test 3: lymphatic system

Question 1

what are the 3 functions of the lymphatic system?

Answer 1

1) produce, maintain, and distribute lymphocytes (immune response)
2) maintain normal blood volume and composition of interstitial fluid
3) alternate route for transport of hormones and nutrient wastes

Question 2

what is the composition of lymph?

Answer 2

1) interstitial fluid
2) lymphocytes
3) macrophages

Question 3

what type of cells are lymphocytes?

Answer 3

agranular WBCs

Question 4

primary lymphatic structures

Answer 4

• where lymphocytes are produced and mature

- e.g. thymus, red bone marrow

Question 5

secondary lymphatic structures

Answer 5

• where lymphocytes are activated and receive additional support
• e.g. lymph nodes and tonsils

Question 6

describe the flow of lymph

Answer 6

-1-way highway coming from periphery to venous system

Question 7

lymphedema

Answer 7

damage to lymphatic vessels or if you get lymph nodes removed, system doesn’t work as well

• get pooling of lymph, swelling
• light pressure massage helps to treat

Question 8

lymphatic capillaries

Answer 8

• sit in capillary beds
• contain one-way “valves”, made of collagenous filaments
• endothelial cells overlap one another - not a full basal lamina surrounding it

Question 9

do lymphatic capillaries contain valves

Answer 9

• not really
• look and act like valves, but they’re really just overlapping endothelial cells - fluid goes in one way then can’t escape

Question 10

how does the lumen of lymphatic vessels differ from blood vessels?

Answer 10

-they have a large lumen, walls are quite thin (don’t see 3 different layers like in arteries and veins)

Question 11

name the lymphatic vessels from distal to proximal

Answer 11

• small lymphatic capillaries

- vessels (has valves)

Question 12

do lymphatic vessels have valves?

Answer 12

-yes, bulges in lymphatic system where there are valves, muscle contraction helps move fluid along the vessels (same as veins)

Question 13

what are the 5 lymphatic trunks?

Answer 13

1) lumbar (R/L)
2) intestinal (R/L)
3) brachiomediastinal (R/L) - drains everything from thoracic cavity
4) subclavian (R/L)
- upper extremity
5) jugular (R/L)
- head

Question 14

cisterna chyli

Answer 14

• gather lymph from lumbar and intestinal trunks

- turns into thoracic duct when it passes the diaphragm

Question 15

thoracic duct

Answer 15

cisterna chyli joins to form thoracic duct

• drains into left subclavian vein
• collects most of the body’s fluid

Question 16

right lymphatic duct

Answer 16

• attaches to right subclavian vein
• right jugular, right subclavian, right brachiomediastinal
• collects a lot less fluid

Question 17

what are the 2 lymphatic ducts and from which areas of the body do they collect fluid

Answer 17

1) right lymphatic duct
- collect fluid from right side of thoracic cavity, right arm, and right side of head/neck
2) thoracic duct
- collects from everywhere else in body

Question 18

describe the movement of interstitial fluid from right ankle to heart

Answer 18

• Lymphatic capillary
• Lymphatic vessel
• Right lumbar trunk
• Cisterna chyli
• Thoracic duct
• Left subclavian vein
• Brachiocephalic vein
• Superior vena cava

Question 19

where do lymphocytes originate from?

Answer 19

• production starts in red bone marrow

- T-cells activate in thymus

Question 20

what are the 3 lymphocytes? Where in the body does each mature?

Answer 20

• T-cells (thymus)
• B-cells (red bone marrow)
• NK cells (red bone marrow)

Question 21

T-cells, B-cells, and NK cells originate from which type of cells?

Answer 21

lymphatic stem cells

Question 22

how does each lymphocyte contribute to immunity?

Answer 22

1) T-cells
- cell mediated immunity
2) B-cells
- antibody mediated immunity
3) NK cells
- immune surveillance

Question 23

T cells

Answer 23

• cell mediated immunity
• attack and destroy foreign pathogens
• most abundant
• 3 types: helper (helps activate B cells), regulatory, and memory

Question 24

B cells

Answer 24

• activated by T cells

- create antibodies to attack foreign cells

Question 25

NK cells

Answer 25

-look for foreign bodies - attach to them and release chemical that signals that the cell is bad

Question 26

what does MALT stand for?

Answer 26

-mucosa-associated lymphoid tissue

Question 27

what systems are MALTs associated with?

Answer 27

- respiratory, reproductive, digestive, urinary | - where you're exposed to different viruses and foreign bodies

Question 28

what are the 2 major sites of MALTs?

Answer 28

1) tonsils (5) | 2) appendix

Question 29

name the 5 tonsils and their location

Answer 29

- pharyngeal (back of nasopharynx) - L/R palatine tonsils (back of throat - L/R lingual tonsils (base of tongue)

Question 30

how is the appendix a MALT?

Answer 30

- contains a lot of lymphatic tissue | - when removed, lack some of the cells that produce gut bacteria

Question 31

what are the 3 lymphatic organs?

Answer 31

1) lymph node 2) thymus 3) spleen

Question 32

lymph node as a lymphatic organ

Answer 32

- widespread throughout the body - cervical, axillary, popliteal, inguinal, thoracic, abdominal, intestinal, mesenteric - should be small when healthy (1-25 mm)

Question 33

thymus as a lymphatic organ

Answer 33

- thoracic cavity in mediastinum | - large and active in childhood - decreases in adulthood

Question 34

spleen as a lymphatic organ

Answer 34

- LUQ - sits between 9th and 11th rib - processes a lot of blood, a lot of damaged blood cells in this area - can be removed, we can function without it - will be a bit immunocompromised however

Question 35

what is the largest lymphatic organ?

Answer 35

spleen

Question 36

what is the capsule of a lymph node

Answer 36

dense CT surrounding the node

Question 37

what are the trabeculae in lymph nodes?

Answer 37

indentations protruding from capsule

Question 38

what is the hilum of the lymph node?

Answer 38

-indentation where a lot of structures come in and out (blood vessels/lymph vessels)

Question 39

describe the movement of lymph in a lymph node

Answer 39

- afferent vessel (there are multiple) - cortex - medulla - efferent vessel (there is only one)