Lymphatic Lecture Flashcards
Lymph Organs -
Spleen
Thymus
What is the largest lymph organ?
the spleen
It does some immune stuff
Distinctly cardiovascular stuff
Thymus – is
- a gland
- produces hormones
(thymopeitin & thymosin) - aids the lymphatic system
(trains the T cells)
(B cells form and mature in the bone marrow)
(T cells form in the bone marrow and mature in the thymus)
Spleen is connected to
vascular system but not the lymphatic system
Children born without a thymus…
DO NOT develop a functional immune system
Functions of the spleen
- has white blood cells - macrophages
- very generalist WBCs
- going to look out for infectious agents (bacteria)
- will do phagocytosis
- helps remove worn-out red blood cells
- helps deal with excess platelets (blood clotting platelets)
- helps deal with bacteria
- Fetal spleen produces RBCs
- Sever anemia can initiate RBC formation
- Spleen can CONTRACT to RELEASE 200-300 ml of BLOOD back to circulation (as in hemorrhaging - severe blood loss_
Lymphatic system connects
lymphatic system and immune system
Basic Lymph function
- Excess NFP (net filtration pressure)
- Disease surveillance - aids in immunity
- Lipid transport to GI to circulation –
(Does NOT transport through the blood). - Lipid absorption from the digestion system:
1. goes into the lymphatic system
2. then to circulation
3. where it plays a normal role in metabolic processes - can take food and use it for energy
Lymphatic system consists of three parts
- A network of lymphatic vessels
- Lymph nodes - filter fluid (around the jaw line)
- Lymphoid organs - disease prevention
The goal of the lymphatic vessels
- ensure one-directional flow
- Lymph vessels are DEAD-END –unlike cardiovascular system which is a circuit
- They hang out in the extremities
- as they soak up fluid they have to push fluid back
There is no force in the lymphatic system - it relies on other factors.
Lymphatic capillaries are made of
single layer of endothelium
The cells overlap instead of being physically connected
Has pseudo valves for one way flow - do not open and shut
Lymphatics - capillaries merge & empty into two ducts:
- R lymphatic duct
- Thoracic duct
The lymphatic ducts empty into the
subclavian veins
Which lymphatic duct does the most work?
Thoracic Duct
What areas of the body do the lymphs drain to (2 areas)
- R lymphatic duct - drains R half of head, R arm, & R upper chest
- Thoracic duct - drains the rest of the body lymph (does the most work)
Similarities of lymphatics relative to veins
- Lymph moves via skeletal muscle, valves, thoracic pump (assists) & fluid pressure gradient
Not a high-pressure system - relies on you to keep moving
Differences of lymphatics relative to veins
- Thinner walls, more valves & modify to form lymph nodes
DISTINCTIVE FEATURE - many more valves than veins.
Also modified to form other tissues.
Because they have overlapping cells - there are a lot more valves in the lymphatic vessels than what you see in the veins
Even though they are thin, they are not structurally organized the way veins are - with more muscle and more CT.
Common blockage that produces edema in this drainage area
Thoracic duct
Edema =
Fluid build up in interstitial space
Lack of albumin
Concentration of albumin - osmotic pressure regulator - in capillary
Blockage of lymph vessels - elephantiasis
Inflammation - change in permeability of blood and lymph vessel walls
Lymphatic Tissues
MALT =
Monitoring system in 4 open pathways
- Respiratory, digestive, urinary, reproductive
- Protects against foreign matter
Monitoring of disease causing pathogens
Example of a MALT that monitors one of the routes into the body - for pathogens
Tonsils
Function similar to lymph nodes, filtering germs entering the nose or mouth and reduce infection
MALT that is all about the intestines
A type of MALT
Peyer’s Patches
- At junction of small & large intestine & in appendix
- Destroy bacteria & generate lymphocytes
Peyer’s Patches are going to seek out any harmful bacterial infections or agents in the nutrients and other substances we might consume.
Will create WBCs called lymphocytes
General Locations of the Lymph Nodes
- Cervical - neck
- Axillary - armpit
- Abdominal Region - inguinal region - AKA groin region
What do the Lymph nodes do?
- Fluids are moving around
- Fluids out of cardiovascular system
- goes into intestinal
- soaked up by the lymphatic system
- WBCs hang out around the Lymph nodes (Hall Monitor)
- Another method to add more protection
Where do WBCs hang out?
Lymph nodes (Hall Monitor)
