Lymphoid System #1

Question 1

Where do lymphoid stem cells come from?

Answer 1

Bone marrow

Question 2

If I were a T cell that wanted to find a good place in the body to go and mature, where would I go?

Answer 2

The Thymus

Question 3

Where do B Cells come from (in cellular origin)

Answer 3

Bone Marrow Lymphoid Progenitor Cell

Question 4

Interaction of B Cells with T Helper Cells and Macrophages results in…

Answer 4

Clonal Expansion and Plasma Cell/Memory B cell production

Question 5

Do B Cells require an MHC complex to conduct their immune-related tasks?

Answer 5

Nope. Recognize free antigen peptides not bound to MHC

Question 6

DO T cells require an MHC complex to conduct their immune related tasks?

Answer 6

Yep.

Question 7

What are the two kinds of T cells addressed in this course?

Answer 7

T helper (CD4) and Cytotoxic T (CD8) cells

Question 8

T Helper cells interact primarily with what cell(s)?

Answer 8

B cell/macrophage

Question 9

What MHC complex do CD4 T cells interact with?

Answer 9

MHC II

Question 10

TH 1 and TH2 cells differ in that…

Answer 10

TH1 – Viral and Bacterial Infection

TH2 – Parasitic Infection

Question 11

CD8 T Cells bind to which MHC?

Answer 11

MHC I

Question 12

What do natural killer cells do (aside from have the most bad ass name in the immune system)

Answer 12

1. Recognize and Kill Virally infected and Cancer Cells

2. Help out B cells by killing cells covered in antibodies (antibody dependent cell mediated cytotoxicity)

Question 13

What do antigen presenting cells do?

Answer 13

Break down antigens internally, grab a piece of the leftover peptide fragments, and show off their trophy on the MHC complex on the outside of the cell.

Question 14

True or False – All nucleated cells have type II MHC

Answer 14

False. All nucleated cells have type I. MHC II is on antigen presenting, endothelial, and thymic reticular cells.

Question 15

Name off a few antigen presenting cells.

Answer 15

Macrophages, specialized macrophages (Kupffer, Langerhans), dendritic cells, some glial cells, fibroblasts, and mast cells

Question 16

I don’t know how to ask this question well…..but…..where can lymphoid cells be found.

Answer 16

Basically everywhere. Lymphatics, Blood, Loose connective tissue, subepithelium of the intestinal and respiratory tract, the genitourinary system

Question 17

Are lymph nodules solitary or aggregated?

Answer 17

Yes. There are examples of both (most we would talk about are solitary, but peyers patches are a good example of an aggregated).

Question 18

Structurally, what is a lymph node?

Answer 18

Dense lymphatic tissue surrounded by dense irregular connective tissue.

Question 19

When the capsule extends into the node, it forms __________ that converge at the _____.

Answer 19

Trabeculae. Hilus.

Question 20

What does a Hilus do anyway?

Answer 20

a hilus is the region where lymph exits the node and arteries and veins come in and out.

Question 21

Capsule + Trabeculae + reticular fibers = ?

Answer 21

Stroma

Question 22

What is a lymph node sinus?

Answer 22

A region separated from the capsule/trabeculae by squamous cells, reticular cells, and macrophages attached to the reticular fiber network.

Question 23

Who are the antigen presenting cells hanging out in the cortex?

Answer 23

Follicular dendritic cells

Question 24

Describe a primary lymphoid nodule.

Answer 24

Unstimulated, no germinal center

Question 25

Describe a secondary lymphoid nodule.

Answer 25

Contains a germinal center (region will larger lymphoblasts and a marginal zone of smaller lymphocytes and some macrophages around the periphery).

Question 26

Where do germinal cells come from?

Answer 26

B cell activation by helper T cells, causing a clonal expansion (the fast track to plasma cells)

Question 27

Tell me about B Cell Selection

Answer 27

Occurs in B cell maturation. The B cells contact FDCs which present antigen to cells. If the antibodies can't hold on so well, THE B CELLS DIE (via apoptosis and eventual phagocytosis by macrophages).

Question 28

Which B cells get to complete maturation?

Answer 28

Cells with high affinity antibodies get to move to medullary cord and become plasma cells.

Question 29

What if the B cell is non-specific for the antigens presented by FDC?

Answer 29

These cells accumulate in the mantle zone of the lymphoid follicle.

Question 30

In a lymph node, where are the B cells and where are the T cells?

Answer 30

B cells -- Nodules and Medullary Cords | T cells -- Paranodular and Inner Cortex Regions

Question 31

Where do lymphatic vessels empty into a node?

Answer 31

Subcapsular sinus located between the capsule and the outer cortex.

Question 32

After subscapular sinus, where does the lymph go?

Answer 32

Intermediate (trabecular) sinuses --> Medullary Sinuses (next to medullary cords)

Question 33

How do lymphocytes get into nodes in the first place?

Answer 33

High endothelial venules have selectins that help lymphocytes in (double check this)

Question 34

Name three kinds of tonsils.

Answer 34

Lingual, Pharyngeal, Palatine

Question 35

Where are lingual tonsils? Describe the nodes.

Answer 35

Small nodules below the epithelium of the posterior third of the tongue.

Question 36

Where are pharyngeal tonsils? Describe the epithelium.

Answer 36

In the posterior wall of the nasopharynx. Covered with ciliated pseudostratified columnar with a dash of squamous (esp in old people)

Question 37

Where are palatine tonsils? Describe the tissue.

Answer 37

in between the glossopalatine and pharyngopalatine arches. Covered in a dense connective tissue capsule. Covered with strat. squamous epithelium with crypts.

Question 38

What are Peyer's Patches? What cells are nodular? Paranodular?

Answer 38

Aggregated nodules in the lower illeum. B cells are nodular. T cells are paranodular.

Question 39

Where do M cells come into play here?

Answer 39

They're in the follicular epithelium and are important for antigen presentation.

Question 40

T or F. The appendix lamina propria is full of lymphoid tissue.

Answer 40

True

Question 41

What is lymphadentitis?

Answer 41

Excessive immune response leading the inflammation and swelling of a node.

Question 42

Why do oncologists care about the lymphatic system?

Answer 42

It is a common site for metastasis.

Question 43

Check out the pictures on page 7 of the packet.

Answer 43

NOW!!!

Question 44

What type of cell is primarily responsible for graft related disorders?

Answer 44

T Cells

Question 45

Why do grafts get rejected?

Answer 45

The patient's immune system recognizes the tissue as foreign and attacks it.

Question 46

How does graft vs. host happen?

Answer 46

Bone marrow transplant = New Immune system. New immune system doesn't recognize new owner as self, so decides to immunologically reject them.

Question 47

What is the primary change that occurs in lymphoid cells over the course of maturation (in a broad sense)

Answer 47

Changes in the antigens, receptors, or integrins on the cell surface.

Question 48

Take a peek at the pictures in the last couple pages, but basically acknowledge that its complicated, have an idea of where some steps happen, know CD4 and CD8 cells.

Answer 48

Hey, you finished this set of flashcards. You're freakin awesome!