Lymphoid system

Question 1

What does lymph consist of (3)

Answer 1

• interstitial fluid
• lymphocytes
• macrophages

Question 2

Functions of the system (the 2 systems)

Answer 2

Primary lyphoid system (thymus)- causes differentiation of lymphocytes (t cells, bcells etc)

Secondary lymphoid structures (lymph nodes)- consists of lymphocytes + more b cells

• Maintains normal blood volume
• maintains comp of interstitial fluid
• alternate route for horomones, nutrients, waste

Question 3

How does fluid travel into the lymphoid system

Answer 3

• blood pressure in capillaries is 35mmhg
• the pressure of this forces solutes and waste out of plasma into interstitial fluid
• some fluid enters lymphoid systems and eventually connects with venous system

Question 4

2 sets of major lymph collecting vessels

Answer 4

1. Superficial lymphatics
   - Found in subcutaneous layer
   - found in mucus lining of digestive/respiratory/ urinary tracts
2. Deep lymphatics
   - collects lymph from skeletal muscle + tissues of the neck, limbs, trunk

Question 5

what are the 5 collecting trunks

Answer 5

• Lumbar
• Intestinal
• bronchomediastinal
• subclavian
• jugular

Question 6

Flow of lymph

Answer 6

capillaries-superficial/deep vessels-trunks-ducts-subclavian vein

Question 7

2 types of lymphatic ducts

Answer 7

1. Thoracic duct
   - drains lymph inferior to diaphram
   - drains from left side of body
   - drains into left subclavian vein
   - 3/4 of body
2. Right lymphatic duct
   - drains lymph from right side (1/4)
   - drains into right subclavian vein

Question 8

T cells- where do they originate and the 4 kinds

Answer 8

-originate in bone marrow but travel to thymus to get activated

1. cytotoxic T- attack foriegn cells + viruses
2. Helper T- coordinate immune response/ get B cells
3. Suppressor T- stop immune response
4. Memory T- become activated if same antigen appears later

Question 9

B Cells- where do they originate and 2 kinds

Answer 9

• originate in bone marrow

1. Plasmocytes- produce antibodies that react w antigens
2. Memory B- become activated if same antigens shows again

Question 10

NK cells

Answer 10

• Attack foreign cells
• attack normal cells that are infected
• attack cancer cells

Question 11

Steps of the immune response

Answer 11

• macrophages activated by antigen
• macrophages phagocytize foreign substance
• macrophages present antigen to specific t cells
• T cells divide to produce different types
• cytotoxic T will kill bacteria, helper t activates B cells
• B cells produce antibodies
• antibodies attach to antigen and attract leukocytes that kill bacteria

Question 12

The 2 sets of lymphoid stem cells that pluripotential stem cells produce

Answer 12

1. migrate to thymus, where upon exposure to thymosin will mature to T cells
   - mature T cells will reside in peripheral tissue
2. Other will stay in bone and differentiate to form B/ NK cells

Question 13

What are lymphoid nodules + 3 types

Answer 13

-germinal center which contains lymphocytes

1. MALT- in digestive system
2. Tonsils (1 pharyngeal, 2 palatine, 2 lingual)
3. Aggregated lymphoid nodules

Question 14

Lymph nodes

Answer 14

1-25mm in diameter

scattered across body

Question 15

Thymus (location + structures)

Answer 15

• lies posterior to manubrium of sternum
• reaches greatest size during puberty

cortex- stem cells that differentiate to form t cells
-mature t cells migrate to medulla

medulla- t cells remain inactive until in circulation

Question 16

Spleen ( locations + structures)

Answer 16

• located on left edge of stomach

- consists of diaphragmatic and visceral surface

Question 17

What is red and white pulp

Answer 17

red- contains large quantities of blood (erythrocytes and platlets

white- filters blood of antibody antigen complexes