Lymphatic System

Question 1

How does the lymphatic system return fluid to the blood?

Answer 1

The fluid (lymph) enters a network of tiny blind-ended tubes distributed in the tissue spaces. These tiny vessels (lymphatic capillaries) permit excess tissue fluid & other substances to leave the tissue spaces.

Thus the lymph returns to the blood from the tissues spaces via the capillaries.

Question 2

What is the primary role of lymph nodes in the body?

Answer 2

• Create WBC’s
• Defend (filter microorganisms)

Question 3

Why is the thymus important for immunity?

Answer 3

-Source of lymphocytes before birth

• important in the maturation/development of specialized lymphocytes that leave Thymus to Spleen, Tonsils, Lymph Nodes & other Lymphatic Tissues

Question 4

What is the difference between ADAPTIVE and INNATE immunity?

Answer 4

Adaptive Immunity = Specific Immunity
- SPECIFIC protection against specific types of threats or microorganisms
- SLOWER reaction
- ANTIBODIES
- LYMPHOCYTES (B cells and T cells)

Innate Immunity = Nonspecific Immunity (General Protection)
- Born with defences that attack any irritant or abnormal substances that threaten internal environments.
- VARIETY of non-self or abnormal cells and particles
- FAST reaction
- PROTEINS
- PHAGOCYTES (neutrophils, macrophages, dendritic cells)

Question 5

What are the changes that occur in the body’s inflammatory response?

Answer 5

1) Bacteria enter the body
2) Tissue damage occurs
3) Mediators are released
4) An attraction of WBCs, increased blood flow, & increased vascular permeability. Resulting in increased numbers of leukocytes & mediators at the site of damage.
5) Bacteria are contained, destroyed, & phagocytized.
6) If bacteria remain, additional mediators are activated, which stimulates the process again.
7) If no bacteria remain, the tissue heals.

Question 6

What are antibodies?
How do they function in the body?

Answer 6

They are protein compounds that are normally present in the body.
They combine with specific antigens to remove them.

Question 7

What are complement proteins?
How do they function in the body?

Answer 7

Group of protein enzymes that are normally present, an inactive state in the blood.

They form specialized proteins to destroy foreign cells that have been targeted.

Question 8

What are phagocytes and how do they function in the body?

Answer 8

Phagocytic cells (WBCs) are important immune system cells.
They surround, ingest, & destroy foreign cells or other harmful substances by phagocytosis

Question 9

What is the role of the B Cells in immunity?

Answer 9

Indirectly produce HUMORAL immunity

Question 10

What is the role of T Cells in immunity?

Answer 10

Directly produce CELL-MEDIATED immunity

Question 11

What are memory cells?

Answer 11

“Remember” their ancestor-activated B cell’s encounter with an antigen.
Ready to produce antibody that will combine with a certain antigen.