Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

bio > mod 4.1 snaprevise > Flashcards

mod 4.1 snaprevise Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

when does disease occur

A

when pathogens enter the body and cause damage

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

what are primary defences

A

non specific defences that prevent pathogens entering the body (its always the same response)

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

examples of primary defences

A

skin, mucus and membranes, expulsive reflexes

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

state stuff about the primary defence: skin

A

made up of cells called keratinocytes
keratinisation- cells die by the time they reach the surface- they act as barriers.
a large number of harmless microbes called skin flora also live on the skin- prevents pathogenic microbes from colonising on the skin by competing with them for nutrients

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

state stuff about the primary defence: blood clotting and wound repair

A
  • when the skin is damaged, the blood is open for pathogens to enter.
  • this is prevented by a blood clot forming in the wound
  • when this blood clot dries, it forms a temporary seal called a scab which allows for skin to repair.
  • to cause blood clotting, platelets and damaged tissues release clotting factors which activate an enzyme cascade
  • to repair skin under the scab, fibrous collagen is deposited and new cells form stem cells in the epidermis
  • these new cells are supplied with oxygen and nutrients by the growth of new blood vessels.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

state stuff about the primary defence: mucous and membranes

A

exchange surfaces occur where o2 and nutrients enter the blood are thinner and more exposed to pathogens. e.g lungs and digestive systems

  • to protect these surfaces in the airway there are goblet cells which secrete mucus.
  • the mucus forms thick mucous membranes which line the passages and trap any pathogens
  • the epithelium also contains ciliated cells which have tiny hair like structures called cilia.
  • the cilia waft in a coordinated fashion to move mucus with the pathogen trapped in it at the top of the trachea .
  • the mucus is then swallowed and enters the stomach where the pathogen is killed by the low PH of stomach acid.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

state stuff about the primary defence: expulsive refluxes

A

-some pathogens can release toxins
-areas that are at risk of infection are very sensitive to pathogens and their toxins.
-when these sensitive areas are irritated, they respond with an expulsive reflex.
- examples: coughing, vomiting, sneezing
it causes air or fluid to be suddenly forced out of the body which carries the pathogen out with it.

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

what are the non-specific chemical defences

A

saliva and tears

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

what do tears and salvia contain and what does it do

A

their secretions contain an enzyme called lysozyme.

lysozyme kills bacteria by breaking down the cell wall- prevents it from causing disease

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

state stuff about the innate (non-specific) immune response: inflammation

A

inflammation is the swelling and redness of a tissue caused by infection.
- inflammation helps destroy invading pathogens.
- first the pathogen is detected in the tissue by mast cells, this causes mast cells to release the cell signalling chemical called histamine
-histamine causes vasodilation which makes the capillary wall in the tissue more permeable to white blood cells
-this allows more white blood cells to get to the site of infection.
vasodilation causes more tissue fluid to be produces and this causes swelling known as oedema, this excess tissue fluid is then drained into the lymphatic system where other immune cells are stored.
these immune cells then attack the pathogens present in the tissue fluid

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

what are interferons

A

non- specific defence against viruses, protozoa and some bacteria. infected cells produce interferon which diffuses to surrounding cells where it prevents microbes from multiplying.
inhibits microbial protein synthesis.

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

whats phagocytosis

A

when cells engulf and digest pathogens to stop them causing damage

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

what are the most common examples of phagocytes

A

macrophages and neutrophils

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

how are macrophages and monocytes related

A

a monocyte is a macrophage which hasn’t become a macrophage yet

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

where are monocytes and neutrophils made

A

in the bone marrow

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

monocytes are present in the blood, when do they become macrophages

A

when they enter the tissue

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

what do neutrophils do when a pathogen infects a tissue

A

they arrive and engulf them

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

state how long macrophages and neutrophils live for and their relationship

A

neutrophils dies quickly after a few days
monocytes are long lived
- when neutrophils die, the macrophages then arrive at the infected tissue

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

state the mechanisms of phagocytosis

A
  • phagocyte recognises a foreign marker on the pathogens outer membrane called the antigen.
  • small non specific protein molecules attach to the antigen
  • the phagocyte can then bind to the opsonin attached to the pathogen antigen
  • the pathogen is then engulfed and enclosed in a large vacuole called a phagosome.
  • the phagosome fuses with lysosomes which are vesicles containing digestive enzymes called lysozomes
  • lysozomes are released and they break down the pathogens structure
  • ONLY MACROPHAGES- they save the pathogen antigen
  • they are antigen presenting cells, put the pathogen antigen on a special protein complex- moved to the surface membrane so can be recognised
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

specialisations of a phagocyte

A
  • well developed cytoskeleton to help them change shape to engulf the pathogen and move lysosomes around
  • many mitochondria to release energy for cell movement
  • lots of ribosomes to synthesise the lysosome enzymes
  • lobed nucleus to squeeze between narrow gaps between cells in the tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

opsonin’s are involved in the ____ ____ ____

A

innate immune response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

whats a neutrophil and what does it have

A
  • a white blood cell- has a pm containing receptors for opsonin’s
  • well developed cytoskeleton for phagocytosis
  • many mitochondria for respiration
  • many ribosomes to make enzymes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are opsonins

A

non- specific antibodies, they bind to antigens (they’re markers )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the name for white blood cells

A

leukocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what do white blood cells make up

A

the immune system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

4 examples of white blood cells

A

macrophage, neutrophil, T lymphocytes, B lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what do leukocytes do

A

recognise foreign material and provide immunity against it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is immunity

A

the ability of organisms to resist infection by protecting against disease causing microorganisms or their toxins that invade their body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

leukocytes ( white blood cells) can be divided into two types, what are the non specific types and what are the specific types

A

non specific leukocytes:
macrophages, neutrophils
specific leukocytes:
T+B lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

state basic things about non- specific immunity

A

made up of macrophages and neutrophils.
produce a response regardless of what the pathogen looks like (phagocytosis)
-provide short term protection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

state basic things about specific immunity

A

made up of T and B lymphocytes- they come from stem cells in the bone marrow and T mature in Thymus and B mature in bone marrow. lymphocytes have a large nucleus and specialised specific receptors on their pm- provide specific and long term infection.

  • specific immune cells produce an adaptive response- this means they adapt their response appropriate for the destruction of a specific pathogen.
  • lymphocytes can recognise specific antigens and only produce responses to certain infections- only respond to specific pathogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what are b lymphocytes responsible for doing

A

for producing antibodies which are protein molecules to that are specific to an antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what can the antibodies form b lymphocytes then do

A

bind to their specific antigen and neutralise it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what are antibodies present in and what can they bind to

A

present in the plasma and can bind to specific antigens free in bodily fluids or antigens on cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what type of immunity are b lymphocytes involved in

A

involved in humoral immunity- the antibodies are present in body fluids known as humour.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what type of immunity are T lymphocytes involved in

A

involved in cell mediated immunity.
- t cells have specific receptors on their pm for specific antigens- t cells can only bind to antigens presented on body cells, could be an infected cell ( host cell)e.g

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

describe the cellular response of lymphocytes

A

the lymphocyte with the correct receptor has to be found and activated when a specific pathogen invades the body.

  • the receptor on the lymphocyte is complimentary to the shape of the antigen
  • this contact and activation is called clonal selection.
  • this contact is direct ( contact occurs when the lymphocyte comes across the pathogenic cells in the lymph nodes) or indirect (contact occurs when the lymphocyte comes across an antigen presenting cell which phagocytosed the pathogen)
  • other immune like cells like macrophages secrete a type of cell signalling molecule called interleukins.
  • these interleukins can bind specifically to the selected lymphocyte and cause it to divide by mitosis and produce a lot of clones (clonal selection), slow process
  • b make antibodies
  • t bind to antigens or antigen presenting cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what is cell mediated immunity

A

the recognition of antigens by T cells and the response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what does cell mediated immunity not include

A

doesn’t include antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

A T cell can only detect an antigen if its presented to them via…

A

via another cell- this is usually a host cell, these are known as antigen presenting cells( examples= infected body cell, transplanted cells, cancer cells.) a T cell cannot recognise an antigen if its free

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

for there to be a response in cell mediated immunity…

A

the correct T cell must bind to the specific antigen

42
Q

what happens after in cell mediated immunity when the correct T cell binds to the specific antigen

A

the T cell divides by mitosis ( clonal expansion) then starts to specialise into T killer, T helper, T regulatory or T memory

43
Q

what do t killer cells do

A

destroy our own body cells infected with the pathogen.

most effective against viruses, makes hole in Pm

44
Q

what do t helper cells do

A

release cell signalling molecules called cytokines to help stimulate other immune cells.
- can stimulate phagocytosis and b cells to produce antibodies

45
Q

what do t memory cells do

A

remain in the blood for years and provide long term protection- immunological memory

46
Q

what do t regulatory cells do

A

inhibit the immune response when the pathogen has been destroyed- slow down immune system so healthy body cells are not damaged

47
Q

what does humoral immunity refer to

A

the action of immune molecules which are found in bodily fluids (antibodies are found floating in the bodily fluids)

48
Q

what does humoral immunity include

A

includes secreted antibodies (immunoglobins) which are soluble in bodily fluids

49
Q

humours=_____

A

fluids

50
Q

state what happens in the humoral response

A

to trigger a humoral response, a free antigen/pathogen has to bind to a complimentary receptor on a B cell.

  • the pathogen is then endocytosed by the B lymphocyte and the antigen is presented on the Pm.
  • T helper cells then bind to the presented antigen and stimulate B cell to divide by mitosis ( cytokines)
  • clonal expansion occurs- all clones produce antibody specific to target antigen- they are now plasma cells which can secrete antibodies- antibodies now float in the humour rather than stuck to Pm.
  • after clonal expansion, a B lymphocyte can differentiate into a plasma cell or B memory cell
51
Q

what are the two cells B cells can differentiate into

A

into a plasma cell or B memory cell

52
Q

role of plasma cell

A

specialised to secrete large numbers of antibodies into blood plasma
short lived

53
Q

role of B memory cell

A

provide long term protection
-memory b cells do not produce antibodies during og infection however if memory B cell encounters the same antigen in future, they rapidly divide into plasma (clear infection quickly- produce the same antibodies) cells and B memory cells

54
Q

when the pathogen infects for the first time, how quick is the immune response

A

slow

55
Q

whats the primary immune response

A

the initial response caused by the 1st infection

56
Q

in the primary response, what occurs

A

antibodies specific to the pathogens are produced:

  • new pathogen enters
  • lymphocytes have to detect this and produce response
  • to produce antibodies, B cells have to undergo clonal selection and expansion.
  • then has to differentiate into plasma or B memory
  • plasma produces lots of antibodies
  • takes a long time and symptoms usually occur
57
Q

whats the secondary immune response

A

a more rapid and vigorous response caused by a second or subsequent infection by the same pathogens.

58
Q

in the secondary response, what occurs

A

when same pathogen present, there are already memory cells which recognise it

  • memory B cells rapidly differentiate into plasma cells (makes antibodies).
  • memory T cells also activated and differentiates into T killer or T helper
59
Q

why is the scondary response quicker

A

because clonal selection and clonal expansion are skipped

60
Q

during lymphocyte development, lymphocytes specific to self- antigens are normally destroyed but…

A

sometimes they are not causing harm to our own antigens

61
Q

what is an autoimmune disease

A

when your immune system mistakenly attacks ur own body

62
Q

3 examples of autoimmune diseases

A

arthritis, lupus, myasthenia gravis

63
Q

an autoimmune disease: arthiritis

A

antibodies attack membranes around the joint= inflammation

64
Q

an autoimmune disease: lupus

A

antibodies attack proteins in nucleus of cells= swelling and pain

65
Q

an autoimmune disease: myasthenia gravis

A

attack receptor (essential for reflexes) at neuromuscular joints which causes muscle weakness

66
Q

definition of immunity

A

the ability of organisms to resist infection by protecting against disease casing microorganisms or the toxins they produce

67
Q

2 infections which the immune system is ineffective against…

A

smallpox

measles

68
Q

whats vaccinaition

A

a way of stimulating an immune response so immunity is achieved

  • its given as a precaution
  • not used to treat people who already have the disease
  • mostly protect against infectious diseases
  • protect against the non self and specific to a single organism
69
Q

how does vaccination make the immune system effective

A

before encounter…
-vaccination makes the immune system more effective by stimulating it to produce specific antibodies and memory cells
later on in life…
when the actual pathogen invades there is a rapid response simmilar to secondary immune response

70
Q

how does vaccination work, what does it involve

A

involves deliberately exposing the immune system to the antigen (rendered harmless) of a specific pathogen

  • delivered orally or via injection
  • immune system produces a response to specific antigen
  • b cell stimulated with receptor
  • memory cells produced (specific)
  • when the actual pathogen invades the vaccinated host, the memory cells differentiate into plasma cells
  • infection=rapidly overcome dur to production of antibodies
71
Q

what are the 4 types of vaccine

A
  • live vaccine
  • attenuated vaccine
  • dead pathogen
  • pathogen fragments
72
Q

state stuff about live vaccines

A

contain whole living microorganisms with simmilar antigens to the pathogen.

  • the antibodies produced will be effective against the actual pathogen
  • live microorganism used is less destructive
73
Q

state stuff about attenuated vaccines

A

contain a weak version of the actual pathogen so it cant produce disease but can still multiply

74
Q

state stuff about dead pathogen vaccines

A

contain the dead pathogen so the antigen is intact but the pathogen cant cause harm

75
Q

state stuff about pathogen fragment vaccines

A

contain only specific antigens that stimulate the immune system

76
Q

what does a vaccine do to an individual

A

makes an individual immune to a disease by stimulating their immune system to produce memory cells

77
Q

if a vaccination is done on a large scale, what does this mean

A

it can protect populations from disease

78
Q

what do vaccination programmes involve

A

vaccinating almost all the population- leads to herd immunity

79
Q

whats herd immunity

A

herd immunity occurs when the vaccination of a significant proportion provides protection for individuals who have not developed immunity

80
Q

when there is no herd immunity, what dos this lead to

A

people who are not immunised are not protected

81
Q

what type of people does herd immunity protect

A

protects non-immunised people because its highly unlikely they will come into contact with an infected person

82
Q

who is it not possible to immunise

A

babies

83
Q

whats ring vaccination

A

protects against the spread of new diseases as when a new disease is reported everyone in immediate vicinity of the case is vaccinated

84
Q

why can immunity be lost after being vaccinated

A

some pathogens can mutate their antigens so memory cells produced by vaccination cannot produce them anymore, this can cause the disease so spread again causing an epidemic

85
Q

whats an epidemic

A

the rapid spread of disease through a high proportion of the population

86
Q

to prevent epidemics, what do vaccines have to do

A

have to be changed- new modified vaccines specific for mutated antigens are made each year

87
Q

give an example of a pathogen that as caused an epidemic

A

the influenza virus that causes the flu

88
Q

what is immunity

A

the ability of an organism to resist infection

89
Q

what are the two types of immunity

A

active and passive

90
Q

when does active immunity occur

A

active immunity occurs when specific antibodies are produced by individuals own immune system

91
Q

what’s an example of active immunity

A
  • when a person is infected with a pathogen and their immune system produces specific antibodies and memory cells
  • when a person is vaccinated and their immune system produces antibodies and memory cells
92
Q

when does passive immunity occur

A

passive immunity occurs when specific antibodies are introduced to the individual from an outside source- no direct contact with the specific pathogen is needed to achieve passive immunity

93
Q

whats an example of passive immunity

A

when antibodies from the mother are transferred to the baby through breast milk

94
Q

what are the other two types of immunity

A

natural and artificial

95
Q

how is natural immunity achieved

A

through normal life processes

96
Q

what’s an example of natural active immunity

A

immunity through a regular infection

97
Q

what type of immunity is breastfeeding

A

natural passive

98
Q

whats artificial immunity

A

its induced by medical intervention and the individual does not suffer from any symptoms of disease

99
Q

an example of artificial active immunity

A

vaccination

100
Q

an example of artificial passive immunity

A

injection of antibodies made by another individual (antibodies from an outside source)

101
Q

what type of immunity is long term and which is short term

A

long term=active

short term=passive

102
Q

explain how vaccines can still work even when not all the population is vaccinated

A

herd immunity- where enough ( 90%) of a population is immunised to prevent effective pathogen transmission. ring vaccination can also reduce pathogen spread. this is because in both cases the pathogen may not find a new host before being eradicated by an infected persons immune system

bio (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions