Lymphatic System

Question 1

What is the function of the lymphatic system?

Answer 1

Return tissue fluid to circulation

Filter damaging material

Production of antibodies and lymphocyte maturation - defence for the body

Transport digested fat from intestine to liver/storage sites around the body

Question 2

What are the components of the lymphatic system?

Answer 2

Capillaries, lymph vessels, ducts
Lymph nodes
Spleen
Thymus
Tonsils
Gut associated lymph tissue (GALT)
Lymph

Question 3

What are the major lymphatic ducts?

Answer 3

Right lymphatic duct
Tracheal duct contribution

Thoracic duct

Cisterna chyli

Question 4

What is the Right lymphatic duct?

Answer 4

Right caudal part of neck
Lymph from right thoracic limb and right side of neck and head
Right sup. Cervical, axillary and thoracic LN

Tracheal duct contribution - empties into right subclavian vein

Question 5

What is the thoracic duct?

Answer 5

Main channel to return lymph of body into venous system

Caudally - start at sublombar region or diaphragmatic cruca

Cranially - left venous angle (subclavian vein and left internal jugular vein)

Question 6

What is the cisterna chyli?

Answer 6

Two part lymph channel, retroperitoneally, association with cranial abdominal aorta

Question 7

What are the major lymphatic nodes?

Answer 7

Parotid
Mandibular
Lat retropharyngeal
Superficial cervical
Axillary
Inguinal
Popliteal

Non palpable: femoral, mesenteric, bronchial

Question 8

Where is the submandibular node?

Answer 8

2-5 nodes lying at edge of angle of the jaw

Question 9

Where is the prescapula node?

Answer 9

Cranial to scapula

Question 10

Where is the axillary node?

Answer 10

Within tissues of axilla (armpit)

Question 11

Where is the popliteal node?

Answer 11

Within tissues of gastrocnemius muscle, caudal to stifle joint

Question 12

Where is the inguinal node?

Answer 12

2 nodes either side of the groin, between thigh and abdominal wall

Question 13

What is the anatomy of a lymphatic node?

Answer 13

Bean shaped - indented area named hilus

Capsule - fibrous connective outside layer

Cortex - location of residential lymphocytes

Medulla - contains tissue macrophages embedded in a coarse fibrous mesh

Question 14

What is the spleen?

Answer 14

Largest lymphoid organ
Haemopoietic multi lobal
Attached to greater curvature of stomach on left side of abdomen

Question 15

What is the function of the spleen?

Answer 15

Storage of blood, removal of old RBC, activation of WBC

Removal of bacteria and foreign material by action of phagocytic cells

Question 16

Blood supply to the spleen?

Answer 16

Splenic artery (branch of celiac)
Splenic vein (portal vein)

Question 17

Is the spleen essential?

Answer 17

Not essential to life

Can be surgically removed (splenectomy)

Question 18

What is the thymus?

Answer 18

Thorax, cranial to heart
Prominent in young animals

Question 19

What is the function of thymus?

Answer 19

Thymocytes
T cells

Question 20

What are tonsils?

Answer 20

Lymphoid tissue in pharynx

Located at beginning of lymph drainage system, not along lymph vessels like lymph nodes

Question 21

What is the function of tonsils?

Answer 21

Prevent spread of infection into respiratory/digestive systems

Question 22

What is Gut associated Lymph Tissue?

Answer 22

GALT

Lymphoid tissue found in interstitial mucosa and submucosa

Largest lymphoid organ

Question 23

What are peyers patches?

Answer 23

Located in wall of intestine

Assist with battle against invading antigens

Question 24

How is lymph formed?

Answer 24

Arterial blood under pressure forces fluid out of capillaries and into tissues

Lack of blood pressure results in less fluid being absorbed back into veins = fluid accumulates in tissues (interstitial fluid)

Excess interstitial fluid drained to lymphatic capillaries

Lymphatic capillaries merge to form larger vessels With valves

Lymph is filtered in lymph nodes

Lymphatic vessels drain into ducts

Question 25

What is the lymphatic system?

Answer 25

Circulates lymph which is like plasma but with more lymphocytes, more fat and less proteins

Question 26

What is the direction of lymph?

Answer 26

Lymph moves towards heart = unidirectional

Question 27

Where does lymph enter the heart?

Answer 27

Cava

Question 28

How is lymph pumped?

Answer 28

Body movements propel lymph towards heart

Question 29

Where is blood plasma located?

Answer 29

Arteries, capillaries and veins

Question 30

Where is tissue fluid located?

Answer 30

Between cells in tissues

Question 31

Where is lymph located?

Answer 31

In lymph vessels

Question 32

What is the protein content of blood plasma?

Answer 32

High

Question 33

What is the protein content of tissue fluid?

Answer 33

Very low

Question 34

What is the protein content of lymph?

Answer 34

Very low

Question 35

What is the oxygen and nutrient content of blood plasma?

Answer 35

High

Question 36

How does oxygen and nutrient content vary in tissue fluid?

Answer 36

High at the arterial end, low at the venous end.

Question 37

What is the oxygen and nutrient content of lymph?

Answer 37

Low oxygen, varied nutrient content.

Question 38

What is the waste content of blood plasma?

Answer 38

Low (removed via kidneys).

Question 39

How does waste content vary in tissue fluid?

Answer 39

Low at the arterial end, high at the venous end.

Question 40

What is the waste content of lymph?

Answer 40

High

Question 41

What cells are found in blood plasma?

Answer 41

RBCs and WBCs

Question 42

What cells are found in tissue fluid?

Answer 42

WBCs (e.g., neutrophils) patrolling and protecting tissues

Question 43

What cells are found in lymph?

Answer 43

WBCs (as in tissue fluid) and lymphocytes matured in lymph nodes