Lymphatic System

Question 1

Lymphatic capillaries contain flaplike _________ which allow fluid to only move in and not out of the capillaries. Fluid moves in only when the hydrostatic pressure is greater outside of the capillary than inside of it.

Answer 1

minivalves (made of overlapping endothelial cells anchored by collagen fibers)

Question 2

True/False. Lymphatic capillaries are more permeable than blood capillaries.

Answer 2

True- large molecules like proteins, pathogens, and cancer cells can pass across the plasma membrane.

Question 3

This specialized set of lymphatic capillaries transport absorbed fats from the small intestine to the blood stream. This fatty lymph is called chyle.

Answer 3

Lacteals

Question 4

What is the sac at the end of the intestinal trunk that chyle drains into?

Answer 4

Cisterna chyli (part of thoracic duct).

Question 5

Organize these vessels from smallest to larges. Lymphatic trunks, ducts, collecting vessels, and capillaries.

Answer 5

Capillaries-collecting vessels-trunks-ducts

Question 6

Name the two main ducts in the lymphatic system that drain into the blood near internal jugular and subclavian veins. Which one drains the right side of the head and thorax and right upper limb?

Answer 6

Thoracic duct and right lymphatic duct; right lymphatic duct. The thoracic drains lymph from the rest of the body.

Question 7

This condition is caused when the vasa vasorum of larger lymphatics becomes congested with blood.

Answer 7

Lymphangitis (site of infection distal to inflammation due to one way flow of lymph)

Question 8

Lymphedema (severe localized edema) is the result of a blockage of lymph returning to the blood. Name one or two things that might cause this.

Answer 8

Cancer/tumor, removal of lymphatics due to cancer

Question 9

________cell produces the _______ fiber stroma, which is the network that supports other cell types in lymphoid organs.

Answer 9

Reticular

Question 10

Activated B-cells produce _______ cells which secrete anti-bodies into the blood.

Answer 10

plasma

Question 11

This specialized macrophage is found mainly in the skin and mucous membranes. After using it longs arms to grab an invader, it enters the lymphatics and presents part of the invader to T-cells.

Answer 11

Dendritic cell

Question 12

Name the two types of lymphoid tissues

Answer 12

Diffuse lymphoid tissue and lymphoid follicles

Question 13

Lymphoid follicles are tightly packed spherical bodies of lymphoid cells and reticular fibers. The _______ is where proliferating B cells dominate. The exterior ______ is where resting and memory B cells hang out.

Answer 13

germinal center, mantle

Question 14

Lymphoid follicles are found mainly in lymph nodes, the appendix, and ______ ________, isolated aggregations in the intestinal wall.

Answer 14

Peyer’s patches

Question 15

Lymphoid tissue is largely composed of _______ connective tissue. Macrophages live on the fibers of this network.

Answer 15

reticular

Question 16

Name the primary lymphoid organs

Answer 16

Red bone marrow (B cells mature here) and thymus (T cells mature here)

Question 17

______ _______ ______ are where mature lymphocytes first encounter antigens and are activated.

Answer 17

Secondary lymphoid organs (lymph nodes, spleen, MALT (tonsils, Peyer’s patches, appendix).

Question 18

Which secondary lymphoid organs cleanse the lymph and activate the immune system?

Answer 18

Lymph nodes (large clusters are found in the inguinal, axillary, and cervical regions

Question 19

Macrophages and plasma cells are found in the _____ of the lymph node.

Answer 19

Medulla

Question 20

T-cells and dendritic cells are found in the _____ of the lymph node.

Answer 20

Paracortex

Question 21

B-cells, follicular dendritic cells, and subscapular macrophages are found in the ______ of the lymph node.

Answer 21

Cortex

Question 22

What benefit is there of lymph nodes having more afferent vessels than efferent vessels?

Answer 22

Slows the flow of lymph

Question 23

Afferent lymphatic vessels-> subscapular sinus->cortical sinus->medullary sinus->efferent lymphatic vessels (exits via hilum). This describes the flow of lymph through _____ _____.

Answer 23

Lymph nodes

Question 24

This can form when the the nodes are overwhelmed by infection leading to inflamed, swollen, and tender lymph nodes.

Answer 24

Buboes (bubonic plague named after these)

Question 25

Largest lymphoid organ critical to blood cleansing functions and is home to a large number of lymphocytes and macrophages.

Answer 25

Spleen

Question 26

This part of the spleen is where immune functions take place (composed mostly of lymphocytes on reticular fibers) and clusters around central arteries.

Answer 26

White pulp

Question 27

Consists of splenic cords, regions of reticular CT, that separate the blood-filled splenic sinusoids. Worn-out blood cells and bloodborne pathogens are also destroyed here.

Answer 27

Red pulp

Question 28

True or false. In children younger than 12, the spleen will regenerate if a small part is left in the body.

Answer 28

true

Question 29

What does MALT stand for and what are the 3 largest collections in the body?

Answer 29

Mucosa-associated lymphoid tissues; tonsils, Peyer's patches, appendix

Question 30

The 4 tonsils (all of which contain lymphoid follicles with germinal centers) are palatine, lingual, pharygeal, and tubal tonsils. Name their location.

Answer 30

Palatine- posterior end of oral cavity, lingual- base of tongue, pharyngeal-posterior wall of nasopharynx, tubal- openings of pharyngotympanic tubes

Question 31

This invagination of epithelium is where bacteria gets trapped and destroyed in the tonsils.

Answer 31

tonsillar crypts

Question 32

This MALT destroys bacteria and prevents breach of the intestinal wall. They contain clusters of lymphoid follicles.

Answer 32

Peyer's patches

Question 33

This offshoot of the large intestine contains a large number of lymphoid follicles and performs a similar function to Peyer's patches as well as protecting gut flora.

Answer 33

Appendix

Question 34

T-lymphocytes become immunocompetent in this bilobed structure.

Answer 34

Thymus

Question 35

True/false. The thymus is most active and largest during adulthood.

Answer 35

False

Question 36

_____ ______ , like flowerets of cauliflower, contain an outer cortex of immature T cells and an inner medulla of mature T cells.

Answer 36

Thymic lobules

Question 37

Thymic corpuscles, located in the medullary area of the lobule, are involved in the development of _____ _____, a class of lymphocytes important for prevent ________ response.

Answer 37

regulatory T cells; autoimmune

Question 38

How does the thymus differ from secondary lymphoid organs?

Answer 38

No follicles (lacks B cells), doesn't directly fight antigens (strictly maturation site for T cells), stroma consist of epithelial cells rather than reticular fibers.