Chapter 23 - Lymphatic System

Question 0

What do lymphatic vessels transport?

Answer 0

Transport fluid called lymph from tissues to the venous systems?

Question 1

Functions of the lymphatic system

Answer 1

• Produce, maintain, and distribute LYMPHOCYTES
• Maintain normal blood and interstitial fluid volume
• Alternate route for the transport of nutrients, hormones, and waste

Question 2

Sizes of lymphatic vessels

Answer 2

• Small lymphatic capillaries
• Medium lymphatic vessels
• Large lymphatic trunks
• Lymphatic ducts

Question 3

Lymphatic vessels are almost always found with ____

Answer 3

Blood vessels

Question 4

Location of lymphatic vessels

Answer 4

• Most tissues

- Absent in avascular tissue and CNS

Question 5

What is lymph?

Answer 5

Lymph is a fluid connective tissue

- Only occurs in lymphatic vessels

Question 6

Where is lymph derived from?

Answer 6

• Interstitial fluid of the tissues
• Lymphocytes
• Macrophages

Question 7

How is interstitial fluid derived from lymph?

Answer 7

• Originates from the plasma
• Water and dissolved materials leak out of capillaries due to diffusion and filtration
• 27L/day enters the interstitial spaces
• Fluid lacks proteins and has lower Oxygen
• Interstitial fluid moves into the lymphatic capillaries and is known as LYMPH

Question 8

How much of interstitial fluid is absorbed

Answer 8

90%

Question 9

Five facts explaining lymphatic capillaries

Answer 9

• Closed ended tubes
• In interstitial spaces
• Form networks
• Single layer of squamous cells with incomplete basal lamina
• Fenestrated

Question 10

How do lymphatic capillaries differ from blood capillaries

Answer 10

• Large diameter
• Thinner walls
• Flat and irregular
• Have anchoring filaments to keep the passage open
• Overlapping endothelial cells

Question 11

Explain the formation of lymph

Answer 11

• Interstitial fluid enters capillaries
• Overlapping cells function as one way valves
• Moves through fenestrations
• Large things such as viruses and debris follow

Question 12

Characteristics of medium lymphatic vessels (4)

Answer 12

1. Merging of lymph capillaries
2. Similar to veins (interna, media, adventitia, and valves)
3. Merge to form trunks
4. Travel with arteries of same size

Question 13

What are lymphatic trunks named for?

Answer 13

For the region the drain

Question 14

Examples of lymphatic trunks

Answer 14

• Lumbar
• Intestinal
• Broncomediastinal
• Subclavian
• Jugular

Question 15

What do lymphatic trunks drain into?

Answer 15

Lymphatic ducts

Question 16

Two lymphatic ducts

Answer 16

Thoracic and right lymphatic

Question 17

What do lymphatic ducts do? (3)

Answer 17

• Deliver lymph to venous circulation at subclavian
• Reintroduced to bloodstream
• Becomes part of plasma and is circulated

Question 18

What does the thoracic duct drain?

Answer 18

• Lower body
• Left arm
• Head
• Neck

Question 19

Route of the thoracic duct

Answer 19

• Arises from CISTERNA CHYLI
• Through diaphragm
• Ascends in front of vertebral column
• Empties into LEFT SUBCLAVIAN VEIN

Question 20

What does the Right Lymphatic Duct drain?

Answer 20

• Right side of head
• Neck
• Right arm

Question 21

Route of the Right Lymphatic Duct

Answer 21

• Starts in right thorax

- To the Right subclavian vein

Question 22

The rate at which ducts drain (3)

Answer 22

• Unevenly drain fluid from body
• Thoracic does the majority
• It is much longer and drains the entire inferior half of the body

Question 23

What are valves in lymph and what do they do?

Answer 23

• Occur at bulges

- Prevent backflow

Question 24

How do valves prevent backflow?

Answer 24

- Pressure is lower in lymphatics than in veins | - Lymph is moved using similar methods to veins (skeletal muscles and breathing)

Question 25

If drainage does not occur

Answer 25

lymphedema

Question 26

Primary cells of the lymphoid system

Answer 26

Lymphocytes

Question 27

What do lymphocytes allow for?

Answer 27

Specific (or adaptive) immunity

Question 28

Multi-faceted immune response to the detection of specific foreign antigens

Answer 28

Specific immunity

Question 29

Characteristics of NK-cells (5)

Answer 29

1. Natural killer cells 2. Derived directly from bone marrow 3. NON-specific immunity 4, Detect chemical signals other than specific antigens (like other leukocytes) 5. Induce apoptosis

Question 30

Characteristics of B-cells (3)

Answer 30

1. Originate and develop in the bone marrow 2. Stimulated by an antigen to produce antibodies 3. Can survive for years as MEMORY CELLS, and become active once exposed to a similar antigen

Question 31

Characteristics of T cells (4)

Answer 31

1. Originate in the bone marrow but develop in the thymus 2. Attack cells with antigens indicating viral infection or detrimental mutations (cancer) 3. Induce apoptosis 4. Have MEMORY CELLS similar to B-cells

Question 32

Reticular connective tissue dominated by lymphocytes

Answer 32

Lymphoid nodules

Question 33

What are lymphoid nodules NOT?

Answer 33

NOT organs

Question 34

Digestive lymph nodules

Answer 34

M.A.L.T. (Mucosa associated lymphoid tissue)

Question 35

Three types of M.A.L.T.

Answer 35

- Tonsils - Aggregated lymphoid nodules - Appendix

Question 36

Where are the tonsils and what do they do?

Answer 36

- Positioned around the pharynx | - Remove pathogens that enter via air or food

Question 37

Three types of tonsils with descriptions

Answer 37

1. Pharyngeal tonsil - one nodule in nasopharynx (adenoids) 2. Palatine tonsils - two nodules on the soft palate 3. Lingual tonsils - two nodules at the base of the tongue

Question 38

Line the mucosa of the small intestine

Answer 38

Aggregated lymphoid nodules

Question 39

Bind tube at the beginning of the small intestine

Answer 39

Appendix

Question 40

Areas of the appendix prone to infection

Answer 40

- Appendicitis | - Intestinal flora enter underlying tissues

Question 41

Surrounded by a fibrous connective tissue capsule

Answer 41

Lymphatic organs

Question 42

Examples of lymphatic organs

Answer 42

- Lymph nodes - Thymus - Spleen

Question 43

Five components to lymph nodes

Answer 43

1. Bean shaped 2. Between several AFFERENT and one EFFERENT vessels 3. Hilus 4. Cortex 5. Medulla

Question 44

What is the hilus in lymph nodes?

Answer 44

Indented region where BV's, nerves, and efferent lymph vessels connect

Question 45

The cortex capsule has ____ that subdivide it

Answer 45

Trabeculae

Question 46

Two regions of the cortex with their characteristics

Answer 46

1. Outer cortex - consists of aggregated B-cells | 2. Inner cortex - T cells enter blood here

Question 47

What happens in the Medulla?

Answer 47

Where B-cells leave through the efferent vessel

Question 48

Six locations of the lymph nodes

Answer 48

- Cervical - Axillary - Inguinal - Pelvic - Abdominal - Thoracic

Question 49

Where is the spleen found?

Answer 49

On the left side of stomach

Question 50

This is the largest lymphatic organ

Answer 50

Spleen

Question 51

Two sections of the spleen with meanings

Answer 51

1. White pulp - resembles lymph node | 2. Red pulp - large amounts of RBC (sinuses, macrophages, T/B cells)

Question 52

Functions of the spleen

Answer 52

- Remove old RBC's - Store/recycle iron - Initiate immune responses - Blood reservoir - RBC production in fetus

Question 53

Where is the thymus?

Answer 53

In mediastium

Question 54

What is special about the thymus?

Answer 54

- First lymph organ to develop - Grows until puberty - Shrinks with age - Replaced by fibrous and adipose tissue

Question 55

Two lobes with lobules of thymus

Answer 55

Cortex - mostly immature Tcells | Medulla - mostly reticular epithelial cells

Question 56

What do T-cells in the thymus do? (3)

Answer 56

- Cortex produces T-cells - Mature and migrate into medulla - Enter blood vessels and go into circulation

Question 57

What do Reticular cells in the thymus do? (2)

Answer 57

- Produce thymosin | - Promote T cell differentiation