HISTO - Lymphatic System

Question 1

What are the 3 major functions of the Lymphatic system?

Answer 1

1. Drain excess interstistial fluid - return to bloodstream to help maintain normal blood volume.
2. Immune Response - produce, maintain, and distribute lymphocytes.
3. Provide an alternative transportation route fro hormones, nutrients and Waste products.

Question 2

What are the 3 types of lymphocytes?

Answer 2

1. B cells = produce and secrete antibodies along with their derivative cell; involved with humoral immunity; 20-30% of circulating lymphocytes.
2. T cells = Differentiate in the thymus; attach and destroy cells; involved with cell-mediated immunity; 60-80% of circulating lymphocytes.
3. Natural Killer cells = kill certain transformed cells; 5-10% of circulating lymphocytes

Question 3

What is Diffuse Lymphatic tissue?

Answer 3

Accumulations of lymphocytes in the lamina propria of the alimentary canal, as well as respiratory, urinary and reproductive tracts.

• no surrounding capsule
• also find plasma cells and eosinophils.

Question 4

What are lymphatic nodules?

Answer 4

similar to diffuse lymphatic tissue, it is accumulations of lymphocytes in the wall of alimentary canal, as well as respiratory, urinary and reproductive tracts.

• No surrounding capsule
• sharply defined
• Meshwork of reticular fibers
• Lymphocytes, plasma cells, eosinophils.

Question 5

What are the 2 types of Lymphatic nodules?

Answer 5

1. Primary Nodule = aggregation of primarily small lymphocytes
2. Secondary Nodule = will have a germinal center and a mantle zone (follicular dendritic cells (FDC’s) are present in germinal centers.

Question 6

True or False, Lymphatic nodules are normally found randomly dispersed by themselves.

Answer 6

True.

However in central location of the alimentary canal, they are grouped together (aggregated lymphatic nodules).

Question 7

Where are the 2 regions of aggregated lymphatic nodules?

Answer 7

1. Tonsils = create ring around entrance to the oropharynx and the nasopharynx.
2. Peyer’s patches = in ileum.

Question 8

What is MALT?

Answer 8

Mucous associated lymphatic tissue.

Question 9

What is GALT?

Answer 9

Gut associated lymphatic tissue (associated with the alimentary canal)

Question 10

What is BALT?

Answer 10

Bronchus associated lymphatic tissue; associated with the respiratory system

Question 11

What are the supporting cells?

Answer 11

Reticular cells, monocytes, macrophages, neutrophils, basophils, eosinophils, dendritic cells, follicular dendritic cells, langerhans cells, and epithelioreticular cells.

Question 12

______ is a capsule organ along the pathway of lymphatic system,

Answer 12

Lymph node

Question 13

What is the function of the lymph node?

Answer 13

Filtering system

Question 14

What are the 5 parts of the Lymph node?

Answer 14

1. Capsule
2. Trabeculae
3. Reticular Tissue/Meshwork
4. Cortex
5. Medulla

Question 15

Describe the layers of the cortex of the lymph node….

Answer 15

1. Superficial (Nodular) cortex.
   - Primary & secondary nodules (Secondary have germinal centers)
2. Deep cortex (paracortex)

Question 16

What are the 2 structures of the lymph node medulla?

Answer 16

1. Medullary cords (Purple bean shapes made of purple dots)

2. Medullary sinuses

Question 17

What are the 4 cells of the reticular Meshwork?

Answer 17

1. Reticular cells
2. Dendritic cells
3. Macrophages
4. Follicular Dendritic cells

Question 18

What is the flow of lymph through the lymph node?

Answer 18

Afferent lymph vessel —> subcapsular (cortical) sinus—>trabecular sinus—>Medullary sinus—>Efferent lymph vessel

Question 19

The Thymus is the site of, thymic cell education…What occurs in this process?

Answer 19

T cells mature and differentiate into immunocompetent T cells.

Question 20

What is the Function of the Spleen?

Answer 20

Filters and monitors the blood immunologically just at the lymph nodes monitor lymph.

Question 21

The spleen consists of a variety of pulps….what are they?

Answer 21

just kidding its only 2 pulps….The Red and white Pulp.

Question 22

Describe the red pulp of the spleen…

Answer 22

Consists of blood filled venous sinuses surrounded by cords of splenic tissue called splenic cords.

• The cords consist of rbc’s, macropahges, lymphocytes, plasma cells, and granulocytes.
• Primary role of red pulp is blood filtration!

Question 23

Describe the White Pulp of the Spleen…

Answer 23

lymphatic tissue consisting mostly of lymphocytes lymphocytes aggregate around branches of splenic artery creating a periarterial lymphatic sheaths.
* Function of white Pulp is to carry out immune functions similar to lymph nodes.