42 - Lymphatics

Question 1

What are the functions of lymphatics

Answer 1

Drains interstitial fluid
Transports dietary lipids from GI tract to blood
Protects against invasion through immune responses
Pathway for spread of malignancy

Question 2

How much lymph remains in the interstitial fluid?

Answer 2

3L/day

Question 3

What is the lymphatic plexus

Answer 3

Collection of lymphatic vessels in the capillary bed

Question 4

What is the flow of lymph

Answer 4

Lymphatic plexus - lymphatic capillary - lymphatic collecting vessels - lymph nodes to lymph trunk - lymph duct to right side of heart

Question 5

How many lymph trunks are there in total?

Answer 5

9

Question 6

What is lymphatic filariasis

Answer 6

Also knows as elephantitis
obstruction of vessels/ducts so lymph cannot drain
caused by mosquitos

Question 7

How do lymphatic vessels aid the flow of lymph

Answer 7

Low pressure conduits

Question 8

What other mechanisms are there which aid the flow of lymph

Answer 8

Milking action of active skeletal muscle
Numerous valves
Pressure changes in thorax

Question 9

How do lymph nodes (principle lymph organ) filter lymph

Answer 9

o Macrophages remove and destroy microorganisms and debris

Question 10

What does the right lymphatic duct drain and where does it end?

Answer 10

= Drains right upper quadrant
= Right side head, neck, thorax and right arm
= Duct ends in RSCV at junction with IJV (right venous angle)

Question 11

What does the thoracic duct drain and where does it end?

Answer 11

= Drains rest of body
= Begins in abdomen as cisterna chyle
= Duct ends at left venous angle

Question 12

What does the superficial component drain and what is it made up of

Answer 12

Drains the skin
Cervical nodes
Axillary nodes
Inguinal nodes

Question 13

What are the two types of inguinal lymph nodes and what do they drain

Answer 13

 Horizontal (run superficial to inguinal ligament)
• Superficial lymphatics from anterior abdominal wall, the perineum, and the external genitalia (excl. testes)
 Vertical (lie along termination great saphenous vein)
• Majority of superficial lymphatics from leg

Question 14

vertical and deep inguinal lymph node clearance

Answer 14

 Inguinal lymph node clearance during surgery to remove malignant melanoma from sole of foot

Question 15

o Horizontal (superficial) lymph node clearance

Answer 15

 Vulva cancer
 Scrotal cancer
 Penis - deeper inguinal lymph nodes
 Testes - preaortic

Question 16

What do kerley B lines show

Answer 16

Pulmonary Oedema
Ladder up the side - engorged interlobular lymphatic
inc pulmonary VENOUS pressure

Question 17

When does lymphoid tissue increase in mass to twice and adults size?When does lymphoid tissue regress back to adult levels?

Answer 17

• twice adults mass - 6-9 years of age

- regresses by puberty

Question 18

What happens to lymph nodes as you age

Answer 18

The number and size decreases
Some lymphoid elements are lost
nodes are more fibrotic and fatty - impaired ability to resist infection

Question 19

Where else can lymphoid tissue aggregate?

Answer 19

Spleen
Thymus
Peyer's patches of intestine
Tonsils/adenoids
Myeloid tissue in bone marrow

Question 20

What is the tissue make up of lymphoid organs

Answer 20

Reticular connective tissue

however only lymph nodes filter lymph

Question 21

Functions of spleen

Answer 21

Site for lymphocyte proliferation
Immune surveillance and response
Blood cleansing function
Stores/release products of RBC
Erythrocyte production in foetus
Stores platelets

Question 22

What are the blood cleansing functions of the spleen?

Answer 22

Extracts aged and defective blood cells and platelets

Macrophages remove debris and foreign matter

Question 23

Where is the thymus

Answer 23

Inferior neck and superior thorax deep to the sternum

Question 24

What does the thymus secrete and what does it do?

Answer 24

Secretes thymopoietin and thymosins – cause T lymphocytes to become immunocompetent

Question 25

When does the thymus grow and atrophy?

Answer 25

Grows in 1st year (highly active)

After puberty atrophies

Question 26

What do the tonsils do

Answer 26

Gather and remove some pathogens entering the pharynx in food or inhaled air

Question 27

Name the 4 tonsils

Answer 27

o Palatine
o Lingual
o Pharyngeal (adenoids if enlarged)
o Tubal tonsils

Question 28

What are peyer’s patches and where are they located?

Answer 28

Large isolated clusters of lymphoid tissue located in wall of distal small intestine

Question 29

What are the functions of peyer’s patches?

Answer 29

o Destroy bacteria and so prevent pathogens from breaching intestinal wall
o Generate many memory lymphocytes for long term immunity