the local support and defense system

Question 1

what makes up the Innate Immune System?

Answer 1

• non-specific defenses
• first line: physical and chemical surface barriers
• second line: internal cellular and chemical defense

Question 2

what is the first line of defense made up of?

Answer 2

• tears
• skin/sweat and oil/pH
• large intestine
• saliva
• respiratory tract
• stomach
• bladder

Question 3

what is the second line of defense made up of?

Answer 3

• defensive cells
• defensive proteins
• inflammation
• fever - slows the growth of bacteria
• identifies as foreign matter but isn’t specific and doesn’t develop a memory

Question 4

what makes up the adaptive immune system?

Answer 4

• specific defenses
• the third line of defenses
• only kicks in if the pathogen survives the nonspecific internal defenses

Question 5

what makes up cell-based defense?

Answer 5

• phagocytes
• non-phagocytes
• eosinophils
• natural killer cell
• destruction by phagocytosis

Question 6

how do phagocytes work? what are the different types?

Answer 6

• neutrophils - first on the scene and consume bacteria
• macrophages - consume almost anything

Question 7

how do non-phagocytes work?

Answer 7

target pathogens/invading organisms are too large for phagocytosis

Question 8

how do eosinophils work?

Answer 8

discharge enzymes that digest the target

Question 9

how do natural killer cells work?

Answer 9

• constantly circulate and ‘patrol’ for non-self.
• target cancer cells
• release perforin and proteases to destroy cells

Question 10

why are protein-based defense mechanisms so important?

Answer 10

• lysis by the complement system
• enhances the ability of antibodies and phagocytic cells to clear microbes and damaged cells from the body, promotes inflammation, and attacks the pathogen’s cell membrane.

Question 11

what are parenchymal cells?

Answer 11

• the critical ‘functional’ portion of the tissue (gland, organ)
• usually the most prominent cell type in terms of mass

Question 12

name some examples of parenchymal cells

Answer 12

• liver
• skeletal muscle
• heart
• brain
• adipose tissue
• pancreas

Question 13

what are stromal cells?

Answer 13

• also called non-parenchymal cells
• support the parenchymal cells, forming the LSDS

Question 14

name some examples of stromal cells

Answer 14

• neurons
• astrocytes
• capillary endothelial cells
• fibroblasts
• stem cells
• gap junctions

Question 15

what is the purpose of T-Cells?

Answer 15

• they kill by chemical means
• i.e., perforins, which punch holes in the target cell membrane
• memory t-cells are stored for continued surveillance in the bone marrow and thymus

Question 16

what are the other names for a T suppressor cell?

Answer 16

• T regulatory cell
• Foxp3+

Question 17

what is the purpose of T suppressor cells?

Answer 17

to suppress activation of the immune system, particularly the production of T helper cells
- important in allowing tolerance to self antigens

Question 18

how does too little T suppressor response affect the body?

Answer 18

association with:
- autoimmune disease
- allergies
- graft rejection
- inflammatory bowel disease

Question 19

how does too much T suppressor response affect the body?

Answer 19

possible connection to
- cancer
- increased incidence of infectious diseases

Question 20

what does the LSDS do?

Answer 20

• local tissue damage by processes that are not due to infectious pathogens
• normal tissue turnover such as cell death and tissue repair or regeneration during wound healing
• looks out for the appearance of transformed cell populations such as cancerous cells

Question 21

why is the LSDS said to be like the CCN?

Answer 21

because it’s always on!

Question 22

what is required to trigger T and B cell responses to foreign antigens?

Answer 22

macrophages are required as the antigens or peptides will not be detected unless attached to an MHC