Module 8 - Lymphatic System

Question 1

In comparison to veins, lymphatic vessels:
1. have overlapping endothelial cells that allow the passage of large materials
2. have smaller diameters and lumens
3. absorb more proteins and carbohydrates from the GI tract
4. are not anchored to the surrounding tissues; thus, they have great flexibility

Answer 1

1. have overlapping endothelial cells that allow the passage of large materials

Question 2

The _______ collects lymph from both sides of the body inferior to the diaphragm.

Answer 2

thoracic duct

Question 3

Lymph is transported through a network of increasingly larger lymphatic vessels. What is the correct order of these, from smallest diameter to largest diameter?

Answer 3

Capillaries - vessels - trunks - ducts

Question 4

Compared to blood capillaries, lymphatic capillaries:

Answer 4

are more permeable

Question 5

The lymphatic system functions to maintain normal blood volume and eliminate local variations in the:

Answer 5

composition of interstitial fluid

Question 6

Lymphatic capillaries:
1. are only located around vital organs
2. are interlaced with blood capillaries (and arterioles and venules) of the cardiovascular system are interlaced with blood capillaries (and arterioles and venules) of the cardiovascular system
3. fill by increases in the interstitial pressure rather than a pump (e.g., the heart)
4. are vessels where interstitial fluid can enter the lymphatic system
5. have collagen fibers to anchor them to surrounding tissue
6. have cuboidal endothelial cells

Answer 6

2, 3, 4, 5

Question 7

The cells of the lymphatic system are collectively known as:

Answer 7

lymphocytes

Question 8

Which of the following statements are true:
1. Plasma cells secrete antibodies
2. B cells are lymphocytes that produce antibodies
3. NK cells are the body’s first line against viruses and some types of cancer
4. NK cells are lymphocytes that produce antibodies
5. T cells mature in the thymus
6. T cells are lymphocytes that produce antibodies

Answer 8

1, 2, 3, 5

Question 9

What are the primary lymphoid organs:

Answer 9

bone marrow and thymus

Question 10

Which of the following statements are true:
1. tonsils are primary lymphoid organs
2. tonsils are most active in children
3. swelling of the tonsils is an indication of an active immune response
4. tonsils are found in the small intestine
5. tonsils are collections of lymphoid nodules

Answer 10

2, 3, 5

Question 11

Mucosa-associated lymphoid tissue (MALT):

Answer 11

is important for immune responses to ingested substances

Question 12

Vessels

Answer 12

arteries, veins, capillaries

Question 13

Lymphatic capillaries

Answer 13

-are extremely permeable, allowing larger molecules and excess fluid from interstitial spaces to enter the lymphatic vessels
-Closed-ended tubes interspersed around blood capillary beds
-Receive fluid from interstitial fluid in connective tissue
-Overlapping endothelial cells act as one-way valves
(clefts between endothelial cells)

Question 14

Collecting lymphatic vessels

Answer 14

Have the same three tunics as veins, but the collecting vessels have thinner walls and more internal valves, and they anastomose more.

Question 15

Lymphatic trunks

Answer 15

The superficial and deep lymphatics eventually merge to form this larger lymphatic vessel; drains lymph from the lymphatic vessels

Question 16

Lymphatic ducts

Answer 16

right lymphatic duct and thoracic duct

Question 17

Right lymphatic duct

Answer 17

-Deep to the right clavicle
-Returns lymph from the right side of the head and neck, right upper limb and the right side of the thorax

Question 18

Thoracic duct

Answer 18

-begins just inferior to the diaphragm
-begins as a saclike structure called the cisterna chyli
-collects lymph from most of the body

Question 19

Lymphatic System

Answer 19

• associated with the immune system to such a degree that the two systems are virtually indistinguishable
  -system of vessels, cells, and organs that carries excess fluids to the bloodstream and filter pathogens from the blood

Question 20

Lymph

Answer 20

contains a liquid matrix and white blood cells

Question 21

Lymphedema

Answer 21

An accumulation of interstitial fluid due to lymphatic drainage issue or
lymphatic failure

Question 22

Lymphatic Cells (Lymphocytes)

Answer 22

are the primary cells of adaptive immune responses; consist of T, B, and NK cells

Question 23

T-Cells

Answer 23

-thymus-dependent cells
-cell mediated immunity
-do NOT secrete antibodies
-Recognize antibodies on infected cells
-Secrete chemical messengers
-Destroy cells infected with intracellular pathogen

Question 24

B-Cells

Answer 24

-bone marrow–derived cells
-Generate diverse antibodies (secrete antibodies)
- isolation and destruction of invading bacteria and viruses.

Question 25

NK Cells

Answer 25

-aka natural killer cell -Among the first line of defense -Destroy virally infected cells/certain cancerous cells

Question 26

Lymphatic Organs

Answer 26

-Separated from surrounding tissue by a fibrous capsule -include lymph nodes, thymus gland, spleen

Question 27

Afferent lymphatic vessels

Answer 27

Vessels that bring lymph draining from connective tissue into a lymph node en route to the blood.

Question 28

Lymph nodes

Answer 28

-function to remove debris and pathogens from the lymph -site of adaptive immune responses mediated by T cells, B cells, and accessory cells of the adaptive immune system -site of adaptive immune responses mediated by T cells, B cells, and accessory cells of the adaptive immune system

Question 29

Efferent lymphatic vessels

Answer 29

Cells and lymph fluid that leave the lymph node may do so by this set of vessels

Question 30

Thymus

Answer 30

-a bilobed organ found in the space between the sternum and the aorta of the heart -connective tissue holds the lobes closely together but also separates them and forms a capsule.

Question 31

Spleen

Answer 31

-major secondary lymphoid organ -highly vascularized -fragile organ without a strong capsule and is dark red due to its extensive vascularization

Question 32

Red pulp

Answer 32

-80% -Contains mostly erythrocytes, platelets, macrophages, and some plasma cells -Functions in filtration of blood -consists of reticular fibers with fixed macrophages attached, free macrophages, and other cells typical of the blood, including some lymphocytes

Question 33

White pulp

Answer 33

-"cuffs” of lymphoid tissue, lymphocytes, and macrophages -Functions heavily in adaptive immunity

Question 34

Lymphatic nodules

Answer 34

-Lymphocytes aggregated within a supporting framework of reticular fibers -Wall of segments of the digestive tract -Nodules have a germinal center, which contains the lymphocytes

Question 35

Mucosa-associated lymphatic tissue (MALT)

Answer 35

-consists of an aggregate of lymphoid follicles directly associated with the mucous membrane epithelia -lymphatic tissue found in mucous membranes that line passageways open to the outside world; these include the respiratory, gastrointestinal, urinary, and reproductive tracts

Question 36

Tonsils

Answer 36

lymphoid nodules located along the pharynx’s inner surface and are important in developing immunity to oral pathogens

Question 37

Aggregated lymphoid nodules (Peyer’s patches)

Answer 37

-a type of MALT in the small intestine, are especially important for immune responses against ingested substances -contain specialized endothelial cells called M (or microfold) cells that sample material from the intestinal lumen and transport it to nearby follicles so that adaptive immune responses to potential pathogens can be mounted

Question 38

Appendix

Answer 38

-A similar process occurs involving MALT in the mucosa and submucosa of the appendix -A blockage of the lumen triggers these cells to elicit an inflammatory response that can lead to appendicitis.