection is short lived as no memory cells are produced and the antibodies themselves identified as foreign and destroyed Natural - antibodies are transferred to the foetus via the placenta, or to the baby in breast milk Artificial - pre synthesised antibodies are injected into an individual
46
Vaccinations
- A vaccination stimulates artificial active immunity in an individual - A vaccine must contain an immunogenic antigen that stimulates a strong immune response - Vaccinations for pathogens that exhibit low levels of antigenic variation can protect an organism after one immunisation - Some pathogens have many antigenic types and mutate frequently, these require seasonally repeated immunisations Immunisation programmes require consideration of the following: -cost vs effectiveness of the vaccine -protection of the individual compared to protection of the community -the rights of the individual when considering mandatory or voluntary programmes -side effects

Unit 4 Biology (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions