Cells And Organs

Front 1

What is the most prominent immune cell?

Back 1

Neutrophils

Front 2

Second most prominent immune cells?

Back 2

Lymphocytes (B and T cells)

Front 3

Two progenitor cells derived from hematopoietic stem cells

Back 3

Myeloid progenitor cells (Blood related cells i.e. basophils, neutrophils, monocytes/macrophages etc.)

Lymphoid progenitor cells (lymphocyte related cells i.e. b cells, t cells, nk cells)

Front 4

Unique origin of dendritic cells

Back 4

Are found to differentiate from both myeloid and lymphoid progenitors

may also arise from monocytes instead of forming macrophages

Front 5

Site of t cell maturation

Back 5

thymus

Front 6

Granulocytes and their function

Back 6

Basophils: inflammatory mediators (specifically in allergic response)

Eosinophils: parasite removal

Neutrophil: phagocytes

Front 7

Granulocyte not found in circulation and its role

Back 7

Mast cell; contain granules that release inflammatory mediators such as histamine (present in allergic response)

Front 8

Monocytes to macrophages

Back 8

Monocytes are phagocytic cells found in circulation that can enter into the tissue through diapedesis where they mature into macrophages and can additionally function in antigen presentation.

Front 9

Types of dendritic cells

Back 9

1. Langerhans Cells: found in epidermis (skin) and mucosal membranes

2. Interstitial Cells: present in organs

3. Interdigitating: found in areas of the secondary lymph organs that contain t cells (lymph nodes) and in the thymus

4. Circulating

5. Follicular

Front 10

Unique dendritic cell

Back 10

Follicular dendritic cells: do not function in antigen presentation, instead are found in the lymph nodes where they express lots of Fc receptors to bind opsonized antigens

possibly activates B cells

Front 11

Two types of T-cells

Back 11

Helper T-cells and Cytotoxic T-cells

Front 12

Platelet function

Back 12

Release inflammatory mediators and aid in the clotting process

Front 13

How does the lymph return to general circulation?

Back 13

The lymph returns to circulation through the thoracic duct

Front 14

What is the lymph produced from?

Back 14

The lymph is a product of blood plasma and other soluble contents that seeps through fenestrations in the capillaries according to a pressure gradient

Front 15

Primary lymphoid organs

Back 15

Bone Marrow

Thymus

- where the production and development of lymphatic cells occur

Front 16

Secondary Lymphoid Organs

Back 16

1. Lymph Nodes

2. Spleen (important for the filtration of blood not lymph)

3. MALT (consisting of the GALT, specifically peyer's patches and the BALT)

Front 17

Structure of the Lymph Nodes

Back 17

Consist of a cortex (outer and paracortex) and the medulla

Front 18

Where are B cells found in the lymph nodes, where are T cells? How about plasma cells?

Back 18

B cells are found in the follicles where they can encounter antigen and mature to plasma cells which migrate to the medulla

T cells are found in the paracortex

Front 19

Describe the different vessels that supply the lymph node and what role they play in immune cell activation and pathogen removal

Back 19

The lymphatic afferent carry lymph to the nodes which will contain antigens and APCs that will activate adaptive immune cells and eventually result in pathogen neutralization

The efferent lymphatics will carry mature lymphocytes to the thoracic duct and into the circulation

Arteries and Veins are responsible for carrying naive lymphocytes from the bone marrow to the lymph nodes for final maturation and activation

Front 20

Centre of a lymph follicle and what is its role?

Back 20

Germinal Centre (region of intense B cell activation)

Front 21

What are HEVs and what is their role?

Back 21

HEV stands for high endothelial venules which are responsible for enabling easier transport of immune cells into the lymphoid organs

Front 22

In addition to T cells, what other cells are prominent in the paracortex?

Back 22

Interdigitating Dendritic Cells, which conduct antigen presentation specifically for T-cells

Front 23

What structure does blood first encounter as it enters the spleen?

Back 23

Blood enters the spleen through the splenic artery and will then move to smaller central arteries that pass through lymph follicles (like follicles in the nodes these structures primarily contain B-cells)

Front 24

What is the marginal Zone?

Back 24

Primarily acts as the border between the white pulp (containing the lymphocytes) and the red pulp

Front 25

What does PALS stand for and what is its function?

Back 25

PALS is the periarteriolar lymphatic sheath which surrounds the central arteries and contain primarily T-cells activated by myeloid dendritic cells

Front 26

What happens after blood has passed through the arterioles of the white pulp?

Back 26

Arterioles will either directly connect to the venous sinuses or the arterioles will terminate and the blood will freely flow through the thread like structure of the spleen (removes damaged and old rbcs)

Front 27

How do lymphocytes enter the white pulp?

Back 27

Lymphocytes travel through the general circulation and enter the white pulp where they are either sorted to the follicles or PALS

Front 28

Where are the Peyer's Patches found?

Back 28

They are found in the intestinal tract, specifically in the ileum

Front 29

Do the Peyer's Patches require afferent lymphatics, why or why not?

Back 29

They do not, unlike the lymph nodes, antigens reach the peyer's patches through specialized epithelia from the intestinal lumen

Front 30

What are M cells?

Back 30

M cells are specialized epithelial cells that direct antigens to the immune cells of the peyer's patches

Front 31

What is the primary immunoglobulin of the MALT?

Back 31

IgA