1. UNIT 5- Lymphatic System

2. What is Interstitial Fluid?
As blood travels through capillaries, the blood is squeezed and fluid from the blood is forced out into the spaces between nearby cells – this fluid is known as interstitial fluid (composition is different from the blood).

3. What is Lymph?
Some interstitial fluid is immediately reabsorbed back into the blood, but some remains, which then moves into (by osmosis) nearby lymphatic capillaries, [LYMPH]which is the beginning of the lymphatic pathway.
Primary functions of lymph.
return the proteins to the bloodstream that have leaked out of the blood capillaries
transport bacteria /foreign particles to the lymph nodes.

4. Explain how the Lymphatic system is related to the Cardiovascular system.
Network of capillaries /vessels that assist in circulating fluids
Vessels have valves
Drain excess fluid from interstitial spaces
Filter and return excess fluid to the blood stream

9. Similar to Blood Capillaries
Similar to Veins and have Valves
Filter Lymph
Located in trunk of body
Right Lymphatic and Thoracic
Under each clavicle

11. What are Collecting Ducts and where are they located?
Right Lymphatic Duct – drains lymph from the right half of the upper body
Thoracic Duct – drains lymph from the left half of the upper body and the entire lower body

13. What is the importance of the Lymph node/gland?
Located along lymphatic pathways
Have lymphatic vessels leading in and out of them
Only lymphoid structures that filter lymph
Produce lymphocytes (most are produced in the bone marrow)
Contain lymphocytes and macrophages to help in cleaning lymphatic fluid

17. Name 2 Major Lymphatic Organs and their functions.
THYMUS GLAND
in the mediastinum (superior to the heart)
shrinks with age
contains lymphocytes (produced in the bone marrow), then travel to the Thymus, where they remain as they mature – known as T- lymphocytes/ T- cells
SPLEEN
upper left abdominal cavity
largest of the lymphatic organs
contain lymphocytes (fight off viral attacks) and macrophages (fight bacteria, engulf damaged tissue)
filters the blood of old, fragile RBC (RBC graveyard)

18. Tonsils: considered a lymph gland and contain lymphocytes

20. WBC aka Leukocytes
Can leave the bloodstream (diapedesis)to fight infection
Engulf damaged tissue [phagocytosis]
Produce pus- indication of fighting infection
Produce antibodies to fight foreign invaders
Neutrophils (60%) – 1st to arrive at infection site
Lymphocytes (30%) – Two varieties (T-cells and B-cells)
Monocytes (8%) – Become macrophages and engulf
bacteria, dead cells, and damaged tissue (phagocytosis)
Eosinophils (2%) – Controls allergic reactions
Basophils (0%) – Release histamine at site of damaged
tissue (inflammation), and heparin (inhibits clotting)

21. Difference between B and T Lymphocytes
B CELLS:
Produced and mature in Bone Marrow
Located in lymph nodes, spleen, tonsils
Plasma cell-type of B cell that is an antibody factory to fight invaders [antigens-cause immune reactions]
T CELLS:
Produced in Bone Marrow and mature in THYMUS gland
Located in lymph nodes,
spleen, tonsils
3 Special T Cells:
Helper T
Cytotoxic T
Memory T

22. 3 Special T cells Helper T- assist B cells in producing antibodies
Cytotoxic T- attack cancer/virally infected cells
Memory T- produced due to exposure to an antigen but are used for future exposure to same antigen
Vaccines/Immunizations= weak/dead virus stimulate Memory T cells preventing future infection

23. 2 Types of Defense 1) Innate (Non-Specific) Species Resistance Skin
Chemical –
Fever
Infection – Pus – WBC, Bacteria, Damaged Tissue Redness – d/t vasodilation