Ch 21: Immune System Flashcards Preview

A&P II: BIO426 > Ch 21: Immune System > Flashcards

Flashcards in Ch 21: Immune System Deck (122)
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61

What are the two types of Lymphocytes?

B-lymphocytes

T-lymphocytes

62

Lymphocytes are produced from _______ in _______.

homopoietic stem cells, bone marrow

63

Lymphocytes that have matured but not yet received their antigens are called...

naive lymphocytes

64

Where does each type of lymphocyte mature?

B-cells mature in bone

T-cells mature in thymus

65

What are the characteristics of a Naive lymphocyte

  • They are fully mature
  • Have not received their antigens yet (they don't know their purpose of being)

66

Naive lymphocytes receive their antigens from

secondary lymphatic organs

67

What are some secondary lymphatic organs?

  • Lymph nodes
  • Tonsils
  • Spleen

68

What are the primary lymphatic organs?

  • Bone marrow
  • Thymus

(Where the B & T cells mature)

69

When T-cells mature, the must first pass through the _______ of the thymus to undergo ________.

cortex, positive selection

70

In positive selection, the receptors of lymphocytes are checked for _______. 

Explain what that means.

  • immunocompetence
  • ability to bind to antigens

71

What happens to a lymphocyte that fails positive selection?

it is tagged for apoptosis

72

What happens to a lymphocyte that passes positive selection?

It passes through the cortex to medulla of the thymus for negative selection.

73

In negative selection, lymphocytes are checked for

"self" antigens (if will it bind to cells the body needs)

74

The ability of the body to deal with a certain amount of lymphocytes that may attach to cells the body needs is called

tolerance

75

What happens to lymphocytes that fail negative selection?

Tagged for apoptosis

76

What happens to a lymphocyte that passes negative selection?

It is released to pick up its antigen from secondary lymphatic organs

77

The process of positive and negative selection results in a 

mature lymphocyte

78

True or False

Naive lymphocytes have been activated.

False

79

B-cells go through negative and positive selection _______ in _______.

locally, bone marrow

80

T-cells go through negative and positive selection in

the thymus

81

True or False

T-cells traveling from bone marrow to the thymus are mature.

False

82

The binding of a lymphocyte to an antigen is called

activation

83

T-cell receptor binding requires an

Antigen Presenting Cell (APC)

84

What kind of cells can be APCs?

neutrophils, b-cells

85

What is MHC?

Major Histocompatibility complex

A group of genes found on the surfaces of cells that help the immune system recognize foreign substances.

86

How are APCs created?

  • a neutrophil or b-cell finds an antigen
  • engulfs antigen
  • presents that antigen on its surface along with MHC
  • MHC+Antigen then bind to t-cell receptor

87

Once a t-cell is activated, it initates

cell mediated immunity

88

Cell mediated immunity is when a specific t-cell...

proliferates and differentiates 

89

What is t-cell proliferation and differentiation also known as?

Colonal selection

90

What are the four types of t-cells

  1. Cytotoxic
  2. Helper
  3. Regulatory
  4. Memory