Lecture 6: Lymphoid System/Immunity Flashcards Preview

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Flashcards in Lecture 6: Lymphoid System/Immunity Deck (108)
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1
Q

Lymphatic Vessels

A

Carries lymph, that has leaked out of capillaries. from peripheral tissues to the venous system

2
Q

Lymph

A

Fluid similar to plasma but does not have plasma proteins

3
Q

Why doesn’t lymph contain plasma proteins?

A

They can’t leave the blood vessels

4
Q

What does lymph contain?

A

Glucose
Hormones
Electrolytes

5
Q

What does the lymphoid system produce, maintain, and distribute?

A

Lymphocytes

6
Q

Where does the lymphoid system return fluid and solutes to?

A

The blood

7
Q

Another function of the lymphoid system:

A

Distribut hormones, nutrients, and waste products from their tissues of origin to the general circulation

8
Q

Which lymphatic vessels have valves?

A

Contractile vessels

9
Q

Thoracic Duct

A

Left upper body

Lower body

10
Q

Right Lymphatic Duct

A

Right upper body

11
Q

3 Classes of Lymphocytes

A

T cells
B cells
NK cells

12
Q

T Cells Derived In…

A

Thymus

13
Q

B Cells Derived In…

A

Bone marrow (bursa)

14
Q

General Types of T Cells (4)

A

Cytotoxic
Helper
Suppressor
Memory

15
Q

Cytotoxic T Cells

A

Directly attack foreign infected cells

Cause lysis/destruction

16
Q

Helper T Cells

A

Stimulate T and B cells to become active

Attract macrophages

17
Q

Suppressor T Cells

A

Inhibit T and B cells

Secrete chemicals that moderate immune response once it is active

18
Q

Memory T Cells

A

Respond to previously encountered antigens by cloning more T cells
Turn into cytotoxic or helper cells if they recognize certain bacteria

19
Q

What percent of lymphocytes are T cells?

A

80%

20
Q

What percent of lymphocytes are B cells?

A

10-15%

21
Q

B Cells

A

Differentiate (change) into plasma cells

22
Q

Plasma Cells

A

Produce and secrete antibodies that bind to and help destroy foreign cells and infected cells

23
Q

What percent of lymphocytes are NK cells?

A

5-10%

24
Q

Natural Killer Cells

A

Attack foreign cells, virus-infected cells, and cancer cells

25
Q

Immunological Surveillance

A

Activity of NK cells

26
Q

Where do lymphocytes constantly move around?

A

Blood
Lymph/Lymph nodes
Peripheral tissue
Lymphoid organs

27
Q

Life Span of Lymphocytes

A

Years to decades

28
Q

Where are blood cells produced?

A

Red bone marrow

29
Q

Hemocytoblasts

A

Produce stem cells that can travel to the thymus (then become T cells)
Some stay in bone marrow to become B cells and NK cells

30
Q

Lymphoid Tissue

A

Connective tissues containing large numbers of lymphocytes (macrophages)

31
Q

Lymphoid Organs

A

Lymph nodes
Thymus gland
Spleen

32
Q

Lymph Nodes

A

About 400 in body

Filters lymph from extremities before it reaches the trunk/torso

33
Q

MALT

A

Mucosa-Associated Lymphoid Tissue

Collections of lymphoid tissue in digestive, respiratory, urinary tracts

34
Q

Types of Tonsils

A

Pharyngeal
Lingual
Palentine

35
Q

Tonsillectomy

A

Removal of tonsils

Slight risk of damage to internal carotid artery

36
Q

Where do lymph nodes lie?

A

Along lymphatic vessels

37
Q

What happens in a lymph node?

A

Lymph flows through several regions and is filtered

It then warns the immune system of any pathogens

38
Q

What do macrophages in lymph nodes do?

A

Removes 99% of antigens in the lymph before it reaches the veins and then present the antigens to lymphocytes

39
Q

Spleen

A

Largest lymphoid organ with good blood supply

40
Q

What are the functions of the spleen? (3)

A

Macrophages phagocytize and recycle damaged/old RBCs
Stores iron
Exposes B and T cells to antigens/microorganisms in blood

41
Q

What does the spleen contain?

A

Red Pulp

White Pulp

42
Q

Red Pulp

A

Lots of red blood cells

43
Q

White Pulp

A

Lymphoid tissue (lymphocytes)

44
Q

What is the spleen hard to fix if ruptured?

A

Its soft tissue doesn’t like to hold stitches

45
Q

2 Types of Immune Defenses

A

Innate Defenses

Adaptive Defenses

46
Q

Innate Defenses

A

Nonspecific

47
Q

Adaptive Defenses

A

Specific

48
Q

7 Types of Nonspecific Defenses

A
Physical barriers
Phagocytes
Immunological surveillance
Interferons
Complement
Inflammatory response
Fever
49
Q

Physical Barriers

A

Pathogens must cross skin or mucous membrane to enter body

50
Q

How is the skin used as a physical barrier?

A

Multiple layers of cells, keratin, desmosomes

Oil and sweat gland secretions

51
Q

How do desmosomes work as a physical barrier?

A

Their interlocking creates a barrier

52
Q

How are mucous membranes used as a physical barrier?

A

Mucous secretions

Stomach acid

53
Q

Types of Phagocytes

A

Neutrophils
Eosinophils (microphages)
Macrophages

54
Q

Reticuloendothelial System

A

Removing bacteria

Also called monocyte-macrophage system

55
Q

Fixed Macrophages

A

Stay in certain part of body and wait for antigen to approach it

56
Q

Free Macrophages

A

Travel through body

57
Q

Functions of Phagocytes (3)

A

Bind to pathogen and phagocytize
Bind to pathogen and wait for other cells to assist
Release chemicals to destroy pathogen

58
Q

Immunological Surveillance

A

NK cells recognize abnormal antigens in cells and then attack those cells, whether they are self or bacterial

59
Q

NK Cell Activation Process (3)

A

Recognition of antigen and adhesion to cell
Realignment of golgi apparatus toward target cells
Secretion of perforin via exocytosis

60
Q

What does perforin do when secreted?

A

Perforates plasma membrane of a foreign cell making it unable to maintain homeostasis

61
Q

Interferons

A

Proteins released form activated lymphocytes, macrophages, and viral-infected cells
Warn other cells of a virus in the body

62
Q

Where do interferons bind to?

A

Membrane receptors in normal cell and use a second messenger to cause production of antiviral proteins which interfere with viral replication

63
Q

What do interferons act like when released?

A

Hormones

64
Q

What is the complement system made up of?

A

11 plasma proteins

65
Q

How do complement reactions occur?

A

If a complement is activated by contact with antibody-coated cells (fastest) or contact with bacterial capsules

66
Q

What do complement reactions result in?

A

MAC

67
Q

MAC

A

Membrane Attack Complex (pore in bacteria)

Forms multiple holes in bacterium plasma membrane

68
Q

What does MAC enhance?

A

Phagocytosis (opsonization) by making cells easier targets for macrophages and microphages

69
Q

What does MAC trigger?

A

Histamine release by basophils and mast cells which increases local inflammation and blood flow

70
Q

Inflammation

A

Tissue response to injury or infection
Release of chemicals from damaged cells
Release of histamine and heparin from mast cells

71
Q

Result of Inflammation (5)

A
Redness
Heat
Swelling
Pain
Loss of function
72
Q

Inflammation Protective Result

A

Capillaries allow clotting proteins and complement to enter wound site
Phagocytes are attracted

73
Q

How does clotting help inflammation?

A

It walls off the area, slowing the spread of bacteria

74
Q

What regulates body temp?

A

Hypothalamus

75
Q

What do pyrogens do?

A

They are circulating proteins that can trigger hypothalamus to increase body temp

76
Q

How are pyrogens secreted?

A

By macrophages

77
Q

What does a fever indicate?

A

It is a signal that an infection is being fought

78
Q

Functions of a Fever (2)

A

Increased metabolic activity

Inhibition of bacterial and viral activity

79
Q

What results in an increase of metabolic activity?

A

Increased activity of immune cells

Increased speed of chemical reactions

80
Q

Specific Defenses

A

Activity of T cells and B cells

81
Q

What type of immunity are T cells?

A

Cell-mediated

82
Q

What type of immunity are B cells?

A

Antibody-mediated

83
Q

Active Immunity

A

Your body develops immunity

84
Q

Naturally Acquired Active Immunity

A

Through environment exposure to pathogens

85
Q

Induced Active Immunity

A

Through vaccines containing heat killed/treated/neutralized pathogens

86
Q

Passive Immunity

A

Antibodies come from other source

87
Q

Naturally Acquired Passive Immunity

A

Antibodies acquired from the mother through placenta and breast feeding

88
Q

Induced Passive Immunity

A

By an injection of antibodies (meds create antibodies)

89
Q

4 Properties of Immunity

A

Specificity
Versatility
Memory
Tolerance

90
Q

Specificity of Immunity

A

T and B cells respond to one specific antigen

91
Q

Versatility of Immunity

A

T and B cells can respond to millions of different antigens

92
Q

Memory of Immunity

A

In an immune response some cells are produced to fight and some to act as memory cells for future exposure

93
Q

Tolerance of Immunity

A

Immune cells do not respond to self antigens unless an autoimmune disease is acquired

94
Q

What must happen before T cells can be activated?

A

They must encounter an antigen that is presented to them by an infected cell or a phagocyte

95
Q

MHC Proteins

A

Major histocompatibility complex

Continuously synthesized and added to plasma membrane

96
Q

What is required to activate T cells?

A

T cell sensitization exposure

Chemicals released by macrophages

97
Q

What do B cells have sticking off of them?

A

Antigens

98
Q

How are B cells sensitized?

A

Encounter with foreign antigen

99
Q

How are B cells activated?

A

Encounter with helper T cells

100
Q

What do activated T cells allow B cells to do?

A

Attack

101
Q

What happens when B cells are activated?

A

They divide, producing populations of plasma cells and memory B cells

102
Q

Plasma Cells

A

Produce antibodies specific to the antigen being attacked

103
Q

Antibodies

A

Y shaped
2 pairs of polypeptide chains (heavy & light)
Constant and variable regions

104
Q

Antigen-Binding Site

A

Variable region
Tips of chains
Region that will stick to antigen to form antigen-antibody complex that can cause agglutination

105
Q

Action of Antibody (7)

A
If bonded to antigen..
Neutralization
Precipitation/Agglutination
Activation of complement
Attraction of phagocytes
Opsonization
Stimulates inflammation
Prevention of bacterial or viral adhesion to external surfaces
106
Q

What does neutralization do?

A

Prevent viruses from entering cells

107
Q

Agglutination is…

A

Clumping

108
Q

Opsonization

A

Makes phagocytes easier