Lymphatics (Ch 24)

Question 1

Functions of the Lymphatic System

Answer 1

1. return excess fluid to bloodstream
2. maintain blood volume level
3. transport dietary lipids (waxes/fats - not absorbed by GI tract)
4. generates immune response
   - ->lymphacytes (WBCs) monitor blood/internal fluid to detect antigens

Question 2

Lymph Vessels

Answer 2

merge to form lymphatic ducts/trunks

-reabsorb excess fluid and return it to venous circulation

Question 3

Lymph

Answer 3

excess interstitial fluid and solutes (sometimes foreign material)

Question 4

Lymph + Lymph Vessels =

Answer 4

• secondary venous drain system

- shortcut from capillary bed to the heart

Question 5

Lymphatic Capillaries

Answer 5

one way valves that open for interstitial fluid, merge into lymphatic vessels

Question 6

Lymphatic Ducts

Answer 6

responsible for draining specific parts of the body

1. Thoracic Duct
2. Right Lymphatic Duct

Question 7

Thoracic Duct

Answer 7

starts in posterior abdomen as cistern chyli (large vessel that holds fluid, inferior to diaphragm) –> drains into L venous angle –> heart
*drains lymph from lower limbs, L abdomen, L thorax, L upper limb, L head/neck

Question 8

Right Lymphatic Duct

Answer 8

*drains R upper limb, R thorax, R head/neck

Question 9

Lymphedema

Answer 9

accumulation of fluid due to blocked lymph duct

Question 10

What are the primary lymphatic organs?

Answer 10

• -> sites for lymphocyte formation/maturation
  1. Red Bone Marrow
  2. Thymus

Question 11

Red Bone Marrow

Answer 11

• produce B and T cells
• B cells mature here
• located in long bones

Question 12

Thymus

Answer 12

• located in anterior mediastinum, superior, covers great vessels and heart
• bilobed
• prominent in children –> atrophies –> replaced by adipose tissue
• T cells mature here

Question 13

What are the secondary lymphatic organs?

Answer 13

• -> populated with lymphocytes from primary organs, series of filters for blood
  1. Spleen
  2. Lymph Nodes
  3. Tonsils

Question 14

Spleen

Answer 14

in abdomen on L side

• largest, destroys pathogens/old blood cells
• blood flows through, white pulp monitors for foreign materials –> red pulp destroys old RBCs

Question 15

Lymph Nodes

Answer 15

circular nodules of lymphatic material distributed throughout body

• remove pathogens from lymph
• all over body: clusters at neck (cervical), armpits (axillary), groin (inguinal)
• lymph enters through vessels and exits out different vessels
• lymph seeps through sinuses in node = foreign materials destroyed/pathogens removed

Question 16

Tonsils

Answer 16

• -> destroy pathogens entering body
  1. Pharyngeal- on superior border of pharynx
  2. Palatine- back of palate
  3. Lingual- back of tongue