Lymphatic System

Question 1

What are the 2 basic functions of the lymph node?

Answer 1

• Filtration – macrophages in lymph nodes destroy micro and debris
• Immune system activation – lymphocytes in nodes encounter antigens and attack them

Question 2

What does the spleen do?

Answer 2

• Clean blood
  o Destroy worn out RBC (red pulp)
• Site of lymphocyte proliferation (white pulp)
• Immune surveillance and response

Question 3

What are the two methods of defense for immune system?

Answer 3

• Innate (nonspecific) – always prepared
  o 1. Surface barriers – skin and mucous
  o 2. Internal defenses – phagocytes, natural killer cells, inflammation, antimicrobials, fever
• Adaptive (specific, acquired) – fights particular
  o Humoral – B cells
  o Cellular – T cells

Question 4

How do innate defenses work?

Answer 4

• Physical/mechanical barriers that cover body
• Present at birth
• Reduce workload of adaptive through prevention of entry

Question 5

What makes up the first line of defense?

Answer 5

• Physical barriers – skin, mucous membranes, secretions
• Chemicals
  o Acids – inhibit bacteria
  o Enzymes – lysosome and protein digestive
  o Mucin – sticky mucus for trapping
  o Defensins – control bacterial colonization

Question 6

What is the 2nd line of defense?

Answer 6

• Phagocytes
  o Macrophages
  o Neutrophils
• Natural killer cells – kill cancer and virus body cells before adaptive
  o Not phagocytic – apoptosis (programmed cell death with chemicals for inflammation)
• inflammation - local response
  o prevents spread
  o rids of debris and alerts system
  o stage of repair

Question 7

What are the four signs of inflammation?

Answer 7

redness, heat, swelling, pain

Question 8

What are the three processes of inflammation?

Answer 8

chemical release –> vasodilation and vascular permeability –> phagocyte mobilization

Question 9

What happens during chemical release?

Answer 9

histamine –> dilate arterioles and caps to become leaky

Question 10

What happens during vasodilation and vascular permeability?

Answer 10

*hyperemia - redness and heat
*swelling for clotting
*pain from edema

Question 11

What happens during phagocytize mobilization?

Answer 11

*floods area to destroy

• Leukocytosis (neutrophils) –> margination (cling to capillaries) –>diapedesis (escape capillaries) –>chemotaxis (follow chemical trail)
• monocytes follow neutrophils –> macrophages with endless consumption

Question 12

What do antimicrobial proteins do?

Answer 12

attack microorganisms and inhibit their production

Question 13

What are interferons and complement proteins?

Answer 13

interferons - small proteins secreted by infected cells to protect uninfected

complement proteins - group of 20 proteins that destroy foreign

Question 14

What are the mechanisms of complement proteins?

Answer 14

1. enhance inflammation
2. lysis of pathogens - swell with

Question 15

What makes up the third line of defense?

Answer 15

B cells - humoral (anti-body)

T cells - cellular (cell-mediated)

Question 16

Describe the 3rd line of defense?

Answer 16

specific - particular pathogen
systemic - whole system
memory - stronger against repeated offenders

Question 17

What makes up the humoral defense?

Answer 17

*antibodies made by B lymphocytes = freely circulate
*bind to extracellular targets (bacteria, virus)
*immobilize targets and mark for destruction

Question 18

What makes up the cellular defense?

Answer 18

*T lymphocytes
*cellular targets (virus infected, cancer, foreign grafts cells)
*act directly by killing (Tc) or indirectly by releasing chemicals to help others do the job

Question 19

What are antigens?

Answer 19

*substance causing immune response
*intruders
*ultimate target