The Immune System

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The Immune System

• Marie Cerná

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Immune system

• belongs to basic homeostatic mechanisms of
  organism
• Its function is maintaining the integrity of
  organism by recognition of harmful from harmless,
  and by this way it protects organism against
  injurious matter of external and internal origin.

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Immune system

• An antigen is any substance
• biological / chemical, natural /
  artificial,
• self / nonself
• that elicits an immune response.

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Organs of immune system
Cellular components
Humoral components
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Leucocytes (white cells) the defense of the
organism

• 4-10 .103 / mm3 4-10 .109 / l
• size 10 µm in diameter
• agranulocytes (lymphoid cells) 30
• lymphocytes (upper slide)
• monocytes (lower slide)
• granulocytes (presence of granules in the
  cytoplasm) 70
• granules have a different affinity towards
  neutral, acid or basic stains and give the
  cytoplasm different colors.
• neutrophils
• eosinophils (or acidophils)
• basophils

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Monocytes

• 3-8 of all leukocytes
• the biggest leukocytes 16-20 µm
• Their nucleus is a great reniform or
  horseshoe-shaped.
• The cytoplasm is transparent, but with an
  appearance of "ground glass"
• Monocytes are the precursors of macrophages.
  After attaining maturity in the bone marrow,
  enter the blood circulation where they stay for
  24-36 hours. Then they migrate into the
  connective tissue.

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Neutrophils

• 60-70 of all leukocytes
• Their nucleus is divided into 2 - 5 lobes
  connected by a fine nuclear strand.
• The cytoplasm is transparent because its granules
  are small, pink colored.
• Neutrophils are very active in phagocyting
  bacteria
• gt are present in large amount in the pus of
  wounds.

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Eosinophils

• 3-5 of all leukocytes
• Their nucleus is bi-lobed (glasses-like shape).
• The cytoplasm is full of pink-orange colored
  granules.
• Eosinophils attack parasites and phagocyte
  antigen-antibody complexes.

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Lymphocytes

• 20-40 of all leukocytes
• Their nucleus is round and large in comparison to
  the cell and it occupies most of it.
• The cytoplasm is transparent.
• Lymphocytes are cells which, besides being
  present in the blood, populate the lymphoid
  tissues and organs too, as well as the lymph
  circulating in the lymphatic vessel.

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Basophils

• 0.5-1 of all leukocytes
• Their nucleus is bi- or tri-lobed.
• The cytoplasm is very rich in dark purple colored
  granules.
• Basophils secrete anti-coagulant and vasodilatory
  substances as histamines and serotonin gt
  mediate the hypersensitivity reaction.

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Immunity

• Innate immunity
• First line integrity of the skin and the mucosa
• Second line nonspecific defense itself
• - cellular components
• - humoral components
• Acquired immunity
• - cellular components
• - humoral components

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Innate immunity

• First line
• integrity of the skin and the mucosa
• defense mechanisms
• mechanical (movement of cilia)
• chemical (fatty acids, pH 3-5, lysozyme)
• microbial (normal microbes)

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Innate immunity

• Second line nonspecific defense itself
• - cellular components
• phagocytic cells
• natural killer (NK) cells
• - humoral components
• complement system
• interferons

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Acquired immunity

• Specific defense only in vertebrates
• - cellular components
• T - lymphocytes
• B - lymphocytes
• - humoral components
• antibodies produced by B - lymphocytes
• Induction of immunological memory

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Literature

• Biology, eighth edition,
• Campbell, Reece
• Unit seven Animal Form and Function
• Chapter 43 The Immune System
• Pages 930 953