Lymphatic System

Question 1

What is the lymphatic system?

Answer 1

• Due to the high pressure with our atteries, there is fluid that moves out of capillaries and it’s important so nutrients can move through the tissue also the plasma in blood can leak
• Consists of very thin vessels all over the body and interwoven with capillaries
• Less define and very thin only one cell thick, no cell cell junctions, no support cells
• Minivalves way valves - fluid can only move in and it fluid comes back it would cause the valve to close
• Attached to the minivalves are filaments that are achored to the surrounding connective tissue as soon as we get swelling these filaments will open up so fliud can move into the lymphatic vessels
• One fluid is in the vessels called Lymph, cells can move into this also a pathway for bacteria and for cancer
• Have them everywhere in the body and bring the fliud back into circulation

Question 2

What is a Lymph Node?

Answer 2

• Afferent lymphatic vessels
• Serve as immune organs see white blood cells in lymph node
• Outerpart is a fibrous capsule and trabeculae that come inwards and made of reticular fibers to form sort of loose stroma. Reticular fibers short pieces of collagen we don’t have many of them but purpose to kind of rudimentary skeleton, structual support
• Most of lymph nodes are open space. Sinusoids similar to sinusodial capillaries wide twisting passage ways to slow down movement of the lymph as they come in. Purpose of slowing it down bc they’re full of B and T cells (immune cells) that will be able to identify or attack foregin pathogens
• Lymph nodes are sentinel that try to protect us bc these are ways where cancer or bacteria travel through our body
• Assuming the lumph are non pathogens it will travel throuugh efferent lymphatic vessels
• Sometimes the lymph nodes are attached to chain where it’ll go through 3 or 4 lympy nodes in a row to ensures lymph is cleaned of anything that’s harmful before it can get back into the system
• Cortex (outerpart) means bark
• Medulla inner part
• Antigens are proteins or molecules on surface of infected cells or bacteria or pathogens what’s sensed in the white blood cells to signal an attack

Question 3

Where do we find lymph nodes in the body?

Answer 3

• Over 500 lymph nodes in the body
• Especially common near jugular vein, axilla, groin, and abdomen/thorax, around the knee
• Sometimes lymph nodes swell which is due to bacteria getting in and causes an inflammotory response, cancerous cells getting caught in lymph nodes causing replication
• Lymph nodes that swell and painful would be an indicative of bacteria - inflammtory responses
• Swollen lymphnodes and non painful then it could be cancerous
• lymph nodes will help return blood back into the venous system that fluid enters right atrium and ultimately can reenter the circulation

Question 4

What causes movement of lymph?

Answer 4

• Muscle pumps
• Pulsating arteries help move fluid along
• Tunica media (very thin)
• Normal movements of limbs

Lymphs aren’t moving in continous cycle through our lymphatic vessels - goes in fits and starts

Lymph nodes get larger as you get closer to the heart bc of all the lymphatic capilaries that have fed into the system. Only these largest lymphatic ducts have smooth muscle, not the small capillaries that we started talking about

Lymphatic vessels get progressiblely larger as you get closer to the heart bc of the lympathic capillares that have fed into the system

Only the largest lympthatic ducts have smooth muscle not the small capillaries

Question 5

Lymphedema

Answer 5

• Chronic condition caused by lymphatic disruption
  
  • surgery, women undergone mastectomies or suffering from breast cancer and some of the avillary lymph nodes have been dissected to look for cancer that can interrupt the flow of lymph and get massive swelling in the extremidites
  • or infection, cancer in lympathic system
• Non-pitting (means when you push into it springs back) edema, often in the extremdities, actual problem with the lympathic system
• difficulty moving extremities Impact with the quality of life, painful
• Difficult to treat, no ability to regenerate
• Physical therapy - lympathic massage to move the lympathic fluid along
• Exercises, garments to help move the fluid along
• Pitting edema is when you push into the skin and left with an identation bc there pushing fluid and some going back to lympathics

Question 6

Primary Lymphoid Organs

Answer 6

• organs that make white blood cells
• Thymus - large in new borns
  
  • decreases in size as we age by 20 years old decreases after
  • still able to produce T cells (immune cells that coordinate and kill foreign invaders)
• Bone marrow
  
  • Both B cells and other immune cells sometimes T cells are formed primary lympohid organ (new immune cells are made)
• Sweetbread come from calf or lamb

Question 7

Spleen

Answer 7

• Largest lymphoid organ
• Functions in immune system and red blood cells
  
  • Red plump significant amount of macrophages and phagocytose old red blood cells. Red blood cells carry oxygen within our bloodstream but after about three to four months, 90 to 120 days, they kind of beat up but they don’t have any organelles to help repair themselves
  • Spleen will be filter those out and the macrophages within the red pulp will be responsible for consuming and destroying them.
• White pulp lymphatic tissue is so T cells and B cells these cells will be here bc anything can move out of the bloodstream. Having immune cells here will have them sense the pathogens
• Enlarged when you get monocleosis due to changes involved with B cells
• spleen surrounded by fibrous capsule but if the spleen swells too much that capsule can brust(nnot a good thing) but if it ruptures you can live without it and we have other sites that contain white blood cells
• Individuals without a spleen tend to get sick more often bc they don’t have the cells that can attack the pathogens

Question 8

Mucosa-Associated Lymphoid Tissue (MALT)

Answer 8

• Found in digestive, urinary, respiratory, and reproductive tracts below the epithelium
• Malt is located in the Sumucosal Layer
• Destroys microrganisms, but also generate memory cells
• Benefit - those are areas where we’re having particles by having the sites where we’re having Malt all the lympathtic cells and white blood cells will be able to sense the new microoganism and destroy them and generate memory cells. Once we come into to contact with the foreign pathogen we have a memory of it so if we get into contact of it in the future we can quickly ramp off an immune response
• Malt is cirtical of generate immune functions specifically with memory cells

Question 9

Tonsils

Answer 9

• Swellings of mucosa lining pharynx
• Arranged in a ring around the pharynx
• Contain significant MALT
• Trap particulates and bacteria crypts then our immune cells can attack
• Once you remove tonsils you remove the surveillance factor that’s helping to prevent oyu from getting sick
• Tonsils stones Halitosis - bad breath bc of sulfur compounds release with the bacteria

Question 10

Lymphomas

Answer 10

• Maligancy of lymph nodes
• Swollen, non painful lymph nodes
• fatigue, persistent fever, night sweats
• Hoddkin’s Lumphone (treatable) B cells are very large vs non-hodgkin Lymphone (cancerous cells are replicating) 5 year survival rate 60-80 percent, has a higher cure rate for younger adults than older adults