LYMPHATIC

Question 1

What 5 things encompass the lymphatic system and explain each of them

Answer 1

FLUID - Lymph - protein rich
VESSELS - Lymphatics run close the A&Vs run superficial to deep
CELLS - 1) Lymphocytes (B, T and NK cells) 2) Supporting cells (Follicular dendritic cells, macrophages)
TISSUES - 1) Diffuse lymphatic tissue in mucosal, gut and bronchial areas 2) Lymphatic Nodules: Tonsils (x3), Peyers patches (intestine), Vermiform appendix
ORGANS - Lymph nodes, thymus, spleen

Question 2

How much lymph is drained per day?

Answer 2

3L

Question 3

What is the lymphatic system?

Answer 3

A network of vessels that carry lymph drained from tissue - role in immunity

Question 4

What basic roles do B and T cells have, what kind of cell are they?

Answer 4

Both lymphocytes - type of leukocyte (WBC)

B cells - produce antibodies, seek out antigens
T cells - Different types but ‘destroy’ antigens.

Question 5

What is innate vs adaptive immunity? What two kinds of adaptive immunity are there? Which cells initiate all of these?

Answer 5

Innate: (initial response to antigen): Inflammation response = Macrophages and neutrophils, and also NK cells.

Adaptive:
1) Humoral (e.g. Blood) - Antibody production mediated by B cells that transform into plasma cells and work ‘outside of cell’

2) Cell mediated - cytotoxic T tell mediated

Question 6

Which two major cells initiate the immune response vs the two that initiate the inflammation response?

Answer 6

IMMUNE: T cells and macrophages initiate as B cells need to be activated

INFLAMMATION: Macrophages and neutrophils

Question 7

How is lymph made?

Answer 7

Lymph is a protein rich fluid that leaves capillaries - to interstitium and into lymphatics before venules

Question 8

Are B and T cells present in both blood and lymph?

Answer 8

Yes - until activated then do their job

Question 9

How do lymph nodes work?

Answer 9

Filters, traps antigen, processes antigen, presents it to T cells/NK cells for destruction.

Lymphatic system carries the white blood cells and antigens to lymph nodes where they are processed

Question 10

What are the roles of the spleen (3)? Explain them.

Answer 10

Like lymph nodes filter lymph, it filters blood. It also filters old/faulty erythrocytes and platelets. Thirdly is rescues iron from Hb.

Immune response: 1) Antigen presentation by APCs 2) Activation and prolif of B and T cells - production of antibodies 3) Removal of macromolecular substance from blood - macrophages.

Question 11

What’s the role of the thymus? Why would you do a thymectomy?

Answer 11

Thymus is responsible for maturing T cells that have come from bone marrow. Once puberty hits the thymus involutes and turns mostly to fat. You may do a thymectomy in someone with myasthenia gravis as up to 20% of these pts can get Thymomas (cancer).

Question 12

What three organs are involved in the lymphatic system?

Answer 12

Lymph nodes
Spleen
Thymus

Question 13

What are Peyers Patches? What are their function?

Answer 13

Lymphoid tissue in gut, immune response in GI with incoming pathogens via food.

Question 14

Is there any lymph tissue in CNS?

Answer 14

No

Question 15

How does lymph flow through lymph node?

Answer 15

Afferent to Efferent through medulla

Question 16

Name 3 professional antigen presenting cells that will present an antigen to a T cell

Answer 16

Macrophages
B cells
Dendritic cells

Question 17

What are three roles of B cells

Answer 17

Seek antigens
Make antibodies
Present antigens to T cells to destroy

Question 18

Where are follicular dendritic cells located? What are two roles?

Answer 18

In germinal centres of lymph nodes

1) Hold antigen/antibody complexes for months
2) Cause prolif of B cells espesh memory B cells

Question 19

What is the immune role of the spleen? Which 3 cell types mediate this?

Answer 19

Immune role of spleen is it contains APCs that can remove pathogens from blood. Using normal immune response - B cells T cells macrophages.

Question 20

What is the haemopoietic function of the spleen (2)?

Answer 20

1) Removal of old/damage/abnormal RBCs

2) Retrieval of iron from Hb

Question 21

What is lymphatic tissue split into and where can it be found? Think diffuse vs nodules (3 of each)

Answer 21

Diffuse: MALT GALT BALT
Mucosal, gut, bronchial

Nodules: Tonsils, Peyers Patches, appendix

Question 22

Do lymphocytes (B/T cells) enter lymph nodes via lymph or blood mostly? Do they leave via lymph or veins?

Answer 22

Normally through feeding artery (a few in lymph). Mostly leave via lymph vessel.

Question 23

What lymphadenopathy? What causes it?

Answer 23

Enlarged lymph nodes due to infection. Increased numbers of lymphocytes causes the swelling.

Question 24

How do cancers metastasise to lymph nodes?

Answer 24

Via afferent lymphatics

Question 25

Can the body function if spleen is surgically removed? How? How does this increase risk of DVT?

Answer 25

Yes liver and bone marrow take over role of spleen. However increased number of platelets increases the risk of DVT as increases the risk of thrombus forming. Spleen normally breaks up platelets.

Question 26

Are NK cells involved in both innate and adaptive immunity?

Answer 26

Yes

Question 27

Which type of collagen is found in lymphatic tissue?

Answer 27

III

Question 28

Which 3 things aid flow of lymph round lymph vessels back to venous system?

Answer 28

-ve Pressure in thorax
Arteries nearby
Skeletal muscle contraction