General Lymphatic System

Question 1

What is the lymphatic system responsible for?

Answer 1

Immune defense

Question 2

What type of cells are responsible for support in the lymphatic system?q

Answer 2

Reticular cells

Question 3

What do NK cells and T/B lymphocytes do in the lymphatic system?

Answer 3

Protect

Question 4

What are two functions of vessels in the lymphatic system?

Answer 4

• return tissue fluid to circulating blood
• Create plasma

Question 5

List the 4 organs of the Lymphatic System

Answer 5

• Thymus
• Spleen
• Lymphoepithelial structures (MALT, tonsils)
• Lymph and hemal nodes

Question 6

Where are lymphocytes produced?

Answer 6

In germinal centers in cortex of LN

Question 7

Filtration is the function of?

Answer 7

LN

Question 8

Which organ of the lymphatic system stores blood, removes particles, produces lymphocytes and destroys used erythrocytes?

Answer 8

Spleen

Question 9

Describe the function of the thymus and what happens to it during life

Answer 9

It involutes with age. Its function is to train and develop T-lymphocytes and produce thymosins

Question 10

What are thymosins?

Answer 10

Antibody stimulating hormones

Question 11

What is the function of the Circulatory System?

Answer 11

Transport blood and lymph to/from tissues

Question 12

The heart, blood vessels and lymphatic vessels are all structures associated with which body system?

Answer 12

Circulatory System

Question 13

Describe some similarities of the lymph vessels compared to blood vessels

Answer 13

• T. Adventitia
• One directional flow thanks to valves (like some veins)
• endothelium

Question 14

What are 2 differences of lymphatic vessels compared to blood vessels?

Answer 14

• no T. Media
• All lymphatic vessels have valves

Question 15

Lymph capillaries have adjacent cells joined by what 3 types of junctions?

Answer 15

Interdigitations, simple overlapping and adhering

Question 16

What allows extra cellular fluid to flow in but not out in lymph capillaries?

Answer 16

Flap-like valves

Question 17

Define Lymphedema

Answer 17

Acute or chronic build up of lymph fluid due to an obstruction in a vessel

Question 18

The lymphatic system filters out before dropping back in the circulatory system where?

Answer 18

Right before the heart in a vein (caudal vena cava)

Question 19

A lymph node will have multiple Afferent vessels and ____________ efferent

Answer 19

Only one with an artery and vein

Question 20

What are 3 clinically significant issues associated with LN?

Answer 20

• Lymphadenopathy - enlargement
• Lymphadenitis - infection caused by an agent
• LN tumors

Question 21

Which center is responsible for the parotid and mandibular center drainage?

Answer 21

Medial and Lateral Retropharyngeal Center behind the pharynx

Question 22

What structures does the parotid center drain lymph from?

Answer 22

Dorsal head - skin, dorsal skull, orbit, masticatory m

Question 23

The lower jaw (muzzle, salivary glands, tongue, etc) are drained by the ______________ center

Answer 23

Mandibular

Question 24

What are the 3 centers that drain the neck from lymph?

Answer 24

Superficial cervical, deep cervical and tracheal trunk

Question 25

The axillary center and right lymphatic duct drain what area of lymph?

Answer 25

Forelimb

Question 26

What is the major lymph collecting channel?

Answer 26

Thoracic duct

Question 27

Which forelimb lymph drainage arises from cisterna chyli?

Answer 27

Thoracic duct

Question 28

What are the 3 lymph drainage centers of the hindlimb, pelvis, and abdominal wall?

Answer 28

Lumbar aortic Medial iliac Hypogastric

Question 29

The lumbar, celiac, cranial/caudal mesenteric, cisterna chyli, popliteal and lumbar trunks drain lymph from which 2 areas?

Answer 29

Abdominal Viscera and Loins

Question 30

List the 3 primary Lymphoid organs

Answer 30

- thymus - Bone marrow - Fabricius bursa in birds

Question 31

What primary lymphoid organ is responsible for production of B-lymphocytes in birds?

Answer 31

Fabricius bursa

Question 32

Describe where are T and B lymphocytes produces in primary lymphoid organs

Answer 32

T lymphocytes - Thymus B lymphocytes - Bone marrow

Question 33

Are the lymph nodes, tonsils, and spleen primary or peripheral lymph organs?

Answer 33

Peripheral

Question 34

Where do lymphatic capillaries originate from?

Answer 34

Lacteals

Question 35

What is another name for lymph and it is similarly composed to ?

Answer 35

Chyle. Similar composed to plasma

Question 36

List the 5 structures of the lymph node

Answer 36

- Medulla - cortex - subscapular sinus - follicle - paracortex

Question 37

List the 5 structures of the lymph nodes

Answer 37

- Medulla - cortex - subscapular sinus - follicle - paracprtex

Question 38

In the lumen of the subscapular sinus of a LN, which structure slows lymph flow?

Answer 38

Stellate reticular

Question 39

Which follicle of the LN has a germinal center?

Answer 39

Secondary follicle

Question 40

Describe lymphocyte homing

Answer 40

When lymphocytes re-enter the lymphoid organs through endothelial vessels

Question 41

What increases the chance of a lymphocyte of finding its target?

Answer 41

Circulation btw blood and lymph of lymphocytes

Question 42

Which lymphoid organ is in charge of maturation and activation of lymphocytes?

Answer 42

Lymph nodes

Question 43

The largest lymphatic organ is the _______________

Answer 43

Spleen

Question 44

Which pulp in the spleen surrounds and follows central arteries?

Answer 44

White pulp

Question 45

In white pulp of the spleen, what is the T-cell dominant tissue around the central Arterioles called?

Answer 45

Periarterial lymphatic sheath (PALS)

Question 46

Describe the red pulp of the spleen

Answer 46

Spongy red mass composed of splenic sinuses and cords

Question 47

What WBC is present in red pulp of the spleen?

Answer 47

Macrophages

Question 48

Describe the primary role of macrophages

Answer 48

Remove damaged erythrocytes and iron metabolism

Question 49

What is a common invasive cancer that can give way to splenic or cardiac tumors, is prevalent in large breed dogs, and causes blood vessel branching and even rupture?

Answer 49

Hemangiosarcoma

Question 50

Which lymphoid organ is fully formed at birth and involutes with puberty?

Answer 50

Thymus

Question 51

Multipotent T cell go through which 2 differentiating to become what in the thymus?

Answer 51

Thymic Nurse cells and Epithelioreticular cells

Question 52

There are ____ Epithelioreticular cells

Answer 52

6

Question 53

Which ERC of the thymus expresses MHC I and II antigens?

Answer 53

II

Question 54

Which ERC regulates T-lymphocyte selection in the thymus?

Answer 54

V

Question 55

Why are cortical capillaries impermeable to macromolecules in the thymus?

Answer 55

Blood Thymus Barrier in the thymus cortex