2C

Question 1

what does the lymphatic system do?

Answer 1

-supports cardiovascular system by collecting extra interstitial fluid and returning it to venous circulation in order to maintain blood volume, bp, and fluid balance
- transports immune cells and houses them in secondary lymphatic structures

Question 2

How do immune cells get transported?

Answer 2

1. interstitial fluid moves into lymphatic capillaries (lacteals in gi) where it becomes lymph
2. lymphatic capillaries drain into lymph vessels
3. lymph nodes found in clusters along lymph vessels cleanse lymph and activate immune cells
4. regional lymph vessels drain into lymphatic tunnels which drain into the right lymphatic duct or thoracic duct which then dump lymph back into venous circulation near the heart

Question 3

How does lymph move into the lymphatic capillaries?

Answer 3

• movement of interstitial flood into the lymphatic capillaries is driven by hydrostatic pressure through open intercellular openings between endothelial cells
• once the interstitial fluid enters the lymphatic capillary it becomes lymph
• when the lymphatic capillary fills pressure forces intercellular openings of capillary wall to close preventing a backflow of lymph

Question 4

What makes up lymph?

Answer 4

• water, dissolved solutes (ions), small amounts of protein
  -sometimes debris, pathogens, or cancer cells (metastasis)

Question 5

What are the lymph vessels?

Answer 5

lymph ducts, primary and secondary structures

Question 6

describe the lymph vessels and how they move toward the

Answer 6

-located adjacent to arteries and veins
- similar in structure to veins in that they contain all 3 vessel tunics (medial, intima, externa) and have valves that prevent pooling and backflow of lymph
- lacks a pump and lymph moves toward heart using skeletal muscles and respiratory pumps (seen in veins ) , pulsatile movement of blood in nearby arteries, rhythmic contraction of smooth muscle in larger lymph vessel walls
- some vessels connect to clusters of lymph nodes where lymph is cleansed and immune cells are activated
- regional lymph vessels drain into lymph trunks and eventually into 1 of the 2 lymphatic ducts which dump the lymph into the venous blood supply near the heart

Question 7

What are lymphatic ducts and what are the two main ones?

Answer 7

lymphatic ducts route collected lymph into venous blood near heart
- right lymphatic and thoracic

Question 8

What does the right lymphatic duct do?

Answer 8

drains upper right quadrant of the body
returns lymph into venous circulation at junction of right subclavian and internal jugular veins

Question 9

What does the thoracic duct do?

Answer 9

• is largest lymphatic vessel that drains the rest of the body
• runs from inferior sac-like cisterna chyle ( receives lipid-rich chlye from gi tract ) through the thoracic cavity before returning the lymph into venous circulation at the junction of the left subclavian veins

Question 10

What happens in primary lymphatic structures>

Answer 10

• where lymphocytes mature
  b-lymphocytes mature in bone marrow
  t-lymphocytes mature in the thymus

Question 11

What happens in secondary lymphatic structures?

Answer 11

• anywhere where immune cells are housed in lymphoid organs
  -lymph nodes cleanse lymph, house immune cells, complete capsule
• spleen cleanses blood, houses immune cells, complete capsule
• incomplete capsule: tonsils, MALT

Question 12

What are primary lymphatic structures?

Answer 12

red bone marrow and thymus

Question 13

What happens in red bone marrow?

Answer 13

site of hemolysis
b-lymphocytes fully develop and enter circulation
t-lymphocytes development begins
pre-t-lymphocytes exit bone marrow and migrate to thymus to complete maturation

Question 14

What happens in the thymus?

Answer 14

• larger in kids, shrinks in adults
• grows until puberty and then regresses gradually replaced by adipose tissue
• encapsulated thymus has trabeculae that subdivide the two fused lobes into interior regions called lobules
  -each lobule has outer cortex and inner medulla
• as t-lymphocytes mature they migrate form cortex to medula

Question 15

What is hemopoiesis?

Answer 15

production of blood formed elements, rbs, wbs, platelets

Question 16

What happens in lymph nodes?

Answer 16

occurs in clusters along lymph vessels receiving lymph from specific body regions
-lymph is monitored for the presence of foreign material
macrophages remove any foreign debris from lymph lymphocytes may initiate immune responses by proliferation resulting in enlarged/ swollen nodes
lymph enters lymph node through several afferent vessels and exists through one efferent vessel

Question 17

Is the lymph node a primary or secondary vessel?

Answer 17

secondary

Question 18

What does the cortex do?

Answer 18

contains lymphatic nodules to hilum where it exists through the efferent lymphatic vessel

Question 19

What does the medulla do?

Answer 19

moves it and is the site of something that didnt get said on slide

Question 20

What happens to lipids?

Answer 20

they get absorbed into the lymph