Chapter 16: Lymphatic System

Question 1

what type of system is the lymphatic system?

Answer 1

closed ended

Question 2

3 functions of the lymphatic system

Answer 2

1. defends body against diseases
2. absorbs lipids from digestive system & transports them into bloodstream
3. transports excess fluid away from interstitial spaces & returns it back to bloodstream

Question 3

important cells to lymphatic system

Answer 3

T cells & B cells

Question 4

lymphatic pathway

Answer 4

1. lymphatic capillaries
2. lymphatic vessels (afferent)
3. lymph nodes
4. larger lymphatic vessels (efferent)
5. lymphatic trunks
6. lymphatic collecting ducts
7. subclavian veins in thorax

Question 5

lacteals

Answer 5

found in small intestine; specialized lymph capillaries that absorb lipids/fats & transfer them back to bloodstream

Question 6

capillaries

Answer 6

• microscopic, closed ended tubes
• thin walled
• networks parallel blood capillaries through body
• walls formed from simple squamous tissue

Question 7

vessels

Answer 7

• similar to veins, but thinner
• contain semilunar valves
• 3 layers

Question 8

3 layers of lymphatic vessels

Answer 8

1. endothelial (inner)
2. smooth muscle (middle)
3. connective tissue (outer)

Question 9

trunk

Answer 9

• drain lymph from lymphatic vessels
• named for region they serve

Question 10

lymphatic trunks

Answer 10

• lumbar
• jugular
• subclavian
• bronchomediastinal
• intercostal
• interstitial

Question 11

collecting ducts

Answer 11

• drain lymph from trunks
• thoracic duct (large) and right lymphatic duct (small)

Question 12

the thoracic duct drains to

Answer 12

left subclavian vein near junction w/ left jugular vein

Question 13

the small right lymphatic duct drains to

Answer 13

right subclavian vein

Question 14

afferent vessel

Answer 14

leads to lymph node

Question 15

efferent vessel

Answer 15

leads away from lymph node

Question 16

lymph

Answer 16

interstitial fluid once its entered lymphatic vessels

Question 17

what does capillary blood pressure do?

Answer 17

filers water & small molecules from the blood

Question 18

resulting tissue fluid (after capillary bp filters)

Answer 18

• same composition as blood plasma
• contains water, nutrients, gases, & hormones
• exception: tissue fluid does not contain large plasma proteins

Question 19

lymph formation

Answer 19

formation from the plasma normally exceeds reabsorption leading to the net formation of tissue fluid; increases the tissue fluid hydrostatic pressure within interstitial spaces, forcing fluid into lymphatic capillaries & forming lymph

Question 20

edema

Answer 20

excess tissue fluid accumulation

Question 21

when is lymph flow highest?

Answer 21

physical activity & exercise

Question 22

lymph flow

Answer 22

muscle activity influences the movement of lymph through lymphatic vessels

Question 23

what factors determine lymph flow?

Answer 23

• contraction of skeletal muscles compresses lymphatic vessels, moving the lymph
• respiratory process creates low pressure in thorax & high pressure in abdomen during inspiration; sends lymph from abdomen to thorax
• smooth muscle in larger lymphatic vessels contract to aid in flow of lymph

Question 24

roles of lymphatic capillaries (6)

Answer 24

• absorption of dietary fat
• delivery of absorbed fats to bloodstream
• return of small proteins filtered by blood capillaries to bloodstream
• collection of excess interstitial fluid
• delivery of excess fluid to bloodstream
• delivery of foreign particles to the lymph nodes

Question 25

what allows easy entry of tissue fluid?

Answer 25

flap like valves between cells of lymphatic capillaries

Question 26

mucosa associated lymphoid tissue (malt)

Answer 26

unencapsulated lymphatic tissue of the digestive, urinary, respiratory, & reproductive tracts

Question 27

tonsils & appendix

Answer 27

composed of lymphatic nodules (compact masses of lymphatic tissue)

Question 28

peyers patches

Answer 28

aggregates of lymphatic nodules found in ileum (distal part of small intestine)

Question 29

lymphatic organs

Answer 29

- consist of encapsulated lymphatic tissue - lymph nodes, spleen, thymus

Question 30

how do antibodies react to antigens?

Answer 30

in 3 different ways

Question 31

3 ways antibodies react to antigens:

Answer 31

1. direct attack on antigens 2. activation of complement 3. stimulation of local change, inflammation, to help prevent spread of infection

Question 32

immune responses (2)

Answer 32

primary & secondary

Question 33

primary immune response

Answer 33

produced by first encounter with antigen; 1st antibodies appear in 5-10 sys, and remain for several weeks; memory B cells also produced

Question 34

secondary immune response

Answer 34

subsequent exposure to antigen produced high concentration of antibodies in 1-2 days; antibodies remain for months or years; memory B cells live for many years

Question 35

colostrum

Answer 35

very first breast milk; antibody rich

Question 36

autograft

Answer 36

transplant from self

Question 37

isograft

Answer 37

transplant from identical twin

Question 38

allograft

Answer 38

transplant from same species

Question 39

xenograft

Answer 39

transplant from different species

Question 40

which transplants tend to cause rejection?

Answer 40

allograft & xenograft

Question 41

which transplants don't usually cause rejection?

Answer 41

autograft & isograft

Question 42

HIV

Answer 42

- virus that breaks down immune system - caused by infected needles, sexual contact, birth/milk from infected mother - attacks macrophages and helper T cells - when helper T cells decrease, B cells can't produce antibodies - person dies from loss of immune response against pathogens